PUGET SOUND HERRING STOCKS

Local Adaptation and Seasonal Distribution of Puget Sound Herring Stocks

Researchers sequence the Puget Sound herring genome to study the species’ distribution and look for signs of local adaptation.

Principal Investigator

Lorenz Hauser, University of Washington, School of Aquatic and Fishery Sciences

Co-Principal Investigators

Project

Puget Sound herring continue to decline, and longevity of the resource will require careful resource management, conservation and restoration—work that requires additional understanding of species populations. The project examines molecular genetic evidence for local adaptation of Puget Sound herring populations by resequencing entire genomes for six stocks. Genetic markers will be used to establish geographic and temporal distribution of genetically distinct populations outside their spawning season. The new information will allow resource managers to better identify causes for specific population declines, anticipate future threats and adjust management strategies to protect population diversity.

Research Updates

Background

Pacific herring is a foundation of the Puget Sound food web and a cultural keystone species for Northwest tribes. However, Washington’s herring stocks have significantly declined since the 1970s—the state’s biggest herring population has shrunk by at least 90 percent. Understanding the population structure of local herring and how it has changed over time is essential to recovery efforts.

Results Thus Far

In 2017, the researchers discovered that modern-day Puget Sound herring that spawn in winter are genetically distinct from herring that spawn in spring. In 2018, the researchers isolated eight genetic markers to identify herring that spawn in winter versus spring, and successfully genotyped 90 percent of the 174 archaeological samples they had collected. The ancient samples clustered closely with the modern ones, which supported the researchers’ ability to identify the season that herring from almost a millennium ago spawned. The ancient samples appeared to be mostly winter spawners, suggesting it is a more recent development for herring to spawn in spring. This is the first known ancient DNA population study on a marine species using such robust sample sizes.