Commercial and recreational fishermen are among the most intensive users of Prince William Sound. With the ever-changing populations of fish and shellfish that can often seem to drop with no explanation, fisheries managers are doing all they can just to keep up.
In recent years however, evidence has shown that these population shifts could be related more to environmental forces than was originally thought. Through the long-term real-time data sets provided by the PWSOS, fisheries management can gain a greater understanding of the physical processes that affect fish and shellfish populations in the Sound.
"Population change often results from environmental variation, but physical data on environments is lacking," said Bill Bechtol of the University of Alaska, Fairbanks. "The environmental data that is available doesn't match up with the population over the long term."
The fish and shellfish industries went through a major regime shift in the 1970s and 1980s when shrimp, crab, and other crustaceans all but disappeared. Instead of these species, fishers' nets have lately been filled largely with haddock, halibut and pollock. As managers begin to understand the relationship between fisheries and their environments, they can tailor yearly management plans to fit the needs of a population.
"Really what we're managing is not the fish themselves; we're managing our take of the fisheries," said Bechtol. This is a practice Bechtol calls managing for Sustained Yield, and it cannot be done without an extensive knowledge of the variability of the ocean environment. For example, pink salmon populations have jumped around in numbers for the last decade, despite managers' best efforts to stabilize the population. Then, several years ago, researcher Dr. Milxsoes Adkison from the University of Alaska Fairbanks compared pink salmon population changes to changes in the sea surface temperature, and found that they nearly exactly correlated to each other.
Knowing this environmental matching could allow fisheries managers to predict harvest numbers based on the forecasted seasonal sea surface temperatures, or it could allow them to tailor their release dates to days when the temperatures are optimal for pink salmon survival. Coupling environmental data with fisheries data could lead to many more similar discoveries. The cooperation between PWSOS and fisheries managers in PWS could lead to a greater understanding of the many varieties of fish and shellfish that live in the Sound, as well as the environmental factors that affect them and the best way to ensure their survival for many years to come.
"We need to look at things on both a coarse and a fine scale," Bechtol said. "I'm a believer in data sharing and trying to figure out how all these linkages work between the different species that are out there."
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