Mercury and selenium status of bottlenose dolphins ( Tursiops truncatus ): A study in stranded animals on the Canary Islands

García‐Álvarez, Natalia; Fernández, Antonio; Boada, Luís D.; Zumbado, Manuel; Zaccaroni, Annalisa; Arbelo, Manuel; Sierra, Eva; Almunia, Javier; Luzardo, Octavio P.

doi:10.1016/j.scitotenv.2015.07.040

Cited by 30 publications

(9 citation statements)

References 74 publications

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“…It has long been recognized that deceased, stranded bottlenose dolphins from U.S. coastal waters contain high levels of Hg in skin, liver, kidney and muscle [ 9 , 10 , 11 , 12 , 13 ]. Similar observations have been made in coastal dolphins of various species in other hemispheres [ 14 , 15 , 16 , 17 ]. However, relatively few studies have measured Hg in healthy, free-ranging individuals.…”

Section: Mercury Bioaccumulation In Dolphinssupporting

confidence: 85%

Atlantic Bottlenose Dolphins (Tursiops truncatus) as A Sentinel for Exposure to Mercury in Humans: Closing the Loop

Reif

Schaefer

Bossart

2015

Veterinary Sciences

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Mercury (Hg) is a ubiquitous global contaminant with important public health implications. Mercury is released from a variety of anthropogenic, industrial processes, enters the earth's atmosphere and is re-deposited onto the earth’s surface in rainfall. Much of this Hg enters the oceans which cover the majority of the earth’s surface. In the marine environment, inorganic Hg is converted to the most toxic form of the element, methylmercury, and biomagnified through the trophic levels of the food web. The bottlenose dolphin (Tursiops truncatus) is the apex predator in many estuarine and coastal ecosystems. Due to their long life span and trophic position, bottlenose dolphins bioaccumulate high concentrations of contaminants including Hg, thus making them an important sentinel species for ecosystem and public health. Bottlenose dolphins in Florida bioaccumulate high concentrations of Hg in their blood, skin and internal organs. The concentrations of Hg in blood and skin of bottlenose dolphins of the Indian River Lagoon, FL (IRL) are among the highest reported world-wide. In previous studies, we demonstrated associations between concentrations of total Hg in the blood and skin of IRL dolphins and markers of endocrine, renal, hepatic, hematologic and immune system dysfunction. The predominant manifestation of exposure to mercury in humans is neurotoxicity. During the 1950s and 1960s, residents of Minamata bay, Japan were exposed to high concentrations of methyl mercury as the result of ingestion of fish and shellfish that had become contaminated in this infamous environmental disaster. Affected adults had severe motor and sensory abnormalities often leading to death. Methyl mercury crosses the placenta during pregnancy. Children exposed in utero were born with multiple congenital anomalies and also suffered from neurologic disorders. Significantly, local cats that consumed Hg contaminated fish developed severe signs of neurotoxicity which led to their subsequent description as the “dancing cats of Minamata bay”. Unfortunately, the cause of these strange manifestations in cats was not recognized in time to prevent hundreds of additional cases from occurring. More recent studies have shown that exposure to mercury as a result of seafood consumption during pregnancy may result in multiple cognitive and neurodevelopmental effects in children. The levels of mercury found in bottlenose dolphins and the health effects we identified alerted us to the possibility of an important public health hazard. The IRL occupies 40 percent of the east coast of Florida and is bordered by counties with approximately 2.5 million human inhabitants. Therefore, we hypothesized that local inhabitants in communities bordering the IRL could be at risk of exposure to Hg from the consumption of fish and shellfish. We measured hair Hg in 135 local residents and found a mean concentration of 1.53 µg/g which was higher than that from previous studies of sport fishermen and coastal residents in other states. Over 50% of participants had a hair Hg concen...

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Section: Mercury Bioaccumulation In Dolphinssupporting

confidence: 85%

Atlantic Bottlenose Dolphins (Tursiops truncatus) as A Sentinel for Exposure to Mercury in Humans: Closing the Loop

Reif

Schaefer

Bossart

2015

Veterinary Sciences

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“…A few animals included in this study had known high levels of certain pollutants per parallel studies, e.g. heavy metals in dolphins stranded in Italy, and elevated blubber and hepatic levels of polychlorinated biphenyls, organochlorides pesticides, polycyclic aromatic hydrocarbons, persistent organic pollutants, mercury, and selenium in dolphins stranded in the Canary Islands [58,59]. Future studies on CeMV may benefit from integrative eco-toxico-pathologic analyses with individual and population level emphasis [60].…”

Section: Discussionmentioning

confidence: 99%

Comparative histopathologic and viral immunohistochemical studies on CeMV infection among Western Mediterranean, Northeast-Central, and Southwestern Atlantic cetaceans

et al. 2019

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Cetacean morbillivirus (CeMV) is a major natural cause of morbidity and mortality in cetaceans worldwide and results in epidemic and endemic fatalities. The pathogenesis of CeMV has not been fully elucidated, and questions remain regarding tissue tropism and the mechanisms of immunosuppression. We compared the histopathologic and viral immunohistochemical features in molecularly confirmed CeMV-infected Guiana dolphins (Sotalia guianensis) from the Southwestern Atlantic (Brazil) and striped dolphins (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus) from the Northeast-Central Atlantic (Canary Islands, Spain) and the Western Mediterranean Sea (Italy). Major emphasis was placed on the central nervous system (CNS), including neuroanatomical distribution of lesions, and the lymphoid system and lung were also examined. Eleven Guiana dolphins, 13 striped dolphins, and 3 bottlenose dolphins were selected by defined criteria. CeMV infections showed a remarkable neurotropism in striped dolphins and bottlenose dolphins, while this was a rare feature in CeMV-infected Guiana dolphins. Neuroanatomical distribution of lesions in dolphins stranded in the Canary Islands revealed a consistent involvement of the cerebrum, thalamus, and cerebellum, followed by caudal brainstem and spinal cord. In most cases, Guiana dolphins had more severe lung lesions. The lymphoid system was involved in all three species, with consistent lymphoid depletion. Multinucleate giant cells/syncytia and characteristic viral inclusion bodies were variably observed in these organs. Overall, there was widespread lymphohistiocytic, epithelial, and neuronal/neuroglial viral antigen immunolabeling with some individual, host species, and CeMV strain differences. Preexisting and opportunistic infections were common, particularly endoparasitism, followed by bacterial, fungal, and viral infections. These results contribute to understanding CeMV infections in susceptible cetacean hosts in relation to factors such as CeMV strains and geographic locations, thereby establishing the basis for future neuro- and immunopathological comparative investigations.

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“…Although the waters of the Canary Islands are considered a hotspot for marine biodiversity, for cetaceans in particular, this does not exempt marine mammals from being subjected to pressure and threats. Some of these threats are due to natural causes, such as predation, but, for the most part, they are consequences of direct or indirect anthropogenic activities (Parsons, 2012), including by-catch, competition with fisheries, habitat degradation (Ruíz de la Rosa et al, 2015), marine pollution (Baulch and Perry, 2014;García-Álvarez et al, 2014García-Álvarez et al, , 2015Puig-Lozano et al, 2018), acoustic/ noise disturbance (Aguilar de Soto, 2006;OSPAR, 2009), stranding (Tejedor and Carrillo, 2018;Puig-Lozano et al, 2020), and maritime traffic, including high-speed ferries-nearly 60% of sperm whale deaths are due to ship collisions in the Canaries (Arregui et al, 2019). These marine mammals are a highly mobile species; their distribution areas cover extensive oceanic areas, which pose a major challenge for their conservation.…”

Section: Introductionmentioning

confidence: 99%

Distribution of Cetaceans in the Canary Islands (Northeast Atlantic Ocean): Implications for the Natura 2000 Network and Future Conservation Measures

et al. 2021

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The waters of the Canary Islands are considered a hotspot for marine biodiversity, especially regarding cetacean species. Based on this fact, this study pays attention to the spatial distribution pattern of cetacean species and the conservation role of the Natura 2000 Network, a set of Special Areas of Conservation (SACs), which were defined mainly based on data compiled in 1996, under the framework of the European Habitats Directive. In recent years, the declaration of conservation areas for cetaceans between the Tenerife—La Gomera Islands by two global conservation programs, Mission Blue (“Hope Spots”) and Whale Heritage Site (“Whale Sanctuary”) sent clear signals of scientific and social interest to promote better protection of the cetacean species in the Canary Islands. The main aim of the designated SACs is the conservation of its biological and ecological diversity, ensuring the long-term survival of the target species in the waters around islands. In this case, the enactment of the SACs was based only on the sparse data available for the common bottlenose dolphin, Tursiops truncatus. This study shows that the spatial distribution of cetaceans in the Canary archipelago generated from a large database of cetacean sightings, from 2007 to 2018. The results obtained show the main marine areas where the different cetacean species are distributed around the different islands of the archipelago. The spatial distribution maps of the cetacean species, when compared with the existing SACs of the Natura 2000, show the need to extend these SACs into the open sea to include more cetacean species and a larger number of individuals for better conservation of the endangered marine mammals. As a consequence, some suggestions were proposed to improve and update the role of SACs in European Northeast Atlantic waters as a key environmental tool for cetacean conservation. The data supporting the recent declarations of these two new milestones the “Hope Spot” and the “Whale Sanctuary” enhance more keystone information to promote a large marine protected area in the Eastern Atlantic Ocean, such as the “Macaronesian Biodiversity and Ecological Migration Corridor for Cetaceans,” a conservation figure that has been already proposed in the scientific literature as a deserving candidate of governmental regulations and policies by Portugal and Spain; it would also require joint cross-border cooperation efforts for marine spatial planning.

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Mercury and selenium status of bottlenose dolphins ( Tursiops truncatus ): A study in stranded animals on the Canary Islands

Cited by 30 publications

References 74 publications

Atlantic Bottlenose Dolphins (Tursiops truncatus) as A Sentinel for Exposure to Mercury in Humans: Closing the Loop

Atlantic Bottlenose Dolphins (Tursiops truncatus) as A Sentinel for Exposure to Mercury in Humans: Closing the Loop

Comparative histopathologic and viral immunohistochemical studies on CeMV infection among Western Mediterranean, Northeast-Central, and Southwestern Atlantic cetaceans

Distribution of Cetaceans in the Canary Islands (Northeast Atlantic Ocean): Implications for the Natura 2000 Network and Future Conservation Measures

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