By Jeff Rice
One of the first steps in protecting any species is understanding as much as you can about it. When it comes to Pacific herring in the Salish Sea, much is known but until recently many of the key scientific findings about the species had not been gathered together in a single place. A new state of the knowledge report published by the Puget Sound Institute and the Washington Department of Fish and Wildlife is a step toward remedying that.
The report, “Assessment and Management of Salish Sea Herring” was prepared with support from a grant from the SeaDoc Society. It will be used to advance herring conservation in the region, including potential herring recovery work related to the state’s Pacific herring ‘Vital Sign’. Herring are also a critical food source for many species such as Chinook salmon, which in turn feed Puget Sound’s endangered orcas. Tessa Francis of the Puget Sound Institute and Dayv Lowry of the Washington Department of Fish and Wildlife were the principle investigators on the report and received input from a cross-border team from state and federal agencies, universities and area tribes.
Did you know:

• Many herring stocks have declined in Puget Sound while herring numbers are at historic highs in the Strait of Georgia.
• Herring stocks at Puget Sound’s Cherry Point — once one of the largest herring populations in the United States — have been the hardest hit, declining by nearly 97% over the past 40 years.
• Sky glow: Higher intensity lighting used in shoreline areas is creating what is known as “sky glow” that reflects off the atmosphere and lights up the water’s surface, making herring more vulnerable to predators. “Increasing [artificial light at night] has created a perpetual twilight from dusk until dawn, and has reduced or eliminated the nocturnal dark refuge for feeding and migrating fishes in the Salish Sea region,” the report reads.
• Vessel noise has been a hot topic when it comes to Puget Sound’s endangered orcas, but underwater noise may also impact other species such as herring. Scientists have observed changes in the behavior of Pacific herring’s cousin the Atlantic herring due to exposure to human-caused noise.
• PAH’s from stormwater lead to shorter body lengths and cardiac defects among larval herring.
• Seals and sea lions don’t just eat juvenile salmon. Increasing numbers of harbor seals in Puget Sound are suspected of impacting Chinook salmon populations, but harbor seals eat primarily Pacific herring, especially during the winter and spring.
• Early Salish Sea tribes and first nations may have helped to cultivate herring populations by transplanting herring eggs to new locations.

To find out more about Salish Sea herring, read the full report on the Encyclopedia of Puget Sound.
Citation:
The Salish Sea Pacific Herring Assessment and Management Strategy Team. 2018. Assessment and Management of Pacific Herring in the Salish Sea: Conserving and Recovering a Culturally Significant and Ecologically Critical Component of the Food Web. The SeaDoc Society, Orcas Island, WA. 73 pp.