Biomarker sensitivity to temperature and hypoxia - A seven year field study

Abstract

We examined the response of a set of reproduction biomarkers to natural climate variables such as oxygen concentration, temperature and organic carbon (OC) in sediment. The data used was from field studies of the amphipod Monoporeia affinis covering 7 consecutive years from 1994 to 2000. Our aims were to evaluate the sensitivity of the biomarker 'malformed embryos' to oxygen deficiency, temperature increase and OC in sediments and to perform a field validation of some reproduction biomarkers targeted at these factors. The biomarker 'malformed embryos' was related neither to oxygen concentration nor to temperature, while a relationship was found with OC content of the sediment. A negative correlation was found between females carrying a dead brood and the oxygen concentration of the bottom water. Fecundity was positively correlated with the carbon content of the sediment but negatively correlated with the temperature of the bottom water. These results confirm the findings of previous laboratory experiments. By combining a set of biomarkers of different sensitivity to various stressors, we have obtained a powerful tool capable of monitoring the effects of both contaminants and other environmental stressors, and with the ability to discriminate between the effects of different environmental disturbances.