Affiliation:
1. Department of Physical Sciences, Earth, and Environment, University of Siena, Via Mattioli, 4, 53100 Siena, Italy
2. Sharks Studies Center—Scientific Institute, 58024 Massa Marittima, Italy
Abstract
Seas and oceans are contaminated by persistent organic pollutants (POPs), which are released into the environment by human activities. The chemical-physical properties of POPs induce high persistence and toxicity in marine organisms from the lowest to the highest trophic levels. Phyto- and zooplankton are at the base of the food chain, and they can adsorb and accumulate these xenobiotic compounds. Therefore, all planktophagous species, including the whale shark (Rhincodon typus), are susceptible to ingesting these contaminants during feeding. From October to December, whale sharks migrate along the north-west coast of Madagascar in search of dense patches of plankton. During scientific expeditions to the whale sharks’ foraging areas in the waters of the island of Nosy Be (which is in the north-west of Madagascar), plankton samples were taken. In these samples, the presence and levels of some chlorinated xenobiotics (HCB, DDT and its metabolites, and PCBs) were evaluated in order to estimate the possible impact of whale shark diet on organochlorine (OC) accumulation. The fresh plankton biomass sampled from this region did not seem to be sufficient for the sustenance of the animals, which suggests that the daily contamination input of Rhincodon typus individuals, depending on their plankton diet, is minimal.
Subject
Nature and Landscape Conservation,Agricultural and Biological Sciences (miscellaneous),Ecological Modeling,Ecology
Reference94 articles.
1. Bettinetti, R., and Manca, M. (2013). Zooplankton: Species Diversity, Distribution and Seasonal Dynamics, Nova Science Publishers, Inc.
2. First Results on Zooplankton Community Composition and Contamination by Some Persistent Organic Pollutants in the Gulf of Tadjoura (Djibouti);Boldrocchi;Sci. Total Environ.,2018
3. Nybakken, J.W. (2001). Marine Biology: An Ecological Approach, Benjamin Cummings. [5th ed.].
4. Compagno, L.J.V. (2001). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date, Food and Agriculture Organization of the United Nations.
5. Norman, B. (2000). The IUCN Red List of Threatened Species 2000, IUCN.