King County began zooplankton monitoring as part of the Marine Monitoring Program in 2014. Zooplankton samples were collected in 2023 twice per month at three locations: Point Jefferson (KSBP01), Point Wells (LSNT01), and East Passage (NSEX01).

Samples were collected by the King County Environmental Laboratory using two types of net tows: a single ring net was towed vertically to sample zooplankton throughout the full water column; double-ring (bongo) nets were towed obliquely through the upper 30 meters of the water column to sample the larger, more motile zooplankton. Samples were analyzed by Dr. Julie Keister’s lab at the University of Washington. Results from 2023 are provided in this report, as well as comparisons with prior years.