Trace elements and δ15N values in micronekton of the south-western Indian Ocean. (November 2022)

• Record Type: Journal Article
• Authors: Annasawmy, Pavanee; Bustamante, Paco; Point, David; Churlaud, Carine; Romanov, Evgeny V.; Bodin, Nathalie
• Is Part Of: Marine pollution bulletin. Volume 184(2022)
• Publication Date: 2022-11
• Subjects: Crustaceans -- Fishes -- Myctophids -- Squids -- Body size -- Seamounts -- Principal Component Analysis; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2022.114053
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Trace elements and δ 15 N values were analysed in micronekton (crustaceans, fishes and squids) sampled in the south-western Indian Ocean. Myctophids were associated with high concentrations of arsenic at La Pérouse and MAD-Ridge seamounts, and with lead and manganese at MAD-Ridge and in the Mozambique Channel. The difference in cadmium, copper and zinc concentrations between micronekton broad categories reflected differing metabolic and storage processes. When significant, negative relationships were found between micronekton body size and trace element concentrations, which can possibly be attributed to differing metabolic activity in young and old individuals, dietary shifts and/or dilution effect of growth. No relationships were found between trace element concentrations and δ 15 N values of micronekton (except cobalt which decreased with increasing δ 15 N values), since most trace elements are not biomagnified in food webs due to regulation and excretion processes within organisms. All trace element pairs were positively correlated in fishes suggesting regulation processes. Highlights: Elemental concentrations vary among myctophids across the south western Indian Ocean study sites. Cu and Zn were higher in crustaceans than fishes. Trace element concentrations decreased/showed no change with micronekton body size. Only Co decreased with increasing δ 15 N values of fishes.