Environmental DNA for the surveillance of biosecurity threats in Mediterranean lagoons.

Invasive species that outcompete endemic ones and toxic harmful algae that cause algal blooms threaten marine resources like fisheries, aquaculture, and even tourism. Environmental DNA (eDNA) metabarcoding can help as a method for early alert. In this study, we have analyzed communities inhabiting six lagoons within the Gulf of Lion (northwest Mediterranean Sea) with spatial protection as RAMSAR and Natura 2000 sites. Employing the COI gene as the only metabarcode, we found 15 genera that have caused recognized algal bloom outbreaks in the studied lagoons since 2000. In addition, seven alien invasive species that can pose risks to the rich marine resources of the zone and lagoons were also found. The results found from eDNA are consistent with events of toxic algae blooms before and after the sampling moment and with reported occurrences of the invasive species in nearby Mediterranean areas. Multivariate multiple analysis showed the importance of anthropic pressure in the abundance of these nuisance species. Mitigation actions and routine eDNA metabarcoding in zones of special interest like these fragile French Mediterranean lagoons are recommended for early alert of nuisance species in order to plan timely management actions.

New dockside eDNA based protocol to detect the seaweed Asparagopsis armata evaluated by stakeholders.

Early detection of invasive species is crucial to deal effectively with biological invasions in ports, which are hotspots of species introductions. In this study, a simplified end-time PCR methodology conducted on eDNA from water samples was developed for rapid detection of the invasive seaweed Asparagopsis armata (four hours from water collection to result visualization). It was tested dockside in four international Spanish ports in presence of stakeholders, whose feedback was obtained to explore the real applicability of this biotechnology. Although biological invasions were not a main concern for them, results indicate a unanimous approval of the methodology by the stakeholders, having detected the presence of A. armata in three of the ports. Stakeholders suggested further developments for easier application of the tool and multiple species detection, to be adopted for the control of invasive species in ports.

Plankton assessment across the distribution of West African hake and tuna based on eDNA metabarcoding.

The richness of plankton communities determines the fish productivity in the ocean, including important resources that rely on extractive fisheries, such as hakes (genus Merluccius) and tunas (genus Thunnus). Their preys forage on zooplankton, and the latter feed on phytoplankton. Inventories of plankton communities for scientific advice to sustainable fishing are essential in this moment of climate change. Plankton is generally inventoried using conventional methodologies based on large water volumes and visual morphological analyses of samples. In this study, we have employed metabarcoding on environmental DNA (eDNA) samples extracted from small water volumes for plankton inventory from twelve distant sampling stations in the East Atlantic Ocean. Zones rich in hake and tuna prey were detected from eDNA, and multivariate multiple regression analysis was able to predict those zones from diatom-based indices and planktonic diversity based on functional groups. Salinity was negatively correlated with the proportion of diatoms in phytoplankton, highlighting expected impacts of current global change on marine plankton communities. The results emphasise the importance of the plankton richness for fish productivity and support the utility of environmental DNA as a tool to monitor plankton composition changes.

High microplastics concentration in liver is negatively associated with condition factor in the Benguela hake Merluccius polli.

Microplastics (MPs) affect both marine and terrestrial biota worldwide for their harmful effects, which range from physical cell damage to physiological deterioration. In this research, microplastics were quantified from gills, liver and muscle of demersal Benguela hakes Merluccius polli (n = 94), caught by commercial trawling from northwest African waters. Plastic polymers were identified using Fourier Transformed-infraRed spectroscopy (FT-iR). Fulton's k condition factor and the degree of DNA degradation in liver were measured. None of the individuals were free of MPs, whose concentration ranged from 0.18 particles/g in muscle to 0.6 in liver. Four hazardous polymers were identified: 2-ethoxyethylmethacrylate, polyester, polyethylene terephthalate, and poly-acrylics. MP concentration in liver was correlated negatively with the condition factor, suggesting physiological damage. Positive association of MP concentration and liver DNA degradation was explained from cell breakage during trawl hauls during decompression, suggesting an additional way of MPs harm in organisms inhabiting at great depth. This is the first report of potential MPs-driven damage in this species; more studies are recommended to understand the impact of MP pollution on demersal species.

Towards a plastic-less planet. Gender and individual responsibility predict the effect of imagery nudges about marine (micro)plastic pollution on R-behavior intentions.

Emerging microplastics (MP) pollution is one of the biggest threats for the oceans today. Consumers could reduce MP pollution adopting R-behaviors such as reducing consumption of plastic, refusing products with MP, replacing them for green products, and recycling. Here we tested the efficiency of online nudges (images and short messages) for promoting MP-conscious behavior in Spain (n = 671). The perceived level of environmental responsibility and the willingness to adopt R-behaviors were measured. Messages about seafood with MP and plastic-polluted marine environment were more efficient than images of animals killed by plastics. Feeling responsible for MP pollution predicted R-behavior intention. Women would adopt more R-behaviors than men, while men were more sensitive than females to the proposed nudges. Raising the sense of environmental responsibility would be priority in education campaigns. For different cultural sensitivities to animal suffering, evoking environmental health instead of threats to wildlife would be generally recommended.

Water security determines social attitudes about dams and reservoirs in South Europe.

River barriers affect river dynamics and aquatic biota, altering the entire ecosystem. Nevertheless, dams and reservoirs provide goods like water supply and low-carbon energy that are becoming increasingly critical under current climate change. To know to what extent dams and reservoirs are important to the population, we explored social attitudes towards dams and reservoirs using a face-to-face questionnaire in two regions of contrasting climate and water security in Spain, a country with one of highest densities of dams in Europe. Results (N = 613) revealed a higher support for dams, mediated by the recognition of the services they provide, in the drier Mediterranean Malaga province (Andalusia), than in the wetter Atlantic Asturias province (Bay of Biscay), where water shortages are rare. Awareness of the impacts of the dams was more pronounced in Malaga, coupled with a higher willingness to pay for reconnecting rivers. Social awareness of both impacts and services provided by dams and reservoirs may depend on local climate and water security; different dam acceptance emphasizes the need to involve local citizens in the decision-making processes about water management.

Microplastics across biomes in diadromous species. Insights from the critically endangered Anguilla anguilla.

Microplastic pollution affects freshwater and marine biota worldwide, microplastics occurring even inside the organisms. With highly variable effects, from physical damage to toxicity of plastic compounds, microplastics are a potential threat to the biodiversity, community composition and organisms' health. This emerging pollutant could overstress diadromous species, which are exposed to both sea and river water in their life cycle. Here we have quantified microplastics in young European eel Anguilla anguilla, a critically endangered catadromous fish, entering three rivers in southwestern Bay of Biscay. River water, sediments and seawater were also analysed for microplastics. The microplastic type was identified using Fournier-Transform Infrared spectroscopy and then searched for their hazard potential at the European Chemical Agency site. Both riverine and sea microplastic pollution were predictors of eels' microplastic profile (types of microplastics by shape and colour): A. anguilla juveniles entering European rivers already carry some marine microplastics and acquire more from river water. Potentially hazardous plastic materials were found from eels, some of them dangerous for aquatic life following the European Chemical Agency. This confirms microplastics as a potential threat for the species. Between-rivers differences for microplastics profiles persistent over years highlight the convenience of analysing and preventing microplastics at a local spatial scale, to save diadromous species from this stressor. Since the origin of microplastics present in glass eels seems to be dual (continental + seawater), new policies should be promoted to limit the entry of microplastics in sea and river waters.

Microplastics in seafood: Relative input of Mytilus galloprovincialis and table salt in mussel dishes.

Due to current marine pollution, microplastics ingestion through seafood is an increasing risk for consumers. In this study, microplastics from mussels (Mytilus galloprovincialis) and table salt employed in popular dishes in Bay of Biscay (Spain) were quantified and analysed by Fourier-Transformed Infrared spectroscopy. Microplastics varied in mussels (mean 0.55-3.20 items/g) depending on the environmental pollution of the collection point (seawater, 0.002-0.015 items/mL; sand, 0.06-0.38 items/g). Microplastics content in table salt (0.1-0.38 items/gr) was much lower than in mussels. Chemical substances found from microplastics in mussels and salt are catalogued as hazardous for human health. Significant correlation between microplastics in sand and mussels was found, suggesting that consumers' risk of microplastics ingestion depends on the harvesting area. Routine microplastics analysis in mussels and disclosure of microplastics content on seafood labels are recommended for conscious, informed consumption.

Heavy metals in fish nearby electronic waste may threaten consumer's health. Examples from Accra, Ghana.

Electronic waste sites are rich in heavy metals contained in electronic and electric equipment waste and pose a risk of pollution if metals enter in the environment nearby. The Korle lagoon, located in the center of Accra, is receiving waste effluents from industries, households and the adjacent e-waste burning site Agbogbloshie which is the biggest in the country. Thus, the risk of heavy metal contamination of the water body and subsequent uptake in the aquatic food chain is particularly relevant. Small-scale fishing, not entering the commercial chain, occurs in the lagoon despite its consideration of biologically dead. We assessed if the exposure to heavy metals through these fish consumption is posing higher health risks than fish sold on Ghanaian markets. Using ICP-MS technology, we quantified concentrations of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in fish caught from the Korle Lagoon (Trachinotus ovatus, Mugil curema and Mugil cephalus) and compared them to fish from the Tema Newtown fishing market (Scomber colias, Pseudotolithus senegallus). Cobalt and lead concentrations, typical e-waste metals, were higher in fish from the Korle lagoon, even though they were of lower trophic level. Calculated risk indices revealed risk of elevated arsenic and mercury exposure, particularly through T. ovatus from the Korle lagoon, if consumed daily as it is common in the region. This study suggests the need of monitoring programs of Ghanaian catch, with a special focus in environmental risk areas like Korle lagoon to ensure human food safety.

Potential microplastics impacts on African fishing resources.

Microplastic (MP) pollution is increasing worldwide and affecting aquatic fauna in different ways, which endangers current aquatic resources in a still unknown extent. MP-induced threats to marine fauna are critical for developing countries, where waste treatment may be not optimal and coastal communities rely heavily on marine resources for dietary protein. In this study, we assess the importance of MP pollution for African fishing resources. A new meta-database was created from published studies, containing 156 samples with more than 6200 individuals analysed for microplastic content from African and adjacent waters. A combination of research landscape analysis and rank analysis served to identify main research targets and to determine regional fishing resources especially affected by MP. A network of relevant terms showed fish health as a concern in Mediterranean waters, environmental pollution in freshwater and an emphasis on plastic items in South Africa. MP contents in fishing resources from Nile countries and the Gulf of Guinea, followed by Tunisia, are significantly higher than in other regions. Some of the most exploited species are among the most polluted ones, highlighting the threat of MP pollution in valuable but already compromised African fishing resources. Large geographic gaps with almost absent data about MP in aquatic fauna were revealed, especially in freshwater and in East African coasts. These results emphasize the importance of increasing the coverage of MP pollution in African fishing resources, and improving plastic waste management in the continent.

Greater willingness to reduce microplastics consumption in Mexico than in Spain supports the importance of legislation on the use of plastics.

Introduction: Microplastics (MP) threaten all organisms worldwide. MP are produced directly as microbeads in cosmetics and hygiene products, or indirectly from breakage of larger plastics. The control of MP requires consumers' engagement to refuse products containing microbeads. Methods: We conducted a survey on 572 university students from Mexico and Spain, two countries where microbeads are not banned yet. More strict laws for plastic control areenforced in Mexico than in Spain. Results: Controlling for age and education, despite knowing less about MP, Mexicans checked for microbeads on product labels more frequently than Spaniards, and desired to reduce MP consumption more. A stronger correlation between individual awareness and willingness of MP control was found for Mexican than for Spanish students. Discussion: Perhaps more strict legislation against plastics creates an environment favorable to MP control. Unclear statement of microbeads on labels was the main reason for not checking microbead contents; environmental education and a stricter control of plastics and MP were identified as necessary policy changes in the two countries. Corporation engagement on clearer product labeling is also suggested.

Dangerous microplastics in topshells and anemones along the north coast of Spain.

While levels of microplastics and other pollutants keep increasing in all coastal habitats, seafood is being eaten all over the world. In this research, three edible species were sampled from six points along the central north coast of Spain: Actinia equina anemones and Phorcus lineatus and Steromphala umbilicaris topshells (N = 100). Putative microplastics (N = 2157) were identified, counted, and many analyzed through FT-IR spectroscopy. Herbivorous topshells contained significantly more microplastics than carnivorous anemones. The most common particles were fibers, with transparent, blue and black as most prominent colours. Plastics included PE, polyester, PET, PP, nylon, PS, PVB and acrylic fibers. The sampled items contained several harmful compounds, including PTTC of which even one particle could be fatal if inhaled. This highlights the urgent need for studies regarding the safety of seafood.

On the way to reduce marine microplastics pollution. Research landscape of psychosocial drivers.

Current human lifestyle generates enormous amounts of plastics and microplastics that end in the ocean and threaten marine life. Exposure to microplastics seems to threaten human health too. Although the degree of damage is not clear yet, precautionary approach urgently requires a change of societal habits. The objective of this study was to discover emerging issues of priority for psychosocial investigation. For this we have compared the landscape research of Reviews with that of Perspectives articles of the last decade, to identify mismatches that unravel still understudied subjects. Results revealed that circular economy is a focus in Perspectives but is not main topic of current psychosocial research. Regarding the actors involved in the change towards circular economy, although companies are priority in Perspectives current research is focused on consumers. Results suggest the need for more efforts on the investigation of corporative responsibility in the way to stop microplastics pollution.

Virgin Polystyrene Microparticles Exposure Leads to Changes in Gills DNA and Physical Condition in the Mediterranean Mussel Mytilus Galloprovincialis.

The ever-growing concentration of microplastics in the marine environment is leading to a plethora of questions regarding marine organisms' present and future health status. In this article, the Mediterranean mussel (Mytilus galloprovincialis), a commercial species distributed worldwide, has been exposed to 21 daily doses of polystyrene microparticles (10 µm) at four different concentrations that are environmentally realistic (control: no microplastics, C1: 0.02 mg/L, C2: 0.2 mg/L, and C3: 2 mg/L). The physical status through the condition index, and damages in DNA integrity in gills, through DNA fragmentation, were determined. Results showed a minor effect on DNA integrity but a worse physical status at higher doses. Results could be interpreted as a decrease in mussel feeding activity/filtration rates when exposed to high microplastic concentrations, thus reducing the direct exposure to microplastics in gills. These effects could be happening currently and/or may happen in the near future, threatening populations inhabiting microplastics-polluted environments.

DNA Analysis Detects Different Mislabeling Trend by Country in European Cod Fillets.

Atlantic cod, Gadus morhua, is a highly appreciated fish in European seafood markets and is one of the most substituted fish species in the world. Fraud have been detected in European markets in the last decade, finding different substitute species sold as G. morhua or Atlantic cod on the label. In this study, we analyzed 252 samples of fresh and frozen cod fillets sold in Germany, the Netherlands, and France using DNA barcoding. Different trends were found in different countries: while the level of mislabeling found in Germany and the Netherlands remained at zero in the last years, a significant increase was found in the French markets comparing the current results with previous studies on fillets in France. On the one hand, this mislabeling proves the need to encourage European efforts to control seafood authenticity; on the other, zero mislabeling in two countries shows the success of current European regulations.

Illegal, Unreported, and Unregulated Fisheries Threatening Shark Conservation in African Waters Revealed from High Levels of Shark Mislabelling in Ghana.

Mislabelling of fish and fish products has attracted much attention over the last decades, following public awareness of the practice of substituting high-value with low-value fish in markets, restaurants, and processed seafood. In some cases, mislabelling includes illegal, unreported, and unregulated (IUU) fishing, contributing to overexploit substitute species that are undetectable when sold under wrong names. This is the first study of DNA barcoding to assess the level of mislabelling in fish marketed in Ghana, focusing on endangered shark species. Genetic identification was obtained from 650 base pair sequences within the cytochrome c oxidase I (COI) gene. All except one of 17 shark fillets analysed were wrongly labelled as compared with none of 28 samples of small commercial pelagic fish and 14 commercial shark samples purchased in Europe. Several substitute shark species in Ghana are endangered (Carcharhinussignatus and Isurusoxyrinchus) and critically endangered (Squatina aculeata). Shark products commercialized in Europe (n = 14) did not reveal mislabelling, thus specific shark mislabelling cannot be generalized. Although based on a limited number of samples and fish markets, the results that reveal trade of endangered sharks in Ghana markets encourage Ghanaian authorities to improve controls to enforce conservation measures.

Fraud in highly appreciated fish detected from DNA in Europe may undermine the Development Goal of sustainable fishing in Africa.

Despite high effort for food traceability to ensure safe and sustainable consumption, mislabeling persists on seafood markets. Determining what drives deliberate fraud is necessary to improve food authenticity and sustainability. In this study, the relationship between consumer's appreciation and fraudulent mislabeling was assessed through a combination of a survey on consumer's preferences (N = 1608) and molecular tools applied to fish samples commercialized by European companies. We analyzed 401 samples of fish highly consumed in Europe and worldwide (i.e. tuna, hake, anchovy, and blue whiting) through PCR-amplification and sequencing of a suite of DNA markers. Results revealed low mislabeling rate (1.9%), with a higher mislabeling risk in non-recognizable products and significant mediation of fish price between consumer´s appreciation and mislabeling risk of a species. Furthermore, the use of endangered species (e.g. Thunnus thynnus), tuna juveniles for anchovy, and still not regulated Merluccius polli hake as substitutes, points towards illegal, unreported and/or unregulated fishing from African waters. These findings reveal a worrying intentional fraud that hampers the goal of sustainable seafood production and consumption, and suggest to prioritize control efforts on highly appreciated species.

DNA metabarcoding illustrates biological pollution threats of Red Sea - Dead Sea water conveyance to Dead Sea biodiversity.

The Dead Sea has a hypersaline environment where only extremophile species like Archaea, Bacteria, and fungi can survive. The Red Sea-Dead Sea Water Conveyance (RDSC) is constructing a pipeline of 180 km to import water from the Red Sea in the shrinking Dead Sea. Both seas exhibit highly different hydrographic features that determine their biodiversity. Using environmental DNA (eDNA) metabarcoding and amplifying a fragment of the cytochrome oxidase subunit I gene (COI) from water samples, we compared the communities of the Red Sea and the Dead Sea to understand the potential impact of the water conveyance project on biodiversity, following by an identification of potential biopollutants able to enter the Dead Sea for their small size. The results suggest a high likelihood of acquiring harmful algae into the Dead Sea. This study alerts about the real risk of losing the unique Dead Sea biota when the conveyance is actually undertaken.

Poorer diversity but tougher species in old ballast water: Biosecurity challenges explored from visual and molecular techniques.

Millions of tons of water cross the oceans inside ships' ballast tanks every day. Planktonic species hitch-hike with water and some may pose risks to ecosystems and economies if get released and establish outside their native range. We monitored ballast water in different trans-equatorial travels, visually and using molecular techniques, and found significant increases of potential nuisance taxa over travel duration, despite evident diversity depletion. Thus, less diverse but more resistant and potentially more harmful communities persist in ballast water over long voyages. If we consider the enormous volume transported every day, the persistence of resistant species in ballast water would be threating the global marine biodiversity. This should be taken into account when modeling and assessing the bioinvasion risks associated with the ballast water and transfer considered in the future research.