Transgenerational impairments of reproduction and development of the marine invertebrate Crepidula onyx resulted from long-term dietary exposure of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47)

Highlights: • The first multigenerational study (F₀ to F₂) on the effects of PBDEs. • Bioaccumulation and maternal transfer of BDE47 were evident in marine invertebrates. • BDE47 exposure reduced fecundity and delayed sexual maturity in F₀ and F₁. • BDE47 impeded embryonic development in F₁ and transgenerational group of F₂. • BDE47 exposure reduced survivorship in F₀, but not F₁. Polybrominated diphenyl ethers have become ubiquitous in the environment and elevated concentrations have often been found in marine organisms. Using the gastropod Crepidula onyx as a study model, this multigenerational study sets out to test the hypotheses that 1) parental dietary exposure to environmentally realistic levels of 2,2′,4,4′-tetrabrominated diphenyl ether (BDE-47) would lead to transgenerational impairments on fitness traits of marine invertebrates, and 2) the organisms might develop adaptation/acclimation after exposure for one or more generations. F₀ generation of C. onyx was fed with the dinoflagellate Isochrysis galbana encapsulated with two concentrations of BDE-47 (1.78 and 16.0 ng million cells⁻¹, respectively), and half of the F₁ offspring from the higher concentration treatment was returned to control condition (transgenerational group), while the other half received BDE-47 treatment continuously (continuous treatment group). Bioaccumulation and maternal transfer of BDE-47 were evident in all life stages of the F₀ generation and in F₁ eggs, respectively. Exposure to BDE-47 reduced fecundity, delayed sexual maturity, and impeded embryonic development in F₀ to F₂. In particular, developmental toxicity of F₂ embryos was apparent in the transgenerational group, but not in the continuous treatment group, even when BDE-47 was not detected in the F₂ embryos nor in their mothers and they have never been exposed to the chemical. This study also suggested that the offspring might have developed adaptation/acclimation to the exposure of BDE-47 within two generations of exposure, and that the physiological alterations associated with acclimation/adaptation might have hindered the normal larval development under a stress free condition. These findings highlighted the need for long-term multigenerational studies in the ecological risk assessment of chemicals alike.