Valuable Seafood Research Articles

Blue Bounty: Italy's Dual-Use Solution for Crab Invasion, Nutritional Value, Safety, and Valorization.

In the past few years, non-native blue crab has been expanding its range in the Adriatic and Mediterranean Seas. However, when non-indigenous species establish a lasting presence in a novel ecosystem and actively expand into other regions, posing potential risks to local biodiversity and economic harm, they are classified as invasive species. For this study, two different batches of blue crabs were collected: one from the Mediterranean Sea and the other from the Adriatic coast area. Considering the negative ecological impact that blue crab has had and continues to have on the Italian coasts, this work was aimed to evaluate the characteristics of the Adriatic Sea "variant"; another goal was to propose the potential use of blue crab as a commercially profitable source due to its organoleptic characteristics. Data obtained revealed a high protein content, a good lipid profile, a low number of plastic particles, and the absence of toxic metals and pathogenic microorganisms. A deep statistical analysis was conducted to compare different portions of blue crab from the Adriatic and Mediterranean Seas. The results suggest that Callinectes sapidus is beneficial for human consumption and represents a valuable seafood, and its carapace could be used as compliant feed for aquaculture due to its metal composition and microbiological content.

An analysis combining proteomics and transcriptomics revealed a regulation target of sea cucumber autolysis

Sea cucumber is a valuable seafood product and autolysis is the main concern for the aquaculture industry. This study employed proteomics and transcriptomics to investigate the autolysis mechanism of sea cucumbers. The fresh sea cucumber was exposed to UV light to induce autolysis. The body wall samples were cut off to analyze by proteomics and transcriptomics. The angiotensin-converting enzyme (ACE) inhibitor of teprotide and the activator of imatinib were gastric gavage to live sea cucumbers, respectively, to identify the regulation target. Autolysis occurrence was evaluated by appearance, soluble peptide, and hydroxyproline content. Four gene-protein pairs were ACE, AJAP10923, Heme-binding protein 2-like, and Ficolin-2-like. Only the ACE protein and gene changed synchronously and a significant down-regulation of ACE occurred in the autolysis sea cucumbers. Teprotide led to a 1.58-fold increase in the TCA-soluble protein content and a 1.57-fold increase in hydroxyproline content. No significant differences were observed between imatinib-treated sea cucumbers and fresh ones regarding TCA-soluble protein content or hydroxyproline levels (P > 0.05). ACE inhibitor accelerated the autolysis of sea cucumber, but ACE activator inhibited the autolysis. Therefore, ACE can serve as a regulatory target for autolysis in sea cucumbers.

Enzyme-treated microalgal co-product diets for rainbow trout aquaculture: Supporting fish growth, phosphorus digestibility, and reducing phosphorus waste emission

Aquaculture is one of the fastest-growing food sectors, producing almost 50% of fish for human consumption worldwide. However, relying on fish meal and oil for aquaculture diets is not sustainable economically or environmentally. Aquaculture feeds also contain terrestrial plant ingredients with indigestible forms of phosphorus (P), of which 70%–80% can be released into aquatic environments. This P influx contributes to eutrophication of freshwater ecosystems that can lead to anoxic conditions. This study explores a more sustainable diet for salmonids, an important and valuable seafood. Our aim was to test ingredients with highly digestible forms of P in nutritionally balanced portions to support fish growth and reduce P loading. We determined the digestibility of three feeds containing raw, extruded, and enzymatically processed microalgal co-product of Nannochloropsis oculata compared to a conventional diet. We also quantified how much P was retained and excreted. We detected highest growth in trout fed enzymatically processed co-product feed, though it was not statistically different (p = 0.846) from growth of fish fed the reference or other co-product diets. The enzyme-treated, microalgal co-product ingredient and diet had comparable values for P digestibility and solid P excretion to the reference diet, but the lowest average solid P excretion of all test diets. Trout fed the enzyme-treated diet had the highest P retention, while the reference diet had the lowest (p = 0.0429). Trout fed the enzyme-treated diet had the lowest (p = 0.0174) and negative dissolved P excretion, while those fed the reference diet had the highest. Results showed that enzyme-treated N. oculata co-product maintains digestibility, increases P retention, and reduces dissolved P excretion compared to the reference diet in rainbow trout. These findings encourage follow-up research to design and test growth performance of diets containing enzyme-treated microalgal co-product as sustainable trout aquafeed.

Neurotoxic non-protein amino acids in commercially harvested Lobsters (Homarus americanus H. Milne-Edwards)

Cyanobacteria produce neurotoxic non-protein amino acids (NPAAs) that accumulate in ecosystems and food webs. American lobsters (Homarus americanus H. Milne-Edwards) are one of the most valuable seafood industries in Canada with exports valued at > $2 billion. Two previous studies have assessed the occurrence of β-N-methylamino-L-alanine (BMAA) in a small number of lobster tissues but a complete study has not previously been undertaken. We measured NPAAs in eyeballs, brain, legs, claws, tails, and eggs of 4 lobsters per year for the 2021 and 2022 harvests. Our study included 4 male and 4 female lobsters. We detected BMAA and its isomers, N-(2-aminoethyl)glycine (AEG), 2,4-diaminobutyric acid (DAB) and β-aminomethyl-L-alanine (BAMA) by a fully validated reverse phase chromatography—tandem mass spectrometry method. We quantified BMAA, DAB, AEG and BAMA in all of the lobster tissues. Our quantification data varied by individual lobster, sex and collection year. Significantly more BMAA was quantified in lobsters harvested in 2021 than 2022. Interestingly, more BAMA was quantified in lobsters harvested in 2022 than 2021. Monitoring of lobster harvests for cyanobacterial neurotoxins when harmful algal bloom events occur could mitigate risks to human health.

Bioactivity-Guided Fraction from Viscera of Abalone, Haliotis discus hannai Suppresses Cellular Basophils Activation and Anaphylaxis in Mice.

Basophils and mast cells are specialized effector cells in allergic reactions. Haliotis discus hannai (abalone), is valuable seafood. Abalone male viscera, which has a brownish color and has not been previously reported to show anti-allergic activities, was extracted with acetone. Six different acetone/hexane fractions (0, 10, 20, 30, 40, and 100%) were obtained using a silica column via β-hexosaminidase release inhibitory activity-guided selection in phorbol myristate acetate and a calcium ionophore, A23187 (PMACI)-induced human basophils, KU812F cells. The 40% acetone/hexane fraction (A40) exhibited the strongest inhibition of PMACI-induced-β-hexosaminidase release. This fraction dose-dependently inhibited reactive oxygen species (ROS) production and calcium mobilization without cytotoxicity. Western blot analysis revealed that A40 down-regulated PMACI-induced MAPK (ERK 1/2, p-38, and JNK) phosphorylation, and the NF-κB translocation from the cytosol to membrane. Moreover, A40 inhibited PMACI-induced interleukin (IL)-1β, IL-6, and IL-8 production. Anti-allergic activities of A40 were confirmed based on inhibitory effects on IL-4 and tumor necrosis factor alpha (TNF-α) production in compound (com) 48/80-induced rat basophilic leukemia (RBL)-2H3 cells. A40 inhibited β-hexosaminidase release and cytokine production such as IL-4 and TNF-α produced by com 48/80-stimulated RBL-2H3 cells. Furthermore, it's fraction attenuated the IgE/DNP-induced passive cutaneous anaphylaxis (PCA) reaction in the ears of BALB/c mice. Our results suggest that abalone contains the active fraction, A40 is a potent therapeutic and functional material to treat allergic diseases.

Diverse uses of valuable seafood processing industry waste for sustainability: a review.

Seafoods are rich in untapped bioactive compounds that have the potential to provide novel ingredients for the development of commercial functional foods and pharmaceuticals. Unfortunately, a large portion of waste or discards is generated in commercial processing setups (50-80%), which is wasted or underutilized. These by-products are a rich source of novel and valuable biomolecules, including bioactive peptides, collagen and gelatin, oligosaccharides, fatty acids, enzymes, calcium, water-soluble minerals, vitamins, carotenoids, chitin, chitosan and biopolymers. These fish components may be used in the food, cosmetic, pharmaceutical, environmental, biomedical and other industries. Furthermore, they provide a viable source for the production of biofuels. As a result, the current review emphasizes the importance of effective by-product and discard reduction techniques that can provide practical and profitable solutions. Recognizing this, many initiatives have been initiated to effectively use them and generate income for the long-term sustainability of the environment and economic framework of the processing industry. This comprehensive review summarizes the current state of the art in the sustainable valorisation of seafood by-products for human consumption. The review can generate a better understanding of the techniques for seafood waste valorisation to accelerate the sector while providing significant benefits.

Sustainability Of Octopus Food Industry

Octopus is a valuable seafood product consumed in many countries worldwide, with a billion-dollar industry and different species and markets in various regions. However, the octopus industry faces challenges related to sustainability, quality control, and food safety. This paper aims to provide an overview of the current state of the octopus industry, highlighting key issues and potential solutions. The sustainability of octopus fisheries is a major concern due to their vulnerability to overfishing and the lack of effective management strategies. Octopus fisheries are often unregulated, and there is a need for effective management strategies that balance conservation and economic interests. This can include implementing measures such as closed seasons, gear restrictions, and size limits to protect the species and ensure the long-term sustainability of octopus fisheries. Overall, the octopus industry has a promising future, but it will require continued innovation and collaboration to overcome the challenges facing the industry and ensure the sustainability and safety of octopus products. Effective management strategies, quality control measures, and food safety protocols must be implemented to maintain the long-term viability of the industry and ensure the health and safety of consumers.

Lobster Position Estimation Using YOLOv7 for Potential Guidance of FANUC Robotic Arm in American Lobster Processing

The American lobster (Homarus americanus) is the most valuable seafood on Canada’s Atlantic coast, generating over CAD 800 million in export revenue alone for New Brunswick. However, labor shortages plague the lobster industry, and lobsters must be processed quickly to maintain food safety and quality assurance standards. This paper proposes a lobster estimation orientation approach using a convolutional neural network model, with the aim of guiding the FANUC LR Mate 200 iD robotic arm for lobster manipulation. To validate this technique, four state-of-the-art object detection algorithms were evaluated on an American lobster images dataset: YOLOv7, YOLOv7-tiny, YOLOV4, and YOLOv3. In comparison to other versions, YOLOv7 demonstrated a superior performance with an F1-score of 95.2%, a mean average precision (mAP) of 95.3%, a recall rate of 95.1%, and 111 frames per second (fps). Object detection models were deployed on the NVIDIA Jetson Xavier NX, with YOLOv7-tiny achieving the highest fps rate of 25.6 on this platform. Due to its outstanding performance, YOLOv7 was selected for developing lobster orientation estimation. This approach has the potential to improve efficiency in lobster processing and address the challenges faced by the industry, including labor shortages and compliance with food safety and quality standards.

Costly crustaceans: A hedonic price analysis of the Florida stone crab

The stone crab (Menippe mercenaria and Menippe adina) fishery is the second most valuable commercial fishery in the state of Florida, with $30 million in dockside annual landings in 2019, It is a unique fishery in that only the claws are harvested, and the crab is returned to the sea where a high portion of them survive. There is substantial variability in the ex-vessel prices paid to fishers for stone crab claws, with claws yielding from $5 to over $30 per pound. However, there is limited knowledge with respect to what influences the prices of this valuable seafood product. Hedonic models allowed us to estimate the effect that different product attributes of a harvested stone crab claw have on the price. Here, we used commercial landings data from 2009 to 2020 to investigate the impact of attributes including claw size, county landed, fishing year, month, and area fished (inshore or offshore). The premiums associated with these attributes are highly variable with the largest premiums based on claw size followed by county landed, with south Florida and the Keys having higher price premiums than northwest Florida. There was interannual variation for the month attribute, with the middle of the fishing year having the highest price (January, February) and the lowest was placed on the start and end of each fishing year (October, November, May). These results provide basic economic information and regional insights into one of the most valuable fisheries in Florida and the Gulf of Mexico, and can help inform managers and stakeholders on the balance between profitability and sustainability of this unique fishery.

Impacts of sub‐optimal water quality on the haemolymph biochemistry, immune status and condition of post‐harvest Southern Rock Lobsters (Jasus edwardsii)

AbstractPalinurid rock (or spiny) lobsters constitute valuable seafood fisheries around the world. Post‐harvest mortality can have a substantial economic impact on the value of these fisheries and damage the brand identity of an otherwise fungible commodity. In this study, sudden, large‐scale mortalities in the Australian Rock Lobster industry were investigated through comprehensive haemolymph biochemistry panels, measurements of immune status and nutritional condition. A cohort of lobsters (n = 25) was sampled over a 4‐week period at a commercial processing facility, with the final sample occurring during a mortality event. A comparison of 22 biochemical parameters, including electrolytes, minerals, ions, metabolites and enzymes, showed a notable disruption in osmoregulation, protein content and enzymes during weeks 3 and 4 of the study. Haemocyte counts showed a decline in circulating haemocytes by the time of the mortality event along with a shift in the proportion of hyalinocytes to granulocytes favouring the former. The condition index was variable over the sampling schedule, possibly linked to observed incidences of cannibalism, with no evidence of an overall low condition that would explain mortalities. The lobsters sampled in this study did not show any consistent or progressive changes in biochemistry that may indicate a pathogen or disease as a causative agent. Rather, analysis of the water quality within the facility suggested that mortality was due to sub‐optimal water quality characterized by a combination of two factors, a substantial decrease in the pH and potential nitrogen toxicity, that caused a physiological response comprised of an ion imbalance, altered enzyme activity and, ultimately, mortality. These results offer a comprehensive characterization of the impact of unexplained morbidity on the biochemistry and physiology of lobsters, illustrate the harm of sub‐optimal aquaculture practices and highlight the need for a better understanding of aquaculture practices and their effects on economically important seafood industries.

Genome-wide SNPs reveal fine-scale genetic structure in ornate spiny lobster Panulirus ornatus throughout Indo-West Pacific Ocean

Abstract Genome-wide, single nucleotide polymorphism (SNP) typing can improve the management of valuable marine species by delineating finer scale population structure compared with traditional markers. This approach was applied to the spiny lobster, Panulirus ornatus distributed in the Indo-West Pacific and is one of the most highly valuable seafood products in the world. A total of 3008 SNPs was generated from DArTseq sequencing of 224 lobsters sampled at 13 locations across the Indo-Pacific. SNPs revealed a highly significant genetic structure among samples (analysis of molecular variance FST = 0.046). Pairwise genetic comparison showed significant differences among the majority of sampling locations. Outlier loci (including an outlier SNP mapped to the CASc gene with different allele frequencies among sampling locations) revealed highly significant pairwise differentiation, especially a genetic break between regional populations in northern Australia and South East Asia. Significant pairwise differences in outliers among sampling locations, even over small geographic scales, suggest a possible role of local adaptation on the population structure. Genetic differences identified among samples from northern Australia and South East Asia are sufficient to refute the single-stock hypothesis proposed using conventional genetic markers. The results of genome-level SNPs identify five management units across the species’ range, with significant implications for the future fisheries management and aquaculture development of this species.

Elemental fingerprinting of sea urchin (Paracentrotus lividus) gonads to assess food safety and trace its geographic origin

Sea urchin gonads are an economically valuable seafood item, considered a delicacy in many parts of the world. However, its consumption can either pose a food safety threat, as they accumulate potentially toxic elements from contaminated environments or promote the depletion of natural stocks due to the high demand. Knowing their harvesting location is therefore paramount to guarantee food safety and the conservation of natural stocks. In this study, the elemental fingerprints of sea urchin (Paracentrotus lividus) gonads collected in several locations along the Portuguese coast, in 2020 and 2021, were used to assess the levels of some potentially toxic elements (i.e., As, Cu, Pb and Zn) and to trace the harvesting location of this marine resource. P. lividus gonads presented mean levels of As, Cu, Pb and Zn above the thresholds recommended for human consumption (considering mollusks due to the absence of safety thresholds for echinoderms), in at least one of the sampling locations. The elemental fingerprints of gonads hold the potential to trace the harvesting location of P. lividus, even when it was used elemental fingerprints of different years to train and test the models.

Nutritional quality traits of Mediterranean mussels (Mytilus galloprovincialis): A sustainable aquatic food product available on Italian market all year round.

In this study, Mediterranean mussels (Mytilus galloprovincialis) coming from Italian production were purchased in the most important Italian wholesale fish market in different seasons. Biometrical parameters and chemical composition were investigated, with a particular focus on lipid quality and fatty acids (FAs) composition. Results showed a valuable nutritional profile independently by the season of production, represented by high protein and low-fat content, with the lipid portion represented by high amounts of beneficial FAs, particularly the long chain of the n-3 series. Some differences (p < 0.05) were found in carbohydrates and fat content of mussels edible tissues and in FAs profile of specimens collected in different seasons. The most favourable composition in terms of lipid quality was found in mussels collected during spring, corresponding to the moment of the year when mussels store energy reserves in the form of carbohydrates and fat (preparing for the spawning events) and when seawater is enriched in phytoplankton. The lipid health indices calculated (n6/n3, AI, TI) showed optimal values independently by the season of production. The outcomes obtained in this study could help supporting the appreciation of Mediterranean mussels as nutritional valuable seafood product, thus helping encouraging their consumption and promoting the appraisal of this farming sector essential for Italian aquaculture and related to low environmental impact.

Physiological and comparative proteomic analyzes reveal immune defense response of the king scallop Pecten maximus in presence of paralytic shellfish toxin (PST) from Alexandrium minutum

The king scallop, Pecten maximus is a highly valuable seafood in Europe. Over the last few years, its culture has been threatened by toxic microalgae during harmful algal blooms, inducing public health concerns. Indeed, phycotoxins accumulated in bivalves can be harmful for human, especially paralytic shellfish toxins (PST) synthesized by the microalgae Alexandrium minutum. Deleterious effects of these toxic algae on bivalves have also been reported. However, its impact on bivalves such as king scallop is far from being completely understood. This study combined ecophysiological and proteomic analyzes to investigate the early response of juvenile king scallops to a short term exposure to PST producing A. minutum. Our data showed that all along the 2-days exposure to A. minutum, king scallops exhibited transient lower filtration and respiration rates and accumulated PST. Significant inter-individual variability of toxin accumulation potential was observed among individuals. Furthermore, we found that ingestion of toxic algae, correlated to toxin accumulation was driven by two factors: 1/ the time it takes king scallop to recover from filtration inhibition and starts to filtrate again, 2/ the filtration level to which king scallop starts again to filtrate after inhibition. Furthermore, at the end of the 2-day exposure to A. minutum, proteomic analyzes revealed an increase of the killer cell lectin-like receptor B1, involved in adaptative immune response. Proteins involved in detoxification and in metabolism were found in lower amount in A. minutum exposed king scallops. Proteomic data also showed differential accumulation in several structure proteins such as β-actin, paramyosin and filamin A, suggesting a remodeling of the mantle tissue when king scallops are subjected to an A. minutum exposure.

Production of juvenile mud crabs, Scylla serrata: Captive breeding, larviculture and nursery production

The mud crab, Scylla serrata, is one of the most traded and valuable seafood in several Indo-Pacific countries. Most challenges in mud crab hatchery production are rooted not only in the mass production of the megalopa or crab instar 1, but also in the production of juveniles of stockable size in the grow-out production system. In the present study, large-scale production of S. serrata in hatchery was carried out to obtain fundamental data for developing hatchery production of this species. Additionally, the spawning characteristics and reproductive performance of wild broodstocks under captivity were studied to facilitate the management of brood stocks in the hatchery. Adult wild broodstock (n = 202), obtained from the inshore fishery from 2015 to 2019 were eyestalk ablated to promote reproductive maturation. Almost 50% of eyestalk ablated animals successfully spawned within a latency period of ~36 days. The crabs were found to be highly fecund in terms of zoeal production (3.84 × 106 ± 0.65 × 106 zoea 1) and captive spawning was achieved throughout the year, with a peak in November. Juvenile production was carried out in three phases: (1) Zoea 1 to megalopa (3 days old); (2) Pre-nursery phase, megalopa (3 days old), to ~3 g; and (3) nursery phase, ~3 g, to 2 8 g BW. In the first phase, a series of experiments were carried out on pilot scale and at the commercial level to evaluate optimum rearing conditions. In the pilot-scale studies, the highest survival up to the megalopa stage was obtained at lower stocking densities (50–75 larvae/L), and survival declined progressively at higher rearing densities. A series of trials was carried out at commercial scale (5000 L fiberglass tank), and survival from Zoea 1 to megalopa ranged from 0.6% to 7.9%, with a mean of 3.3%. This study also demonstrated that rotifer grown on commercial algal concentrate could be used in larviculture without compromising the survival rate. The second phase of rearing experiment (pre-nursery and nursery) was extended for sixty-eight days. During the pre-nursery phase, the effect of different rearing systems was evaluated: hapa net constructed either in an earthen pond or in open water bodies (lagoon) and direct stocking of megalopa in an earthen pond. During the pre-nursery phase, the highest survival was obtained in the hapa constructed in the earthen pond (60.5 ± 19.9%), whereas a significantly higher growth rate was obtained when megalopa was reared directly in the pond (5.9 ± 2.1 g). During the nursery phase, crabs were reared at 5 crabs/m2 and 10 crabs/m2; crabs reared at the lower stocking density attained significantly higher growth (28.2 ± 2.02 g), without significant differences in crab survival between these rearing densities. These results advance the method for the large-scale production of stockable juveniles of the mud crab, S. serrata

The global rise of crustacean fisheries

Globally, wild decapod crustacean fisheries are growing faster than fisheries of any other major group, yet little attention has been given to the benefits, costs, and risks of this shift. We examined more than 60 years of global fisheries landings data to evaluate the socioeconomic and ecological implications of the compositional change in global fisheries, and propose that direct and indirect anthropogenic alterations and enhancements to ecosystems continue to benefit crustaceans. Crustaceans are among the most valuable seafood, but provide low nutritional yields and drive 94% of the projected increase of global fishery carbon emissions, due to low capture efficiency. Unequivocally, the increasing global demand for luxury seafood comes with serious environmental costs, but also appears to offer lucrative fishing opportunities. The potential for more prosperous fisheries carries unevaluated risks, highlighting the need for a nuanced perspective on global fisheries trade‐offs. Addressing this unique suite of trade‐offs will require substantive changes in both science and management.

Государственные меры по развитию рыбохозяйственного комплекса Российской Федерации. Политика кластеризации. Потенциал развития рыбопромышленных кластеров в Азово-Черноморском бассейне полуострова Крым

The issues of state regulation and clustering policy in the Russian fisheries complex are considered, organizational shortcomings, obstacles to the full use of the biological potential of fisheries, difficulties in financing the business of cluster participants are revealed, and the need for an adaptation period for the formation of intra-cluster relations is justified. The need for leveraged sources of financing requires the development of financial models with affordable loans under the current investment lending mechanism. A special credit product will provide a transparent system of relations between state structures, participants of the fishing cluster and credit institutions. The proposed scheme of lending to clusters with real estate collateral and collateral for manufactured products is aimed at stable relations with credit institutions. This will lead to the formation of a collective share capital and the creation of management structures responsible for operational management and interaction with investors and financial institutions. The Azov-Black Sea basin of the Crimean Peninsula has the potential to restore biological resources, develop aquaculture, and produce feed for aquaculture. Clusters for targeted programs of artificial breeding in the marine area of rainbow trout, so-iuy mullet, oysters, mussels and other valuable biological resources successfully implement the projects «Valuable seafood», «Food pelagic». The renewal of the fishing fleet will increase the volume of fish production by 2.5-3 times and expand the raw material base of processing enterprises. The development of various forms and channels of sales of fish products with high added value will increase the profitability of the business and meet consumer demand in the domestic market.

Preliminary Results on the Growth of Larval European Lobster (Homarus gammarus (Linneaus, 1758)) in Turkey

Sea lobsters are among the most valuable seafood traded commodities. Since its production with fishing has decreased every year in the world, many types of cultural studies have been carried out and success has been achieved. The aim of this research is to investigate the survival of European lobster (Homarus gammarus) larvae in Turkey and to determine the nature of the direction of growth opportunities. This research is the first study in Turkey investigating the nature of the direction of growth opportunities and the survival of European lobster larvae. Larval release, larvae feeding and survival possibilities were investigated on two egg-bearing lobsters obtained from Çanakkale coasts. Both broodstock larvae were able to survive until the post larval stage. The larvae of the first mature lobster reached 10.857 mm total length and 0.025 g live weight after approximately 30 days. The larvae of the second mature lobster reached 26.9 mm total length and 0.502 g live weight after 33 days. A significant difference was found in the larvae of two mature lobsters at the end of the experiment according to their initial dimensions in both length and weight (p &amp;lt;0.05). In addition, it was determined that the growth was higher due to the higher temperature in the larvae of the second mature lobster.

A review of American lobster (Homarus americanus) records around the British Isles: 2012 to 2018

Although native to eastern Canada and the USA, American lobsters (Homarus americanus) have been reported from British coastal waters in recent years. The introduction of most have been as escapees from holding facilities or releases by members of the public for animal welfare or religious reasons. Life-history traits of H. americanus put them at a potential competitive advantage over and hybridisation with the European lobster (Homarus gammarus), the 5th most valuable seafood to the UK. While yearly reported numbers of H. americanus found in British waters have been low, a mass release of 361 H. americanus into the English Channel off Brighton, southern England, took place in June 2015. This review identified 162 records of H. americanus in British waters between 2012 and 2018, with specimens caught mainly in or around Brighton, although additional H. americanus released may have gone undetected. While this evidence suggests a growing potential for establishment of the species, further information is provided evidencing hybridisation between released H. americanus and native H. gammarus via genetic analysis. This review highlights the need for a more robust means of detecting H. americanus and other non-native species in British waters.

Microplastics in specific tissues of wild sea urchins along the coastal areas of northern China

Sea urchins serve as an essential niche for benthic ecosystems and are valuable seafood for humans. However, little is known about the microplastics (MPs) accumulation in sea urchins. Here, we investigated the abundances and characteristics of MPs in specific tissues of wild sea urchins for 12 sites across 2, 900 km of coastlines in northern China. Sea urchins from all sites were detected to have MPs, with a total detection rate of 89.52%. The MPs abundance in sea urchins from all sites ranged from 2.20 ± 1.50 to 10.04 ± 8.46 items/individual or 0.16 ± 0.09 to 2.25 ± 1.68 items/g wet weight. The samples from Dalian were found to have the highest value by individual, and samples from Lianyungang had the highest value by gram. Furthermore, MPs were found in different tissues of sea urchins, i.e., gut, coelomic fluid and gonads. The highest abundance of MPs was found in the gut of sea urchins, followed by coelomic fluid and gonads. The size of MPs ranged from 27 to 4742 μm, and the mean size found in gut was bigger than coelomic fluid and gonads. More interestingly, the MPs abundance increased with the decrease of anus size, shell diameter and gonad index (the wet weight ratio of gonad to total soft tissues). The MPs were dominated by fiber in shape, blue-green in colour and cellophane in composition. The high MPs abundance in sea urchins indicates the potential risks to human as they are consumed in many parts of the world, particularly in Asia and Europe.