Herring mature at 3 to 4 years of age and grow to 25 - 45 cm in length. In Southern Alaska and British Columbia, they can reach an age of 8 years; in the Bering Sea the maximum recorded age is 19 years!  Recently, a shift to younger ages and smaller sizes of only about 20-25 cm has been observed [link to TEK on herring size] in British Columbia and southern Alaska. Although some mixing occurs between schools, tagging studies show that most Pacific herring remain in the same school for years.

Herring school

Adult herring live in huge schools of many millions of fish and forage in the open coastal and offshore waters.

Observations over the last century indicate a change in herring populations and their behavior. Up until recent decades, some schools tended to stay in particular large bays.  These “resident” or “homesteader” stocks are largely extirpated. Historical documents record the huge extent of some herring schools. For instance in 1893 in the Strait of Georgia, “a small tug passed for three hours through a continuous mass of migrating herring in the month of June” (Carothers 1941). 

Monday, October 7, 2013