Their fillets are used for fish burgers, fish fingers, as well as different surimi products. Alaska pollock can be utilized for different purposes and at relatively affordable cost. Their stocks constitute the largest and the most economically important ground fish resources in the North Pacific Ocean. They are both, well managed and fished on sustainable basis. Yet depletion of their stocks occurs primarily due to natural causes. On that score, a dramatic role is played by the climate change.
Although the walleye pollock (Theragra chalcogramma) known also as the Alaska pollock is a close relative of Atlantic cod, saithe and haddock, intensive fishing started only 50 years ago. Before that, interest in this species was surprisingly low which could possibly be explained by its relatively small body Despite a record length of 91 cm, the length of individuals caught in the net seldom exceeds 50 cm while the weight barely reaches 500 to 600 g. The brownish or greenish coloured, beautifully spotted fish live in large schools at a depth of between 30 and 500 m. In terms of biomass, the stocks of Alaska pollock belong to the largest and most important stocks of food fish due to three main reasons. First, they grow relatively quickly reaching 30 to 40 cm length already at the age of three or four years. From this point onwards, they can spawn virtually every year thus contributing to the survival of the species. It is universally assumed that Alaska pollock lives a maximum 14 to 15 years. Second, their fertility rate is really high. The exact number of eggs depends upon a number of factors including the age, the size and the nutritional status of females, however on average it ranges from 100,000 to 1.2 million. The third reason for the high importance of Alaska pollock is the wide spectrum of feed they use. Although carnivorous they can consume plankton-eating krill or young herrings available in copious amounts in the North Pacific. In the Bering Sea, Alaska pollock accounts for almost 60% of the total fish biomass, while in the Gulf of Alaska and Aleutian Islands they constitute about one fifth of the total fish biomass.
A number of institutions are involved in deciding how much fish can be harvested from the sea
Fishing quotas have an immediate impact on the players in the fisheries sector and the release of the numbers is closely watched by all concerned. The route by which raw data is converted into the precise figures that are published as fishing quotas is long, with inputs from several institutions, and gives an idea of the enormous significance attached to these numbers.
Fish, individually or in swarms, can usually be found in places offering them the best for their lives: where they find food, where it is safe to reproduce and survive as species. Such preferences, together with environmental conditions, may vary from year to year, and hence the number of fish coming together may vary as well. Fishermen know where to find the fish and are familiar with annual fluctuations. Fishing grounds, when seen as fish habitats, do not feature national borders, whereas fishing vessels carry the flags of their home ports. Fish stocks which are international by nature thus have national owners when turned into catches. The subsets of these fishable stocks allocated to and harvested by sovereign states are called fishing quotas.