Mariko Koseki joined BCPU as an intern in autumn 2021. Mariko has a Masters in Environmental Science which she obtained at Hokkaido University in Japan.

“I, Mariko Koseki, am an intern within BCPU, and I have been working with Dr. Anne Britt Sandø at the Institute of Marine Research since autumn of 2021.
During the internship, we have focused on the Northeast Arctic cod (NEA cod/Gadus Morhua) biomass in the Barents Sea and developed regression models to predict variations in cod biomass in the future.
The NEA cod is one of the most important species in the Barents Sea for both the ecosystem and as a commercial stock. Several earlier studies reported that the recent warming condition in the Barents Sea has led to high cod biomass.
To construct regression models for total stock biomass of the NEA cod, we used hydrographic and biological variables, such as temperature, salinity, sea ice fraction, primary- and secondary production as explanatory variables. These variables were obtained from hindcast simulations with regional ocean and ecosystem models. Finally, we used the same regression models with variables from downscaled climate scenarios to project future variations in the NEA cod.
We found that several of the regression models have high prediction skills and captured the variations in total stock biomass in the Barents Sea well. Moreover, based on downscaled climate projections, we made maps of spatial distributions of cod biomass in the future. However, errors between observations and predictions of cod biomass necessitate further improvement of the regression models. Now we are preparing to publish this study as a scientific article.
I would like to thank everyone who has supported my internship, and I hope to make use of my experience in my next steps.” – Mariko