Report: Study panel on ecosystem-based management of forage fish in Puget Sound
Forage fish represent a critical link in the Puget Sound food web and help to sustain key species like salmon, marine mammals and sea birds. But the region’s forage fish may be vulnerable on a variety of fronts, according to a new study panel report from the University of Washington Puget Sound Institute. Download the panel's summary and proposed research plan.
Executive Summary
In the Spring of 2013, the Puget Sound Institute convened a 9-member study panel (“the Study Panel”) to assess the state of the science, and to recommend and conduct data analyses related to ecosystem-based management of forage fish in Puget Sound. Members include forage fish experts from across the West Coast, from universities and state and federal (including Canadian) government agencies. In August 2013, the Study Panel met for its first workshop. A day of presentations from and discussions with other regional scientists and stakeholders, followed by 3 days of discussions internal to the Study Panel, resulted in this summary and proposed research plan.
The Study Panel agreed upon several facts with respect to Puget Sound forage fish and, specifically, Pacific herring (a Puget Sound Partnership Dashboard Indicator):
- Spawn deposition surveys are sufficient for estimating herring adult spawner biomass, and for describing trends in adult spawner biomass through time. However, the assumptions contained in the model that converts egg density estimates to adult biomass should be re-evaluated. The spawn deposition surveys and acoustic/trawl surveys (conducted before 2009) estimate the same abundance trends overall.
- The major herring spawning locations are known.
- Herring and sand lance are key prey items in the diets of several Puget Sound predators, including fish, birds and mammal.
However, several key gaps exist in our understanding of Puget Sound forage fish, preventing effective management. The Study Panel’s work plan was developed to address these gaps (where possible), which include:
- Status of/trends in abundance of forage fish (species other than herring)
- Key vulnerabilities of forage fish
- Abundance/biomass of forage fish needed to support key ecosystem predators
- Prey base/food supply for forage fish
- Consequences of herring age truncation
- Partial migration by herring out of Puget Sound