Sentinels of Change 2025 Light Trap Network Report

Sunset at the Echo Bay light trap photo by Priya Payment

The Sentinels of Change light trap network monitors the arrival and abundance of Dungeness crab (Metacarcinus magister) megalopae—the final larval stage before settlement. Established in 2022 as an expansion of the Pacific Northwest Crab Research Group’s monitoring program in Puget Sound (Buckner et al. 2022, 2025), the network connects scientists, resource managers, and community partners to collect standardized data along the coast from Haida Gwaii to southern Puget Sound.

In 2025, the network completed its fourth year of monitoring with approximately 250 participants across 29 sites. Partners operated light traps from April 15 to September 1, recording 26,481 Dungeness crab megalopae and juvenile instars across the network, with peak larval arrival occurring in June. The highest catches were recorded at Silva Bay (Gabriola Island) and Quathiaski Cove (Quadra Island).

The network also supported collaborative research, including studies on population genetics, climate impacts on juvenile crab development, and early detection of invasive European green crab (Carcinus maenas) using environmental DNA.

Click here to read the full report.

Report prepared by Lauren Krzus and Heather Earle | Hakai Institute