Metal bioavailability in natural diets: Toxicological implications for fish.

David Boyle

King's College London
School of Biomedical and Health Sciences
Nutritional Sciences Research Division

Supervisors: Dr. Nicolas Bury, Prof. Christer Hogstrand

Dietary metals are increasingly recognised as important determinants of chronic metal toxicity in fish populations however current legislation considers only waterborne metal exposure. My research has focused on the toxicological significance of metal transfer from a natural metal-contaminated invertebrate prey item collected from an impacted estuary to a model fish species. Zebrafish fed polychaetes from Restronguet Creek exhibited a series of impairments to reproductive fitness, including reduced frequency of spawning, decreased egg production, reduced expression of the egg-yolk pre-cursor protein vitellogenin and a lower hatch rate of embryos. Tissue metal analysis revealed high concentrations of endocrine disrupting inorganic arsenic species in polychaetes and arsenic accumulation in zebrafish tissues indicating arsenic as the probable causative agent. These results demonstrate that dietary metals at ecologically relevant concentrations may contribute to toxicity in fish and this route of exposure should be duly considered in environmental metals legislation.

A publication has resulted from some of this work:

Boyle, D., Brix, K. V., Amlund, H., Lundebye A-K., Christer Hogstrand, C. & Bury, N. R. (2008). Natural arsenic contaminated diets perturb reproduction in fish. Environ. Sci. Technol. Accepted, April 2008.