Forsøksdyr: Fish functional integrity biomarker after an oil exposure: study on Gadus morhua performance traits


Godkjenningsdato 26.10.2018

The oil and gas industry has massively invested in the European Arctic. Thus, due to an augmentation of human activity in these areas, the probability of oil spills will undoubtedly increase. To limit the impact of an oil spill, dispersant is currently used as a technical response. However, questioning about the biological impact of the dispersant use is still debated. Indeed, information is scarce about the sensitivity and specially the long-term effects of the discharge of oil and the use of dispersants on Arctic seas. In this project, short and long terms ecophysiological and ecotoxicological data will be assessed on an ecological and economical key specie, Gadus morhua using performance traits, such as thermal susceptibility or hypoxia tolerance. These performance traits can be used as biomarkers of fish functional integrity and consequently of fish health. With these biomarkers, cumulative outcome of an organism’s environmental history, resilience and vulnerability of fish will be assessed in an oil spill pollution context.
These parameters will provide relevant ecological information on the behavior of juveniles fish after an oil spill in the Arctic. Furthermore, it will give information of the biological impact of dispersant use as a technical response during an oil spill which will increase scientific knowledge in term of Spill Impact Mitigation Analysis (SIMA).
During the experimentation, the maximum expected distress is the loss of equilibrium (inversely of the dorso-ventral axis of the fish). This state is immediately reversible when fish are placed in a water with good abiotic conditions (Roze et al., 2012, Claireaux et al., 2013). This limit endpoint will be reached during the assessment of performance traits.
This project will consider the 3Rs (Replacement, Reduction and Refinement) rule. With regard to the replacement rule, this project requires the use of live fish in view of the biological phenomena studied (multifactorial stress), the targeted approach (adaptative capacity), the levels of biological organization studied (individual level) and the long term assessment. Regarding the reduction rule, this project requires a minimum of 360 fish. Below this number, the results are no longer usable because of the high interindividual variability of the biological parameters to be measured. The species chosen is the cod Gadus morhua, a fish whose biology and zootechnics are well known and which is frequently used in experimentation. To respect the rule of refinement, the entire project will take place in dedicated and isolated facilities, in breeding conditions respecting the physiological needs of the fish and using protocols that will aim to answer the scientific question asked and limiting as much as possible the malaise of animals.