Sockeye salmon can also occur and can lead to interactive segregation, which is when species emphasize their differences in diet and habitat to avoid competition. Interspecific competition can affect the growth rates of the salmon if their access to resources is limited. The total registered fisheries harvest of the sockeye in 2010 was some 170,000 tonnes, of which 115,000 tonnes were from the United States and the rest was equally divided between Canada and Russia. This corresponds to some 65 million fish in all, and to some 19% of the harvest of all Pacific salmon species by weight. Commercial fishermen in Alaska
Fish tug the 1930s it became common to add a pilothouse amidship or near the stern, and to continue the cabin covering to the bow in what was known as a "sprayhood." Steel-hulled boats began to replace wooden-hulls in the late 1950s. Beginning in the 1970s, new regulations began to greatly restrict gill-net fishing, making the fish tug all but obsolete. The few fish tugs that remain in use today are largely objects of historical preservation efforts and not under commercial ownership. Fish tug A fish tug (sometimes called fishtug, fish tugboat, fishing tug, etc.) is a type of boat that was