Different transfer pathways of an organochlorine pesticide across marine tropical food webs assessed with stable isotope analysis

Abstract

Chlordecone is a persistent organochlorine pesticide used in the banana fields of the French West Indies from 1972 to 1993. Three marine habitats (mangroves, seagrass beds and coral reefs) of two study sites located downstream contaminated rivers were chosen to evaluate the level of contamination of marine food webs. On each habitat, the food chain collected included suspended organic matter, primary producers (macroalgae, algal turf, seagrass), zooplankton, symbiotic organisms (corals, sea anemones), primary consumers (herbivores, suspension feeders, biofilm feeders), omnivores and detritivores (lobsters, fish), secondary consumers (carnivores 1: invertebrate feeders, planktivores) and tertiary consumers (carnivores 2: invertebrate and fish feeders, piscivores). Log-linear regressions of the concentrations of chlordecone versus nitrogen isotopic ratios (δ15N) were used to assess the bioaccumulation of chlordecone along trophic food webs. At each site, bioconcentration and bioamplification take part on the transfer of chlordecone in marine organisms. In mangroves (i.e. close to the source of pollution), lower trophic magnification factors (TMF) indicated that bioconcentration prevailed over bioamplification phenomenon. The opposite phenomenon appeared on coral reefs in which bioconcentration processes were less important and bioamplification pathway became dominant. Far from the source of pollution, molecules of chlordecone seemed to be transfered to organisms mostly via trophic interactions rather than water contact.

Levels of selected pesticides and trophic transfer of DDTs through the aquatic food web in the Lake Ziway ecosystem

“…In the present study, the TMF value for total DDTs exceeded 1, indicating that the level of DDT bioamplify along with the food webs. In this study, the TMF values were 1.18 and 1.19 for p,p'DDE, and ΣDDT respectively which is in agreement with studies reported by Kidd et al (2001) in African lake food web (TMF for DDT = 1.16, TMF DDE = 1.25,), also constant with marine food web investigation by Dromard et al (2018), with TMF of chlordecone ranged from 1.07-1.25. However, the TMF values of ΣDDT in this study were lower than those reported by Sun et al (2017) in South China mangroves with TMF of 2.61 and 2.76 for DDT and PCB respectively.…”

Environmental fate of chlordecone in coastal habitats: recent studies conducted in Guadeloupe and Martinique (Lesser Antilles)

“…Bioaccumulation phenomena of chlordecone have been demonstrated experimentally (Bahner 1977) and in the field (Dromard et al 2018). Two processes of bioaccumulation were demonstrated in the present study.…”

Detection of Adsorbed Chlordecone on Microplastics in Marine Sediments in Guadeloupe: A Preliminary Study

“…Chlordecone adsorbed on microplastic particles suggests the possible existence of a new pathway of transfer of the molecule into marine trophic food-webs. However, while models of accumulation and biomagnification of chlordecone in the marine environment have been studied (Coat et al 2011, Dromard et al 2018, none of them have considered this potential pathway of contamination. The competitiveness of chlordecone compared to other pollutants, such as DDT or DDE found in the waters around Guadeloupe, is also not known.…”