FN Archimer Export Format
PT J
TI Trophic resources and mercury exposure of two silvertip shark populations in the northeast Pacific Ocean
BT 
AF Le Croizier, Gaël
   Lorrain, Anne
   Schaal, Gauthier
   Ketchum, James
   Hoyos-Padilla, Mauricio
   Besnard, Lucien
   MUNARON, Jean-Marie
   LE LOCH, Francois
   Point, David
AS 1:1,2;2:2;3:2;4:3,4;5:3,4,5;6:2;7:2;8:2;9:1;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;
C1 Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées (OMP), UMR 5563 CNRS/IRD/Université Paul Sabatier, 14 Avenue Edouard Belin, 31400, Toulouse, France
   Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
   Pelagios Kakunjá A.C., Sinaloa 1540, Las Garzas, 23070, La Paz, Baja California Sur, Mexico
   Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, Baja California Sur, 23096, Mexico
   Fins Attached Marine Conservation, Colorado Springs, USA
C2 OBSERV MIDI PYRENEES, FRANCE
   IRD, FRANCE
   PELAGIOS KAKUNJA A.C., MEXICO
   CIBNOR, MEXICO
   FINS ATTACHED MARINE CONSERVATION, USA
UM LEMAR
IN WOS Cotutelle UMR
   copubli-france
   copubli-int-hors-europe
   copubli-sud
IF 7.086
TC 10
UR https://archimer.ifremer.fr/doc/00619/73114/72257.pdf
LA English
DT Article
DE ;Top-predators;Mercury transfer;Food webs;Foraging habitat;Stable isotopes;MPAs
AB Worldwide shark populations have experienced rapid declines over the last decades, mainly due to overfishing. Marine protected areas (MPAs) have thus become an indispensable tool for the protection of these marine predators. Two recently-created MPAs in the Northeast Pacific Ocean, the Revillagigedo National Park and Clipperton atoll, are characterized by different trophic structures potentially influencing trophic niche and contaminant exposure for resident sharks in these two sites. In this context, we used carbon (δ13C) and nitrogen (δ15N) stable isotope analyzes as well as total mercury concentrations ([THg]) to assess the role of foraging site on the trophic niche and Hg levels of juvenile ST sharks Carcharhinus albimarginatus. Analyzing fin clip samples from both Revillagigedo and Clipperton, we found that shark δ15N varied spatially in relation to δ15N baselines, suggesting similar trophic position in both MPAs. Moreover, δ13C values indicated that ST sharks from Revillagigedo would feed on different food webs (i.e. both benthic and pelagic) while individuals from Clipperton would only rely on benthic food webs. These differences between MPAs led to a weak overlap of isotopic niche between the two populations, highlighting site residency for juvenile ST sharks. Within populations, [THg] was not correlated to trophic tracers (δ15N and δ13C) and was also similar between populations. This study revealed no influence of site or food web in [THg] and raises the question of the origin of Hg exposure for reef shark populations in the Northeast Pacific Ocean. 
PY 2020
PD AUG
SO Chemosphere
SN 0045-6535
PU Elsevier BV
VL 253
UT 000536175700027
DI 10.1016/j.chemosphere.2020.126645
ID 73114
ER

EF