The biodiversity and habitats of the Salish Sea have sustained thriving cultures and livelihoods for thousands of years. Today, with nearly 9 million residents, the region is undergoing significant change in the face of an ever-expanding suite of threats, including climate change impacts and pollution.
As part of the United Nations Decade of Ocean Science for Sustainable Development, in 2022 Hakai Institute launched Sentinels of Change, a decade-long community-centered initiative investigating patterns of biodiversity, change, and resilience. Sentinels currently has five focus areas, primarily in the Salish Sea:
Light Traps
By suspending a light trap—handmade from a water jug, a bucket, funnels, and LED light strips— from an ocean dock, researchers and community participants are able to attract marine organisms, trap them, and count them. Inspired by the work of the Pacific Northwest Crab Research Group, the main focus of the Sentinels Light Trap project is Dungeness crab megalopae, the crab’s last larval stage.
Dungeness crab are of major ecological and cultural importance on the Pacific coast: they have been an important food source for many Indigenous communities for millennia, and are one of the highest-value fisheries in both British Columbia and Washington State. Reported stories on the project can be found here and here.
Autonomous Reef Monitoring Systems (ARMS)
Part of the Global ARMS Programs coordinated by the Smithsonian National Museum of Natural History, this program investigates the development of invertebrates—such as coral, nudibranchs, barnacles, snails and worms—using standardized stacks of PVC plates that mimic natural habitat. These seafloor condominiums are then retrieved annually to see who moved in, helping to monitor ocean health and how pollution (or protection measures) affect biodiversity.
Black and White Tiles
The intertidal zone is naturally exposed to a wide range of environmental variables, including temperature. In recent years, heat waves and cold snaps have become more frequent and more extreme across much of the Pacific coast. The Black and White Tile experiment aims to investigate the effects of extreme temperature events on various sessile organisms—including barnacles, mussels, oysters, snails, seaweeds, and others—in rocky intertidal environments.
Multi-Agency Rocky Intertidal Network (MARINe) Biodiversity Surveys
The MARINe program is one of the largest-spanning and longest-running monitoring networks of its kind, with established sites from Southeast Alaska to Mexico. MARINe surveys use standardized methods to study the diversity, abundance and community composition of algae and invertebrates on rocky intertidal shores. Gathered data is helping reveal the long-term effects of climate change and coastal development on biodiversity. In collaboration with researchers from MARINe, the Sentinels project will be establishing 17 new sites within the Salish Sea, spanning the Washington and BC borders.
Oyster Bags: Investigating Invasive European Green Crab
Over the past forty years the invasive European green crab has made its way northward from California to the coastal waters of British Columbia. Sentinels is using bags of oyster shells—structures that aim to mimic oyster reef habitat in order to recruit crab larvae and juveniles— to investigate the settlement timing of European green crab and potential impacts on native crab species.
Partners
The Sentinels project encompasses partnerships with communities, government agencies, universities, and First Nations across the Salish Sea and beyond. For a detailed listing of Light Trap partners, click here.
Timeframe
Sentinels of Change kicked off in 2022 with the light trap pilot program. Efforts across all five current areas of investigation are ongoing.
Context
The Sentinels project builds on the biodiversity and coastal ecology research that has been ongoing at Hakai Institute for over a decade. The light trap program in particular incorporates community partnerships to draw on place-based knowledge across the diverse communities of the Salish Sea.
Along with gathering vital data, projects like the Light Trap initiative offer training, education, and capacity-building within communities that can be transferable to other local projects and monitoring initiatives. Offering training opportunities and empowering robust approaches to research and data collection continues to be a core part of the Hakai Institute’s mission.
Outcomes
These initiatives are at different stages, but there are some notable highlights. Via the Light Trap program, Sentinels engaged with more than 300 community participants over three seasons enabling them to gather data across the Salish Sea, and beyond.
Three long-term MARINe biodiversity monitoring sites have been set up in the Canadian Salish Sea in 2024, with four more coming in 2025, In parallel, Sentinels supported the set-up of seven MARINe biodiversity sites in Washington, enabling comparable observation throughout the Salish Sea.
Black and white tiles have been placed in the mid-intertidal at six sites in the Salish Sea, and oyster bags for recruiting green crab larvae have also been deployed in the waters around Sooke, British Columbia, where there are established populations of adult green crab.
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