Assessment of long-term effects of oil exposure on early life stages of Atlantic haddock using state-of-the-art genomics tools in combinatio

In this project we aim at generating experimental data to assess the chronic toxicity during early life stages as well as evaluating the long-term effects of oil pollution in Atlantic haddock - using state-of-the-art genomics tools in combination with fitness observations. It is important to identify special high-risk scenarios and more data are need on the long-term effects of exposure during different life stages in the early development of relevant fishes. Preliminary data from an ongoing project (funded by VISTA) indicate that haddock embryos may be especially vulnerable to exposure to dispersed oil droplets. We will apply the new risk assessment model, SYMBIOSES, for estimating a realistic exposure scenario for early life stages of haddock (embryo and larvae) after a blow-out from four hypothetic platforms localities around the Lofoten area. These models will make the basis to design the exposure regimes that will be used in the experimental laboratory experiments. The goal is to deliver results that can be used directly in the SYMBIOSES modeling, addressing the question about which compounds should be used in egg/larvae-Oil overlap modeling; only water soluble PAH or total dispersed oil? Which body burden of oil compound that is obtained at different life stages and what are the long-term effects of oil exposure on the fitness of haddock. In addition, the project will be a contribution to the general knowledge about the mechanism of oil toxicology. In 2014/2015 have there been carried out 5 exposure studies at the Research Station Austevoll where embryo (cod and haddock) and larvae (haddock) have been exposed for realistic low doses of dispersed oil in a ranges of 33 µg oil/L ? 600 µg oil/L ( corresponding 0.2 ? 7 µg TPAH/L). 1. Comparative exposure studies on haddock and cod embryo (pilot study in 2014 and new study in 2015). Newly fertilized eggs from cod and haddock are exposed to dispersed oil in and followed until hatching. This experiment is used to study uptake and departure kinetic of PAHs in fish embryos. 2. Long-term embryo experiment on haddock (two studies; 2014 and 2015). Haddock embryos were exposed from for 7 days and transferred to clean water two days before hatching and larvae were followed through first feeding until juvenile age. 3. Long-term larval experiment on haddock (2014). Newly hatched larvae haddock were exposed for 20 days and then transferred to clean water and long term effects are monitored until juvenile age. The results show that haddock embryos are very sensitive to exposure of dispersed oil droplets because oil droplets are found to stick to the eggshell and thereby increase the absorption of harmful substances from the oil. Similar effects were not observed with cod embryos at these low concentrations that were tested. Haddock Embryos developed irreversible heart failure leading to a number of secondary effects due to loss of circulation, such as spinal deformities and jaw, which in turn results in reduced swimming and liner, and finally death during the larval stages. It was found 100% mortality in the two highest dose groups (down to 3.4 µg TPAH / L). The low group and pulse dose (0.7 µg TPAH / L) also showed a high frequency of severe morphological damage and a large increase of mortality through the larval stage observed. Haddock larvae were less sensitive to oil exposure and increased mortality was observed only in the high dose group at 10 µg TPAH /L. The "no observable effect" concentration (NOEC) was found to be 0.2 µg TPAH /L for embryo and 0.7 µg TPAH/L for larvae. From the comparative exposure experiments with both cod and haddock embryos, were it also confirmed that haddock embryo were especially sensitive to dispersed oil, and measurement of gene expression of CYP1A (a biomarker for PAH exposure) showed that haddock embryos had up to 150 times the response that it was found in cod embryo at the same exposure dose. RNA sequencing data for the embryonic and larval tests are currently being analyzed. Similar are large amounts of video and photographic material also under analysis. At the chemistry laboratory at IMR have there been developed a analytical method for ultrasensitive PAH analysis methods on a new purchased GC-MS / MS instrument. This method is currently being used to estimate body burdens of PAHs in exposed embryo/larvae. The results from the exposure studies will in 2016 be incorporated into the SYMBIOSES models and risk assessment of worst case scenarios after blow-out from four hypothetic platforms localities around the Lofoten area. The project is conducted in collaboration between IMR, CEES, NIFES, NIVA, UiB and SINTEF, some of the leading research institutes within marine biology/toxicology/genomics in Norway, together with NOAA, USA and University of Plymouth, UK, merging several scientific disciplines, including ecotoxicology, embryology, genomics, analytical chemistry and risk assessment.

In this proposed project we aim at generating experimental data to assess the chronic toxicity during early life stages as well as evaluating the long-term effects of oil pollution in Atlantic haddock - using state-of-the-art genomics tools in combination with fitness observations. It is important to identify special high-risk scenarios and more data are need on the long-term effects of exposure during different life stages in the early development of relevant fishes. Preliminary data from an ongoing pro ject (funded by VISTA) indicate that haddock embryos may be especially vulnerable to exposure to dispersed oil droplets. We will apply the new risk assessment model, SYMBIOSES, for estimating a realistic exposure scenario for early life stages of haddoc k (embryo and larvae) after a blow-out from four hypothetic platforms localities around the Lofoten area. These models will make the basis to design the exposure regimes that will be used in the experimental laboratory experiments. The goal is to deliver results that can be used directly in the SYMBIOSES modeling, addressing the question about which compounds should be used in egg/larvae-Oil overlap modeling; only water soluble PAH or total dispersed oil? Which body burden of oil compound that is obtained at different life stages and what are the long-term effects of oil exposure on the fitness of haddock. In addition, the project will be a contribution to the general knowledge about the mechanism of oil toxicology. The project are relevant both for ac cidental oil spill and chronic exposure from operational discharges of produced water and the results are expected to contribute significantly to understand the risk of opening up high-latitude marine environment to oil exploration and production.