This spring, Western Fisheries Research Center sent a team of scientists to Alaska to conduct Pacific herring surveys. By plane and by boat, they conducted research and witnessed some of the great natural phenomena that this northern state is known for, including the northern lights and massive Pacific herring spawning events.

Western Fisheries Research Center took flight with partners at Alaska Department of Fish and Game and the Prince William Sound Science Center, who are investigating factors that limit the recovery of herring in Prince William Sound, Alaska. Herring spawn on coastal waters in the North Pacific, turning the dark blue waters into a milky turquoise. Female herring lay eggs near the shore in eelgrass and seaweed. The males release the milky sperm substance “milt” to fertilize the eggs. Active spawn, measured in miles of milt, are used to estimate biomass. Herring play an important role in the marine food web, feeding salmon and predator species such as orcas. Without herring, many species would struggle to survive.

Aerial view of herring actively spawning along Kayak Island Alaska. Active spawn is measured in ‘miles of milt’ and used to estimate biomass of the spawning herring population. Milt is the seminal fluid from male herring and appears along the shallow shoreline, obscuring the bottom. The shallow water appears milky and opaque, and concentrated milt can be seen in bright white clumps closer to shore. A small gillnet boat is pictured here, just outside of the active spawning area.

Western Fisheries Research Center scientists have been conducting these surveys every March/April since 2007 as part of a herring disease program that involves a combination of field observations, controlled laboratory experiments, novel tool development, and mathematical models; all aimed at better understanding, forecasting, and mitigating disease impact to Prince William Sound herring populations.

Visit these articles from our partners at the Prince William Sound Science Center to learn more about the research:

• Herring Research and Monitoring
• Herring Disease Research

USGS

  Alaska, herring, research