Fisheries managers studying poor ocean survival of salmon are concentrating their research on juvenile fish and their preferred prey.
Several tribes are collaborating on studies slated to begin in 2014 as part of the Salish Sea Marine Survival Project. The Tulalip, Nisqually, Port Gamble S’Klallam, Lummi, Swinomish and Sauk-Suiattle tribes are among the collaborators that have signed on to sample zooplankton throughout the region.
Zooplankton and ichthyoplankton are the preferred prey for juvenile salmon. Researchers want to find out whether prey availability has changed in the Salish Sea during the critical period of juvenile salmon development, leading to poor growth and survival.
“This effort will fill critical knowledge gaps in understanding the lower levels of the marine food web that affect juvenile salmon,” said Paul McCollum, director of natural resources for the Port Gamble S’Klallam Tribe. “The data will contribute to the development of ecosystem indicators that have already been demonstrated to greatly improve adult salmon return forecasting.”
“The increasing inability in recent years to accurately estimate annual salmon returns is impacting tribal treaty rights and implementation of the U.S.-Canada Pacific Salmon Treaty,” said Terry Williams, commissioner of fisheries and natural resources for the Tulalip Tribes. “It also impairs the critical decision-making necessary to achieve salmon recovery goals and sustainable fisheries.”
The Tulalip and Nisqually tribes also are partnering on a study of juvenile salmon in the Snohomish and Nisqually river watersheds and adjacent nearshore and offshore marine areas.
The study will examine the entire community structure of competitors and predators, including plankton and other fish species. Smolt traps operate continuously on both rivers from winter through summer to collect timing, size and abundance data for out-migrating salmon. Both tribes also sample juvenile fish use of nearshore marine areas and pocket estuaries and the nearshore using fyke nets and beach seines.
This sampling data should allow researchers to identify the life stage, timing and locations where growth of juvenile salmon is limited, which correlates to adult returns.
An additional juvenile salmon study is planned for the nearshore and offshore of the San Juan Islands where threatened Whidbey basin and Nooksack river chinook are present. That effort aims to identify the periods of critical growth during early marine residence and determine where that growth is occurring.
In Hood Canal and Admiralty Inlet, the Port Gamble S’Klallam Tribe has been conducting nearshore research and monitoring on juvenile salmon and forage fish, using acoustics, trawl and beach seine methods as well as zooplankton sampling.
“We’re looking forward to being a collaborative partner of this important large-scale project,” McCollum said.
For more information about the Salish Sea Marine Survival project, visit the Long Live the Kings website.
Related article: Tribes partner in marine survival research