Zooplankton: a Puget Sound-wide sampling program

Zooplankton Sampling

Investigators: Julie Keister (U. of Washington), with substantial sample collection from multiple parties in Puget Sound, including: Tulalip Tribes, Nisqually Indian Tribe, King County, Port Gamble S’Klallam Tribe, Lummi Nation, KWIÁHT, NOAA Fisheries, Hood Canal Salmon Enhancement Group, Washington Department of Fish and Wildlife, Washington Department of Ecology, and other U. of Washington affiliates

A Puget Sound-wide zooplankton sampling program began in 2014. This research activity:

  1. Estimates the temporal-spatial availability of key zooplankton prey for juvenile Chinook and coho by depth strata in offshore regions of Puget Sound through the spring-summer growth period.
  2. Contributes to the development of Ecological Indicators of salmon survival in Puget Sound. Data generated by sampling throughout Puget Sound are compared to salmon growth and growth-survival time series to explore spatial and seasonal relationships between prey availability and survival. Zooplankton samples collected by NOAA in 2011 and diet data collected by D. Beauchamp (USGS) and L. Duffy in 2001-2002 and by CDFO 2001-2012 in some Puget Sound sub-basins, will be compared to salmon SARs as a baseline.

Sampling occurs bi-weekly from March through October, over the juvenile salmon outmigration period. Deep water vertical tows are performed to establish “Ecosystem Indicators”, and oblique tows are performed to evaluate the salmon prey field via “Prey Field Indicators”. This is a massive collaborative effort, involving ten different entities collecting zooplankton samples throughout Puget Sound.

Now in the fourth year of the program, we continue to focus on the objectives above while also expanding the program to inform Puget Sound recovery as a whole. Monitoring zooplankton communities in Puget Sound sub-basins allows researchers to develop robust metrics of ecosystem health. These metrics are used to evaluate impacts of physical change on the Puget Sound food web, understand the impact of global or local stressors on Puget Sound recovery indicators (e.g., forage fish and marine bird abundances), and provide guidance towards improved salmon harvest management and Puget Sound stewardship.

Puget Sound Zooplankton Sampling Sites Zooplankton monitoring locations representative of the PSNERP geographical basins and geographic range of key salmon and steelhead-producing systems within Puget Sound, Washington.