Restoration Objective:
The bull kelp forest off Squaxin Island in Southern Puget Sound is culturally and ecologically significant. As “People of the Water,” the Squaxin Island Tribe has been sustained by these waters and kelp forests for thousands of years. Over the last 145 years, ~80% of bull kelp forests in southern Puget Sound have disappeared. But the bed off Squaxin Island has persisted, despite being the innermost bed within Puget Sound, and the farthest from the Pacific Ocean. The resilience of the Squaxin Island bed is a powerful symbol for the Tribe, and they watch this kelp bed closely.
In 2013, based on surveys conducted by Washington Department of Natural Resources (DNR), the Squaxin Island kelp bed started noticeably contracting and shoaling. DNR monitors this bed closely as well, in partnership with the Squaxin Island Tribe. Annual surveys conducted over a 10-year period indicate that the kelp bed off Squaxin Island declined 97%, between 2013 and 2022. This was followed by a partial natural recovery in 2023; the 2023 extent was similar to 2016-2021. The most precipitous decline occurred in 2022, following a heat dome event in 2021, during which unusually high daytime tempertures (over 100 °F) coincided with daylight low tides. Only 89 plants reached the surface in 2022.
The near loss of the Squaxin Island kelp bed created an all-hands-on-deck, collective effort to work with the Tribe to re-grow and maintain the kelp forest off Squaxin Island. In fall of 2022, Squaxin Island Tribe worked with DNR to identify the location of a bull kelp enhancement site off Squaxin Island. Simultaneously, the Tribe worked with PSRF to plan bull kelp seed production for an experimental outplanting in winter 2023, with additional outplants planned for 2024, 2025, and 2026.
In July 2024, DNR’s Commissioner of Public Lands announced a formal partnership with the Squaxin Island Tribe to conserve and recover the Squaxin Island kelp bed as the first priority kelp habitat identified via Washington State's Kelp and Eelgrass Health Plan.
Site Selection Criteria:
Cause Of Decline:
One major stressor of concern at Squaxin is increasing seawater temperature. To improve understanding, Brooke Weigel, a former post doc at Friday Harbor Labs, conducted a temperature study of the Squaxin Island bed; Helen Berry (DNR) summarized the results as follows: “Brooke Weigel’s paper on the effect of temperature on the early life stages of bull kelp showed gametophyte growth and sporophyte production thermal limits at 16C and 18C. Temperature sensor data from Squaxin Island showed that in 2021 the water temperature exceeded the 16C threshold for a total 618 hours, which preceded the 2022 decrease of kelp. In 2022, the water temperature exceeded the 16C threshold for a total of just 360 hours, which preceded the 2023 partial recovery. Perhaps we saw a partial natural recovery of bull kelp in 2023 in part due to the shorter duration over the 16C temperature threshold in 2022.”
In addition to warm temperature, water quality in Southern Puget Sound is a potential culprit. There are many signals that all is not well with water quality in southern Puget Sound. Bull kelp declines are just one. Dungeness crab fisheries have been closed since 2018, due to population declines. Rockfish populations have also declined. This has exacerbated bull kelp declines, since the decline of top-down predators (such as rock fish and lingcod), has contributed to massive levels of grazing by kelp crabs. Ocean acidification (OA) is also a concern. Excess nutrients from multiple inputs exacerbates OA by fueling algae blooms that settle and decompose, releasing CO2 at depth.
