2006: Fitzroy River (Qld). Mud Crabs. Pesticides: DDT, Dieldrin

Water Quality Issues in the Barron WQIP Area ACTFR Report No. 08/06

Australian Centre for Tropical Freshwater Research

p81 Bioaccumulation sampling
While passive sampling detect contemporary pesticides, chiefly herbicides, mud crabs have
provided better evidence of residual organochlorine (OC) contaminants such as the
insecticides DDT and dieldrin (Negri et al., 2006). In a survey of the rivers draining to the
GBR, Negri et al. found the greatest incidence and concentrations of these OCs detected in
crabs came from the most populated catchments, i.e. the Barron, Pioneer, Fitzroy and
Burnett Rivers. Hence, the presence of DDT and dieldrin, albeit at low concentrations, was
clearly correlated to urban influences. Due to their higher polarity and comparatively short
half-lives, contemporary pesticides such as chlorpyrifos and diuron were not detected in
individual crabs.