Having the appearance of a bullwhip, bull kelp—Nereocystis luetkeana—is an annual seaweed that can grow up to 100 feet in height. Bull kelp forests are found along the coast from Alaska to central California and are prevalent in the San Juan Islands, Strait of Juan de Fuca, and the Olympic Peninsula. Bull kelp forests, along with eelgrass meadows, provide important habitat for a wide array of marine life, contribute to climate mitigation and adaptation by sequestering carbon and locally reducing ocean acidification impacts, and have important cultural value to Indigenous people of the Northwest by playing a prominent role in traditional fishing, hunting, and food preparation and storage.

The Washington Department of Natural Resources (DNR) has been tracking long-term trends of kelp forests and eelgrass meadows. According to DNR, bull kelp in South and Central Puget Sound regions declined by more than 90 percent in the last 150 years. The Legislature, in 2022, required DNR to develop a Native Kelp Forest and Eelgrass Meadow Health and Conservation Prioritization Plan to identify at least 10,000 acres of priority kelp and eelgrass habitat for conservation and restoration by 2040. The prioritization plan was submitted to the Legislature on December 1, 2023.

Bull kelp—Nereocystis luetkeana—forests are designated as the official marine forest of Washington.