Impact of brominated flame retardants on embryo development of Atlantic Cod (Gadus Morhua) during early life stages

Abstract

Brominated flame retardants (BFRs) are ubiquitous industrial chemicals likely to persistently exist in the environment, bioaccumulate in food chains, and even may cause adverse health effects in human. Borgundfjorden fjord system, an important spawning ground for the Norwegian coastal cod (Gadus morhua) stock, was contaminated by significant levels of pollutants such as BFRs, due to the local previous industrial activities. In this study, we demonstrated high level of the BFRs polybrominated biphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in cod liver and gonad samples from Borgundfjorden using mass spectroscopy (MS) detectors by Norwegian National Institute of Nutrition and Seafood Research (NIFES). Acute embryo toxicity test was further conducted using fertilized cod eggs. The eggs were short-term exposed to serial dilutions of five BFRs mixtures, BDE-47, or PCB mixture Aroclor 1254. At a concentration 10 times that detected in cod liver, the mixture of the five BFRs significantly reduced the embryo survival rate (p < 0.01). Correspondingly, at 224 μg/L, which was around 10 times of that detected in cod liver, BDE-47 exhibited obvious cod embryo toxicity (p < 0.01). As a positive control, Aroclor 1254 significantly reduced the embryo survival rate at 400 and 1600 μg/L (p <0.001). This experiment has laid the foundation for further research on environmentally hazardous impact on the reproductive capacity of aquatic organisms, which will directly influence the fish stocks growing potential and thereby the Norwegian fishery activity.