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Naccari C, Ferrantelli V, Cammilleri G, Galluzzo FG, Macaluso A, Riolo P, Lo Dico GM, Bava R, Palma E. Metal Levels in Striped Dolphins ( Stenella coeruleoalba) and Common Dolphins ( Delphinus delphis) Stranded along the Sicilian Coastlines of the Mediterranean Sea. Animals (Basel) 2024; 14:2063. [PMID: 39061525 DOI: 10.3390/ani14142063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/02/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Dolphins, top predators of the aquatic food chain, are used as sentinel species of marine pollution as they are sensitive to environmental changes and able to accumulate a large content of contaminants. Several EU directives promote study of marine mammalians as bio-indicators to evaluate the presence of contaminants in the aquatic environment, such as the Mediterranean Sea, which is rich in environmental pollutants due to its geographic and geo-morphological characteristics. The aim of this study was to evaluate the content of toxic and essential metals and metalloids (Hg, Pb, Cd, As, Se and Zn), through ICP-MS analysis, in organs/tissues (liver, muscle, lung, kidney and skin) of striped dolphins (Stenella coeruleoalba) and common dolphins (Delphinus delphis) stranded along the Sicilian coastlines of the Mediterranean Sea. The results confirm the exposure of dolphins to toxic metals and metalloids, with the highest Hg levels observed in skin and liver, although a low Metal Pollution Index (MPI) was found in all samples of both dolphin species. From a comparative analysis of trace metals and metalloids according to sex and state of development, the highest levels of Cd and As were found in females vs. males and adults vs. juveniles, except for Pb in both species, and significant differences were observed between the two species, size of specimens, and organs/tissues analyzed. The highest Hg levels were correlated to those of essential metals Se and Zn, expressed as molar ratios, to evaluate the potential synergic effect of these detoxifying elements against Hg toxicity. This study confirms the rule of Stenella coeruleoalba and Delphinus delphis as valid sentinel species of the Mediterranean Sea, to verify the trend of metals pollution in this aquatic environment and, consequently, the health of these marine species.
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Affiliation(s)
- Clara Naccari
- Department of Health Sciences, University "Magna Græcia" of Catanzaro, 88100 Catanzaro, Italy
| | - Vincenzo Ferrantelli
- Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", 90129 Palermo, Italy
| | - Gaetano Cammilleri
- Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", 90129 Palermo, Italy
| | | | - Andrea Macaluso
- Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", 90129 Palermo, Italy
| | - Pietro Riolo
- Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", 90129 Palermo, Italy
| | | | - Roberto Bava
- Department of Health Sciences, University "Magna Græcia" of Catanzaro, 88100 Catanzaro, Italy
| | - Ernesto Palma
- Department of Health Sciences, University "Magna Græcia" of Catanzaro, 88100 Catanzaro, Italy
- Interdepartmental Service Center-Center for Pharmacological Research, Food Safety, High Tech and Health (CIS-IRC-FSH) University "Magna Græcia" of Catanzaro, 88100 Catanzaro, Italy
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Malcolm EG, Coleman SE, Smith EM, Cooke ME, Rice Jeff H, Ellick RM, Volker KM. The potential use of skin and liver as biomarkers to estimate mercury in the brain, kidney, and muscle of bottlenose dolphins (Tursiops truncatus). MARINE POLLUTION BULLETIN 2023; 191:114903. [PMID: 37062130 DOI: 10.1016/j.marpolbul.2023.114903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 05/13/2023]
Abstract
For marine cetaceans, Hg biomagnification can negatively affect neurological, hepatic, renal, and immune functions. To evaluate the use of biomarkers for Hg in dolphins, multiple tissues were analyzed from 127 stranded common bottlenose dolphins (Tursiops truncatus) from the estuarine and oceanic waters of Virginia, USA. Twenty-two percent of liver Hg concentrations exceeded the published observed effect level for liver abnormalities, and 26 % of cerebrum samples exceeded the published threshold for neurochemical changes, suggesting that Hg may have impacted dolphin health. Mercury tissue levels were similar to or lower than those reported from other locations (liver range: 1.4-943 μg/g-dw). Significant correlations were found between tissue types, indicating that skin or liver can be used as a biomarker to estimate the total Hg concentrations in the other tissue types (kidney, liver, cerebrum, cerebellum, pons). This is the first study to measure Hg concentrations in multiple brain regions of T. truncatus.
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Affiliation(s)
- Elizabeth G Malcolm
- Department of Earth and Environmental Sciences, Virginia Wesleyan University, Virginia Beach, VA, USA.
| | - Sherie E Coleman
- Department of Earth and Environmental Sciences, Virginia Wesleyan University, Virginia Beach, VA, USA
| | - Erin M Smith
- Department of Earth and Environmental Sciences, Virginia Wesleyan University, Virginia Beach, VA, USA
| | - Matthew E Cooke
- Department of Earth and Environmental Sciences, Virginia Wesleyan University, Virginia Beach, VA, USA
| | - Hannah Rice Jeff
- Department of Earth and Environmental Sciences, Virginia Wesleyan University, Virginia Beach, VA, USA
| | - Rachel M Ellick
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - Kristen M Volker
- Virginia Aquarium & Marine Science Center, Virginia Beach, VA, USA
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McCormack MA, Jackson BP, Dutton J. Relationship between mercury and selenium concentrations in tissues from stranded odontocetes in the northern Gulf of Mexico. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:141350. [PMID: 33370896 DOI: 10.1016/j.scitotenv.2020.141350] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/13/2020] [Accepted: 07/27/2020] [Indexed: 06/12/2023]
Abstract
Odontocetes are apex predators that, despite accumulating mercury (Hg) to high concentrations in their tissues, show few signs of Hg toxicity. One method of Hg detoxification in odontocetes includes the sequestering of Hg in toxicologically inert mercury selenide (HgSe) compounds. To explore the tissue-specific accumulation of Hg and Se and the potential protective role of Se against Hg toxicity, we measured the concentrations of total mercury (THg) and selenium (Se) in multiple tissues from 11 species of odontocetes that stranded along the northern Gulf of Mexico coast [Florida (FL) and Louisiana (LA)]. Tissues were collected primarily from bottlenose dolphins (Tursiops truncatus; n = 93); however, individuals from species in the following 8 genera were also sampled: Feresa (n = 1), Globicephala (n = 1), Grampus (n = 2), Kogia (n = 5), Mesoplodon (n = 1), Peponocephala (n = 4), Stenella (n = 9), and Steno (n = 1). In all species, mean THg concentrations were greatest in the liver and lowest in the blubber, lung, or skin. In contrast, in most species, mean Se concentrations were greatest in the liver, lung, or skin, and lowest in the blubber. For all species combined, Se:Hg molar ratios decreased with increasing THg concentration in the blubber, kidney, liver, lung, and skin following an exponential decay relationship. In bottlenose dolphins, THg concentrations in the kidney, liver, and lung were significantly greater in FL dolphins compared to LA dolphins. On average, in bottlenose dolphins, Se:Hg molar ratios were approximately 1:1 in the liver and >1:1 in blubber, kidney, lung, and skin, suggesting that Se likely protects against Hg toxicity. However, more research is necessary to understand the variation in Hg accumulation within and among species and to assess how Hg, in combination with other environmental stressors, influences odontocete population health.
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Affiliation(s)
- Meaghan A McCormack
- Department of Biology, Texas State University, Aquatic Station, San Marcos, TX 78666, USA.
| | - Brian P Jackson
- Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, USA.
| | - Jessica Dutton
- Department of Biology, Texas State University, Aquatic Station, San Marcos, TX 78666, USA.
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López-Berenguer G, Peñalver J, Martínez-López E. A critical review about neurotoxic effects in marine mammals of mercury and other trace elements. CHEMOSPHERE 2020; 246:125688. [PMID: 31896013 DOI: 10.1016/j.chemosphere.2019.125688] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 05/26/2023]
Abstract
Marine mammals are more exposed to mercury (Hg) than any others animals in the world. As many trace elements, Hg it is able to impair the brain function, which could be a cause of population decline. Nevertheless, these issues have been scarcely studied because of the technical and ethical difficulties. We conducted a systematic review about marine mammals' brain exposition to Hg and other trace elements, and their neurotoxic effects. Information was scarce and the lack of standardization of nomenclature of brain structures, sample collecting and results presentation made it difficult to obtain conclusions. Hg was the most studied metal and toothed whales the most studied group. Despite being its target organ, brain accumulates lesser concentrations of Hg than other tissues as liver. We found a significant positive correlation between both organs' burden (rho = 0.956 for cetaceans; rho = 0.756 for pinnipeds). Reported Hg values in brain of cetaceans (median 3.00 ppm ww) surpassed by one or two orders of magnitude those values found in other species as pinnipeds (median 0.33 ppm ww) or polar bears (median 0.07 ppm ww). Such values exceeded neurotoxicity thresholds. Although marine mammals ingest mostly the organic and more toxic form MeHg, different fractions of inorganic mercury can appear in brain, which could suggest some detoxification mechanisms. Other suggested mechanisms include Se-Hg interaction and liver sequestration. Although other elements are subjected to a rigid homeostatic control, appear in low concentrations or do not exert an important neurotoxic effect, they should be more studied to elucidate their neurotoxicity potential.
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Affiliation(s)
- G López-Berenguer
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain
| | - J Peñalver
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain; Fisheries and Aquaculture Service (CARM), 30100, Murcia, Spain
| | - E Martínez-López
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain; Toxicology and Risk Assessment Group, Biomedical Research Institute of Murcia (IMIB-Arrixaca), University of Murcia, 30100, Murcia, Spain.
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Martínez-López E, Peñalver J, Lara L, García-Fernández AJ. Hg and Se in Organs of Three Cetacean Species from the Murcia Coastline (Mediterranean Sea). BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 103:521-527. [PMID: 31473774 DOI: 10.1007/s00128-019-02697-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
We determinated Hg and Se concentrations in liver, kidney, brain, lung and muscle of five bottlenose dolphin (Tursiops truncatus), four common dolphins (Delphinus delphis) and four Risso's dolphin (Grampus griseus) stranded along the Murcia coast, Southeast Spain, in order to evaluate the risk of Hg toxicity. Hg concentrations showed similar concentrations to other individuals in the Mediterranean Sea with the same length in the same period. We observed a positive correlation of Hg and Se in liver (r = 0.948, p < 0.001) and kidney (r = 0.939; p = 0.001) and ratio the Se/Hg molar was higher than 1 in most cases. Our results suggest that the protective effects of Se against Hg toxicity occur in cetaceans. However, we detected levels of Hg described as responsible liver damage and neurotoxicological effects so other tools, as biochemical markers, should be included. Besides, more studies are needed to evaluate the risk of Hg exposure in dolphins from Murcia coastline.
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Affiliation(s)
- E Martínez-López
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.
- Laboratory of Toxicology, Biomedical Research Institute of Murcia (IMIB-Arrixaca), University of Murcia, Murcia, Spain.
| | - J Peñalver
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
- Fisheries and Aquaculture Service (CARM), Murcia, Spain
| | - L Lara
- "El Valle" Wildlife Recovery Center (CARM), Murcia, Spain
| | - A J García-Fernández
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
- Laboratory of Toxicology, Biomedical Research Institute of Murcia (IMIB-Arrixaca), University of Murcia, Murcia, Spain
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