This article addresses concerns among Oregon’s fishing community about the potential effects of wave-energy devices on Dungeness crab movement, behavior, and harvests. Though crabbing has been a mainstay of west coast economies for decades, little information had previously been collected or analyzed on adult Dungeness crab movement in general and for the Oregon coast in specific. To begin addressing this critical information gap, the Oregon Wave Energy Trust (OWET), the Oregon Dungeness Crab Commission (ODCC), and Oregon Sea Grant added value to a planned baseline study conducted by H.T. Harvey and Associates. Crabs collected for the baseline study were tagged after they were measured and before they were returned to the ocean. Commercial crabbers who then caught the tagged crabs were paid $20 for each tag returned to Oregon Sea Grant.

The resulting data revealed that crabs travelled distances ranging from 0.27 km to 90.68 km; 65% of crabs traveled less than 20 km, 77.7% of crabs traveled less than 30 km, and 95.5% of crabs traveled less than 50 km. Crabs moved primarily in the alongshore direction, with minimal across-shelf movement.

The distances reported here represent a minimum distance that crabs traveled. Additional tags were returned with general locations indicating that crabs may be moving as far north as Tillamook, Oregon (approximately 140 miles). It remains unknown to what degree Dungeness crab movements vary from year to year. The findings of this study should be treated as preliminary rather than definitive. Additional studies are needed to fully characterize adult Dungeness crab movements in Oregon’s coastal waters.

Authors: 
K. Hildenbrand, A. J. Gladics, & R. Eder
Short Description: 
Oregon's fishing community is concerned about the potential effects that wave energy conversion devices would have on Dungeness crab movement.
Product Number: 
ORESU-T-11-001
Entry Date: 
Tuesday, July 17, 2012
Length: 
21 pp.
Size and Format: 
Online, 8 1/2 x 11
Miscellaneous: 
Technical report prepared by Oregon Sea Grant for Oregon Wave Energy Trust and Oregon Dungeness Crab Commission.
Year of Publication: 
2011
How to Order: 

Available only online from the National Sea Grant Library