The Pacific herring is a small fish species that averages about 25cm in size. They are considered a keystone species, acting as the base of a large and complex marine food web.
The herring’s body is bluish-green on the top of the back, and the stomach and sides are a bright silver. This coloring is known as countershading, and it makes Pacific herring harder to see from above or below. Countershading helps the herring camouflage itself from potential predators, which include larger fish, seabirds, and marine mammals.1 Another distinct feature of the pacific herring is its eyes, which are relatively large for a species of its size.
Herring travel in large schools up to 1,300 feet below the ocean’s surface. This species’ lifespan varies based on its habitat, but individuals can live for up to twenty years in the cold waters of the Bering sea.2 Juvenile herring feed primarily on crustaceans and mollusk larvae while adults’ diets consist of crustaceans and small fish.
Herring migrate to inshore brackish waters to spawn. Females lay their eggs on seagrass beds and seaweed, where they are fertilized by the males. Herring larvae hatch in these sheltered habitats. Once they reach the juvenile stage, they will migrate back to the ocean for two to three years before they mature and return inshore to spawn.
As a keystone species, several other species in the Pacific food web rely on herring to sustain their diets, so changes in herring populations can have a ripple effect on the entire ocean ecosystem. In British Columbia, for example, herring is a primary food source for Chinook and Coho salmon as well as harbor seals.3 Pacific herring are also important for communities whose economy revolves around the herring fishery. However, certain herring populations have historically been vulnerable to overfishing. Local herring fisheries in British Columbia collapsed in the 1960’s, with numbers declining again in the 1990’s.3 With improved fisheries management, herring may have a chance to flourish again. Oceana works to stop overfishing through the establishment of science-based catch limits, ending harmful fishing subsidies and reducing illegal, unreported and unregulated (IUU) fishing. Join Oceana to help protect species like the Pacific herring that are crucial to safe and healthy oceans.
1. Southern Pacific herring species have shorter lifespans than individuals who live in colder northern Pacific waters.
2. Pacific herring can swim with the same school for several years.
3. The Pacific herring’s scientific genus name, Clupea, derives from the Latin word for shield, most likely a reference to the herring’s silvery scales.
4. The Pacific herring’s eggs are considered a culinary delicacy in Japan.
5. First Nations indigenous communities on the western Canadian coast have relied on Pacific herring as a food source for thousands of years.3
Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.