Mercury contamination in gull chicks raised in natural vs. urban habitats.

Anthropogenic activities have increased pressure on marine ecosystems through the continuous overflow of pollutants like mercury (Hg). Seabirds, particularly chicks, serve as effective local bioindicators of marine ecosystem health. This study assessed the influence of trophic ecology (inferred from δC and δN values) and colony location on Hg concentrations in the blood of yellow-legged (YLG, Larus michahellis) and Audouin's (AG, Ichthyaetus audouinii) gull chicks raised in natural (YLG, AG) vs.

The role of seabird foraging strategies on the uptake of mercury: A case study using gulls and shearwaters from the Portuguese coast.

Mercury (Hg) is a non-essential element that bioaccumulates and biomagnifies in food webs through site-specific biogeochemical processes. Seabirds are valuable bioindicators of Hg contamination, yet certain regions, like the Portuguese coast, remain underrepresented. This study measured Hg concentrations in the blood of yellow-legged gulls (Larus michahellis), Audouin's gulls (Ichthyaetus audouinii), and Cory's shearwaters (Calonectris borealis) breeding along the Portuguese coastline.

Mercury Accumulation and Transfer in Hydrothermal Coastal Environment: The Case of the Geothermal Plant of Bouillante.

Geothermal vents can constitute local significant sources of mercury (Hg) in the environment. The geothermal power plant of Bouillante (Guadeloupe, Lesser Antilles) artificially enhances the release of hydrothermal water in shallow areas of the bay. To assess the impact of this release on the Hg transfer in the environment, Hg concentrations were assessed in sediments, sulphur-oxidising bacteria and six animal species (urchin, sponges and fish) with various diets and trophic levels from the Bouillante Bay and a distant Control Site.

Seabirds reveal mercury distribution across the North Atlantic.

Mercury (Hg) is a heterogeneously distributed toxicant affecting wildlife and human health. Yet, the spatial distribution of Hg remains poorly documented, especially in food webs, even though this knowledge is essential to assess large-scale risk of toxicity for the biota and human populations. Here, we used seabirds to assess, at an unprecedented population and geographic magnitude and high resolution, the spatial distribution of Hg in North Atlantic marine food webs.

Spatial distribution of selenium-mercury in Arctic seabirds.

Mercury (Hg) is a metallic trace element toxic for humans and wildlife that can originate from natural and anthropic sources. Hg spatial gradients have been found in seabirds from the Arctic and other oceans, suggesting contrasting toxicity risks across regions. Selenium (Se) plays a protective role against Hg toxicity, but its spatial distribution has been much less investigated than that of Hg.

Mercury contamination in the tropical seabird community from Clipperton Island, eastern Pacific Ocean.

Mercury (Hg) pollution is a global problem affecting remote areas of the open ocean, but the bioaccumulation of this neurotoxic pollutant in tropical top predators remains poorly documented. The objective of this study was to determine Hg contamination of the seabird community nesting on Clipperton Island using blood and feathers to investigate short and longer-term contamination, respectively. We examined the significance of various factors (species, sex, feeding habitat [δC] and trophic position [δN]) on Hg concentrations in six seabird species.

Mercury contamination and potential health risks to Arctic seabirds and shorebirds.

Since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of mercury (Hg) on Arctic biota in 2011 and 2018, there has been a considerable number of new Arctic bird studies. This review article provides contemporary Hg exposure and potential health risk for 36 Arctic seabird and shorebird species, representing a larger portion of the Arctic than during previous AMAP assessments now also including parts of the Russian Arctic. To assess risk to birds, we used Hg toxicity benchmarks established for blood and converted to egg, liver, and feather tissues.

Relationships between stable isotopes and trace element concentrations in the crocodilian community of French Guiana.

Trace elements in the blood of crocodilians and the factors that influence their concentrations are overall poorly documented. However, determination of influencing factors is crucial to assess the relevance of caimans as bioindicators of environmental contamination, and potential toxicological impact of trace elements on these reptiles. In the present study, we determined the concentrations of 14 trace elements (Ag, As, Cd, Cr, Co, Cu, Fe, Hg, Pb, Mn, Ni, Se, V, and Zn) in the blood of four French Guiana caiman species (the Spectacled Caiman Caiman crocodilus [n = 34], the Black Caiman Melanosuchus niger [n = 25], the Dwarf Caiman Paleosuchus palpebrosus [n = 5] and the Smooth-fronted Caiman Paleosuchus trigonatus [n = 20]) from 8 different sites, and further investigated the influence of individual body size and stable isotopes as proxies of foraging habitat and trophic position on trace element concentrations.

Risk and benefit assessment of seafood consumption harvested from the Pertuis Charentais region of France.

Seafood is well recognized as a major source of Long Chain n-3 Polyunsaturated Fatty Acids (LC n-3 PUFA, especially ecosapentaenoic acid, i.e. EPA and docosaheaxaenoic acid, i.

Lead, mercury, and selenium alter physiological functions in wild caimans (Caiman crocodilus).

Environmental contaminants affect ecosystems worldwide and have deleterious effects on biota. Non-essential mercury (Hg) and lead (Pb) concentrations are well documented in some taxa and are described to cause multiple detrimental effects on human and wildlife. Additionally, essential selenium (Se) is known to be toxic at high concentrations but, at lower concentrations, Se can protect organisms against Hg toxicity.

Mercury in the tissues of five cephalopods species: First data on the nervous system.

Mercury (Hg), one of the elements most toxic to biota, accumulates within organisms throughout their lifespan and biomagnifies along trophic chain. Due to their key role in marine systems, cephalopods constitute a major vector of Hg in predators. Further, they grow rapidly and display complex behaviours, which can be altered by neurotoxic Hg.

Trophic and fitness correlates of mercury and organochlorine compound residues in egg-laying Antarctic petrels.

Understanding the drivers and effects of exposure to contaminants such as mercury (Hg) and organochlorine compounds (OCs) in Antarctic wildlife is still limited. Yet, Hg and OCs have known physiological and fitness effects in animals, with consequences on their populations. Here we measured total Hg (a proxy of methyl-Hg) in blood cells and feathers, and 12 OCs (seven polychlorinated biphenyls, PCBs, and five organochlorine pesticides, OCPs) in plasma of 30 breeding female Antarctic petrels Thalassoica antarctica from one of the largest colonies in Antarctica (Svarthamaren, Dronning Maud Land).

Foraging ecology drives mercury contamination in chick gulls from the English Channel.

Although mercury (Hg) occurs naturally, human activity is currently the greatest source of release and the ocean receives Hg inputs by rivers and atmospheric deposition. Seabirds including chicks serve as valuable bioindicators of Hg contamination, reflecting local contamination around the colony. This study investigates the ecological drivers (trophic position and foraging habitat) influencing Hg concentrations in blood and feathers of chicks of three sympatric marine gull species.

Patterns of mercury exposure and relationships with isotopes and markers of oxidative status in chicks of a Mediterranean seabird.

The Mediterranean basin is a hotspot of mercury (Hg) contamination owing to intense anthropogenic emissions, volcanic activity and oligotrophic conditions. Little work has been done to assess the sources of Hg exposure for seabirds and, particularly, the physiological consequences of Hg bioaccumulation. In this study, we (i) describe the individual and temporal variation in blood concentration of total Hg (THg) over three breeding seasons, (ii) identify the factors that affect the THg exposure and (iii) determine the individual- and population-level connections between THg and blood-based markers of oxidative status in chicks of Scopoli's shearwaters (Calonectris diomedea) breeding on the island of Linosa in the southern Mediterranean.

Mercury exposure and short-term consequences on physiology and reproduction in Antarctic petrels.

Mercury (Hg) is a pervasive contaminant reaching Antarctic environments through atmospheric transport and deposition. Seabirds as meso to top predators can accumulate high quantities of Hg through diet. Reproduction is one of the most sensitive endpoints of Hg toxicity in marine birds.

Large-scale geographic patterns of mercury contamination in Morocco revealed by freshwater turtles.

Mercury (Hg) is a toxic contaminant present in most aquatic ecosystems. High concentrations pose serious threats to organisms and to human health. Because previous studies focused on few countries, environmental hazard due to Hg contamination remains obscure in many geographic areas, and for example limited information is available in North Africa.

From Antarctica to the subtropics: Contrasted geographical concentrations of selenium, mercury, and persistent organic pollutants in skua chicks (Catharacta spp.).

Seabirds integrate bioaccumulative contaminants via food intake and have revealed geographical trends of contamination in a variety of ecosystems. Pre-fledging seabird chicks are particularly interesting as bioindicators of chemical contamination, because concentrations in their tissues reflect primarily dietary sources from the local environment. Here we measured 14 trace elements and 18 persistent organic pollutants (POPs) in blood of chicks of skuas that breed in four sites encompassing a large latitudinal range within the southern Indian Ocean, from Antarctica (Adélie Land, south polar skua Catharacta maccormicki), through subantarctic areas (Crozet and Kerguelen Islands, brown skua C.

Mercury exposure in a large subantarctic avian community.

Mercury (Hg) contamination poses potential threats to ecosystems worldwide. In order to study Hg bioavailability in the poorly documented southern Indian Ocean, Hg exposure was investigated in the large avian community of Kerguelen Islands. Adults of 27 species (480 individuals) showed a wide range of feather Hg concentrations, from 0.