The interannual variability of zooplankton and phytoplankton within salmon hatcheries of Prince William Sound, Alaska: 1981-1999

Fishery productivity in an ecosystem is often linked to zooplankton production. Zooplankton communities vary both temporally and spatially, thus extensive effort must be undertaken to describe their broader-scale and seasonal patterns. Once baselines are established, zooplankton communities can become sensitive indicators of environmental conditions. Thus, long-term observations on planktonic communities may be the key to understanding how marine environments, and the higher trophic levels dependent on them, change over time. Furthermore, understanding the feeding environment of juvenile pink salmon when they first enter the ocean may allow hatchery-reared pink salmon to be released coincident with favorable zooplankton conditions. ZooImage was used to process zooplankton and phytoplankton samples from seven salmon hatcheries in PWS between 1981 and 1999. The standing stock for zooplankton and phytoplankton samples was determined for two different stations at each hatchery, one in the bay immediately adjacent to the hatchery and one in the passage immediately adjacent to the hatchery.