The abundance of micro (MPs) and nano (NPs) sized plastic particles in the ocean is concerning due to their harmful effects on marine life. The interactions between MPs and NPs in the marine environment and their impact on marine biota remain not fully understood. This study contributes with new insights into the interaction between polystyrene NPs (PSNPs) and polyethylene MPs (PEMPs) on the clam Ruditapes decussatus. Results showed ingestion of MPs and NPs by clams, with PSNPs demonstrating higher toxicity in hemolymph. While no genotoxicity was observed, clams treated with MPs and the mixture showed increased acetylcolinesterase (AchE) activity over time. Additionally, the antioxidant defense system mitigated oxidative stress, suggesting effective neutralization of reactive oxygen species. Hazard assessment indicated the greatest impact on clam digestive glands after ten days of exposure, with an antagonistic interaction between MPs and NPs noted.

https://doi.org/10.1016/j.marpolbul.2024.116697

Estuaries are among the most degraded and threatened environments worldwide (Scown et al., 2023; Syvitski and Saito, 2007). Highly intervened estuaries with altered environments are the result of human-engineered interventions (e.g., sluice gates, jetties, dikes, impoundments, training walls, port facilities, and dredging), land reclamation, changes in upstream land use, and human-induced pollution (e.g., Nichols et al., 1986; Lotze et al., 2005; Pye and Blott, 2014). Human interventions have modified the hydrodynamics, morphology, and geochemistry of these systems, leading to large deviations from the expected natural state and functioning (e.g., Jiang et al., 2012; Brunier et al., 2014; Zhu et al., 2017; Zarzuelo et al., 2018; Wang and Liu, 2019; Van der Spek and Elias, 2021). Such deviations exhibit non-linear patterns, adding greater complexity to the dynamics of estuarine systems under climate change scenarios. Moreover, anthropogenic actions have altered the estuarine capability to adjust to the environmental change, including responding to increased pressures in the context of climate change. As a result, highly intervened estuaries exhibit a broad range of anomalous responses, including changes in circulation patterns, disturbances in mixing conditions, accelerated siltation, closure of distributary channels, shifts in residence time, severe shoreline retreat, estuarine turbidity maximum zone changes, and the accelerated loss of ecosystem services (e.g., filtering and nutrient recycling) (e.g., Yang et al., 2003; De Jonge et al., 2014; Yang et al., 2015; Restrepo et al., 2020; Guo et al., 2021).

doi: 10.3389/feart.2024.1414862

Silver nanoparticles (AgNPs) have extensive applications in nanomedicine and parasitology, particularly as antifungal, bactericidal, antiviral, larvicidal, mosquitocidal, and tick-killing agents. Plant-based AgNPs (PB-AgNPs) have been studied as a safer and biocompatible strategy to collaborate in disease control. However, knowledge concerning the toxicity of PB-AgNPs in non-target organisms is still limited. A scientometric and systematic review was conducted to comprehensively understand the potential toxicity associated with these nanoparticles. In brief, the assessment of PB-AgNPs toxicological and ecotoxicity aspects needs to be aligned with their development for target organisms. Our review demonstrates that different PB-AgNPs can cause lethal and sublethal effects like increased oxidative stress, cardiotoxicity, neurotoxicity, hepatotoxicity, hematotoxicity, and, DNA damage, alongside others, particularly in aquatic organisms. Besides, the toxicity of PB-AgNPs for terrestrial and some aquatic organisms remains poorly understood. Additionally, the similar LC50 range between non-target aquatic organisms and target organisms highlights the potential ecological impact of PB-AgNPs. Comprehensive toxicological assessments and further research are crucial to ensure the safe and sustainable use of PB-AgNPs in a One Health context.

https://doi.org/10.1080/10643389.2024.2303298

https://doi.org/10.1016/j.jhazmat.2024.134479

This research aims to distinguish genetic sedimentary processes building canyon geomorphological patterns and the factors driving different sedimentary activities in two nearby Mediterranean shelf-incised submarine canyons (Carchuna and Motril) that exhibit different degrees of incision on the narrow margin of the northern Alboran Sea.

The straight Carchuna Canyon incises the shelf up to 200 m off the coastline and exhibit steep canyon walls featuring narrow terraces, muddy sands with high contents of organic matter along the thalweg, and transported shelf benthic foraminifera in distal settings. The Motril Canyon head is wider and incises the shelf edge, ca. 2 km off the coastline. It exhibits a sinuous morphology and less steep walls, wider terraces, and higher sedimentation rates with muddy sediments along the thalweg. In both canyons, cross-section relief, width, incision, and area decrease downslope, although these parameters increase locally.

The downslope variations of geomorphological parameters are attributed to enhanced erosional/depositional processes promoted by tectonically controlled abrupt changes of the axial channel orientation. The degree of shelf incision, the location of the canyon heads in relation with the local sediment sources, and the seasonally variable hydrodynamic regimes determine the different degrees of recent canyon activity. The Motril Canyon is interpreted as a mature system that reflects episodic activity, collecting fine-grained sediments from the nearby Guadalfeo River. The Carchuna Canyon exhibits a youthful developmental stage whose activity is more continuous and involves sediment trapping of littoral cells and continuous downslope sand transport.

 https://doi.org/10.1016/j.geomorph.2024.109127

Despite being considered one of the most pressing global issues, biodiversity loss and the degradation of ecosystems is continuing at an alarming rate. In December 2022, COP15 saw the adoption of the Kunming-Montreal Global Biodiversity Framework, where four overarching international goals for biodiversity and 23 targets. While these targets are a positive step to address the drivers of biodiversity loss, we will not only need public and political will to reach the goals and targets outlined but also more effective methods to integrate and use scientific information. To facilitate this, scientists and research institutions need to establish new and innovative approaches to transform the way science is conducted, communicated, and integrated into the policymaking process. This will require the scientific community to become proficient at working in inter and transdisciplinary teams, establishing connectivity, and engaging in the policymaking process to ensure that the best available scientific evidence is not only comprehensible to decision makers, but also timely and relevant. Here, we detail how scientists can embrace transformative change within and outside of their own communities to increase the impact of their research and help reach global targets that benefit society.

https://doi.org/10.5194/egusphere-2023-1730

The Camargue or Rhône delta is a coastal wetland in southern France of which parts formerly devoted to salt production are undergoing a renaturation process. This study assessed a multisensor approach to investigate the link between sediment size distribution, habitat development mapped with Worldview 2, flooding durations estimated with time series of SENTINEL 2 images and elevation modelled with a LIDAR point cloud in former saltworks. A Random Forest classification algorithm was used to map the vegetation distributions of Sarcocornia fruticosa and Arthrocnemum macrostachyum, main representatives of the NATURA 2000 “Mediterranean and thermo-Atlantic halophilous scrubs (Sarcocornetea fruticosi)” habitat on the site. The best habitat map was obtained when considering the species separately. The random forest Out-of-bag errors were 1.43 % for S. fruticosa and 2.18 % for A. macrostachyum. Both species were generally distributed on different elevation and flooding duration zones considering mean values. Flooding duration was estimated with the Water In Wetland index (WIW) based on 15 Sentinel-2 scenes. Two models related to sediment grain size distribution were developed: one predicting the flooding duration and one predicting the halophilous scrub distribution. Maps of flooding duration, sediment grain size distribution and elevation highlighted two main zones in the study area: a western section with coarser sediments, shorter flooding durations and higher elevations under sea influence; an eastern section with finer sediments, longer hydroperiods and lower elevations under a historic river influence. This multidisciplinary approach offers perspectives for using space-based data over large scales to monitor changes in edaphic conditions of coastal areas facing natural and anthropogenic forcings. The results call for further investigations to predict the dynamic distribution of other coastal habitats following climate change impacts, such as sea level rise.

https://doi.org/10.1016/j.scitotenv.2023.168289

A first characterization of greenhouse gases had been carried out to study their role and impact in a productive transitional coastal system of the southern Portugal – Ria Formosa lagoon. To this purpose, the partial pressure of CO2 (pCO2) and the concentration of dissolved CH4 and N2O have been measured. Two surveys were carried out during 2020, at low tide under typical conditions of Spring (March) and end of Summer (October). The samplings sites were distributed along the costal lagoon covering: i) inner areas with strong human impact (influence of different flows of treated wastewater discharges); and ii) main channels in connection with the main inlets to study the exchanges with the ocean. In general, the highest values of the three greenhouse gases were found at the inner studied areas, especially affected by the disposal of treated effluents from wastewater treatment plans, in October. The mean water - atmosphere fluxes of the CO2, CH4 and N2O are positive, showing that the study area acts as a source of these gases to the atmosphere. On the other hand, it was calculated a rough estimation of the three gases globally exported from Ria Formosa to the ocean, through the main six inlets to evaluate the magnitude of the supply of these gases from Ria Formosa to the adjacent ocean. The mean CO2, CH4 and N2O horizontal water fluxes exported from all the inlets of Ria Formosa to the Gulf of Cadiz for both seasons, during low water, are 8.7 ± 3.9 mmol m−2 s−1, 8.0 ± 3.5 μmol m−2 s−1 and 3.2 ± 1.5 μmol m−2 s−1, which corresponds to a mass transport through the inlets section of 0.7 ± 0.7 kg s−1, 0.2 ± 0.2 g s−1 and 0.2 ± 0.3 g s−1 respectively. From these estimates, as expected, the higher mass transport was found at the larger and deeper inlets (Faro-Olhão and Armona).

https://doi.org/10.1016/j.scitotenv.2023.167094

Islands must reach sustainable lifestyles by improving resources management and by getting accustomed to renewable energy sources. Culatra, a small Portuguese island, is actively increasing renewable energy penetration into local processes in order to be the first 100% sustainable Portuguese territory by 2030. Based on the electric consumption of Culatra, the objective of the present study is to project a photovoltaic unit composed of several sub-fields, each with a distinct orientation, in order to increase the self-consumption ratio while at the same time reducing the surplus of energy production, assessed by the self-sufficiency ratio criteria, resulting in a lower levelised cost of energy of the power system. To achieve this, MATLAB’s implementation of a genetic algorithm was used to find the optimised set of orientations for a given load profile. The results indicate that it is possible to optimise the photovoltaic plant to reach a more continuous electricity generation through daytime, reducing the storage needs and increasing the value of photovoltaic systems. The method can be extended to other locations or demand curves, assisting on comparing different energy management strategies, and their respective advantages and disadvantages.

https://doi.org/10.1016/j.energy.2023.129257

The COVID-19 pandemic has triggered an unprecedented need for single-use face masks, leading to an alarming increase in plastic waste globally. Consequently, the improper disposal of face masks has added to the existing burden of plastic pollution in the oceans. However, the complete environmental and marine ecotoxicological impact remains unclear. This study aims to investigate the ecotoxicological impact caused by the weathering of disposable face masks (DFMs) in the marine environment on mussels Mytilus galloprovincialis (M. galloprovincialis) by assessing biochemical, cytotoxic, and genotoxic effects. The mask leachate was analysed for the presence of nano and microplastics. Furthermore, the leachate was used in in vivo and in vitro toxicity bioassays to assess its impacts on M. galloprovincialis. The in vivo exposure of M. galloprovincialis to face mask leachate for 14 days induced a significant increase in catalase (CAT) activity in mussel gills, although not enough to prevent oxidative damage to cell membranes. DNA damage was also registered in mussel haemocytes after in vivo exposure to mask leachate. The in vitro Neutral Red (NR) cytotoxicity assay indicated that leachate concentrations ≤ 0.5 g/L^-1 pose a significant risk to the health of mussel haemocytes, which seems a reliable tool for the cytotoxicity impact assessment of face masks in the marine environment. Therefore, the leachate obtained from face masks in seawater causes oxidative stress, oxidative damage, cytotoxicity, and genotoxicity in M. galloprovincialis, indicating that the plastic burden generated by DFMs in the ocean and its subsequent weathering represents a ubiquitous and invisible threat to the marine biota.

http://dx.doi.org/10.20517/wecn.2023.57

Water quality in coastal and oceanic zones promotes various benefits for the regional economy, socio-cultural values, and biodiversity. Chlorophyll-a (Chl-a) is one of the most widely used water quality indicators. Monthly time series of Chl-a from 1998 until 2020 from two sites on the south coast of Portugal, Guadiana and Sagres, are used. Sagres is characterized by strong seasonality, and Guadiana with a weaker seasonal variation. A comparison between the months shows that Sagres is statistically significant when comparing the winter months with the early spring/summer months. Guadiana shows higher Chl-a values than Sagres but fewer changes between the months. A decrease in Chl-a concentration is detected in Guadiana, and its magnitude is obtained. Conversely, no monotonic trend is detected in Sagres. The approaches used must be viewed as exploratory. However, the findings might contribute to new ideas on the good environmental status of marine waters.

https://doi.org/10.1007/978-3-031-39864-3_5

Coastal dunes are important habitats that also play an important role in coastal protection. In areas of high tourist activity, they have often been degraded by trampling and intensive use, resulting in a loss of ecological, aesthetic and protective values. As a result, several management actions have been taken to minimise dune degradation and enhance their recovery. One of these measures is the installation of elevated boardwalks and dune crossovers to regulate human access to the beaches. This paper quantifies and analyses the impact of the installation of boardwalks and dune crossovers on dune recovery in a highly touristic area in southern Portugal. This was done using aerial photographs taken before and 5–10 years after the implementation of the measures, and an effectiveness index was applied. The recovery observed was high to very high, ranging from 51% to 98% of the previously degraded dune. The areas with the oldest interventions showed an average recovery of 86% of the degraded area, while the most recently managed areas showed an average recovery of 69%. The high rate of recovery is mainly explained by the new habits developed by the population and tourists to access the beaches. Nevertheless, in some specific cases (i.e. where the use of the boardwalks requires a detour or where they end far from the beach) new degraded areas were observed, indicating the high relevance of the design of the boardwalks to the final recovery result. This work can serve as a basis for assessing the effectiveness of coastal management measures in any other coastal dune area with similar interventions.

https://doi.org/10.1016/j.jenvman.2023.118759

Culatra is a small island located in the Ria Formosa Natural Park in the Algarve region at the south of Portugal, with a Mediterranean climate and facing an increasing water scarcity. The Culatra2030 Project is being developed in the island creating local actions to enhance circularity and improve the sustainability in the natural resources use. Drinking water consumed in Culatra is provided by the mainland, where it is extracted from aquatic ecosystems, treated, and transported to the island. The effluents produced on the island are drained and transported to the mainland where they are treated in a Wastewater Treatment Plant (WWTP). The transport of drinking water and effluents represents high energy consumption and therefore carbon emissions. The first stage of the Culatra2030 was to develop a Sustainable Energy Community, and since the last year we are studying measures to improve water circularity and eco-efficiency, avoiding the drinking water waste, and creating alternative water sources for non-potable uses. Two reference buildings have been chosen for community involvement, the Social Centre and the Primary School, where several educational actions were carried out e.g., the Water Footprint was calculated with teachers and young people, and some devices were installed to flow reducing on taps, showers and toilet flushers. The nexus drinking water /energy /carbon emissions was calculated before and after the installation of the flow reducers. The engagement of the local community on the sustainable water management was assessed through a survey prepared and distributed to families in collaboration with the island residents’ association.

 https://doi.org/10.1007/978-3-031-44006-9_6

This work describes the challenges to create a local energy community at Culatra Island, a small coastal community located in the south of Portugal. Although the creation of local energy communities is recently possible in Portugal after the transposition of the EU directive to the national law, there are no real case studies to follow. The study starts by describing the Portuguese legal framework for these communities, including the defined energy sharing methodologies. Subsequently, it researches into the specific context of Culatra Island, exploring both consumption patterns and renewable energy production. The aim is to propose an energy sharing scheme that prioritizes energy costs reduction for the community while increasing the energy sustainability of island, ensuring fairness and proportionality among the community members. A new economic model is proposed to maximize consumption of locally produced energy, demonstrating how members can simultaneously benefit from discounts on energy bills and invest on increasing future production and energy self-sufficiency. The model will guarantee greater savings for the members during a temporary horizon of decades and can be further replicated on other local energy communities with different social, economic and environmental conditions.

https://doi.org/10.1007/978-3-031-44006-9_13

We employ Duna, a simplified 1D morphodynamic model, to assess the influence of dune morphology (height and slope) on sand transfer and deposition across the dune profile for different beach widths and wind incidence angles through idealized experiments. Simulations of real conditions show good model performance, both in wind flow reproduction and in topographic change along the dune profiles tested. The idealized experiments show that wind speed increases and sand accumulation decreases logarithmically with dune height and linearly with stoss slope along the dune profile. Fetch and cosine transport limiting parameters are reflected in the sand accumulated windwards from the toe, while sand transfer to the dune appears controlled by multiple factors; the higher the dune and/or the narrower the beach, the likelier that maximum accumulation occurs under oblique winds. Results point to two different types of evolution for high dunes. Either the vegetation is dense enough to maintain the stoss position, in which case vertical growth near-ceases and seaward progradation is promoted, or the stoss is eroded and landward retreat dominates, in which case sand transfer to the crest and lee continues as a mixture of low input from the beach and recycled sand from the stoss.

https://doi.org/10.1029/2023JF007080

Planktonic heterotrophic prokaryotes (HProks) are a pivotal functional group in marine ecosystems and are highly sensitive to environmental variability and climate change. This study aimed to investigate the short-term effects of increasing carbon dioxide (CO2), ultraviolet radiation (UVR), and temperature on natural assemblages of HProks in the Ria Formosa coastal lagoon during winter. Two multi-stressor microcosm experiments were used to evaluate the isolated and combined effects of these environmental changes on HProk abundance, production, growth, and mortality rates. The isolated and combined effects of increased CO2 on HProks were not significant. However, HProk production, cellular activity, instantaneous growth rate, and mortality rate were negatively influenced by elevated UVR and positively influenced by warming. Stronger effects were detected on HProk mortality in relation to specific growth rate, leading to higher HProk net growth rates and abundance under elevated UVR and lower values under warming conditions.

Keywords: acidification; ultraviolet radiation; warming; heterotrophic prokaryotes; growth; mortality

https://doi.org/10.3390/microorganisms11102559

Pollutant exposure is considered an important factor responsible for the decline in marine biodiversity of Latin American coastal ecosystems. This threat has been detected in an estuarine system in southern Brazil, which prompted an investigation into the long-term biological effects of a chronic metal contamination on resident oysters from the Laguna Estuarine System (LES). Here, we present the species- and size-specific variations of biomarker responses (catalase, glucose-6-phosphate dehydrogenase, glutathione S-transferase, and protein carbonylation) in the gills and digestive gland of Crassostrea gigas and Crassostrea gasar. In parallel, concentrations of eight metals (Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn) in soft tissues were measured. Our analyses revealed that the metal levels exhibited decreasing order in both species: Zn > Fe > Al > Cu > Mn > Cd. Except for Cu and Al, metal concentrations did not differ between oyster species. Biomarker results highlighted that C. gasar presented higher antioxidant responses, whereas C. gigas showed increased biotransformation upon exposure to LES pollutants, which varied according to the tissue. However, C. gasar showed a significant higher content of protein carbonylation but was not related to metals. In our research approach, the observation of metals presence and biomarkers-related responses are considered biologically relevant from an ecotoxicological perspective and serve as a baseline for future pollution studies in estuaries of Latin America. Finally, we recommend adopting a suite of biomarkers in both C. gasar and C. gigas, regardless their size and weight, as sentinel organisms in future regional biomonitoring studies in southern Brazil.

https://doi.org/10.1016/j.chemosphere.2023.139288

Marine fishing is crucial to the socio-economy of West Africa fishery. However, the sector has many challenges, which have increased the call for an integrated approach that provides links among human needs, activities, changes in the state of the environment, and the resultant effect on ecosystem services for sustainable management in fulfilment of the Conservation on Biological Diversity and the Sustainable Development Goals. This study uses a socio-ecological framework (Drivers (D), Activities (A), Pressure (P), State (S), Impact (I) on welfare (W), and Response (R) as a Measure (M); DAPSI(W)R(M)) to assess the marine fishery sector of Ghana. Data were systematically sampled and analysed from vessel logbooks, fish manifests, observer reports, and relevant publications.

Results show that Drivers, including livelihoods and revenue, food, and social status, contribute to industrial tuna and trawl fishing, and marine artisanal fishing activities. Where illegal fishing methods such as small mesh-size nets (less than 25 mm), lights, poisonous substances, among others, are used. These activities have contributed to the pressures of selective fishing of juvenile and adult pelagic and demersal fish species. This has contributed to (changes in the State) the decline and vulnerability of Sardinella spp., and Engraulis encrasicolus, among others. The Impact on welfare includes Ghana becoming a net importer of marine species with increasing idleness of fishers due to reduced catch. Several management measures, including the Fisheries Act 625 of 2002 and Fisheries (Amendment) Regulations L.I. 2217 of 2015, and quotas in the tuna sector, among others, have been instituted to curb the effect of anthropogenic activities. Management measures, including influencing consumer behaviour for a sustainable fishery, enforcement, and data-driven management, have been recommended, in response to the targets of the Sustainable Development Goals, the United Nations Decade of Ocean and the Convention on Biological Diversity.

https://doi.org/10.1016/j.ocecoaman.2023.106784

The Arrifes section (Algarve Basin, Southern Portugal) has been studied from the viewpoint of charophyte biostratigraphy. The previous sedimentological studies in this section showed that it is built of the interbedding of continental and marine facies that contain both marine and continental palynomorphs (pollen, spores, and dinoflagellates), providing an excellent sedimentary context to perform direct correlations between marine and continental domains. In the present work, the identified charophyte biozones have been correlated with dinoflagellate biozones previously recognized in the Arrifes section, being the first time that these two biochronologies can be directly correlated. From the charophyte biostratigraphy viewpoint, two assemblages are distinguished. The older one is found between 65 and 135 m of the stratigraphic section, and it is composed of the species Echinochara lazarii, Atopochara trivolvis var. triquetra, A. trivolvis var. trivolvis, Clavator grovesii var. jiuquanensis, Clavator harrisii var. harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis. This assemblage belongs to the upper Barremian–lower Aptian Clavator grovesii var. jiuquanensis Eurasian biozone and also to the Ascidiella cruciata-Pseudoglobator paucibracteatus European biozone and it is described in beds with the dinoflagellate cyst Subtilisphaera scabrata (lower to lowermost upper Barremian) and Odontochitina operculata (from upper Barremian upwards). The younger charophyte assemblage is found between 135 and 155 m of the stratigraphic section, and it is composed of the species A. trivolvis var. trivolvis, Clavator grovesii var. corrugatus, Clavator harrisii var. harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis. This assemblage belongs to Clavator grovesii var. corrugatus biozone, previously assigned to upper Aptian (Clavator grovesii var. lusitanicus biozone). However, in the Arrifes section, this assemblage is found in beds assigned to the dinoflagellate cyst Odontochitina operculata (from upper Barremian–lower Aptian). The direct correlation of the base of the C. grovesii var. corrugatus biozone with the dinoflagellate cyst O. operculata, indicates that the base of the Clavator grovesii var. corrugatus biozone is in the upper lower Aptian, which is slightly older than was previously suggested, and it is extended until the middle Albian.

https://doi.org/10.1016/j.cretres.2023.105575

Low biomass, but highly toxic algal blooms are frequent in the Ria Formosa coastal lagoon and adjacent coastal zone (southern Portugal), usually associated with specific oceanographic and nutrient conditions. In June 2019, a massive bloom of the dinoflagellate Lingulodinium polyedra developed along the coast, causing water discolouration, and the closure of beaches and of bivalve harvesting, with significant socioeconomic consequences. This study aims to evaluate the relationships between phytoplankton composition and environmental conditions before, during, and after the L. polyedra bloom. Water samples were collected in the Ria Formosa coastal lagoon throughout June and July 2019 for determination of nutrient and chlorophyll-a concentration using spectrophotometric methods. Phytoplankton composition and abundance were evaluated using inverted microscopy. Upwelling intensity was estimated considering a wind-based index, the cross-shore Ekman transport. Results show strong relationships between phytoplankton community composition and nutrients, particularly a positive relationship between centric diatoms and nitrogen, and a negative relationship between several dinoflagellate genera, and phosphorus and silicon. L. polyedra was not significantly associated with any nutrient variable, most likely due to its mixotrophic capabilities. A clear phytoplankton succession, typical of eastern boundary upwelling locations, was observed throughout the different bloom phases, from dominance of type II dinoflagellates (Heterocapsa, Prorocentrum) in the pre-bloom period, to dominance of L. polyedra (type V) during the bloom, and finally dominance of centric diatoms in the post-bloom period. However, the L. polyedra bloom was not associated with upwelling relaxation, but rather with an active upwelling event.

https://doi.org/10.1016/j.rsma.2023.102998

Keeping citizens informed about the sea is important because it can motivate collective actions to address threats to coastal and marine sustainability. In this article, we wondered how European science and environmental journalists cover marine issues in the print media. We conducted 26 interviews with press journalists in 13 European countries and asked about topics, triggers, and sources to write marine-related news. We found that climate change, marine pollution, and biodiversity are the most important issues and that good working relationships with both scientists and NGOs are key for this media coverage.

https://doi.org/10.22323/2.22050802

Concerns about plastic pollution and its toxicity towards animals and people are growing. Polystyrene (PS) is a plastic polymer highly produced in Europe for packaging purposes and building insulation amongst others. Whatever their source—illegal dumping, improper waste management, or a lack of treatment for the removal of plastic debris from wastewater treatment plants—PS products ultimately end up in the marine environment. Nanoplastics (<1000 nm) are the new focus for plastic pollution, gaining broad interest. Whether primary or secondary, their small size permits nanoparticles to cross cellular boundaries, consequently leading to adverse toxic effects. An in vitro assay of Mytilus galloprovincialis haemocytes exposed to 10 μg/L of polystyrene nanoplastics (PS-NPs; 50 nm) for 24 h was used to test cellular viability along with the luminescence inhibition (LC50) of Aliivibrio fischeri bacteria to evaluate acute toxicity. Cellular viability of mussel haemocytes decreased significantly after a 24 h exposure and PS-NPs LC50 range from 180 to 217, μg/L. In addition, a 28-day exposure of the marine bivalve M. galloprovincialis to PS-NPs (10 μg/L; 50 nm) was performed to evaluate the neurotoxic effects and the uptake of these plastic particles in three bivalve tissues (gills, digestive gland, and gonads). The ingestion of PS-NPs was time- and tissue-specific, suggesting that PS-NPs are ingested through the gills and then translocated through the mussel bloodstream, to the digestive gland and gonads where the highest amount of ingested PS-NPs was reported. Ingested PS-NPs may compromise the digestive glands' key metabolic function and impair mussels' gametogenic and reproductive success. Data on acetylcholinesterase inhibition and those previously obtained on a wide range of cellular biomarkers were elaborated through weighted criteria providing a synthetic assessment of cellular hazard from PS-NPs.

https://doi.org/10.1016/j.envpol.2023.122104

A network of cross-shelf paleovalleys has been recognized over the paleo-inner shelf off the Gilão-Almargem Estuary, a small fluvial drainage system that presently receives minor sediment supply in the eastern Algarve shelf, northern margin of the Gulf of Cadiz (SW Iberian Peninsula). This study is aimed at determining the driving controls that triggered substantially different paleohydrological conditions and sedimentary dynamics of ancient fluvial systems in this margin. We focus on evidences of secondary controls on valley genesis and evolution, superimposed to primary glacio-eustatic control such as antecedent geology, low fluvial supply and changing hydrodynamic regimes. The architecture and spatial distribution of these paleovalleys were interpreted based on a grid of seismic profiles with different resolutions. Likewise, a sediment core obtained in a distal position of the paleovalley system provided information about sedimentary processes during the most recent stage of valley infilling. The chronostratigraphic framework was constructed based on regional seismic horizons defined in previous studies and complemented with two AMS 14C dates obtained from bivalve shells.

The inner shelf paleovalley system is composed of several incised valley features which exhibit a remarkable similar internal architecture. These inner valley features exhibit two major incision phases (from oldest to youngest; IP 2 and IP 1) that are thought to constitute a simple paleovalley system formed during the last glacial cycle. The origins of the incision are considered to be different. The older one is related to fluvial incision during the sea-level fall leading into the Last Glacial Maximum, whereas the recent one is interpreted as the result of tidal scour during the postglacial transgression. Their corresponding infillings are interpreted, respectively, as estuarine bay-fill deposits and estuary-mouth sands. Overlying the paleovalley infilling, a distinctive reflective unit is in agreement with the generation of coastal barriers and related depositional systems.

The formation of the paleo-inner-shelf paleovalley system was strongly conditioned by antecedent geology, which strongly limited the generation of wide incised valleys and determined the amount of incision landward of a well-defined break of slope. Its postglacial infilling was mainly estuarine in nature, likely involving the development of a dendritic system, with numerous barriers interrupted by tidal inlets and channels in a mixed estuarine system with low fluvial supply.

https://doi.org/10.1016/j.csr.2023.105095

The importance of the microbiome in aquaculture species is widely acknowledged. The fish gut microbiota is essential for host fitness, modulated by diet and environment, and affects animal physiology. The gut microbiome optimizes nutrient uptake and immunomodulation and enhances host resilience against infectious diseases. Understanding microbiome dynamics in aquaculture species is vital in promoting animal health and industry sustainability.

In this Research Topic of Frontiers four original papers and one review paper were accepted. This editorial provides an integrated summary of those papers’ main discoveries and clues.

https://doi.org/10.3389/fphys.2023.1276351

The use of several light-related variables, such as the Secchi disc depth, the euphotic depth, and in particular, the diffuse attenuation coefficient (K_d), is deeply rooted in phytoplankton research, but these are not the most appropriate indicators of the amount of light available for photosynthesis. We argue that the variable of interest for phytoplankton is the mean light intensity in the mixed layer (I_m), which represents the mean light to which phytoplankton cells are exposed throughout their life cycle, while being continuously mixed in the mixed layer. We use empirical data collected in different coastal ecosystems in southern Portugal to demonstrate why I_m should be the preferred metric instead of the deeply rooted K_d. We show that, although the relationship between I_m and K_d is inversely proportional, it is not always strong or even significant. Different I_m values can be associated with the same K_d, but distinct I_m have different physiological effects of phytoplankton. Therefore, K_d does not capture the amount of light available for photosynthesis, given that, unlike I_m, K_d calculation does not consider the depth of the mixed layer. Therefore, we urge phytoplankton researchers to consider the measurement and calculation of I_m when evaluating light-related processes in phytoplankton ecology.

Keywords: phytoplankton; light measurements; light limitation; coastal ecosystems

https://doi.org/10.3390/w15162966

Water planning and management, especially during periods of water stress, is becoming challenging for water managers worldwide. The aim of the present study was to provide an integrated water resources management (IWRM) plan designed to water management implementation at the local scale. This study was conducted in Morocco, a country which opts for anticipatory and long-term planning for the 2021–2050. The objective-based stakeholder interaction approach was adopted to establish the impact relationship between stakeholders and to develop an integrated water resources management (IWRM) plan. Thus, ten actors were involved and twelve water-related issues were identified and analysed. As a result, an analysis of stakeholders’ engagement was carried out based on an indicator framework on the impact between actors and the similarity between the actors’ objectives. The stakeholder’s analysis shows a high level of the objective similarity amongst some stakeholders which is very important indicator to recognise in the IWRM planning process. Furthermore, an IWRM plan was developed, which consisted of nine components aimed at either implementing or enhancing the water management process. This IWRM plan emphasised capacity building and stakeholders’ participation as main input of the process. The findings provide a roadmap for effective IWRM implementation through the operationalization of water management actions.

https://doi.org/10.1007/s40899-023-00919-x

Mineralogical assemblages and organofacies are important sources of information to recover the paleoenvironmental and thermal histories of shale deposits. In this study, a detailed qualitative and quantitative characterization of the Permian Irati Formation (Assistência Member) shale is based on mineralogical (XRD and SEM-EDS) and organic components (TOC, Rock-Eval pyrolysis, organofacies, TAI, fluorescence and vitrinite reflectance measurements) and provides integrated data about sediment provenance, depositional environment, diagenesis, and thermal history, while supporting interpretations on the Paraná Basin (PB), Brazil, paleogeography and its correlation to the southwest Gondwana. The results revealed a prevailing type I/II kerogen, with type III kerogen being also present but mainly confined along the paleoshoreline of the PB. The dominance of fluorescent amorphous organic matter (AOM) combined with framboidal pyrite suggests microbial activity in an anoxic-dysoxic neritic-marine paleoenvironment. Additionally, common to abundant well-preserved phytoclasts, as well as the occurrence of Botryococcus braunii, indicates freshwater influx in a brackish marine depositional setting. Immature to early-oil window thermal maturities prevail across the PB, according to the organic maturation indicators. The combined analysis between the organic matter evolution with clay mineralogy, such as the occurrence of interstratified clays (e.g., I/S) and its positive correlation with depth suggest that burial diagenesis reached the transition to early catagenesis on the north, southeast, and south of the basin, attributing a shale oil potential for the Irati Formation on a regional scale. Local scale imprints of the Early Cretaceous Paraná-Etendeka Large Igneous Province (LIP), and its thermal effect in the Irati Formation shale components, are recorded as clay authigenesis (e.g., smectite webby texture and clay coating development), crystallization of minerals by low to high-grade of thermal alteration (e.g., corrensite, talc, lizardite and diopside), and by local scale gas-window maturities. Such thermal alteration, identified in the proximity to intruded sills and dykes, led to a heterogeneous organic maturation pattern with implications on shale gas and shale oil potential of the Irati Formation shale, demonstrating that these subjects in the Paraná Basin should be assessed locally.

https://doi.org/10.1016/j.marpetgeo.2023.106328

Aim: Assessment of the fate of microbial contamination driven from treated wastewater disposal at a highly productive zone on a South European coastal lagoon (Ria Formosa).

Methods and results: Microbial indicators of contamination (Total coliforms, Escherichia coli, and Enterococci) were evaluated monthly during September 2018–September 2020 at three study areas (Faro, Olhão, and Tavira) under different wastewater discharge flows and hydrodynamic conditions. Additional data on E. coli monitoring in bivalves, available from the national institution responsible for their surveillance was also considered. The maximum microbial contamination was found at Faro, the highest-load and less-flushed study area, contrasting the lowest contamination at Olhão, a lower-load and strongly flushed area. The wastewater impact decreased along the spatial dispersal gradients and during high water, particularly at Faro and Tavira study areas, due to a considerable dilution effect. Microbial contamination at Olhão increased during the summer, while at the other study areas seasonal evidence was not clear. Data also indicate that E. coli in bivalves from bivalve production zones next to the three study areas reflected the differentiated impact of the wastewater treatment plants effluents on the water quality of those areas.

Conclusions: Effluent loads together with local hydrodynamics, water temperature, solar radiation, precipitation, and land runoff as well as seabirds populations and environmentally adapted faecal or renaturelized bacterial communities, contributed to microbial contamination of the study areas.

Keywords: Escherichia coli, coastal lagoons, Ria Formosa, microbial contamination, treated wastewater

https://doi.org/10.1093/jambio/lxad166

The clam Galatea schwabi is a bivalve found in the lower Sanaga, and exploited by local people for its meat and shell. This research aimed to determine the proximate and heavy metals (Cd, Pb and Hg) composition contained in fresh and smoked clam meat by standard analytical methods. Fresh clam meat was collected from the fishing area and smoked from Yakalak and Malimba Districts. The results showed a significant difference in the water, protein, lipid, and mineral content of smoked clams in Yakalak and Malimba District, except for the ash content which was similar in the different areas studied. The clam harvested in the lower Sanaga, regardless of its commercialized form is rich in proteins with 27,31 ± 0,27% in fresh, for the smoked clams 59,85 ± 0,24% in Yakalak, 34,66 ± 0,13% in Malimba District, and minerals Ca, Mg and Na. The concentration of heavy metals Pb and Cd in fresh and smoked G. schwabi meat is above the WHO recommended tolerance limits, while Hg is below the same standard. The highest concentrations of heavy metals were observed in smoked clams from Malimba District. Although that G. schwabi clam constitutes an alternative source of nutrients for human and animal, the high concentration of heavy metals, show that the resource is subject to the effects of anthropic activity, and consuming it would be a risk for consumers.

DOI: 10.12691/jfs-11-2-1

Sea level rise will be a major threat to coastal communities within the next century due to the intensity and severity of the floods it can cause. A new methodology considering water infiltration, slope, and hydraulic connectivity was developed to assess the potential inundation extension associated with different total water level and sea level rise scenarios on sandy coasts. This methodology was applied for the current conditions as well as 2050 and 2100 scenarios of storm surge and high tide levels with return periods of 1 year and 100 years. The study area is Culatra village, located on the lagoon side of a barrier island in southern Portugal. The effects of shoreline evolution after the construction of a harbor and associated beach nourishment were also evaluated within the inundation scenarios. The results show that, within the study area, total water level variations caused by sea level rise have a greater influence on the inundation extension than shoreline retreat. The village appears to be safe for the current and 2050 total water level scenarios with a 1-year return period but would be highly affected by 100-year return periods, especially from 2050 onwards. This novel approach represents an improvement on more common flood mapping methods such as the bathtub approach and can be easily applied to other backbarrier environments under sea level rise or facing coastal erosion.

https://doi.org/10.1007/s11852-023-00955-x

The Moatize Coalfield belongs to a network of continental Karoo basins of central Mozambique, known as the Zambezi Basin. Palynological and sedimentological studies were performed on four coal exploration boreholes to determine the age, depositional settings, and overall geological evolution of its extensive coal deposits. Clastic formations recognised in this coalfield, in ascending order, are the Vúzi, Moatize and Matinde formations. Palynomorph assemblages indicate that the Moatize Coalfield succession ranges from Roadian (lower Guadalupian) to Changhsingian (upper Lopingian) in age. Two main depositional phases are identified, whose initiation and development are attributed to regional tectonic events and climate amelioration. The first phase formed towards the end of the deglacial period, characterised initially by fan deltas, represented by the upper Vúzi Formation, and the shift to lake–delta environments, represented by the lower part of the Moatize Formation. This phase took place from Roadian to the Wordian times. The lake–delta settings indicate a sediment aggradation trend with high subsidence rates in the lake basin, which, together with the associated post-glacial climate amelioration, led to the accumulation of coal deposits in swamps of the delta top and lake margins. The second depositional phase took place from Capitanian to Changhsingian times and related to fluvial environments initiated by uplift that reorganised the depocenter into alluvial plains characterised by bedload dominated rivers (braided) and overbank floodplains. Results obtained in this study provide critical information for the onset of the deglaciation events and the age of coal deposits in this part of Gondwana, important for wider stratigraphic correlation of these events in Africa and throughout the Gondwana.

https://doi.org/10.1016/j.palwor.2023.07.001

The Ria Formosa coastal lagoon is a highly productive shallow ecosystem in southern Portugal, subjected to nutrient inputs from anthropogenic and natural sources. Nutrients are major abiotic drivers of phytoplankton in this system, but their effects on phytoplankton assemblages and the occurrence of nutrient limitation are still poorly understood. The main goal of this study was, thus, to evaluate the occurrence, type, and effects of nutrient limitation on phytoplankton community and specific functional groups in the Ria Formosa coastal lagoon. We conducted nutrient enrichment experiments with factorial additions of nitrogen (N) and phosphorus (P) using natural phytoplankton assemblages from distinct locations in the Ria Formosa, throughout a yearly cycle. Phytoplankton composition and abundance were evaluated using inverted and epifluorescence microscopies, and spectrophotometric methods were used for biomass. Limitation was defined as higher phytoplankton growth following enrichment with a particular nutrient in relation to the non-enriched control. The most common type of phytoplankton limitation was simultaneous co-limitation by N and P; diatoms, as r-strategists, were the most frequently limited group. Single N and P limitation, and serial P limitation were also observed, as well as negative responses to nutrient enrichment. Group-specific responses to nutrient enrichment were not reflected in the relative abundance of phytoplankton groups within the whole assemblage, due to the numerical dominance of pico-sized groups (cyanobacteria and eukaryotic picophytoplankton). Ambient nutrient ratios and concentrations did not predict phytoplankton nutrient limitation, given the different nutrient utilisation traits among phytoplankton functional groups. Therefore, nutrient ratios should not be used as indicators of nutrient limitation in eutrophication assessment.

https://doi.org/10.1007/s12237-023-01230-w

Contaminants of emerging concern (CECs) present a new threat to the marine environment, and it is vital to understand the interactions and possible toxicity of CEC mixtures once they reach the ocean. CECs—such as metal nanoparticles, nanoplastics, and pharmaceuticals—are groups of contaminants some of which have been individually evaluated, though their interactions as mixtures are still not fully understood. To ensure a healthy and prosperous future generation, successful reproduction is key: however, if hindered, population dynamics may be at danger leading to a negative impact on biodiversity. This study aimed to understand the effects of silver (20 nm nAg, 10 μg/L), polystyrene nanoparticles (50 nm nPS, 10 μg/L), and 5-fluorouracil (5FU, 10 ng/L) individually and as a mixture (10 μg/L of nPS + 10 μg/L of nAg +10 ng/L of 5FU) in the gonads of Mytilus galloprovincialis. A multibiomarker approach, namely the antioxidant defence system (ADS; superoxide dismutase, catalase, glutathione peroxidases, glutathione – S – transferases activities), and oxidative damage (OD; lipid peroxidation) were analysed in the gonads of mussels. All exposure treatments after 3 days led to an increase of enzymatic activity, followed by an inhibition after 14 and 21 days. Thus, ADS was overwhelmed due to the generation of ROS, resulting in OD, except for nPS exposed mussels. The OD in Mix exposed mussels increased exponentially by 57-fold. When CEC mixtures interact, they are potentially more hazardous than their individual components, posing a major threat to marine species. To understand synergistic and antagonistic interactions, a model was applied, and antagonistic interactions were observed in evaluated biomarkers at all time-points, apart from a synergistic interaction at day 3 relative to LPO. Results indicate that the effects observed in Mix-exposed mussel gonads are mainly due to the interaction of nAg and 5FU but not nPS.

https://doi.org/10.1016/j.scitotenv.2023.163486

Shallow coastal waters receive high anthropogenic nutrients (nitrogen-N and phosphorus-P) from land that can change their nutrient chemistry, algal composition, and food webs with serious effects on marine life, human health, and local livelihoods. Managing anthropogenic nutrient inputs is thus key to ensuring healthy and productive coastal ecosystems. This study conducted a bimonthly sampling for eight months between 2014 and 2015 to determine the influence of agriculture, sewage, and natural nutrient sources on nutrient chemistry, ecological status, and possible implications for aquaculture production in the western side of Ria Formosa lagoon. Ecological Quality Ratios (EQR) were calculated from nutrient ratios (N: P: Si) computed from nutrient concentrations with the Redfield ratio (N: P: Si =16:1:16) used as a reference for ecological status determination. A mean of 3.7, 1.0, and 4.6 μm/L; 6.7, 1.12, and 5.5 μm/L; and 4.6, 0.7, and 2.8 μm/L were recorded for dissolved inorganic nitrogen, phosphorus and silicates concentrations at sewage, agriculture, and natural sites respectively. The site mean EQR values ranged between 0.55 and 0.69. The overall ecological status of the west part of the lagoon was ‘Moderate’, with all the sites grouped under ‘Good’/’Moderate’ and ‘Moderate’/’Poor’ classes based on nutrient ratios. This study demonstrates that the western part of the lagoon’s nutrient chemistry is highly influenced by the nutrient sources with agricultural run-off and sewage discharges associated with nitrates, and ammonia and phosphates respectively. The elevated ammonium and phosphates registered can transform the phytoplankton composition to non-diatomic species and affect the current ecological functions of the lagoon. We recommend further studies, including biological quality elements, to get more comprehensive results on the study area.

https://doi.org/10.1016/j.rsma.2023.102843

Sustainability is a universal goal that requires balancing social, economic and environmental dimensions, and that applies to both terrestrial and marine environments. Several authors argue that arts are valuable tools to frame and engage with current environmental issues related to sustainability, including pollution, climate change and biodiversity loss. Accordingly, our research question is: What is the role of art in the sustainability of coasts and seas? We searched our research question on the two most important scientific databases of articles (Scopus and Web of Science) and retrieved 1,352 articles. We narrowed the articles to 79 studies that actually address our question through screening. The dataset describes a variety of artworks from the four art categories (literary, media, performing and visual) around the world, although the more frequent countries are the US, the UK and Australia. We found that visual arts are more common (~40%), and engagement is a highlighted pursued impact (~40%) by these artistic practices. Other authors also intend to promote marine conservation and restoration, management, education and activism. Only 19 articles of the dataset measured the impact of artistic activities on their audience. This subset shows evidence of art contributions to sustainability mainly through raising awareness, learning, and promoting engagement and enjoyment of project participants. Through this work, we set the current state of knowledge on this emerging topic, and argue that further research and new strategies of impact measurement are needed to thoroughly understand the effect of art on coastal/marine sustainability.

Early warning systems (EWSs) for coastal erosion are cost-effective instruments for risk reduction. Among other aspects, the selection of the pre-storm beach morphology and the definition of storm characteristics can affect EWS reliability. Here, XBeach simulations were used to assess the uncertainties in beach-dune erosion related to the variability of storm severity and duration and pre-storm morphology. Wave height return periods (from 5 to 50 years) determined the severity and the duration variability was established from confidence intervals after an adjustment with wave height. The variability of steep profiles included different berm morphologies (from fully developed to eroded berms). Three indicators, relative eroded volume, proportional berm retreat and proportional dune retreat, were evaluated. The experiments revealed that: (a) Relative eroded volume uncertainties related to the pre-storm morphology variability were slightly lower (maximum 8%) than the uncertainties related to storm duration (11%–18%). (b) Pre-storm profile variability can induce large uncertainties in the proportional berm retreat (up to 88%) for moderate events such as the 5- and 10-year events. Storm duration variability had less influence on this indicator (maximum 12%). (c) The uncertainties in the proportional dune retreat increased with storm severity and they ranged between 14% and 41% for pre-storm profile variability and between 2% and 40% for storm duration variability. Duration variability even governed the occurrence of dune breaching on eroded berm profiles in the most extreme event. Hence, the uncertainties related to initial/forcing conditions, namely pre-storm morphology and storm duration, must be assessed to develop reliable coastal erosion EWSs.

https://doi.org/10.1029/2022JC019339

A major obstacle to mapping Ecosystem Services (ES) and the application of the ES concept has been the inadequacy of data at the landscape level necessary for their quantification. This study takes advantage of free satellite imagery to map and provide relevant information regarding ES and contribute to the sustainable management of natural resources in developing countries. The aim is to assess the flow of ES in mangrove ecosystem of Ungwana Bay, located on the northern coast of Kenya, by adopting the Land Use Land Cover (LULC) matrix approach. This study characterized LULC classes present in the study area, identified the most important ES, and collected data on expert opinions via a survey on ES flow supplied by the mangrove ecosystem. A qualitative and quantitative analysis of the expert scoring produced a LULC matrix which, when integrated with the LULC maps, showed the spatial distribution of ES flow. The assessment indicates very high flow (5.0) for the regulating and supporting services, high flow (4.0) for the cultural services, and medium flow (3.0) for the provisioning services as supplied by mangroves. In addition, the analysis indicates there are sixteen major ES supplied by the mangrove ecosystem of Ungwana bay as of the year 2021. This study highlights the importance of mangroves as a coastal ecosystem and how the visualization of the spatial distribution of ES flow using maps can be useful in informing natural resource management. In addition, the study shows the possibilities of using freely accessible satellite imagery and software to bolster the ES assessment studies lacking in developing countries.

https://doi.org/10.3390/rs15071802

River-mouth systems and deltas are hotspots where many of the coastal syndromes can be found. Moreover, these systems provide essential ecosystem services (e.g., recreation, food provisioning, protection against natural hazards). The present study focuses on the socio-ecological system at the delta of the Magdalena River in the central Caribbean Region in Colombia. This research seeks to assess the multidimensional sustainability of the Magdalena river-mouth system (MRm-SES) to improve the knowledge basis for its integrated management. To do so, an assessment tool named “Circles of Coastal Sustainability” (CCS) was used to evaluate the system splitting it into four domains (environmental, social, economic and governance) that were divided into 5 categories each. These domains were evaluated through a total of 52 indicators distributed like this: 16 for the Environmental domain, 16 for the Economic domain, 12 for the Social and Cultural domain and, 8 for the Governance domain. The results show that the overall sustainability of the MRm-SES is classified as “Satisfactory.” None of the domains is in “Excellent” or “Bad” conditions. However, the evaluation of the categories shows that four (4) of them have “Poor” conditions (i.e., Social Benefits, Demographics, Economic Security, and Resources Management). Hence, it is recommended to put those categories at the centre of the discussion to define management strategies (e.g., Preserving and restoring habitats; tackling sources of pollution and excessive sediment; local reduction of net Greenhouse Gas and adaptation to climate change; participation of local communities in the management design and implementation), without disregarding the interrelation with the other categories and dimensions. Finally, it is argued that despite all the improvement opportunities, the CCS is a valuable tool to evaluate and communicate with different stakeholders (academic community, managers and decision-makers, local communities, etc.), to improve the sustainability of coastal systems in Colombia and the world.

https://doi.org/10.3389/feart.2023.1058122

River-mouth systems and deltas are hotspots where many of the coastal syndromes can be found. Moreover, these systems provide essential ecosystem services (e.g., recreation, food provisioning, protection against natural hazards). The present study focuses on the socio-ecological system at the delta of the Magdalena River in the central Caribbean Region in Colombia. This research seeks to assess the multidimensional sustainability of the Magdalena river-mouth system (MRm-SES) to improve the knowledge basis for its integrated management. To do so, an assessment tool named “Circles of Coastal Sustainability” (CCS) was used to evaluate the system splitting it into four domains (environmental, social, economic and governance) that were divided into 5 categories each. These domains were evaluated through a total of 52 indicators distributed like this: 16 for the Environmental domain, 16 for the Economic domain, 12 for the Social and Cultural domain and, 8 for the Governance domain. The results show that the overall sustainability of the MRm-SES is classified as “Satisfactory.” None of the domains is in “Excellent” or “Bad” conditions. However, the evaluation of the categories shows that four (4) of them have “Poor” conditions (i.e., Social Benefits, Demographics, Economic Security, and Resources Management). Hence, it is recommended to put those categories at the centre of the discussion to define management strategies (e.g., Preserving and restoring habitats; tackling sources of pollution and excessive sediment; local reduction of net Greenhouse Gas and adaptation to climate change; participation of local communities in the management design and implementation), without disregarding the interrelation with the other categories and dimensions. Finally, it is argued that despite all the improvement opportunities, the CCS is a valuable tool to evaluate and communicate with different stakeholders (academic community, managers and decision-makers, local communities, etc.), to improve the sustainability of coastal systems in Colombia and the world.

https://doi.org/10.3389/feart.2023.1058122

The analysis of extreme wave conditions is crucial for understanding and mitigating coastal hazards. As global wave reanalyses allow to extend the evaluation of wave conditions to periods and locations not covered by in-situ measurements, their direct use is common. However, in coastal areas, the accuracy of global reanalyses is lower, particularly for extreme waves. Here we compare two leading global wave reanalyses against 326 coastal buoys, demonstrating that both reanalyses consistently underestimate significant wave height, 50-year return period and mean wave period in most coastal locations around the world. Different calibration methods applied to improve the modelled extreme waves, resulting in a 53% reduction in the underestimation of extreme wave heights. Importantly, the 50-year return period for significant wave height is improved on average by 55%. Extreme wave statistics determined for coastal areas directly from global wave reanalyses require careful consideration, with calibration largely reducing uncertainty and improving confidence.

https://www.nature.com/articles/s43247-023-00819-0#citeas

Beaches combined with sloping structures are frequently the first element of defense to protect urban areas from the impact of extreme coastal flooding events. However, these structures are rarely designed for null wave overtopping discharges, accepting that waves can pass above the crest and threat exposed elements in hinterland areas, such as pedestrians, urban elements and buildings, and vehicles. To reduce risks, Early Warning Systems (EWSs) can be used to anticipate and minimize the impacts of flooding episodes on those elements. A key aspect of these systems is the definition of non-admissible discharge levels that trigger significant impacts. However, large discrepancies in defining these discharge levels and the associated impacts are found among the existing methods to assess floodings. Due to the lack of standardization, a new conceptual and quantitative four-level (from no-impact to high-impact) categorization of flood warnings (EW-Coast) is proposed. EW-Coast integrates and unifies previous methods and builds on them by incorporating field-based information. Thus, the new categorization successfully predicted the impact level on 70%, 82%, and 85% of the overtopping episodes affecting pedestrians, urban elements and buildings, and vehicles, respectively. This demonstrates its suitability to support EWSs in areas vulnerable to wave-induced flooding.

https://doi.org/10.1038/s41598-023-32175-6

The analysis of extreme wave conditions is crucial for understanding and mitigating coastal hazards. As global wave reanalyses allow to extend the evaluation of wave conditions to periods and locations not covered by in-situ measurements, their direct use is common. However, in coastal areas, the accuracy of global reanalyses is lower, particularly for extreme waves. Here we compare two leading global wave reanalyses against 326 coastal buoys, demonstrating that both reanalyses consistently underestimate significant wave height, 50-year return period and mean wave period in most coastal locations around the world. Different calibration methods applied to improve the modelled extreme waves, resulting in a 53% reduction in the underestimation of extreme wave heights. Importantly, the 50-year return period for significant wave height is improved on average by 55%. Extreme wave statistics determined for coastal areas directly from global wave reanalyses require careful consideration, with calibration largely reducing uncertainty and improving confidence.

https://doi.org/10.1038/s43247-023-00819-0

Contaminants of emerging concern (CECs) present a new threat to the marine environment, and it is vital to understand the interactions and possible toxicity of CEC mixtures once they reach the ocean. CECs—such as metal nanoparticles, nanoplastics, and pharmaceuticals—are groups of contaminants some of which have been individually evaluated, though their interactions as mixtures are still not fully understood. To ensure a healthy and prosperous future generation, successful reproduction is key: however, if hindered, population dynamics may be at danger leading to a negative impact on biodiversity. This study aimed to understand the effects of silver (20 nm nAg, 10 μg/L), polystyrene nanoparticles (50 nm nPS, 10 μg/L), and 5-fluorouracil (5FU, 10 ng/L) individually and as a mixture (10 μg/L of nPS + 10 μg/L of nAg +10 ng/L of 5FU) in the gonads of Mytilus galloprovincialis. A multibiomarker approach, namely the antioxidant defence system (ADS; superoxide dismutase, catalase, glutathione peroxidases, glutathione – S – transferases activities), and oxidative damage (OD; lipid peroxidation) were analysed in the gonads of mussels. All exposure treatments after 3 days led to an increase of enzymatic activity, followed by an inhibition after 14 and 21 days. Thus, ADS was overwhelmed due to the generation of ROS, resulting in OD, except for nPS exposed mussels. The OD in Mix exposed mussels increased exponentially by 57-fold. When CEC mixtures interact, they are potentially more hazardous than their individual components, posing a major threat to marine species. To understand synergistic and antagonistic interactions, a model was applied, and antagonistic interactions were observed in evaluated biomarkers at all time-points, apart from a synergistic interaction at day 3 relative to LPO. Results indicate that the effects observed in Mix-exposed mussel gonads are mainly due to the interaction of nAg and 5FU but not nPS.

https://doi.org/10.1016/j.scitotenv.2023.163486

In keeping with the premises of Blue Circular Economy in the European Union, the present study explored the possibility of using the invasive brown alga Rugulopteryx okamurae in aquafeeds for European sea bass (Dicentrarchus labrax). Assuming the raw algae biomass could negatively impact animal performance, four experimental formulations were prepared, by including macroalgae material at 5%, using crude (CR), enzymatically hydrolysed and fermented (EF), enzymatically hydrolysed (E), or fermented (F) R. okamurae biomass, which we tested against a control feed (CT). To evaluate the effects of the experimental diets, besides animal growth performance and biometric parameters, we devised a toolbox focused on the intestine and intestinal function: i) ex-vivo epithelial resistance and permeability in Ussing chambers; ii) microbiota composition through NGS; iii) expression profiles of selected markers for epithelial integrity, transport, metabolism, and immune response, by qPCR. Our results show differentiated allometric growth among diets, coupled with intestinal epithelium alterations in permeability, integrity, and amino acid transport. Additionally, evidence of microbiota dysbiosis and contrasting immune responses between experimental diets, i.e. pro-inflammatory vs. anti-inflammatory, are also described. In conclusion, we believe that R. okamurae could be a suitable resource for aquafeeds for the European sea bass, although its use requires a pre-treatment before inclusion. Otherwise, while the fish still have a positive growth performance, the gastrointestinal tract pays a toll on the integrity, transport, and inflammatory processes.

https://doi.org/10.1016/j.aquaculture.2023.739318

Integrated sedimentological, palynological, and palynofacies analyses of the Arrifes section in the central Algarve Basin (southern Portugal) provided new information on the age and environments of this Lower Cretaceous sequence. The sedimentary succession at the Arrifes section consists of fossiliferous interbedded limestones, marly limestones, and marls, dated as latest Hauterivian to late Barremian age (Lower Cretaceous) based on key dinoflagellate taxa. During this interval, the Arrifes area records climatic shifts and, multiple sea-level fluctuations; overall deposition was in shallow subtidal to intertidal settings, with deposition of carbonate and marly sediments. During the latest Hauterivian to earliest Barremian interval, an evident sea-level fall culminated in the subaerial exposure of the local carbonate ramp with increased influx of clastic sediments. However, during the Barremian, both sedimentological and palynological analyses suggest an overall deepening of the water depth towards the top of the section. These overall increase in the water column are confirmed by oscillation of terrestrial/marine palynomorph groups and supported by dinosaur track levels at the top of the succession; the latter indicate that sedimentation occurred in intertidal to subtidal environments. Finally, an attempt was made to correlate the Arrifes section with other sections from the Algarve Basin, as well as with broader region. These new data suggest a setting in the Tethyan basin influenced during the latest Hauterivian to the end of the Barremian. These new data allow local correlations and new palynological ages and paleoenvironmental interpretations for the Lower Cretaceous succession of the Algarve Basin.

https://doi.org/10.1016/j.cretres.2022.105433

Scientists, industry, and policy-makers have turned increasing attention toward the ocean as a source of climate change mitigation solutions. Efforts to develop ocean-based climate interventions (OBCIs) to remove and sequester carbon dioxide (CO₂), manage solar radiation, or produce renewable energy have accelerated. Questions have been raised about OBCI costs, governance, impacts, and effectiveness at scale, but limited attention has been given to ocean biogeochemistry and ecosystems (1) and particularly to impacts on deepsea ecosystems (>200-m water depth), an ocean region that is understudied but fundamental for Earth’s healthy function. The deep sea, with low energy supply; typically cold, stable conditions; and a low density of organisms with reduced metabolism, requires specific attention. Here we discuss OBCIs that could affect deep-ocean ecosystems and their services, identify governance challenges, and highlight the need for an integrated research framework to help centralize consideration of deep-sea impacts in mitigation planning.

https://www.science.org/doi/10.1126/science.ade7521

Understanding the role of river discharge on tide-river dynamics is of essential importance for sustainable water management (flood control, salt intrusion, and navigation) in estuarine environments. It is well known that river discharge impacts fundamental tide-river dynamics, especially in terms of subtidal (residual water levels) and tidal properties (amplitudes and phases for different tidal constituents). However, the quantification of the impact of river discharge on tide-river dynamics is challenging due to the complex interactions of barotropic tides with channel geometry, bottom friction, and river discharge. In this study, we propose a data-driven model to quantify the impact of river discharge on tide-river dynamics, using water level time series data collected through long-term observations along an estuary with substantial variations in river discharge. The proposed model has a physically-based structure representing the tide-river interaction, and can be used to predict water level using river discharge as the sole predictor. The satisfactory correspondence of the model outputs with measurements at six gauging stations along the Yangtze River estuary suggest that the proposed model can serve as a powerful instrument to quantify the impacts of river discharge on tide-river dynamics (including time-varying tidal properties and tidal distortion), and separate the contribution made by riverine and tidal forcing on water level. The proposed approach is very efficient and can be applied to other estuaries showing considerable impacts of river discharge on tide-river dynamics.

https://doi.org/10.1016/j.jhydrol.2023.129411

From both practical and theoretical perspectives, it is essential to be able to express observed salinity distributions in terms of simplified theoretical models, which enable qualitative assessments to be made in many problems concerning water resource utilization (such as intake of fresh water) in estuaries. In this study, we propose a general and analytical salt intrusion model inspired by Guo's general unit hydrograph theory for flood hydrograph prediction in a watershed. To derive a simple, general and analytical model of salinity distribution, we first make four hypotheses on the longitudinal salinity gradient based on empirical observations; we then derive a general unit hydrograph for the salinity distribution along a partially mixed or well-mixed estuary. The newly developed model can be well calibrated using a minimum of three salinity measurements along the estuary axis and does converge towards zero when the along-estuary distance approaches infinity asymptotically. The theory has been successfully applied to reproduce the salt intrusion in 21 estuaries worldwide, which suggests that the proposed method can be a useful tool for quickly assessing the spread of salinity under a wide range of riverine and tidal conditions and for quantifying the potential impacts of human-induced and natural changes.

https://doi.org/10.5194/os-19-603-2023

The establishment of thresholds is integral to environmental management. This paper introduces the use of thresholds in the context of deep-seabed mining, a nascent industry for which an exploitation regime of regulations, standards and guidelines is still in the process of being developed, and for which the roles and values of thresholds have yet to be finalised. There are several options for integrating thresholds into the International Seabed Authority’s regulatory regime, from being stipulated in regulations to being part of a mining contract, each option having its own advantages and disadvantages. Here we explore the range of ways that thresholds can be derived, set out the challenges in translating ecological and management data into thresholds, highlight factors for acceptance and operationalisation of thresholds in deep-seabed mining, and explain the necessity of refining thresholds as knowledge on impacts to features improves. Some comparable marine industries already use thresholds and these could potentially be used as starting points for the development of thresholds for deep-seabed mining. In order to be acceptable to the wide range of deep-seabed mining stakeholders, thresholds need to strike a balance among levels of harm acceptable by society, levels of environmental precaution justifiable by governments, scientific robustness, and operational practicality.

http://dx.doi.org/10.1016/j.marpol.2023.105505

Microbial populations have evolved intricate networks of negotiation and communication through which they can coexist in natural and host ecosystems. The nature of these systems can be complex and they are, for the most part, poorly understood at the polymicrobial level. The Pseudomonas Quinolone Signal (PQS) and its precursor 4-hydroxy-2-heptylquinoline (HHQ) are signal molecules produced by the important nosocomial pathogen Pseudomonas aeruginosa. They are known to modulate the behaviour of co-colonizing bacterial and fungal pathogens such as Bacillus atropheaus, Candida albicans and Aspergillus fumigatus. While the structural basis for alkyl-quinolone signalling within P. aeruginosa has been studied extensively, less is known about how structural derivatives of these molecules can influence multicellular behaviour and population-level decision-making in other co-colonizing organisms. In this study, we investigated a suite of small molecules derived initially from the HHQ framework, for anti-virulence activity against ESKAPE pathogens, at the species and strain levels. Somewhat surprisingly, with appropriate substitution, loss of the alkyl chain (present in HHQ and PQS) did not result in a loss of activity, presenting a more easily accessible synthetic framework for investigation. Virulence profiling uncovered significant levels of inter-strain variation among the responses of clinical and environmental isolates to small-molecule challenge. While several lead compounds were identified in this study, further work is needed to appreciate the extent of strain-level tolerance to small-molecule anti-infectives among pathogenic organisms.

https://doi.org/10.1099/mic.0.001303

A model for simulating the migration of tidal inlets, called ShorelineS, has been improved to include littoral sediment bypassing and an ebb-tidal delta in order to more accurately predict the rates and patterns of inlet migration. The model was tested on the migrating Ancão inlet in Portugal from 1998 to 2015, and the resulting shoreline evolution agreed with observations. Widely accessible satellite images and shorelines extraction tools allow for the estimation of the bypassing fractions. By including the effects of littoral sediment bypassing and the ebb-tidal delta, the model was able to more accurately predict the evolution of the coastline and the migration of the inlet amidst natural and anthropogenic factors.

https://doi.org/10.1142/9789811275135_0110

The establishment of thresholds is integral to environmental management. This paper introduces the use of thresholds in the context of deep-seabed mining, a nascent industry for which an exploitation regime of regulations, standards and guidelines is still in the process of being developed, and for which the roles and values of thresholds have yet to be finalised. There are several options for integrating thresholds into the International Seabed Authority’s regulatory regime, from being stipulated in regulations to being part of a mining contract, each option having its own advantages and disadvantages. Here we explore the range of ways that thresholds can be derived, set out the challenges in translating ecological and management data into thresholds, highlight factors for acceptance and operationalisation of thresholds in deep-seabed mining, and explain the necessity of refining thresholds as knowledge on impacts to features improves. Some comparable marine industries already use thresholds and these could potentially be used as starting points for the development of thresholds for deep-seabed mining. In order to be acceptable to the wide range of deep-seabed mining stakeholders, thresholds need to strike a balance among levels of harm acceptable by society, levels of environmental precaution justifiable by governments, scientific robustness, and operational practicality.

https://doi.org/10.1016/j.marpol.2023.105505

Marine litter density, distribution and potential sources, and the impact on canyon seafloor habitats were investigated in the Motril, Carchuna and Calahonda canyons, located along the northern margin of the Alboran Sea. During the ALSSOMAR-S2S oceanographic survey carried out in 2019, canyon floor imagery was collected by a Remotely Operated Vehicle along 5 km in the Motril Canyon, 10 km in the Carchuna Canyon, and 3 km in Calahonda Canyon, together with 41 surficial sediment samples. Additionally, coastal uses, maritime traffic and fishing activity data were analyzed. A 50 m resolution multibeam bathymetry served as base map.

https://doi.org/10.3389/fmars.2023.1098927

Transitional ecosystems, including estuaries, lagoons, and coastal lakes, are complex human-environmental systems that offer a wide range of societal benefits, including both commercial and non-commercial values. This book sets the stage for significant advances in several aspects of transitional ecosystem research and management.

https://doi.org/10.3389/fevo.2023.1136750

The postglacial sea-level rise after the Last Glacial Maximum provided ideal conditions to study the transgressive sedimentary response to sudden shelf flooding driven by different rates of sea-level rise. In this study, a high-resolution seismic stratigraphic interpretation and sedimentological analysis were conducted on data from the northern Gulf of Cadiz continental shelf (SW Iberian Peninsula), in order to: 1) understand the succession of sedimentary processes during each shelf flooding episode and 2) explore the significance of variable rates of sea-level rise, sediment fluxes, and climatic conditions on the development of postglacial deposits. Four backstepping seismic postglacial transgressive units (PTUs; 4 to 1 from oldest to youngest) that are linked to the retreating mouth of the Guadiana River were interpreted. Together, these seismic units display a wedge-shape geometry, are located over the inner to middle shelf, and overlie a regional unconformity formed during the Last Glacial Maximum. Each PTU can be divided into several sub-units with distinctive seismic facies that have a similar stratigraphic organization. Each PTU contains lower sub-units that are composed of low-angle tangential-oblique clinoforms. The clinoforms are locally topped by a channelized sub-unit. The distal and/or lateral parts of the clinoforms are occasionally buried by sheet-like semitransparent subunits. The uppermost sub-units are present over the proximal and central parts of each seismic unit and are also sheet-like. PTUs can also be subdivided and described sedimentologically. Fine-grained sands with intercalated silty layers dominate the lower part of each PTU (lower clinoform sub-units). The upper part of each PTU (upper sheet-like sub-units) is characterized by reworked facies, composed of highly fragmented bioclasts within a mixture of silt and coarse to medium sand. Finally, mud deposits occur as a sediment drape over the PTUs. The internal structure of each PTU reveals several phases of development under a general process of transgressive submergence in which both coastal and marine deposits were formed and eventually preserved. The initial phase involved the development of coarse-grained deltas in shallow water, which were locally eroded by a network of distributary channels. In a transitional phase, the infilling of distributary channels and the offshore export of fine-grained sediments is related to a change in sediment sources, possibly triggered by enhanced hydrodynamic processes. The final phase involved the reworking of fluvio-deltaic sediments by shoreface processes to generate a sediment sheet. Age correlation with a suite of postglacial sea-level curves indicates that the formation of the postglacial transgressive deposits is bracketed between 14 ka and 9 ka. The studied deposits are related to a period of reduced sea-level rise, culminating in the Younger Dryas event (two oldest PTUs), and to phases of enhanced sea-level rise, such as Meltwater Pulse (MWP) 1B (two youngest PTUs). In spite of high rates of sea-level rise over MWP-1B, each PTU exhibits progradation and preservation of much of the delta. The preservation of progradational deltaic units is likely caused by increased sediment supply during progradational pulses. We suggest that those pulses of enhanced sediment fluxes during MWP-1B were strongly driven by the overall climatic conditions in the southwest of the Iberian Peninsula, probably resulting from enhanced rainfall runoff during humid periods and scarce land vegetation cover.

https://doi.org/10.2110/jsr.2021.110

The increasing levels of environmental pollutants in combination with global climate change has been a matter of great concern due to the negative impacts caused to natural environments. In this sense, numerous scientific researches have been done aiming to understand how environmental pollutants affect living organisms, and how environmental changes resulting from climate change influence these effects. Studies of this nature are important to predict the environmental risks of pollutants, enabling decision-making towards the development of more efficient laws for the protection and preservation of natural environments against contamination by compounds derived from human activity. This special issue includes high quality papers on the topic that were presented at the “9th Iberoamerican Congress of Environmental Contamination and Toxicology” (CICTA 2015). The meeting covered a wide range of research studies related to negative effects generated to organisms as a result of environmental contamination by emerging compounds (drugs, microplastics, nanomaterials, personal care products, among others), allied to classic pollutants (metals, pesticides, organochlorines, petroleum derivatives, etc.), in a context of global climate change. The event will provide a forum for debate between researchers in order to discuss advances in environmental toxicology that it will enable a better understanding of the sources, dynamics and effects of environmental pollutants on living organisms, as well as will enable the discussion of future goals and challenges for the establishment of better tools for assessing environmental impacts, generating data that effectively result in solutions for their mitigation.

doi: 10.1016/j.chemosphere.2023.138051

The Citizen Observation of Local Litter in coastal ECosysTems (COLLECT) project (2021-2022) is a citizen science initiative, supported by the Partnership for Observation of the Global Ocean (POGO), which aimed to acquire distribution and abundance data of coastal plastic litter in seven countries: in Africa (Benin, Cabo Verde, Côte d’Ivoire, Ghana, Morocco, Nigeria) and Asia (Malaysia). In this paper, we describe the workflow used to establish and run this project, as well as the methodologies to acquire data. The COLLECT project consisted of training local students (15 - 18 years old) from ten second cycle institutions (“high schools”) on sampling and analyzing macro-, meso- and microplastics in beach sediments, using a quantitative assessment protocol. We further describe in detail the methodologies applied in assessing the impact of participating in the activities from a social sciences perspective. All documents and materials resulting from this project will be open access and available according to the FAIR Principles (Findable, Accessible, Interoperable, and Reusable). The results and outcomes from COLLECT will contribute to expanding knowledge and establishing baseline information on coastal plastic pollution, with citizen science being an enabler of open science, allowing data to be freely available to the public, academics and policymakers. Expected results from the use of the COLLECT protocol globally will further contribute to the identification of hotspots of coastal plastic litter, and bring awareness to local communities on the potential consequences of plastic pollution. The COLLECT project actively contributes with data suitable to survey plastic litter to the United Nations’ Sustainable Development Goals (UN SDGs), in particular to SDG 14, on the sustainable use of the ocean.

https://doi.org/10.3389/fmars.2023.1126895 

One of the key questions about wetlands resilience to sea-level rise is whether sediment supply will be enough to keep them coping with growing inundation levels. To address this question, researchers have put a lot of effort into field data collection and ecogeomorphic modelling, in an attempt to identify the tipping points of marsh survival. This study uses fieldwork data to characterize the sediment fluxes between the tidal flats and salt marshes, in the Ria Formosa lagoon (Portugal). Sediment fluxes were measured from the tidal channel towards the mid-upper marsh, during neap and spring tide conditions. The flow magnitude was measured, and induced transport was determined based on shear velocities. Deposition rates, instantaneous suspended sediment and near-bed velocities were linked through theoretical formulas and used to characterize time-averaged conditions for sediment delivery and deposition to the site. The results showed that suspended sediment concentrations and sediment deposition varied across the transect with no specific relation to elevation. Maximum water depths were recorded in the vegetated tidal flat, and the maximum currents were flood dominated, in the order of 0.20 m/s, in the low marsh due to flow-plant interactions and an increase of turbulence. Deposition rates ranged between 20 to 45 g/m²/hr, after a complete tidal cycle, and were higher in the mid-upper marsh. Hydroperiod was not the main contributor to sediment deposition in the study area. Sediment transport was tidally driven, strongly two-dimension during the cycle, and highly influenced by the vegetation. Measurements of marsh sediment flux obtained in our work are diverse from the ones found in the literature and evidence the importance of considering spatio-temporal variability of vegetated platforms in assessing overall marsh bed level changes.

https://doi.org/10.1038/s41598-022-26708-8

Coastal dunes are complex landforms whose morphology results from various interactions between biotic and abiotic factors. Here, we explore the longshore variability of the morphological features, plant community distribution and accumulation patterns of a dune segment (1.4 km-long) located at the downdrift end of a sandy peninsula in the Ria Formosa, Portugal. To understand the main drivers of the observed variability and the implications for dune morphological response, this information was combined with recent multidecadal shoreline evolution data. The integrated results document significant differences in dune morphology, sedimentation patterns and plant zonation, with two distinct dune configurations or states identified in close proximity. One (western sector) shows a narrower dune system, vegetation cover characterised by pioneer species with low densities, and squeezed plant zonation. Conversely, the other (eastern sector) presents a wider dune system with a new foredune, a more developed plant zonation and relatively high vegetation density. Both states could be partially explained by the recent shoreline trends and inlet shifts, with stable to retreating trends in the western sector and shoreline progradation in the eastern one. Plant zonation and accumulation patterns suggest that the dune along the retreating sector is in a cycle of inland migration, encouraged by the reduced accommodation space and the low retention capacity of the vegetation across the dune stoss. Alternatively, observations along the prograding sector suggest that the greater accommodation space and the stabilising feedback between vegetation and topography promoted the seaward progradation of the system and the development of an incipient foredune. Outcomes support the importance of biogeomorphic feedbacks for the dune configuration, but they also evidence that the role of vegetation within the feedback is primarily regulated by physical factors that ultimately promote or inhibit vegetation effects on dune topography.

https://doi.org/10.1016/j.catena.2022.106796

It is generally assumed that the larger the bottle volume, the longer the duration of phytoplankton microcosm experiments. We hypothesize that volume and duration are independent, as volume does not regulate the extension of the exponential growth phase. We conducted two microcosm experiments using 1, 2, and 8 L bottles, inoculated with phytoplankton collected in the Ria Formosa lagoon (SE Portugal) and incubated for 1, 2, 4, and 8 days. Phytoplankton net growth rates were estimated using chlorophyll a concentration and cell abundance, determined with epifluorescence and inverted microscopy. Results show that the experimental duration significantly affected net growth rates, independently of volume, with decreasing net growth rates with time. Regarding volume, we found significant, but weak, differences in net growth rates, and significant two-way interactions only for the larger-sized cells. No significant differences in net growth rates across the different volumes were detected for the smaller, most abundant taxa and for the whole assemblage. We conclude that duration, not volume, is the main factor to consider in microcosm experiments, and it should allow the measurement of responses during the exponential growth phase, which can be detected through daily sampling throughout the duration of the experiment.

https://doi.org/10.3390/w15020372

This paper aims to examine the stakeholders’ interaction in the water management system at the R’Dom Sub-basin (Morocco). For this purpose, The MACTOR participatory approach was implemented to involve all key water stakeholders and to analyze their interactions. The action system was characterized by the analysis of related water issues and relevant actors on the ground. Thus, ten actors and twelve objectives were identified and assessed in this study. The analysis of stakeholder role allowed to identify the typology of stakeholders according to their strategic objectives and to evaluate their power, influence and dependence, as well as their convergence in a global water cycle management. The results show a significant level of convergence among stakeholders, despite the existence of certain stakeholders who may be considered autonomous, given their low involvement in integrated water management. Furthermore, there was a limited involvement of stakeholders in certain strategic objectives such as capacity building, technical means, and awareness-raising actions. The paper shows the need to generate greater collaborative efforts among water stakeholders involved in the implementation of integrated water resources management in the R’Dom sub-basin.

https://doi.org/10.1007/s00267-022-01773-x

This work aimed at testing the capability of the numerical model SWASH to be implemented in the prototype of the overtopping and flooding forecast system HIDRALERTA for Ericeira harbour. In contrast to the neural network NN_OVERTOPPING2, which is currently implemented in HIDRALERTA, SWASH is able to estimate the flood extension and wave propagation along the domain, which makes it a possible improvement to NN_OVERTOPPING2. The one-dimensional version of the SWASH model was implemented to simulate overtopping at two different profiles (antifer and tetrapods) and calibrated for three storms in 2019 by comparing the simulated overtopping discharge to NN_OVERTOPPING2 results. For the calibration, the Manning coefficient was used to represent the friction of the armour layer. Then, for operational purposes, four expressions to calculate the Manning coefficient were developed based on: the relative crest freeboard, the wave steepness, the incident wave angle and the type of armour layer. The expressions showed small errors between the calculated and calibrated Manning coefficients and highlighted the importance of the incident wave angle to obtain an accurate calibration. Despite an underestimation of the overtopping discharge in some cases, the SWASH model was found to provide overall good results when applied with calculated Manning coefficients and suitable to be implemented in HIDRALERTA.

https://doi.org/10.3390/jmse10121881

Coastal dunes are complex landforms whose morphology results from various interactions between biotic and abiotic factors. Here, we explore the longshore variability of the morphological features, plant community distribution and accumulation patterns of a dune segment (1.4 km-long) located at the downdrift end of a sandy peninsula in the Ria Formosa, Portugal. To understand the main drivers of the observed variability and the implications for dune morphological response, this information was combined with recent multidecadal shoreline evolution data. The integrated results document significant differences in dune morphology, sedimentation patterns and plant zonation, with two distinct dune configurations or states identified in close proximity. One (western sector) shows a narrower dune system, vegetation cover characterised by pioneer species with low densities, and squeezed plant zonation. Conversely, the other (eastern sector) presents a wider dune system with a new foredune, a more developed plant zonation and relatively high vegetation density. Both states could be partially explained by the recent shoreline trends and inlet shifts, with stable to retreating trends in the western sector and shoreline progradation in the eastern one. Plant zonation and accumulation patterns suggest that the dune along the retreating sector is in a cycle of inland migration, encouraged by the reduced accommodation space and the low retention capacity of the vegetation across the dune stoss. Alternatively, observations along the prograding sector suggest that the greater accommodation space and the stabilising feedback between vegetation and topography promoted the seaward progradation of the system and the development of an incipient foredune. Outcomes support the importance of biogeomorphic feedbacks for the dune configuration, but they also evidence that the role of vegetation within the feedback is primarily regulated by physical factors that ultimately promote or inhibit vegetation effects on dune topography.

https://doi.org/10.1016/j.catena.2022.106796

Aquatic pollution caused by anthropogenic activities has been one of the major environmental problems worldwide for decades. Rapid industrialization and urbanization is releasing “traditional” and emerging pollutants into waters in unprecedented quantities and diversity, ultimately endangering biodiversity and human health. Meanwhile, the management and control of risks from chemical pollutants, with varying scientific composition, stringency, and efficacy, are being practiced in different countries and regions. A limiting factor for effective ecological risk assessment and management is the lack of knowledge of exposure, bioaccumulation, toxic effects, and mode of action of various types of pollutants in waters with contrasting physicochemical properties. For example, metals’ environmental behavior and bioavailability are highly dependent on their speciation and water chemistry (e.g., organic matter, pH, and hardness), thus requiring site-specific risk assessments. In comparison, organic pollutants are also highly complex in terms of toxicity prediction and risk assessment due to their infinite structural diversity and mode of action. Due to different physicochemical properties and interactive effects of pollutants, the biological impacts and toxicity mechanisms of pollutants in the natural environment are more complex, posing challenges to risk assessment. Therefore, studies on the toxicity mechanisms and ecological risk assessment of typical pollutants in aquatic environments are required.

Frontiers | Editorial: Toxic effects and ecological risk assessment of typical pollutants in aquatic environments (frontiersin.org)

Bebianno, M. J., Mendes, V. M., O’Donovan, S., Carteny, C. C., Keiter, S., & Manadas, B.

Microplastics (MPs) are globally present in the marine environment, but the biological effects on marine organisms at the molecular and cellular levels remain scarce. Due to their lipophilic nature, MPs can adsorb other contaminants present in the marine environment, which may increase their detrimental effects once ingested by organisms. This study investigates the effects of low-density polyethylene (PE) MPs with and without adsorbed benzo[a]pyrene (BaP) in the gills proteome of the peppery furrow shell clam, Scrobicularia plana. Clams were exposed to PE MPs (11–13 μm; 1 mg L⁻¹) for 14 days. BaP was analyzed in whole clams' soft tissues, and a proteomic approach was applied in the gills using SWATH/DIA analysis. Proteomic responses suggest that virgin MPs cause disturbance by altering cytoskeleton and cell structure, energy metabolism, conformational changes, oxidative stress, fatty acids, DNA binding and, neurotransmission highlighting the potential risk of this type of MPs for the clam health. Conversely, when clam gills were exposed to MPs adsorbed with BaP a higher differentiation of protein expression was observed that besides changes in cytoskeleton and cell structure, oxidative stress, energy metabolism and DNA binding also induce changes in glucose metabolism, RNA binding and apoptosis. These results indicate that the presence of both stressors (MPs and BaP) have a higher toxicological risk to the health of S. plana.

https://doi.org/10.1016/J.SCITOTENV.2022.156895

The assessment of contaminants of emerging concern, alone and in mixtures, and their effects on marine biota requires attention. 5-Fluorouracil is a cytostatic category 3 anti-cancer medication (IARC) that is used to treat a variety of cancers, including colon, pancreatic, and breast cancer. In the presence of other pollutants, this pharmaceutical can interact and form mixtures of contaminants, such as adhering to plastics and interaction with metal nanoparticles. This study aimed to comprehend the effects of 5-Fluorouracil (5FU; 10 ng/L) and a mixture of emerging contaminants (Mix): silver nanoparticles (nAg; 20 nm; 10 μg/L), polystyrene nanoparticles (nPS; 50 nm; 10 μg/L) and 5FU (10 ng/L), in an in vivo (21 days) exposure of the mussel Mytilus galloprovincialis. A multibiomarker approach namely genotoxicity, the antioxidant defence system (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), glutathione – S – transferases (GST) activities), and oxidative damage (LPO) was used to assess the effects in gills and digestive gland of mussels. Both treatments cause genotoxicity in mussel's haemolymph, and antagonism between contaminants was observed in the Mix. Genotoxicity observed confirms 5FU's mode of action (MoA) by DNA damage. The antioxidant defence system of mussels exposed to 5FU kicked in and counter balanced ROS generated during the exposure, though the same was not seen in Mix-exposed mussels. Mussels were able to withstand the effects of the single compound but not the effects of the Mix. For oxidative stress and damage, the interactions of the components of the mixture have a synergistic effect.

https://doi.org/10.1016/J.CHEMOSPHERE.2022.135462

Establishing a relationship between tidal current conditions and tidal turbine performance and loads is a critically important consideration for turbine reliability. Nonetheless, obtaining in-situ information is often challenging, and as a result both environmental and load data may be more sparse than desired. This study presents a method to make use of limited data sets by establishing a relationship between measurements of hydrodynamic variability and turbine power or blade strain variability, even when these measurements are not taken simultaneously. The method is tested on data from the deployment of a full-scale pilot tidal turbine: in situ velocity measurements and turbulence characteristics taken at times when the turbine was not installed were associated with power and strain measurements during the turbine’s deployment via a Delft3D proxy. The data show that the variability of active power correlates well with larger turbulence kinetic energy (TKE) when comparing similar populations via the proxy. Examination of blade strain variance against TKE shows a weaker correlation, with fat-tailed distributions and extremely high strain values prominent across all flow speeds. Acceleration or deceleration of the flow influenced the power variability of the turbine, with larger standard deviations recorded across accelerating flows. No significant difference was found when comparing blade strain variance in accelerating and decelerating flows. We conclude that the proxy method studied can establish a population-level relationship between non-simultaneous environmental and load data, but that the accuracy and precision of this relationship depends on the amount of data available: this method is therefore only suitable where there is a sufficiently rich dataset.

Water scarcity is increasing in the Mediterranean and alternative sources of water are needed to meet food production needs, protect the environment and reduce the effects of climate change. Currently, many urban wastewater treatment plants (WWTP) produce high volumes of treated effluents which can be an alternative source of water for agriculture irrigation, since they fulfill the quality requirements for crops and the environment. This work analyzed the quantity and quality of a treated effluent produced by an urban WWTP in Algarve, and the environmental benefits of its use on the irrigation of a citrus orchard, as an alternative to groundwater. Carbon dioxide emissions related to orange production were quantified and the orchard’s potential to sequester CO2 was estimated. The reuse of this urban wastewater is revealed to be technologically feasible and environmentally advantageous, avoiding the overexploitation of the local aquifer and preventing the eutrophication of aquatic ecosystems, contributing to the improvement of soil characteristics and decreasing the carbon emissions in orange production. Furthermore, it was found that during the five-month experimental period, the citrus orchard sequestered 87.5% of the CO2e emitted by WWTP in the effluent treatment, converting 72,623 kg of sequestered CO2 into orange biomass.

Sustainability | Free Full-Text | Urban Wastewater Reuse for Citrus Irrigation in Algarve, Portugal&mdash;Environmental Benefits and Carbon Fluxes (mdpi.com)

Water scarcity is increasing in the Mediterranean and alternative sources of water are needed to meet food production needs, protect the environment and reduce the effects of climate change. Currently, many urban wastewater treatment plants (WWTP) produce high volumes of treated effluents which can be an alternative source of water for agriculture irrigation, since they fulfill the quality requirements for crops and the environment. This work analyzed the quantity and quality of a treated effluent produced by an urban WWTP in Algarve, and the environmental benefits of its use on the irrigation of a citrus orchard, as an alternative to groundwater. Carbon dioxide emissions related to orange production were quantified and the orchard’s potential to sequester CO2 was estimated. The reuse of this urban wastewater is revealed to be technologically feasible and environmentally advantageous, avoiding the overexploitation of the local aquifer and preventing the eutrophication of aquatic ecosystems, contributing to the improvement of soil characteristics and decreasing the carbon emissions in orange production. Furthermore, it was found that during the five-month experimental period, the citrus orchard sequestered 87.5% of the CO2e emitted by WWTP in the effluent treatment, converting 72,623 kg of sequestered CO2 into orange biomass.

https://doi.org/10.3390/su141710715