In this project we studied the seasonal variations in Northern krill (Meganyctiphanes</p><p>norvegica) sensitivity to oil concentrations relevant for discharges of produced water (byproduct of crude oil extraction). Northern krill are key organisms in temperate and Arctic ecosystems, and constitute an important link in marine food webs. Abiotic factors (e.g. temperature and light) and biotic factors (e.g. lipid storage and reproductive status) vary with season and can potentially affect how krill respond to pollutants. These variations may affect accumulation of oil components and hence krill plasticity of response and sensitivity to oil. Genomic approaches will allow us to better understand the physiological responses of Northern krill exposed to oil and how this may vary according to season. Since there has been very little sequence data published for Northern krill, we generated a transcriptome of this species exposed to produced water during spring, autumn and winter using long read PacBio sequencing.