Changes in the spatial distribution of U.S. west coast bottom-trawl effort in relation
to areas of prime habitat for rockfish Sebastes spp. were evaluated between 1992 and 2001. Prime trawlable rockfish habitat (PTRH) was defined based on the spatial distribution of high rockfish catches from logbook data for 1992–1995. Bottom-trawl...
We evaluated how the use of bait as a fish attractant influenced the species and size composition 20 of demersal fishes viewed with a stereo video lander, at 160 sampling sites at Stonewall Bank, a 21 deepwater rocky reef complex in Oregon waters. We also studied the effectiveness of stereo...
Long-term data sets that quantitatively confirm basic ecological theory are rare for field
populations. Highly variable recruitment often causes wide temporal variation in population
age distribution and basic theory for adaptive sex ratio often predicts ‘sex ratio tracking’ to
match the fluctuating age distribution. Using sex-changing shrimp as a model...
Selecting ‘optimal’ strategies to manage Oregon ocean shrimp is challenged by uncertain and variable natural mortality,
recruitment, and growth. Fishery management is focused on measures to prevent long-term biological damage to the stock,
to protect age-1 shrimp from overharvest and to sustain long term fishery benefits. Developing harvest strategies such...
We describe the development and practical field testing of a rugged, unbaited video lander as a visual survey tool for fishes inhabiting structurally complex, high-relief, deepwater rocky reefs. Our autonomous, high-resolution, low-light, color video lander system utilized a smooth frame design that incorporated a series of breakaway attachments and inexpensive...
We used acoustic telemetry techniques to study the movements of eight species of Pacific rockfish (genus Sebastes) inhabiting Siletz Reef, a high-relief rocky reef complex on the Oregon coast. Our primary interest was evaluating potential residence times for rockfish species in small, no-take marine protected areas (MPAs) like those recently...
We evaluated the effect of barotrauma on the behavior of nine species of Pacific rockfish Sebastes spp. after hook-and-line capture and release using a video-equipped underwater release cage. Sampling was conducted across a range of bottom depths (12-194 m), mostly where barotrauma resulting from an expanded swim bladder and gaseous...
Temperate nearshore reefs along the Pacific coast of North America are highly valuable to commercial and recreational fisheries yet comprise a small fraction of the seabed. Monitoring fisheries resources in this region is difficult; high-relief structural complexity and adverse sea conditions have led to a paucity of information on temperate...
We evaluated the external signs of barotrauma and 48-h post-recompression survival for 17 54 canary and 81 yelloweye rockfish captured at depths of 46-174 m, much deeper than a 18 similar prior experiment, but within the depth range of recreational fishery catch and 19 discard. Survival was measured using specialized...
Oregon ocean shrimp annual harvest relies on the successful recruitment and growth of age one shrimp. Changes in oceanic conditions appear to have major impacts on recruitment, spatial abundance and growth rates. Successful recruitment has been identified with the timing and strength of the spring transition generating oceanic conditions favorable...