Elements in muscle tissue of three dolphin species from the east coast of South Africa. (March 2023)

• Record Type: Journal Article
• Authors: Plön, S.; Roussouw, N.; Uren, R.; Naidoo, K.; Siebert, U.; Cliff, G.; Bouwman, H.
• Is Part Of: Marine pollution bulletin. Volume 188(2023)
• Publication Date: 2023-03
• Subjects: Biological variables -- Mercury -- Trace elements -- Dolphins -- South Africa; 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.2023.114707
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: We investigated elemental concentrations in muscle tissue of three species of dolphins incidentally bycaught off the KwaZulu-Natal coastline, South Africa. Thirty-six major, minor and trace elements were analysed in Indian Ocean humpback dolphin Sousa plumbea ( n = 36), Indo-Pacific bottlenose dolphin Tursiops aduncus ( n = 32) and the Common dolphin Delphinus delphis ( n = 8). Significant differences in concentration between the three species were observed for 11 elements (cadmium, iron, manganese, sodium, platinum, antimony, selenium, strontium, uranium, vanadium and zinc). Mercury concentrations (maximum 29 mg/kg dry mass) were generally higher than those reported for coastal dolphin species found elsewhere. Our results reflect a combination of species differences in habitat, feeding ecology, age, and possibly species physiology and exposure to pollution levels. This study confirms the high organic pollutant concentrations documented previously for these species from the same location, and provides a well-founded case for the need to reduce pollutant sources. Highlights: Presents the only recent study on elements in three species of dolphins from South Africa 11 of 36 analysed elements displayed significant concentration differences between the species. Hg concentrations were higher than those reported for similar species elsewhere. Our results provide important baseline values for the region. These and previous data show the need for continued long-term monitoring.