November 1, 2022 — Polar cod is an important part of the food web of the Arctic. Sarah Maes (KU Leuven) and Fokje Schaafsma (Wageningen Marine Research) investigated the diet of polar cod from the Barents Sea, with the help of colleagues from the KU Leuven and the Alfred Wegener Institute. They did this by combining traditional microscopy with DNA analysis. The study resulted in new insights regarding the diet of polar cod which are now published in the journal Marine Ecology Progress Series.
Diet investigations are usually done by opening the stomach and looking what is inside, using a microscope when the investigated animal is small. This way, researchers can see which and how much prey was consumed. However, some prey species are more easily digested than others, leading to a potential biased view on the importance of certain prey species.
Some prey species can even be overlooked altogether. Sarah Maes of the KU Leuven initiated an investigation of the diet of polar cod using DNA analysis to overcome this problem. By combining this method with traditional microscopic analysis results gained from the two different methods could be compared.