It is fact that the cod fishery around Iceland is one of the largest in the world, yielding roughly 200,000 metric tons a year. It is observed that new research on cod genetics suggests that fishing is changing the population in ways that could lead to a partial collapse. Bottom trawling is the main fishing method as Icelandic cod are caught at a variety of depths.
It is found that researchers using data loggers attached to fish discovered that the cod prefer distinct habitats, with some living exclusively in shallow water and others staying offshore, only coming near the coast in the spring to breed. The genetics of the two groups reflect the disparity: They have different versions of a gene called pantophysin I, whose function isn’t known.
Einar Árnason, a geneticist at the University of Iceland, Reykjavík, wondered whether fishing might be altering the genetic composition of the cod stock. It is told that the frequency of different versions of the gene, or alleles, changed in the two populations between 1994 and 2003. He predicts that if fishing remains intense shallow-water fish will disappear within 10 years. If the deep-water cod don’t then spread into the shallows–and Árnason doubts they will, because their genetic difference suggests they are adapted to deep water–the size of the total population would shrink.
