Crab and kelp

Crab Abundance Monitoring

Larval Dungeness Crabs

Swinomish Crab Abundance Monitoring Program (SCAMP) is a study with the goal to build data on larval Dungeness Crab populations: where and when are late-stage larval crab (megalopae) present, do we see the same patterns annually, and is there a relationship with the larval number and adult numbers. The intent is to find a link between larval numbers and future adult Dungeness Crab populations. SCAMP has three light trap sites at Cornet Bay, Rosario Head, and Anacortes.

SCAMP Survey photo of man
SCAMP Survey photo Catch from light trap 1

From April through August, we deploy a light trap made of a 5-gallon water bottle with funnels on the side, a buoyant lid, and a light that turns on at sunset and off at sunrise. The larval crab are attracted to the light and captured in the trap. At each trap check, we count all the Dungeness Crab in a sample (as well as any other crabs that may be present).

SCAMP is partnered with the Pacific Northwest Crab Research Group (PNCRG), a collaboration of partners from tribal, state and federal government, NGOs, and academia. PNCRG has added more sites in the Puget Sound area and the outer Washington coast and hopes to expand to more locations, including more on Whidbey and Camano Island.

For more information on the study, including further details on how the light trap works, visit

Cornet Bay

Cornet Bay light trap’s largest surge of larval Dungeness Crab within a 2 day period.

Metric: 43,861

Megalope count within two-day period at Cornet Bay.

2021 Results