Seasonal effect in nutritional quality and safety of the wild sea urchin Paracentrotus lividus harvested in the European Atlantic shores

Potential of fishing nets for adsorption of inorganic (Cu and Pb) and organic (PAHs) pollutants

This study aimed to evaluate metals and polycyclic aromatic hydrocarbons (PAHs) adsorption on new plastic fishing nets in both laboratory and quasi-real scenario (nets submersed in marina seawater) experiments as well as in situ monitoring of these contaminants in water and sediments in lost fishing gears hotspots. The latter was inconclusive as environmental contaminants levels were very low. Laboratory experiments showed metals (copper and lead) and PAHs adsorption depended on the thickness and polymeric composition of the net, being lower in thinner nylon nets. Experiments in the marina, also showed significant contaminants adsorption, which increased over time, probably due to biofilm formation on net surface. This work showed the potential role of fishing gears as skins of pollutants, increasing organisms' exposition to contaminants present in the environment. So, initiatives to prevent the loss of fishing gear and to retrieve them are needed to reduce and/or eliminate their environmental impact.

Effect of harvesting season and location on the microbial quality and community composition of the edible sea urchin (Echinus esculentus) gonads

Despite the crucial role of microbial community composition in the quality and stability of seafood, little emphasis has been given to the microbiota profile of sea urchin gonads. This study investigates the microbial quality and community composition of sea urchin gonads (Echinus esculentus) as a function of harvesting season (autumn, winter, spring, and summer) and location (one site proximal to urban activity areas while the other is located in open water close to the coastline). Significant season-dependent variations were found in psychrotrophic and aerobic plate counts, with higher counts in summer, followed by autumn, spring, and winter. H2S-producing bacteria and Pseudomonas spp. counts were unaffected by harvesting season or location. Sea urchin gonad microbial composition proved resilient and dynamic, primarily shaped by seasonal variations, and minimally influenced by location. Winter and spring samples exhibited higher diversity than autumn and summer. Key genera like Pseudomonas, Psychromonas, Vibrio, Chryseobacterium, Shewanella, and Photobacterium varied seasonally. Pseudomonas, Vibrio, and Photobacterium are crucial in assessing microbial quality and safety due to their roles as specific spoilage organisms (SSOs) and, in some cases, human pathogens. Though relative abundances differed slightly between locations, harvesting location did not notably impact microbial community shaping in gonads. However, the results suggest that harvesting locations near areas with urban activity may lead to contamination with specific bacterial species, possibly due to water quality variations. These findings emphasize the importance of considering seasonality when evaluating sea urchin gonad microbial quality. Identifying key genera enhances insights into potential SSOs and human pathogens, enhancing food safety considerations in the consumption of raw or lightly processed sea urchin gonads and guiding the development of preservation methods to extend shelf life.

Valorisation of sea urchin (Paracentrotus lividus) gonads through canning

Fresh sea urchin (Paracentrotus lividus) gonads are a delicacy with short seasonal availability, very often heterogeneous in size and intrinsic characteristics. This study aimed to valorise this resource through the preparation of canned products (with/without Porphyra spp.) and evaluate their physicochemical and sensory quality (3-12 months). Canning contributed to a decrease in protein, K and most carotenoids contents; and a concentration of lipids, ash, Na and Se levels. A simulated 12-month ageing led to decrease the protein and β-carotene contents; and the Na and lutein levels concentration. The macroalgae addition resulted in an orange, darker and less soft product, with higher carbohydrates, Na, Se and carotenoids contents. A 25 g-dose contributes to significant daily intakes of protein (8-9%), EPA+DHA (47-53%), I (35-62%) and Se (30-47%). The products were commercially stable/sterile and had good sensory acceptance. Overall, canning constitutes a strategy to provide a nutritionally balanced product available all year-round.

Edible Sea urchins Echinus esculentus from Norwegian waters- Effect of season on nutritional quality and chemical contaminants

This study aimed to characterize Echinus esculentus gonads in terms of biometric parameters and nutritional quality at two sites in Mid-Norway at four different seasons. The chemical contamination of the gonads was also investigated for the first time through the evaluation of 28 macro- and trace elements and 32 components from the emerging and persistent group per- and polyfluoroalkyl substances (PFAS). The spawning period was determined in summer, given that the gonad index was the lowest in this season for both sites. Protein concentrations were constant (8%-10%). However, lipid contents (1%-3%) were noticed to be higher in gonads during autumn and winter. The gonads had high contents of PUFA mainly EPA and DHA, followed by SFA, and MUFA year around for both locations. E. esculentus gonads constitute a good source of fatty acids, macro, and trace elements. This species could also be a bioindicator for the monitoring of marine environments.

Occurrence of microplastics and metals in European seabass produced in different aquaculture systems: Implications for human exposure, risk, and food safety

Microplastics (MPs) are emerging contaminants of increasing concern as they may cause adverse effects and carry other contaminants, which may potentially compromise human health. Despite occurring in aquatic ecosystems worldwide, the knowledge about MP presence in different aquaculture systems and their potential impact on seafood products is still limited. This study aimed to determine the levels of MPs in water, feed, and European seabass (Dicentrarchus labrax) from three relevant aquaculture systems and estimate human exposure to MPs and metals through seabass consumption. The recirculating aquaculture system (RAS) had the highest MP occurrence in water and feed. MP levels in seabass followed the aquaculture system's levels in water and feed, with RAS-farmed fish presenting the highest MP load, both in the fish gastrointestinal tract (GIT) and muscle, followed by pond-, and cage-farmed fish. MPs' characteristics across aquaculture systems and fish samples remained consistent, with the predominant recovered particles falling within the MP size range. The particles were visually characterized and chemically identified by micro-Fourier Transform Infrared Spectroscopy (μFTIR). Most of these particles were fibres composed of man-made cellulose and PET. MP levels in GIT were significantly higher than in muscle for pond- and RAS-farmed fish, MPs' bioconcentration factors >1 indicated bioconcentration in farmed seabass. Metal concentrations in fish muscle were below permissible limits, posing low intake risks for consumers according to the available health-based guidance values and estimated dietary scenarios.

Metallic trace element dynamics in Paracentrotus lividus from Algeria: Environmental large-scale survey and human health risk assessment

This paper evaluates the dynamics of Metallic Trace Elements (MTEs; Cd, Pb, Fe, Cu, Zn, Ni and Co) in the gonads of the sea urchin Paracentrotus lividus collected in five sites: four contaminated and one reference, along the Western coast of Algeria, recontextualizes this contamination within a wider geographical distribution area throughout 83 sites among the Mediterranean Sea and Atlantic and focuses on the potential risk of their consumption on human health for the first time in Algeria. The trace element pollution index places Algeria, and generally the North African coasts, as the region most contaminated by MTEs. The geographical variability in metal contamination levels is greater in the Mediterranean Sea than in the Atlantic. The health risk assessment indicates that Pb exceeds the maximum limit set by the Commission Regulation (EC) No 1881/2006 at two of the four Algerian contaminated sites.

Temporal and spatial variability in the isotopic composition of sea urchins along Portuguese coast

Paracentrotus lividus is a sea urchin widely distributed throughout Mediterranean basin and Atlantic coast, highly appreciated for its gonads. It is broadly distributed along the Portuguese coast and its exploitation has potential to grow. Nevertheless, fluctuations on nutritional composition and sensory traits of P. lividus according to each habitat and seasonality are still little understood. Stable isotopes analysis has been recognised as a powerful tool for exploring environmental-ecological-biological processes in aquatic systems. It is also useful to give indications on how to improve available diets for the aquaculture of this species, contributing to a sustainable rearing. Herein, such technique was used to assess temporal and spatial differences in isotopic composition of P. lividus' gonads and intestines and to evaluate its application as a management tool for the identification of the most suitable locations and periods of the year to collect organisms with high quality gonads. Sampling campaigns were carried out between 2019 and 2020 in five rocky shores along the Portuguese coast (Viana do Castelo, Figueira da Foz, Peniche, Sines and Guia). Three rock pools were selected in each shore, and five specimens were collected per pool. The gonadosomatic index (GSI, %) was calculated and carbon and nitrogen elemental and isotopic composition were determined in gonads and intestine using isotope ratio mass spectrometry. Significant spatial and temporal fluctuations were registered among urchins collected along Portuguese coast. Such variations may be associated with latitudinal gradients along the coast and variations of environmental and ecological conditions within each area, especially those affecting algal biomass, on which urchins primarily feed. More research must be pursued to maximise the use of stable isotopes analysis as a management tool for supporting sustainable exploitation of natural stocks or even to contribute to nutritional studies with new diets for sea urchin production that consider the feeding of these animals in the wild.

The Impact of Sea Urchin as an Ingredient on the Physicochemical, Microbiological, and Sensory Properties of Fish Sauce Fermentation

The consequences of using 25% whole or shelled sea urchin as an ingredient in anchovy sauce on its fermentation and development of its physicochemical properties after 20 days fermentation was studied. Two varieties of fish and sea urchin sauce were made with or without shell at 1:2:1 ratio (salt:fish:sea urchin) plus a control fish sauce at 1:3 ratio (salt:fish). All sauces were fermented at 40-50 °C for 20 days, where for the first 7 days the preparation remained in a static phase. During their fermentation, pH, salt concentration, aw, TVB-N, TMA, total nitrogen, formaldehyde nitrogen, amino nitrogen, and ammonium nitrogen, as well as aerobic mesophiles and lactic acid bacteria were monitored. The fermentation of the experimental sauces proved to follow an evolution rather similar to the control sauce. The whole and shelled sea urchins provided the necessary microbial and enzymatic load to trigger an adequate hydrolysis of the fish and the production of total nitrogen (16.0-17.6 g/L), formaldehyde nitrogen (15.1-16.0 g/L), and amino nitrogen (0.7-0.8 g/L) of the same order as the control sauce, despite the lower fish content. According to TMA (9.2-13.1 mg N/100 g), VBT (40.0-47.2 mg N/100 g) contents, and pH levels (5.41-5.46), no deviation of the fermentation process was observed under the experimental conditions (salt content, temperature, and agitation after the static phase). Quantitative descriptive analysis (QDA) sensory revealed that the use of sea urchin results in high quality products characterized by their aromas of crustaceans and mollusks. The present study investigates the potential use of shelled and even whole sea urchin as an ingredient for the preparation of high quality fish sauces.

Metallic trace element dynamics in Paracentrotus lividus from Algeria: Environmental and human health risk assessment

This paper evaluates the dynamic of Metallic Trace Elements (MTEs; Cd, Pb, Fe, Cu, Zn, Ni and Co) in the sea urchin Paracentrotus lividus collected in five sites: four contaminated and one reference, along the western coast of Algeria, recontextualizes this contamination within a wider geographical distribution area throughout 84 sites among the Mediterranean Sea and Atlantic and focuses on the potential risk on human health for the first time in Algeria. The Trace Element Pollution Index places Algeria, and generally the North African coasts, as the region most contaminated by MTEs. The Trace Element Spatial Variation Index ranks Pb as a MTE of key environmental concern according to global spatial variability. The health risk assessment indicates that Cd and Pb exceed the maximum limits set by the Commission Regulation (EC) No 1881/2006 on three of the four contaminated sites.

Assessment of the contamination by 2,4,6-tribromophenol of marine waters and organisms exposed to chlorination discharges

2,4,6-tribromophenol (TBP) is implied in the production of brominated flame retardants but is also a major chlorination by-product in seawater. A growing number of studies indicate that TBP is highly toxic to the marine biota, but the contribution of anthropogenic sources among natural production is still under question concerning its bioaccumulation in marine organisms. Here, several water sampling campaigns were carried out in the industrialized Gulf of Fos (northwestern Mediterranean Sea, France) and clearly showed the predominant incidence of industrial chlorination discharges on the TBP levels in water, at the 1-10 ng L^-1 level in average and reaching up to 580 ng L^-1 near the outlets. The bioaccumulation of TBP was measured in 90 biota samples from the Gulf of Fos. The concentrations found in European conger muscle tissues (140-1000 ng g^-1 lipid weight, in average), purple sea urchin gonads (830-880 ng g^-1 lipid weight, in average), and Mediterranean mussel body (1500-2000 ng g^-1 lipid weight, in average) were above all published references. Significant correlations with fish length (European conger) and gonad somatic index (purple sea urchin) were also identified. Comparatively, fish, urchins and mussels from other Mediterranean sites analyzed within this study showed a lower bioaccumulation level of TBP, consistently with what found elsewhere. Industrial outflows were thus identified as hotspots for TBP in seawater and marine organisms. The environmental risk assessment indicated a high potential toxicity in the industrial Gulf of Fos, in particular near the outlets, and a limited threat to human but toxicological references are lacking.

Lipid metabolism of sea urchin Paracentrotus lividus in two contrasting natural habitats

Sea urchins Paracentrotus lividus were harvested monthly from April 2015 to March 2016 from two sites in Sardinia (Italy). The two sites, a Posidonia oceanica meadow and a rocky bottom habitat, were naturally characterized by different food sources and availability, being mainly populated by the sea grass Posidonia oceanica and the brown algae Halopteris scoparia, respectively. Total lipids showed a minimum during winter in mature gonads, and a maximum in the summer (recovery stage). Fatty acid (FA) profiles of gut contents and gonads differed from those of the most available food sources. Levels of C18:3 (n-3) (ALA) discriminated samples from the two sites. Despite the very low amounts of C20:5 (n-3) (EPA) and C20:4 (n-6) (ARA) in P. oceanica, the main FA in gonads and gut contents were EPA and ARA in both sites. Increase in green algae intake prior to gametogenesis, especially C. cylindracea, likely affected EPA and ARA levels in gonads. The results show that P. lividus is able to concentrate lipids in gut contents and also to selectively store EPA, ARA and their precursors ALA and 18:2 (n-6) (LA). Moreover, bioconversion of ALA to EPA and of LA to ARA in P. lividus is suggested.

Linking contaminant distribution to hydrodynamic patterns in an urban estuary: The Douro estuary test case

An increase in anthropogenic activities in coastal regions can put at risk their flora and fauna and their ecosystem services. Therefore, it is important to evaluate possible impacts. In particular, we need to understand the links between contaminants concentrations and the hydrodynamic patterns of these highly productive regions to anticipate the effects of contaminants in the environment. Towards that aim there is the need to carry out regular campaigns to monitor the evolution of the coastal systems. In this work we analyse in-situ measurements of physico-chemical parameters, and look for possible relations between observed contaminants patterns and estuarine hydrodynamics. Data collected in the Douro estuary, one of the main estuarine regions of the Iberian western coast, revealed the presence of 5 hazardous and noxious substances (HNS), 14 polycyclic aromatic hydrocarbons (PAHs) and 6 trace metals in water and sediment samples. Water temperature and salinity analysis revealed a strong variability, which can affect the water solubility properties and the organisms' tolerance to certain toxins. A relationship between the salinity and the HNS and PAHs concentrations was found, caused by the existence of a salt-wedge that triggers the salting-out effect. Sinker contaminants (PAHs and trace metals) can be re-suspended both during low and high flow conditions associated with the salt-wedge and with strong river flows. Floater contaminants (HNS) are completely depended on the tide, which has the capacity to distribute them through the entire estuary, during low river flow regimes. However, strong river flows, with associated river plumes, can distribute both sinker and floater contaminants to the coastal region trapping them over the inner-shelf. The results clearly show that hydrodynamic patterns are a major driver for contaminants dispersion and pathways in coastal areas, inducing harmful effects to the flora and fauna and, consequently, to the ecosystem services of these regions.

Adsorption of Cd and Cu to different types of microplastics in estuarine salt marsh medium

This study aimed to investigate if microplastics (MPs) type (polyethylene microspheres (mPE), fishing line fibers, film plastic bags MPs and bottle cap particles) and aging affect MPs capacity to sorb Cd or Cu in estuarine salt marsh medium. Tests were carried out in elutriate solution, a simple medium obtained by mixing rhizosediment (sediment in contact with plants roots) with the respective estuarine water, that can be used to simulate water-sediment exchanges in estuarine salt marsh environments. After 7 days of exposure, metals adsorption was only detected for film MPs. No differences were observed between virgin and aged MPs. Salinity also did not influence metal adsorption to mPE. Present results indicate that in estuarine salt marsh areas some types of MPs might adsorb metals, which could affect metals availability.