@article{fdi:010079505,
  title = {{M}ercury isotopes as tracers of ecology and metabolism in two sympatric shark species},
  author = {{L}e {C}roizier, {G}a{\¨e}l and {L}orrain, {A}nne and {S}onke, {J}. {E}. and {J}aquemet, {S}. and {S}chaal, {G}. and {R}enedo, {M}. and {B}esnard, {L}. and {C}herel, {Y}. and {P}oint, {D}avid},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n coastal ecosystems, top predators are exposed to a wide variety of nutrient and contaminant sources due to the diversity of trophic webs within inshore marine habitats. {M}ercury contamination could represent an additional threat to shark populations that are declining worldwide. {H}ere we measured total mercury, carbon and nitrogen isotopes, as well as mercury isotopes, in two co-occurring shark species (the bull shark {C}archarhinus leucas and the tiger shark {G}aleocerdo cuvier) and their potential prey from a coastal ecosystem of the western {I}ndian {O}cean ({L}a {R}eunion {I}sland). {O}ur primary goals were to (i) determine the main trophic {H}g sources for sharks and (ii) better characterize their diet composition and foraging habitat. {H}g isotope signatures ({D}elta {H}g-199 and delta {H}g-202) of shark prey suggested that bull sharks were exposed to methylmercury ({M}e{H}g) produced in offshore epipelagic waters, while tiger sharks were exposed to offshore mesopelagic {M}e{H}g with additional microbial transformation in slope sediments. {D}elta {H}g-199 values efficiently traced the ecology of the two predators, demonstrating that bull sharks targeted coastal prey in shallow waters while tiger sharks were mainly foraging on mesopelagic species in the deeper waters of the island slope. {U}nexpectedly, we found a positive shift in delta {H}g-202 (>1 parts per thousand) between sharks and their prey, leading to high delta {H}g-202 values in the two shark species (e.g. 1.91 +/- 0.52 parts per thousand in bull sharks). {T}his large shift in delta {H}g-202 {H}g indicates that sharks may display strong {M}e{H}g demethylation abilities, possibly reflecting evolutionary pathways for mitigating their {M}e{H}g contamination.},
  keywords = {{OCEAN} {INDIEN} ; {REUNION}},
  booktitle = {},
  journal = {{E}nvironmental {P}ollution},
  volume = {265},
  numero = {{B}},
  pages = {114931 [11 ]},
  ISSN = {0269-7491},
  year = {2020},
  DOI = {10.1016/j.envpol.2020.114931},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079505},
}