Science activity

The Spring Kodiak Trawl Survey (SKT) has sampled annually since its inception in 2002. The SKT determines the relative abundance and distribution of spawning delta smelt (Hypomesus transpacificus). The SKT samples 40 stations each month from January to May. These 40 stations range from San Pablo Bay upstream to Stockton on the San Joaquin River, Walnut Grove on the Sacramento River, and the Sacramento Deep Water Ship Channel. Each 'Delta-wide' survey takes approximately 4 - 5 days per month to complete. Historically, 'Delta-wide' surveys were followed by a 'Supplemental' survey two weeks later to intensively sample areas of highest delta smelt concentration to estimate the proportion of male and female delta smelt that were in pre-spawning, spawning and spent maturation stages. Beginning in 2008, in an effort to minimize take of spawning adults, routine 'Supplemental' surveys were discontinued and are now only conducted under the recommendation of the Smelt Working Group and the approval of managers.