Atlantic Coast Research Articles

Paralytic Shellfish Toxins in Mollusks from Galicia Analyzed by a Fast Refined AOAC 2005.06 Method: Toxicity, Toxin Profile, and Inter-Specific, Spatial, and Seasonal Variations

Paralytic shellfish poisoning is an important concern for mollusk fisheries, aquaculture, and public health. In Galicia, NW Iberian Peninsula, such toxicity has been monitored for a long time using mouse bioassay. Therefore, little information exists about the precise toxin analogues and their possible transformations in diverse mollusk species and environments. After the change in the European PSP reference method, a refinement of the Lawrence method was developed, achieving a 75% reduction in chromatogram run time. Since the beginning of 2021, when this refinement Lawrence method was accredited under the norm UNE-EN ISO/IEC 17025, it has been used in the area to determine the toxin profiles and to estimate PSP toxicity in more than 4500 samples. In this study, we have summarized three years of monitoring results, including interspecific, seasonal, and geographical variability of PSP toxicity and toxin profile. PSP was detected in more than half of the samples analyzed (55%), but only 4.4% of the determinations were above the EU regulatory limit. GTX1,4 was the pair of STX analogs that produced the highest toxicities, but GTX2,3 was found in most samples, mainly due to the reduction of GTX1,4 but also by the higher sensitivity of the method for this pair of analogs. STX seems to be mainly a product of biotransformation from GTX2,3. The studied species (twelve bivalves and one gastropod) accumulated and transformed PSP toxins to a different extent, with most of them showing similar profiles except for Spisula solida and Haliotis tuberculata. Two seasonal peaks of toxicity were found: one in spring-early summer and another in autumn, with slightly different toxin profiles during outbreaks in relation to the toxicity during valleys. In general, both the total toxicity and toxin profiles of the southernmost locations were different from those in the northern part of the Atlantic coast and the Cantabrian Sea, but this general pattern is modified by the PSP history of some specific locations.

Environmental assessment of the central Atlantic coast of Morocco using a multibiomarker approach in Mytilus galloprovincialis.

A multibiomarker approach helps assess environmental health as it provides a complete tool to understand the effects of environmental stressors on ecosystems and human health. We applied this approach in the central Atlantic Ocean of Morocco, an area subjected to the impact of many types of pollutants, threatening the durability of its resources. In this study, four biomarkers acetylcholinesterase (AChE), glutathione-s-transferase (GST), metallothioneins (MTs), and catalase (CAT) were measured in the digestive gland of the mussel Mytilus galloprovincialis collected from four sites: Imsouane (S1), Cap Ghir (S2), Imi Ouaddar (S3), and Douira (S4). These sites were chosen due to the diversity of impacts ranging from industrial to agricultural and touristic. We also assembled all the enzymatic responses (AChE, GST, CAT, and MTs), using the integrated biomarker response (IBR), to estimate the degree of impact of pollutants at the prospected sites to reveal all the complex interactions between biomarkers and to classify sites via the integrated approach. Results show a seasonal change in biomarker responses with variability between sites. We also recorded the highest levels of AChE inhibition and GST induction in S1, higher levels of catalase activity in S4, and a significant impact on metallothionein concentration in S1 and S3. This project highlights the interest in using a multibiomarker approach to ensure accurate interpretation of biomarker variation to protect the Moroccan coast and its resources.

Long-distance migrations and seasonal movements of meagre (Argyrosomus regius), a large coastal predator, along the Iberian Peninsula coast

BackgroundThe meagre, Argyrosomus regius, is a large coastal predatory fish inhabiting waters from the north-eastern Atlantic and Mediterranean Sea, where it is targeted by commercial and recreational fisheries. Previous genetic studies have found an unexpectedly high population differentiation not only between the Atlantic and the Mediterranean, but also along the Atlantic coast. However, the reasons underpinning this genetic barrier remained unclear. Likewise, even though the species is amongst the world’s largest marine teleosts, knowledge about its movement ecology and migratory behaviour remains notably scarce, and primarily reliant on fisheries-dependent data.MethodsIn this study, we used a combination of acoustic telemetry and pop-up satellite archival tags to investigate the movements of 22 adult meagre (70–143 cm total length) along the Southwestern coast of the Iberian Peninsula.ResultsOur results strongly suggest that the previously reported genetic differentiation is not maintained by limited adult dispersal/movement, as hypothesized. On the contrary, we documented some of the longest individual annual migrations ever recorded for a coastal teleost, up to > 2000 km, with frequent back-and-forth movements between the West and Southern Iberian coasts. Moreover, their detected regional movement patterns support the existence of a marked seasonal behavioural shift, with individuals being less active and moving to deeper waters during winter, and are consistent with spawning philopatry associated to their summer reproductive movements. Finally, we identified putative aggregation areas that may harbour important feeding/overwintering grounds.ConclusionsThese findings shed new light on the movement and behaviour patterns of meagre that may be of particular importance for the conservation and spatial management of this species throughout its range, and open the door to further research on functional connectivity.

Seasonal variation in biochemical and metal content of the invasive seaweed Sargassum muticum along Moroccan Atlantic Coast

Seasonal variation in biochemical and metal content of the invasive seaweed Sargassum muticum along Moroccan Atlantic Coast

First Report of Seropositivity to Trypanosoma cruzi in Mexican Afro-Descendants from Guerrero and Oaxaca States.

Mexican Afro-descendant is a population poorly studied in many aspects, between them the infectious diseases that they suffer. This population is mainly found in the country's Pacific (Oaxaca and Guerrero states) and Atlantic (Veracruz) coast. In these regions, a diversity of triatomine vectors of the Chagas disease is found. Also, all the genotypes of Trypanosoma cruzi DTUs have been reported. That is why the present study aimed to study the presence of antibodies against T. cruzi and cardiac pathology associated with the Chagas disease in the Mexican Afro-descendant population of Guerrero and Oaxaca. ELISA, Western blot, and recombinant antigen's ELISA were used to evaluate the seropositivity of these communities. Furthermore, an electrocardiographic study and evaluation of risk factors associated with T. cruzi infection in the Oaxaca and Guerrero populations were conducted. 26.77% of the analyzed population was positive for two serological tests. These percentages are higher than the previously reported for the mestizo population in similar studies. Electrocardiographic results showed cardiac disorder associated with the Chagas disease in the population. Also, risk factors were identified associated with the men's activities in the outdoor working areas.

Genetic Variability and Genetic Differentiation of Populations in the Grooved Carpet Shell Clam (Ruditapes decussatus) Based on Intron Polymorphisms

Genetic Variability and Genetic Differentiation of Populations in the Grooved Carpet Shell Clam (Ruditapes decussatus) Based on Intron Polymorphisms

Genetic parameters for resistance to field mortality outbreaks and resistance to a pathogenic strain of Vibrio splendidus in Mytilus edulis, Mytilus galloprovincialis and natural hybrid

Since 2014, abnormal mussel mortality (AMM) outbreaks have occurred along the French Atlantic coasts and mortality rates differed among years and sites (30–100%). Still, the etiology of the AMM is undefined. Our study explores the resistance of two mussel species (Mytilus edulis and Mytilus galloprovincialis) and natural hybrids (NH) cultivated in France to AMM. One hundred mussel families were produced using six wild mussel populations in January/February 2017. Mussels were tested in two sites, La Floride (LF) and Maison Blanche (MB), in October 2017, and their mortality/growth was recorded until June 2018. AMM was observed at MB during spring 2018, and reached 70%, 43%, and 63%, for M. edulis, M. galloprovincialis, and NH, respectively, at endpoint. In contrast, mortality was low in LF, reaching 11%, 30%, and 22%, respectively. Heritability for mortality was low to moderate in both sites ranging from 0.12 to 0.37 with higher values in M. edulis, intermediate for NH, and the lowest for M. galloprovincialis. A significant genotype-by-environment interaction was found for mortality between sites, with low genetic correlations not significantantly different from zero (−0.05 to 0.43). In July 2018, mussel families were evaluated under experimental infection using a pathogenic strain of Vibrio splendidus isolated during AMM in 2014. The mean mortality after 72 h post-injection was 53%, 22%, and 31% for M. edulis, M. galloprovincialis, and NH, respectively. The lowest heritability estimates were obtained for NH (0.21) and the highest for M. galloprovincialis (0.41), and the genetic correlation between AMM in MB and experimental infection was not significantly different from 0, suggesting that this Vibrio strain, is not the major cause of AMM outbreak observed in MB in 2018. Finally, significant genetic variation was observed for growth traits with mostly high heritability (> 0.44) for both species. Interestingly, genetic correlation between mortality and growth was weak and non-significant from zero.

SEA TURTLES OF THE BENIN COAST: PRESSURE AND ETHNOZOOLOGY

Sea turtles are threatened by factors associated with overfishing. To identify these factors, we investigated the fishing pressure and the ethnozoological knowledge of turtles along the Benin coast. A questionnaire-based field survey was undertaken in 48 villages on the Atlantic coast through structured interviews. In total, 479 fishermen and 15 traditional healers were interviewed between July and August, 2020. The Use Value in terms of the types of utilisation of the body parts of the turtles, and the frequency of citation, were calculated. More than eighty percent of the interviewees confirmed the use of turtles for food, medicine, and artisanal purposes. Communities demonstrated nonspecific preference for the four-known species -- leatherback turtle, Olive Ridley turtle, green turtle, or hawksbill turtle --within the research area. The flesh is the most used body part (Use Value = 1.5 for food). Body parts of turtles such as the fat, bones etc. are used to treat several diseases, particularly asthma, fever, hypertension, cough, colds, epilepsy, brittle bones in children, and paralysis. The test used shows that the Use Values of sea turtles vary significantly at the 5% threshold from one sociolinguistic group to another. Our research indicates that integrating traditional ecological knowledge on animal-based food and medicines could be extremely useful when developing strategies for sustainable management and conservation of marine species, and in particular sea turtles.

Assessment of Primary Production in an Estuarine Environment: The Case of the Oum Er Rbia Estuary (Atlantic Coast, Morocco)

Assessment of Primary Production in an Estuarine Environment: The Case of the Oum Er Rbia Estuary (Atlantic Coast, Morocco)

Feasibility of ex-situ recruitment and outplanting of Gongolaria nodicaulis (Fucales, Phaeophyceae) for restoration of warm temperate marine forests in Atlantic Morocco

Abstract Brown algal forests provide many ecosystem services but are declining worldwide, prompting a growing number of conservation and restoration efforts. Recent attempts to recover Cystoseira forests are encouraging in the Mediterranean, but whether this is possible in more challenging Atlantic conditions has not yet been investigated. In this study, we assess the feasibility of cultivating Gongolaria nodicaulis by producing ex-situ recruits for reforestation on the Atlantic coast of Morocco. Embryos of G. nodicaulis were cultured on clay tiles for 26 days under controlled conditions without water motion, reaching an average length of 3 mm before being outplanted on the intertidal zone. The transplants were monitored for six months. Recruits experienced high loss rates, approximately 47 % of zygotes within 7 days in culture and 75 % of outplanted seedlings within 10 days in the field. The latter might result from natural self-thinning (competition), but our observations suggested that it was also largely due to the weak attachment of recruits to the tiles resulting from cultivation under calm conditions. Six months after the transplants, the surviving individuals reached the size of wild adult algae (average length of 13.5 cm), and some even became reproductive. Globally, survival rates, growth, physiological condition and fertility in this restoration pilot suggest that ex-situ recruitment and outplanting of G. nodicaulis is a promising approach to recover forests in Atlantic Morocco.

Characterization of MLST-99 Salmonella Typhimurium and the monophasic variant I:4,[5],12:i:- isolated from Canadian Atlantic coast shellfish.

Salmonella enterica subsp. enterica Typhimurium and its monophasic variant I 1;4,[5],12:i:- (MVST) are responsible for thousands of reported cases of salmonellosis each year in Canada, and countries worldwide. We investigated S. Typhimurium and MVST isolates recovered from raw shellfish harvested in Atlantic Canada by the Canadian Food Inspection Agency (CFIA) over the past decade, to assess the potential impact of these isolates on human illness and to explore possible routes of shellfish contamination. Whole-genome sequence analysis was performed on 210 isolates of S. Typhimurium and MVST recovered from various food sources, including shellfish. The objective was to identify genetic markers linked to ST-99, a sequence type specifically associated with shellfish, which could explain their high prevalence in shellfish. We also investigated the genetic similarity amongst CFIA ST-99 isolates recovered in different years and geographical locations. Finally, the study aimed to enhance the molecular serotyping of ST-99 isolates, as they are serologically classified as MVST but are frequently misidentified as S. Typhimurium through sequence analysis. To ensure recovery of ST-99 from shellfish was not due to favourable growth kinetics, we measured the growth rates of these isolates relative to other Salmonella and determined that ST-99 did not have a faster growth rate and/or shorter lag phase than other Salmonella evaluated. The CFIA ST-99 isolates from shellfish were highly clonal, with up to 81 high-quality single nucleotide variants amongst isolates. ST-99 isolates both within the CFIA collection and those isolated globally carried numerous unique deletions, insertions and mutations in genes, including some considered important for virulence, such as gene deletions in the type VI secretion system. Interestingly, several of these genetic characteristics appear to be unique to North America. Most notably was a large genomic region showing a high prevalence in genomes from Canadian isolates compared to those from the USA. Although the functions of the majority of the proteins encoded within this region remain unknown, the genes umuC and umuD, known to be protective against UV light damage, were present. While this study did not specifically examine the effects of mutations and insertions, results indicate that these isolates may be adapted to survive in specific environments, such as ocean water, where wild birds and/or animals serve as the natural hosts. Our hypothesis is reinforced by a global phylogenetic analysis, which indicates that isolates obtained from North American shellfish and wild birds are infrequently connected to isolates from human sources. These findings suggest a distinct ecological niche for ST-99, potentially indicating their specialization and adaptation to non-human hosts and environments, such as oceanic habitats.

Microplastic contamination in marine mussels from the Atlantic coast of North Portugal and human risk of microplastic intake through mussel consumption

Microplastic (MP) pollution has become a global concern due to its potential impacts on the environment, ecosystem services and human health. The goals of the present study were to document the MP contamination in wild specimens of Mytilus galloprovincialis sampled along the Atlantic coast of the North region of Portugal continental (NW Portuguese coast), and to estimate the human risk of MP intake (HRI) through the consumption of local mussels as seafood. Mussels were collected at four sampling sites along the NW Portuguese coast (40 mussels per site), and the whole soft body of each mussel was analysed for MP content. HRI estimates were based on the mean of MP items per wet weight of mussel analysed tissue (MP/g) and consumption habits. A total of 132 MP items were recovered from mussels. MP had diverse sizes (98 to 2690 μm) and colours. The most common shapes were fibres (39%) and pellets (36%). Five polymers were identified in the MP: polyethylene (50%), polystyrene (15%), poly(ethylene vinyl acetate) (14%), polyamide (12%) and polypropylene (9%). From the 160 analysed mussels, 55% had MP. The mean and standard error of the mean of mussel contamination ranged from 0.206 ± 0.067 and 0.709 ± 0.095 MP/g. For consumers of mussels from the sampling sites of the present study, the decreasing order of HRI is MOL > CAB > CAR > EST. Compared to estimates based on MP contamination in mussels from other areas and varied consumption habits, the HRI through the consumption of mussels from the NW Portuguese coast is relatively low.

Dendrometrical Structure and Physicochemical Analysis of Mangrove Sediments from the Nyong River Estuary (Cameroon, Atlantic Coast)

Mangrove estuaries are not immune to the threats posed by climate and anthropogenic constraints on aquatic environments. In the Nyong River estuary, mangrove ecotone has capital importance for biodiversity conservation due to its localization in the Douala-Edéa protected area. For this study, seven quadrats were delimited in aim to evaluate mangrove structure and assessed his interplay with sediment and water physicochemical characteristics. The study revealed a total of 120 individuals of 4 regularly encountered species over a distance of 14 km: <i>Rhizophora racemosa, Avicennia germinans, Rhizophora harrisonii </i>and <i>Phoenix reclinata</i> palms. The marshy soils under the mangrove have Total Nitrogen percentages varying between 0.04 and 0.68%. Total Organic Carbon (from 2.20 to 8.61%) and Total Organic Matter (from 3.66 to 14.64%) contents have a similar pattern. The ratios of Carbon and Nitrogen (C/N) reflect the presence of organic matter and plant debris over a large proportion of the estuary. The ratio of Nitrogen and Phosphate (N/P) reflects the low availability of nitrogen in relation to phosphorus. The cation elements evolve on average in the order Ca<sup>2+</sup> ˃Mg<sup>2+</sup> ˃Na<sup>+</sup> ˃K<sup>+</sup>. This study provides information that would help explore linkages for future research on biogeochemical balance in mangrove sediment and their implementation.

Multi-aspect assessment of operational fog collection systems: A rural development perspective, insights from the Sidi Ifni project in Morocco

Ongoing climate change and anthropogenic impacts will continue to worsen the problem of water crisis. In order to explore practical solutions for drought and climate change adaptation, this work uses a set of different methodologies to evaluate an operational fog collection project and discuss solutions for some emerging challenges. This study uses fog collection rate, Water Quality Index (WQI) and interviews with the community as indicators for the assessment. Results indicate that the project continues to deliver improved drinking water access to the community. Fog harvesting rate yielded an annual average from 1.6 to 6 L/m2/d. Interviews confirm the social commitment of the local community. However, challenging points emerge: (1) ongoing groundwater pollution due to the lack of sanitation; (2) if fog water is the only source, inconsistent fog yields may negatively impact water availability; (3) poor solid waste management. The findings represent a baseline for assessing and benchmarking other similar projects or project proposals in the Atlantic coast of North Africa. Therefore, the proposed methodology can also be used in other fog collection projects around the world.

Interacciones tierra-mar-tierra, con énfasis en la actividad pesquera en la región norte del Ecosistema Costero Bonaerense, Argentina

[Introduction]: Coastal areas constitute the interface between land and marine environments, connected through multiple natural and socioecological processes that contribute to human well-being. [Objective]: Identify land and marine uses and activities with mutual implications and biophysical processes in the northern region of the Bonaerense Coastal Ecosystem (Argentina), in order to evaluate the degree of compatibility or conflict between these activities, with emphasis on the fishing activity. [Methodology]: The land-sea-land (T-M-T) methodological analysis was applied. Uses and activities (U&A) and biophysical processes of marine and land origin were determined. Interactions between marine-land and biophysical processes T-M-T were identified for further categorization and analysis. [Results]: A total of 121 U&A sea-land-sea (L-S-L) interactions related to fishing were detected. Medium conflicts were mainly caused by competition for space or resources and were associated with the coexistence of U&A (tourism, fishing, and communication activities), both spatially and temporally. Of the total, 68 negative interactions were observed between biophysical processes and U&A L-S-L, which were linked to climatic events and the effects of climate change (variation in sea surface temperature, atmospheric and oceanic circulation, as well as variations in sediment transport and coastal erosion). [Conclusions]: The analysis carried out constitutes an advancement in the study of U&A T-M-T in coastal-marine areas of the Atlantic coast and their interactions, with emphasis on fishing activities, as a contribution to their management with an ecosystemic approach.

The 2022 Tonga Tsunami on the Pacific and Atlantic Coasts of the Americas

AbstractThe Hunga‐Tonga volcano eruption on 15 January 2022 generated tsunami waves that impacted both the Pacific and Atlantic coasts of the Americas. A unique feature of this event was the dual tsunami generation mechanism, which led to motions with long (several days) ringing and slow energy decay. The first ocean waves to reach the coast were “atmospheric tsunamis” generated by atmospheric Lamb waves that propagated with the speed of sound (∼314 m/s) and circled the globe in both directions several times before being fully attenuated. The second type of ocean waves were classical “oceanic tsunami” waves forced directly by the volcanic eruption and which propagated across the Pacific at roughly 2/3 the speed of the atmospheric waves. This study focuses on time series of the Hunga‐Tonga event recorded by tide gauges, microbarographs and Deep‐ocean Assessment and Reporting of Tsunamis on and off the Pacific coasts of North and Central America and in the Gulf of Mexico. Atmospheric tsunami waves only were recorded in the Gulf of Mexico, where the sea level response to the second, westward (shoreward) propagating atmospheric wave was stronger than to the first, eastward (seaward) propagating wave. Along the Pacific coast, the atmospheric tsunami waves were approximately 3–4 times smaller than the oceanic tsunami waves, which at several Mexican stations exceeded 2 m in height. The broad frequency range of 0.2–0.25 to 30 cph spanned by the oceanic tsunami in the Pacific indicates that the “effective” source area for the oceanic waves was more extensive than initially proposed.

Understanding the role of Francisella halioticida in mussel mortalities in France: an integrative approach.

Since 2014, mass mortalities of mussels Mytilus spp. have occurred in production areas on the Atlantic coast of France. The aetiology of these outbreaks remained unknown until the bacterium Francisella halioticida was detected in some mussel mortality cases. This retrospective study was conducted to assess the association between F. halioticida and these mussel mortalities. Mussel batches (n = 45) from the Atlantic coast and English Channel were selected from archived individual samples (n = 863) collected either during or outside of mortality events between 2014 and 2017. All mussels were analysed by real-time PCR assays targeting F. halioticida; in addition, 185 were analysed using histological analysis and 178 by 16S rRNA metabarcoding. F. halioticida DNA was detected by real-time PCR and 16S rRNA metabarcoding in 282 and 34 mussels, respectively. Among these individuals, 82% (real-time PCR analysis) and 76% (16S rRNA metabarcoding analysis) were sampled during a mortality event. Histological analyses showed that moribund individuals had lesions mainly characterized by necrosis, haemocyte infiltration and granulomas. Risk factor analysis showed that mussel batches with more than 20% of PCR-positive individuals were more likely to have been sampled during a mortality event, and positive 16S rRNA metabarcoding batches increased the strength of the association with mortality by 11.6 times. The role of F. halioticida in mussel mortalities was determined by reviewing the available evidence. To this end, a causation criteria grid, tailored to marine diseases and molecular pathogen detection tools, allowed more evidence to be gathered on the causal role of this bacterium in mussel mortalities.

From the sky and on the beaches: complementary tools to evaluate common dolphin bycatch in the Bay of Biscay

Since 1989, multiple stranding events of common dolphins have been regularly recorded along the French Atlantic coast. Examination of the carcasses revealed that most animals presented evidence of bycatch. Using stranding data to infer bycatch levels reveals the highest levels of bycatch to have been recorded since 2016 (4000 to 9000 bycaught individuals). This approach is directly influenced by drift conditions, which can greatly contribute to or hinder our ability to estimate bycatch at sea. In the winter of 2021/2022, the French stranding network recorded an unusually high number of strandings until mid-February and few records in March. Investigation of drift conditions revealed low probability of stranding in March due to constant east-west winds. Reverse drift modelling of carcasses stranded in January and February resulted in an estimate of 3670 (95% CI [2750; 5170]) bycaught common dolphins. Dedicated aerial surveys were conducted in the same area during this period, designed to assess abundance and distribution of marine megafauna in French waters. A high number of carcasses of small Delphininae were observed in March 2021, and the number of carcasses floating at sea could be estimated using conventional distance sampling methodology. In March 2021, mortality at sea was thus estimated at 3250 (95% CI [1288;10198]) common dolphins. The complementary use of both methodologies resulted in an estimate of 6920 (95%CI [4038;15368]) bycaught individuals during winter 2021/2022. This case study highlights that a decrease in strandings does not imply a decrease in mortality at sea. Trends in strandings need to be considered in the light of scientific evidence to avoid delays in decision making.

Comparative antioxidant potential, proximal biochemical composition, and pigment content of 11 brown seaweeds from the West of Ireland

The biorefinery and valorisation of sustainable bioresources such as seaweeds have increased in response to global circular economy initiatives. Several seaweed species are exploited worldwide in the biofertilizer, nutrition, bioenergy, cosmetics, or pharmaceutical sectors. Brown seaweeds are widespread, easily accessible, and abundant in northwest Europe regions, with some species being commercially harvested and processed.Here, both commercially exploited, and less studied brown seaweeds (n = 11) were collected from Irelands Atlantic coast and analysed for soluble carbohydrates, lipids, proteins, fatty acid, and pigment profiles as well as antioxidant potential. Soluble carbohydrates (62.7 µg glucose eq mg−1 DW) were highest in Saccharina latissima while lipids (148.2 mg L g−1 DW), fucoxanthin (1.35 mg g−1) and β-carotene (4.10 mg g−1) were greater in Dictyota dichotoma. The highest antioxidant activity (456.3 µmol Trolox eq mg−1 DW with TEAC assay) and soluble protein content (562.5 µg BSA eq mg−1 DW) were in Halidrys siliquosa extracts.Data matrix multivariate ordination indicated that some less studied brown seaweeds have further valorisation potential owing to their biochemical composition and bioactivity. The development of species-specific tailored cultivation strategies as part of integrated multi-trophic aquaculture systems has potential to contribute to environmental sustainability while introducing new natural bioactive products to markets.

When Nature Requires a Resource to Be Used-The Case of Callinectes sapidus: Distribution, Aggregation Patterns, and Spatial Structure in Northwest Europe, the Mediterranean Sea, and Adjacent Waters.

The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems and ecosystem services. Outside its natural distribution range, the species was first found on European Atlantic coasts in the early 1900s and was introduced into the Mediterranean Sea a few decades later, probably through ballast water. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. Based on a systematic review of C. sapidus occurrences, this study describes its distribution, aggregation patterns, and spatial structure in Northwest Europe, the Mediterranean Sea, and adjacent waters through a series of ecological indicators elaborated using GIS spatial-temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. Furthermore, the main species detection methods are analysed, finding that traps and nets are the most frequently used methods, and management suggestions are provided.