Impact of oil discharges on light- and temperature- adapted behaviour in the marine calanoid copepod Calanus finmarchicus

The calanoid copepod Calanus finmarchicus is considered a key species in the North Atlantic ecosystem. C. finmarchicus generally perform diel vertical migration, staying deeper in the water column during day time than during the night. This activity is assumed to be at least partly guided by environmental light cues, although other cues such as nutritional status, predator presence and endogenous rhythms may also play a role.

Organic pollutants may interfere with important behavioural traits, such as migration. The C. finmarchicus population along the Norwegian coast and the Barents Sea is exposed to varying concentrations of oil components. Furthermore, organisms in their natural environment are exposed to several different types of stressors (temperature, nutritional stress, predation risk) in addition to exposure to chemical pollution.

The objective for the current project is to investigate the phototactic behaviour of C. finmarchicus and the effects of oil exposure on this behavioural response. The experiments are being conducted with animals from a C. finmarchicus laboratory culture at NTNU Sealab, which was raised from material collected in Trondheimsfjorden in 2004. The main focus will be on the later copepodite stages, i.e. CV and adult males and females. Exposure to the water accommodated fraction (WAF) of fresh and artificially weathered Troll oil is being used to investigate effects of oil exposure.