title: Bioaccumulation of (63)Ni in the scleractinian coral Stylophora pistillata and isolated Symbiodinium using radiotracer techniques.
abstract: Development of nickel mining activities along the New Caledonia coasts threatens the biodiversity of coral reefs. Although the validation of tropical marine organisms as bioindicators of metal mining contamination has received much attention in the literature over the last decade, few studies have examined the potential of corals, the fundamental organisms of coral reefs, to monitor nickel (Ni) contamination in tropical marine ecosystems. In an effort to bridge this gap, the present work investigated the bioaccumulation of (63)Ni in the scleractinian coral Stylophora pistillata and in its isolated zooxanthellae Symbiodinium, using radiotracer techniques. Results highlight the high capacities of coral tissues (zooxanthellae and host tissues) to efficiently bioconcentrate (63)Ni compared to skeleton (Concentration Factors CF at 14 days of exposure are 3 orders of magnitude higher in tissues than in skeleton). When non-contaminated conditions were restored, (63)Ni was more efficiently retained in skeleton than in coral tissues, with biological half-lives (Tb½) of 44.3 and 6.5 days, respectively. In addition, our work showed that Symbiodinium bioconcentrated (63)Ni exponentially, with a vol/vol concentration factor at steady state (VCFSS) reaching 14,056. However, compilation of our results highlighted that despite efficient bioconcentration of (63)Ni in Symbiodinium, their contribution to the whole (63)Ni accumulation in coral nubbins represents less than 7%, suggesting that other biologically controlled processes occur in coral host allowing such efficient bioconcentration in coral tissues.
authors.affiliation: International Atomic Energy Agency - Environment Laboratories (IAEA-EL), 4a Quai Antoine 1er, MC-98000, Monaco; Littoral Environnement et Sociétés (LIENSs), UMR 6250 CNRS-Université La Rochelle, 2 Rue Olympe de Gouges, F-17042 La Rochelle Cedex 01, France; USR 3278 CNRS EPHE UPVD CRIOBE & Laboratoire d'Excellence "CORAIL", B1013, 98729 Papetoai, Moorea, French Polynesia. Electronic address: laetitia.hedouin@criobe.pf.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Hédouin
authors.affiliation: International Atomic Energy Agency - Environment Laboratories (IAEA-EL), 4a Quai Antoine 1er, MC-98000, Monaco.
authors.forename: Marc
authors.initials: M
authors.lastname: Metian
authors.affiliation: International Atomic Energy Agency - Environment Laboratories (IAEA-EL), 4a Quai Antoine 1er, MC-98000, Monaco.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Teyssié
authors.affiliation: International Atomic Energy Agency - Environment Laboratories (IAEA-EL), 4a Quai Antoine 1er, MC-98000, Monaco.
authors.forename: François
authors.initials: F
authors.lastname: Oberhänsli
authors.affiliation: Centre Scientifique de Monaco, 8 Quai Antoine 1(er), MC-98000, Monaco.
authors.forename: Christine
authors.initials: C
authors.lastname: Ferrier-Pagès
authors.affiliation: International Atomic Energy Agency - Environment Laboratories (IAEA-EL), 4a Quai Antoine 1er, MC-98000, Monaco.
authors.forename: Michel
authors.initials: M
authors.lastname: Warnau
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism*; D057894:Coral Reefs; D004141:Dinoflagellida / Q000378:metabolism*; D004784:Environmental Monitoring; D006207:Half-Life; D008906:Mining; D009510:New Caledonia; D009532:Nickel / Q000378:metabolism*; D011868:Radioisotopes; D013559:Symbiosis; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D011868:Radioisotopes; D014874:Water Pollutants, Chemical; D009532:Nickel
keywords: Bioconcentration; Coral; Metal; Nickel; Zooxanthella