The role of large marine vertebrates in the assessment of the quality of pelagic marine ecosystems

Development of a health index for stranded marine tetrapods

This study presents the development and validation of a Health Index (HI) to assess the overall health of stranded marine tetrapods (seabirds, sea turtles, and marine mammals). The HI is based on parameters collected during necropsies and histopathological analyses, including body condition, systemic conditions (macroscopic and by histopathology), cutaneous injuries, organized lesions, parasitosis, lymphoid depletion, and thyroid alterations. The HI was applied to data from 6,332 marine tetrapods stranded along the Brazilian coast. Results showed that the HI effectively differentiated between animals with good, fair, and poor health, as evaluated by independent veterinary assessments. Sea turtles exhibited the lowest average HI, suggesting poorer health conditions compared to seabirds and marine mammals. The HI has proven to be a valuable tool for monitoring the health of marine tetrapod populations. Using a quantitative measure of an animal's health enables the evaluation of spatial and temporal variations in health status and the identification of more subtle impacts on species or populations. Thus, the HI allows for an objective assessment and comparison of wildlife health, supporting conservation efforts and helping to identify potential threats.

Anthropic Pressure on Cetaceans Stranded Along the Ligurian Coast Within the Pelagos Sanctuary: A Case Series

Data collected by C. Re. Di. Ma over a 3-year period (2020-2022) were considered to assess anthropic pressure on cetaceans living in the Ligurian sea. Out of a total of 37 stranded cetaceans, a complete post mortem examination was performed on 23 cases. Of these, 14 were further selected considering at least one of these conditions: (i) confirmed, probable, or suspected interaction with fishing activities through the application of a standardized diagnostic framework (7/14; 50%), (ii) toxicological stress through the evaluation of OCs hazardous levels (14/14; 100%), and (iii) terrestrial pathogen-associated disease (systemic infection and/or associated lesions) (7/14; 50%). For 9 animals out of a total of 14 selected, the cause of death was classified as natural (6/14; 42,8%), anthropic (3/14; 21,4%), or not determined (5/14; 35,7%) based on gross and histological pathology and ancillary testing. These findings extend our knowledge of the anthropic pressure to which cetaceans stranded along the Ligurian coastline are subjected from a multidisciplinary point of view.

The Ecology of Non-Candida Yeasts and Dimorphic Fungi in Cetaceans: From Pathogenicity to Environmental and Global Health Implications

Cetaceans, which are integral to marine ecosystems, face escalating anthropogenic threats, including climate change and pollution, positioning them as critical sentinel species for ocean and human health. This review explores the neglected realm of non-Candida yeasts in cetaceans, addressing the gaps in the understanding of their prevalence, pathogenicity, and environmental impacts. By examining identified species such as Cryptococcus spp., Paracoccidioides spp., and several dimorphic fungi, this review emphasizes global prevalence, epidemiology and ecology, pathogenicity, and potential zoonotic implications. It also discusses the fine line between yeast commensalism and pathogenicity by considering environmental influences such as pollution, climate shifts, and immune suppression. Environmental impact discussions delve into how rising ocean temperatures and pollution can modify yeast mycobiota, potentially affecting marine host health and broader ecosystem dynamics. The cetacean's unique physiology and ecological niches are considered, highlighting potential impacts on behaviors, reproductive success, and survival rates. Identifying crucial knowledge gaps, the review calls for intensified research efforts, employing advanced molecular techniques to unravel the cetacean mycobiome. Systematic studies on yeast diversity, antifungal susceptibility, and their influence on environmental and ecosystem health are proposed, and the balance between commensal and pathogenic species emphasizes the significance of the One Health approach. In conclusion, as marine mammals face unprecedented challenges, unveiling non-Candida yeasts in cetaceans emerges as a critical endeavor with far-reaching implications for the conservation of marine ecosystems and for both animal and human public health.

Plasmatic B-esterases as potential biomarkers of exposure to marine plastics in loggerhead turtles

Sea turtles are particularly vulnerable to plastic exposures, and the associated chemical additives, due to their feeding strategies. The species Caretta caretta is a proposed sentinel of plastic pollution worldwide. Thus, there is a need to find adequate biomarkers of plastic exposure through non-invasive protocols for this IUCN protected species. Plasmatic acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and carboxylesterase (CE) which participate in xenobiotic and endogenous metabolic reactions could all serve as biomarkers, as they are responsive to plasticizers and have already proved adequate for identifying organophosphorus esters exposures. Here we measured plasmatic B-esterases in wild specimens captured as accidental by-catch. Measurements were taken in each individual either at entry into the rehabilitation program or immediately before release after a recovery period. For CE measurements, 4 commercial substrates were used as potentially indicative of distinct enzyme isoforms. Increased activity was seen with the butyrate-derived substrates. Plasmatic CE activities were over one order of magnitude higher than AChE and BuChE substrates. Moreover, an in vitro protocol with the inclusion of plastic additives such as tetrabromobisphenol A (TBBPA), bisphenol A and some of its analogues was considered a proxy of enzymatic interactions. A clear inhibition by TBBPA was found when using commercially purified AChE and recombinant CE proteins. Overall, from in vitro and in vivo evidences, CEs in plasma are sensitive and easily measurable and have been shown to significantly increase after turtles have been rehabilitated in rescue centres. Nevertheless, the inclusion of plastic (or plasticizers) characterisation would help to confirm its association with plasmatic enzyme modifications before they can be adopted as biomarkers of plastic contamination.

Concentrations of trace elements in tissues of loggerhead turtles (Caretta caretta) from the Tyrrhenian and the Ionian coastlines (Calabria, Italy)

Toxic trace elements from both, natural and anthropogenic origin, pose a threat to aquatic environments and marine wildlife due to their long-range transport, bioaccumulative nature, and biomagnification through the food chain. Being long-lived and migratory animals, sea turtles can be exposed to elevated levels of toxic elements, and are therefore considered sentinel species for chemical pollution. In this study, concentrations of trace elements (arsenic, cadmium, lead, mercury) were determined in tissues of 46 loggerhead sea turtles (Caretta caretta) stranded along Tyrrhenian and Ionian coasts of Calabria, in Southern Italy, between 2014 and 2020. Curved carapace length (CCL), curved carapace width (CCW), body mass (BM), and sex were determined and the correlations of these parameters with toxic elements concentrations were investigated. During necropsy, kidney, liver, and muscle tissues were collected and the concentration and distribution of metals determined. Muscle tissues showed the lowest toxic element burdens, except for As that showed the highest mean concentrations in this tissue. The kidney was the main accumulation organ for Cd, while similar levels of Hg and Pb were measured in kidney, liver, and muscle tissues. The risk assessment performed for Cd, Hg, and Pb in sea turtles' liver highlighted possible negative effects on sea turtles' health and the need for marine turtle toxicology researches. This is the first study reporting levels and distribution of toxic elements in tissues of Caretta caretta turtles from the Tyrrhenian and Ionian coasts of Calabria.

First report from North America of microplastics in the gastrointestinal tract of stranded bottlenose dolphins (Tursiops truncatus)

Microplastics' (MPs) abundance, small size, and global distribution render them bioavailable to a variety of organisms directly or by trophic transfer, yet examinations in marine apex predators are currently limited. The present study investigated the occurrence of MPs sized 125 μm-5 mm in the gastrointestinal tract (GIT) of bottlenose dolphins (Tursiops truncatus) stranded in South Carolina, USA from 2017 to 2018. MPs, mostly fibers, were detected in all GITs (n = 7) of stranded bottlenose dolphins. Total suspected MPs ranged between 123 and 422 particles/individual, a high range among international studies. Comparison to other studies likely reflects differences in both methods and location. This is the first study from North America to quantify MPs in a small coastal cetacean outside Arctic waters and the first specifically in bottlenose dolphins (southeastern United States). Findings and methodology from this investigation can aid future studies examining MP in marine apex predators.

Road impact in a protected area with rich biodiversity: the case of the Sebitoli road in Kibale National Park, Uganda

While road network expansion is crucial for economic development, it can cause a notable disturbance of fauna, especially in protected area in terms of habitat fragmentation, risk of collision, and also indirect threat such as pollution. In this study, we monitored the 4.6-km long tarmac road crossing the Kibale National Park in Uganda, home to a rich variety of wild species including the endangered chimpanzees. We evaluated the effects of collisions and pollution, as well as the impact of the renovation process in terms of disturbance and the mitigation measures deployed. This survey reports the death of 24 wild animals killed by cars, including two chimpanzees. The atmospheric concentrations of O₃, NO₂, SO₂, and BTEX did not exceed recommended limits. More than 5000 plastic bottles were collected along the road within 4 months, and for the first time, the presence of BPA and BPS was detected in the hairs of wild chimpanzees. The road bisecting the Kibale National Park poses a high danger in terms of traffic and an underestimated risk related to plastic pollution. Measures (signpost, speed bumps) should be urgently deployed to decrease the risk posed by the renovated road for emblematic species such as chimpanzees, which are crucial for tourism and economy in Uganda.

Do different habits affect microplastics contents in organisms? A trait-based analysis on salt marsh species

Salt marshes in urban watersheds are prone to microplastics (MP) pollution due to their hydrological characteristics and exposure to urban runoff, but little is known about MP distributions in species from these habitats. In the current study, MP occurrence was determined in six benthic invertebrate species from salt marshes along the North Adriatic lagoons (Italy) and the Schelde estuary (Netherlands). The species represented different feeding modes and sediment localisation. 96% of the analysed specimens (330) did not contain any MP, which was consistent across different regions and sites. Suspension and facultative deposit-feeding bivalves exhibited a lower MP occurrence (0.5-3%) relative to omnivores (95%) but contained a much more variable distribution of MP sizes, shapes and polymers. The study provides indications that MP physicochemical properties and species' ecological traits could all influence MP exposure, uptake and retention in benthic organisms inhabiting European salt marsh ecosystems.

Trace elements levels in muscle and liver of a rarely investigated large pelagic fish: The Mediterranean spearfish Tetrapturus belone (Rafinesque, 1810)

We determined levels of mercury, cadmium, lead and selenium in muscle and liver of 29 specimens of a large pelagic fish rarely investigated, the Mediterranean spearfish Tetrapturus belone (Raf., 1810). The following element concentration ranking (mean ± S.D.; espressed in mg/kg dry weight) was recorded in muscle: Hg (3.401 ± 1.908) > Se (1.727 ± 0.232) > Pb (0.532 ± 0.322) > Cd (0.019 ± 0.015), and Se (6.577 ± 1.789) > Cd (5.815 ± 3.038) > Hg (2.698 ± 2.214) > Pb (0.661 ± 1.334) in liver. Levels of Hg, Se and Cd were compared to those reported for other Istiophoridae from oceanic areas and for other large predators of Mediterranean Sea, like swordfish and tuna. Organotropism of trace elements and their relation to size was discussed. Ecophysiological considerations regarding the Se-Hg relationship as well as Se-Cd indicate a possible detoxification mechanism. The implications for human consumption are briefly discussed.

Foraging habits and levels of mercury in a resident population of bottlenose dolphins (Tursiops truncatus) in Bocas del Toro Archipelago, Caribbean Sea, Panama

A small and genetically isolated bottlenose dolphin (Tursiops truncatus) population resides year-round in the Bocas del Toro Archipelago-Panama (BDT). Photo-identification and genetic data showed that this dolphin population is highly phylopatric and is formed exclusively by individuals of the "inshore form". This study aimed to investigate the trophic ecology and mercury concentrations of bottlenose dolphins in BDT to assess their coastal habits. We collected muscle samples (n = 175) of 11 potential fish prey species, and skin samples from free-ranging dolphins in BDT (n = 37) and La Guajira-Colombia (n = 7) to compare isotopic niche width. Results showed that BDT dolphins have a coastal feeding habit, belong to the "inshore form" (δ¹³C = -13.05 ± 1.89‰), and have low mercury concentrations (mean = 1637 ± 1387 ng g^-1dw). However, this element is biomagnified in the BDT food chain, showing a marginal dolphins health risk (RQ = 1.00). We call for a monitoring pollutant program and conservation strategies aimed to protect the dolphin population at BDT.

Loggerhead sea turtles (Caretta caretta): A target species for monitoring litter ingested by marine organisms in the Mediterranean Sea

Marine litter is any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment. Ingestion of marine litter can have lethal and sub-lethal effects on wildlife that accidentally ingests it, and sea turtles are particularly susceptible to this threat. The European Commission drafted the 2008/56/EC Marine Strategy Framework Directive with the aim to achieve a Good Environmental Status (GES), and the loggerhead sea turtle (Caretta caretta, Linnaeus 1758) was selected for monitoring the amount and composition of litter ingested by marine animals. An analogous decision has been made under the UNEP/MAP Barcelona Convention for the protection of the Mediterranean Sea, following the Ecosystem Approach. This work provides for the first time, two possible scenarios for the Marine Strategy Framework Directive GES, both related to "Trends in the amount and composition of litter ingested by marine animals" in the Mediterranean Sea. The study validates the use of the loggerhead turtle as target indicator for monitoring the impact of litter on marine biota and calls for immediate use of this protocol throughout the Mediterranean basin and European Region. Both GES scenarios are relevant worldwide, where sea turtles and marine litter are present, for measuring the impact of ingested plastics and developing policy strategies to reduce it. In the period between 2011 and 2014, 150 loggerhead sea turtles, found dead, were collected from the Italian Coast, West Mediterranean Sea Sub-Region. The presence of marine litter was investigated using a standardized protocol for necropsies and lab analysis. The collected items were subdivided into 4 main categories, namely, IND-Industrial plastic, USE-User plastic, RUB-Non plastic rubbish, POL-Pollutants and 14 sub-categories, to detect local diversity. Eighty-five percent of the individuals considered (n = 120) were found to have ingested an average of 1.3 ± 0.2 g of litter (dry mass) or 16 ± 3 items.

What difference does a century make? Shifts in the ecosystem structure of the Ross Sea, Antarctica, as evidenced from a sentinel species, the Weddell seal

The arrival of humans to Antarctica's Ross Sea (100+ years ago) led to a slow, but sustained increase in human activities in the area. To investigate if human presence has influenced the structure of the ecosystem over the last century, we compared historical (ca 100 years old) and modern samples of a sentinel species, the Weddell seal (Leptonychotes weddellii), using both bulk tissue and compound-specific stable isotope analysis. The historical isotopic niche of Weddell seals was over five times larger than the modern niche. The isotopic values of individual amino acids showed a clear segregation between historical and modern samples, indicative of differences at the base of the trophic web. Further, we found no significant differences in the trophic position of Weddell seals between the two periods. Our study revealed that the Ross Sea has undergone detectable changes (i.e. in the primary producers community) in the last century, but the presence of humans has not disrupted trophic interactions supporting Weddell seals.

Floating macro-litter along the Mediterranean French coast: Composition, density, distribution and overlap with cetacean range

This study investigated the composition, density and distribution of floating macro-litter along the Liguro-Provençal basin with respect to cetaceans presence. Survey transects were performed in summer between 2006 and 2015 from sailing vessels with simultaneous cetaceans observations. During 5171km travelled, 1993 floating items were recorded, widespread in the whole study area. Plastics was the predominant category, with bags/packaging always representing >45% of total items. Overall mean density (14.98 items/km²) was stable with significant increase reported only in 2010-2011; monthly analysis showed lower litter densities in July-September, suggesting possible seasonal patterns. Kernel density estimation for plastics revealed ubiquitous distribution rather than high accumulation areas, mainly due to the circulation dynamics of this area. The presence range of cetaceans (259 sightings, 6 species) corresponded by ~50% with plastic distribution, indicating high potential of interaction, especially in the eastern part of the area, but effective risks for marine species might be underrepresented.

Levels of perfluorinated acids (PFCAs) in different tissues of Lepidochelys olivacea sea turtles from the Escobilla beach (Oaxaca, Mexico)

Lepidochelys olivacea is the most abundant and globally distributed sea turtle species in the world and thus, monitoring this species for persistent organic pollutants, such as perfluorinated chemicals, is fundamental for their protection. This study was the first to evaluate the occurrence of five PFCAs (PFOA, PFNA, PFDA, PFUnA, PFDoA) in liver and blood samples of Olive Ridley turtle population from the Escobilla beach (Oaxaca, Mexico). PFDA and PFUnA were the predominant PFCs in blood samples (detected in 93% and 84% of samples, respectively) and were also present in the highest concentrations. Liver samples showed higher PFCA concentrations than whole blood samples, with PFNA and PFDA the most abundant PFCs congeners in liver samples, detected in 65% and 47% of the samples, respectively. The measured levels of contaminants in the blood samples of Lepidochelys olivacea sea turtles were compared to the levels reported in the literature for other turtle species. While linear significant correlations between PFNA, PFDA and PFUnA concentrations in blood samples and curved carapace lengths were determined, no correlation was found for PFOA, supporting the hypothesis that sea turtles could have a higher ability to eliminate this perfluorinated chemical from their blood than other PFCAs. However, we do not know if the concentrations are species or sampling areas dependent.

Spatial distribution of floating marine debris in offshore continental Portuguese waters

This study presents data on abundance and density of macro-floating marine debris (FMD), including their composition, spatial distribution and potential sources off continental Portugal. FMD were assessed by shipboard visual surveys covering ±252,833 km(2) until the 220 nm limit. The FMD average density was 2.98 items/km(2) and abundance amounted to 752,740 items. Unidentified plastics constitute the major bulk of FMD (density=0.46 items/km(2); abundance=117,390 items), followed by styrofoam, derelict or lost materials from fisheries, paper/cardboard and wood material. The North sector of the area presents higher FMD diversity and abundances, probably as a result of the high number of navigation corridors and fisheries operating in that sector. Most FMD originate from local sources, namely discharges from vessels and derelict material from fisheries. Considering the identifiable items, cables and fishing lines were the only fishing related items among the top ten FMD items in Portuguese offshore waters.

Pilot study on levels of chemical contaminants and porphyrins in Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), synthetic musks compounds (SMCs), bisphenol A (BPA), para-nonylphenol (p-NP) and polybrominated diphenyl ethers (PBDEs) are known for their toxicity and ability to interfere with the endocrine system. The aim of this study was to determine levels and distribution of the above mentioned compounds in liver samples of Caretta caretta and levels of porphyrins that have been proposed as sensitive biomarkers of exposure to contaminants. This paper reports the results for 9 specimens yet analysed. Musk ketone was never detected, PFOA was found in one sample, while PFOS was the prevalent contaminant. For PFCs the levels are lower than the results of studies of comparison. The porphyrins profile showed a predominance of protoporphyrins on coproporphyrins and uroporphyrins, with a positive statistical correlation between levels of PFOS and uroporphyrins. These data represent, for several parameters, the first evidence of contaminant levels and biomarker responses in loggerhead turtles.

Monitoring the impact of litter in large vertebrates in the Mediterranean Sea within the European Marine Strategy Framework Directive (MSFD): constraints, specificities and recommendations

In its decision (2010/477/EU) relating to the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), the European Commission identified the following points as focuses for monitoring: (i) 10.1.1: Trends in the amount, source and composition of litter washed ashore and/or deposited on coastlines, (ii) 10.1.2: Trends in the amount and composition of litter in the water column and accumulation on the sea floor, (iii) 10.1.3: Trends in the amount, distribution and composition of micro-particles (mainly microplastics), and (iv) 10.2.1: Trends in the amount and composition of litter ingested by marine animals. Monitoring the impacts of litter will be considered further in 2014. At that time, the strategy will be discussed in the context of the Mediterranean Sea, providing information on constraints, protocols, existing harm and research needed to support monitoring efforts. The definition of targets and acceptable levels of harm must take all factors into account, whether entanglement, ingestion, the transport and release of pollutants, the transport of alien species and socio-economic impacts. It must also reflect on the practical deployment of "ingestion" measures (10.2.1). The analysis of existing data will reveal the potential and suitability of some higher trophic level organisms (fish, turtles, birds and mammals) for monitoring the adverse effects of litter. Sea turtles appear to be useful indicator species, but the definition of an ecological quality objective is still needed, as well as research on alternative potential indicator species.

Interaction between loggerhead sea turtles (Caretta caretta) and marine litter in Sardinia (Western Mediterranean Sea)

Anthropogenic debris in the environment affects many species that accidentally ingest it. The aim of this study is to evaluate the quantity and composition of marine litter ingested by loggerheads in Sardinia, thus supplying for the lack of data in the existing literature for this area. Seventeen of the 121 (14.04%) monitored turtles presented debris in their digestive tracts. Litter in faecal pellet of alive individuals (n = 91) and in gastro-intestinal contents of dead ones (n = 30) was categorized, counted and weighed. User plastic was the main category of ingested debris with a frequency of occurrence of 13.22% of the total sample, while sheet (12.39%) and fragments (9.09%) were the most relevant sub-categories. This study highlights for the first time the incidence of litter in alive turtles in Sardinia. This contribution improves the knowledge about marine litter interaction on Caretta caretta as bio-indicator. Results will be useful for the Marine Strategy implementation.

Using a multibiomarker approach and behavioural responses to assess the effects of anthracene in Palaemon serratus

Polycyclic aromatic hydrocarbons (PAHs) are recognised as one of the main groups of contaminants that assume more importance in the marine environment, enhancing the need of studies concerning their adverse effects and more efficient and ecologically relevant tools for environmental monitoring purposes. This study aims to apply an integrated approach including several multi-level biological responses (accumulation levels, biochemical responses important for different physiological functions and behavioural alterations) to assess the ecological relevance of the effects induced by sub-lethal concentrations of anthracene (ANT) in Palaemon serratus (common prawn). ANT accumulation was assessed by measuring the levels of ANT-type compounds in prawn digestive gland, muscle and eye; biochemical responses were determined using biomarkers involved in biotransformation, oxidative damage, energy production and neurotransmission processes; and behavioural alterations through swimming performance after 96 h exposure bioassay (ANT:16-1,024 μg/L). The rationale behind this approach is to assess the ecologically relevant effects induced by ANT in prawn, given by the association between behavioural alterations with biochemical responses, in search for more efficient tools for environmental risk assessment. Results show a significant decrease of swimming velocity (LOEC=128 μg/L) along with increased levels of ANT-type compounds in digestive gland (LOEC=128 μg/L), muscle (LOEC=256 μg/L) and eye (LOEC=32 μg/L) in prawn exposed to ANT. Increased activities of glutathione peroxidase (GPx) and catalase (CAT), involved in anti-oxidant defence system, were also observed (LOEC=256 μg/L; 1024μg/L, respectively) in the digestive gland of prawn, induction of oxidative damage in lipids (LPO) also occurred (LOEC=32 μg/L). The inhibition of swimming velocity showed a correlation with some biochemical parameters measured, including the levels of ANT-type compounds in tissues and LPO, and thus these may be considered sensitive and ecologically relevant criteria as well as early warning endpoints for assessing polycyclic aromatic compounds exposure effects on marine organisms.

Searching for the true diet of marine predators: incorporating Bayesian priors into stable isotope mixing models

Reconstructing the diet of top marine predators is of great significance in several key areas of applied ecology, requiring accurate estimation of their true diet. However, from conventional stomach content analysis to recent stable isotope and DNA analyses, no one method is bias or error free. Here, we evaluated the accuracy of recent methods to estimate the actual proportion of a controlled diet fed to a top-predator seabird, the Little penguin (Eudyptula minor). We combined published DNA data of penguins scats with blood plasma δ¹⁵N and δ¹³C values to reconstruct the diet of individual penguins fed experimentally. Mismatch between controlled (true) ingested diet and dietary estimates obtained through the separately use of stable isotope and DNA data suggested some degree of differences in prey assimilation (stable isotope) and digestion rates (DNA analysis). In contrast, combined posterior isotope mixing model with DNA Bayesian priors provided the closest match to the true diet. We provided the first evidence suggesting that the combined use of these complementary techniques may provide better estimates of the actual diet of top marine predators- a powerful tool in applied ecology in the search for the true consumed diet.

Plastic litter in the sea

On June 2013 a workshop at the University of Siena (Italy) was organized to review current knowledge and to clarify what is known, and what remains to be investigated, concerning plastic litter in the sea. The content of the workshop was designed to contribute further to the European Marine Strategy Framework Directive (MSFD) following an inaugural workshop in 2012. Here we report a number of statements relevant to policymakers and scientists that was overwhelming agreement from the participants. Many might view this as already providing sufficient grounds for policy action. At the very least, this early warning of the problems that lie ahead should be taken seriously, and serve as a stimulus for further research.

Involvement of the antioxidant system in differential sensitivity of Carcinus maenas to fenitrothion exposure

Carcinus maenas is an invertebrate with worldwide distribution and high ability to adapt to different environments, which is frequently used in environmental monitoring. Despite this, it is not clear how historical exposure to moderate contamination may influence sensitivity to further chemical stress in this important decapod species. This study investigated differential responses to organophosphate fenitrothion of C. maenas from a moderately contaminated estuary and a low impacted one, using in vitro and in vivo biomarker assays. To clarify potential differences in sensitivity, a biochemical characterisation of muscle cholinesterases was first performed. The results indicated acetylcholinesterase (AChE) as the main form present in C. maenas muscle. Exposure assays revealed that crabs from the moderately contaminated site were less sensitive to fenitrothion showing lower AChE inhibition than those from the low impacted site. Other biomarker changes detected in these animals were: increased anaerobic metabolism (muscle lactate dehydrogenase), enhanced phase II biotransformation (glutathione S-transferases in the digestive gland) and antioxidant defences (i.e., activities of glutathione reductase, glutathione peroxidase and catalase, and levels of total glutathiones in the digestive gland). Altogether, the results pointed out a role for the glutathione redox system towards tolerance to fenitrothion exposure.

Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found.

Changing views of the interconnections between the oceans and human health in Europe

Early steps in the emergence of the discipline of "Oceans and Human Health" are charted in the USA and discussed in relation to past and present marine environment and human health research activities in Europe. Differences in terminology are considered, as well as differences in circumstances related to the various seas of Europe and the intensity of human coastal activity and impact. Opportunities to progress interdisciplinary research are described, and the value of horizon scanning for the early identification of emerging issues is highlighted. The challenges facing researchers and policymakers addressing oceans and human health issues are outlined and some suggestions offered regarding how further progress in research and training into both the risks and benefits of Oceans and Human Health might be made on both sides of the Atlantic.

Overcoming the challenges of studying conservation physiology in large whales: a review of available methods

Large whales are subjected to a variety of conservation pressures that could be better monitored and managed if physiological information could be gathered readily from free-swimming whales. However, traditional approaches to studying physiology have been impractical for large whales, because there is no routine method for capture of the largest species and there is presently no practical method of obtaining blood samples from free-swimming whales. We review the currently available techniques for gathering physiological information on large whales using a variety of non-lethal and minimally invasive (or non-invasive) sample matrices. We focus on methods that should produce information relevant to conservation physiology, e.g. measures relevant to stress physiology, reproductive status, nutritional status, immune response, health, and disease. The following four types of samples are discussed: faecal samples, respiratory samples ('blow'), skin/blubber samples, and photographs. Faecal samples have historically been used for diet analysis but increasingly are also used for hormonal analyses, as well as for assessment of exposure to toxins, pollutants, and parasites. Blow samples contain many hormones as well as respiratory microbes, a diverse array of metabolites, and a variety of immune-related substances. Biopsy dart samples are widely used for genetic, contaminant, and fatty-acid analyses and are now being used for endocrine studies along with proteomic and transcriptomic approaches. Photographic analyses have benefited from recently developed quantitative techniques allowing assessment of skin condition, ectoparasite load, and nutritional status, along with wounds and scars from ship strikes and fishing gear entanglement. Field application of these techniques has the potential to improve our understanding of the physiology of large whales greatly, better enabling assessment of the relative impacts of many anthropogenic and ecological pressures.