We used a combination of seabird data (both fishery-dependent and fishery-independent) and fishing-effort data to evaluate the relative fisheries risk of five west coast groundfish fisheries and oneshrimp fishery to black-footed (Phoebastria nigripes), short-tailed (P. albatrus) and Laysan albatrosses(P. immutabilis). To assess risk, an overlap index was derived as the...
Many endemic species, particularly those on
remote islands, have been driven to extinction or near extinction
by anthropogenic influences. The short-tailed albatross
Phoebastria albatrus once numbered in the millions
but was thought to be extinct by the mid 20th century.
Albatrosses, of the family Diomedeidae, are among the most
threatened...
Satellite imagery of chlorophyll a concentration (chl a) provides the only holistic perspective
of productivity in marine ecosystems worldwide, yet its utility for understanding and
predicting the distribution of upper trophic-level predators remains equivocal. We tested the
hypothesis that remotely sensed chl a measurements spanning a decade can predict marine...
Variable ocean conditions can greatly impact
prey assemblages and predator foraging in marine ecosystems.
Our goal was to better understand how a change in
ocean conditions influenced dietary niche overlap among
a suite of midtrophic-level predators. We examined the
diets of three fishes and one seabird off central Oregon
during...
Non-breeding sooty shearwaters are the most abundant seabird in the California Current Large Marine Ecosystem (CCLME) during boreal spring and summer months. This, combined with relatively great energy demands, reliance on patchy, shoaling prey (krill, squid, and forage fishes), and unconstrained mobility free from central-place-foraging demands-make shearwaters useful indicators of...
In 2014, the California Current (~28˚–48˚N) saw average, or below average, coastal upwelling and relatively low productivity in most locations, except from 38˚–43˚N during June and July. Chlorophyll-a levels were low throughout spring and summer at most locations, except in a small region around 39˚N. Catches of juvenile rockfish (an...
Bird scaring lines (BSLs) protect longline fishing gear from seabird attacks, save bait, reduce incidental seabird mortality and are the most commonly prescribed seabird bycatch mitigation measure worldwide. We collaborated with fishermen to assess the efficacy of applying BSL regulations from the demersal longline sablefish fishery in Alaska to a...
Ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects of ocean state propagating to higher trophic levels. In many regions throughout their range, common murre (Uria aalge) exhibit narrow dietary breadth in feeding chicks and therefore are vulnerable to recruitment failures of dominant prey...
As central-place foragers, seabirds from colonies located close to multiple and/or productive marine habitats might experience increased foraging opportunities and enhanced resilience to food shortages. We tested whether this hypothesis might explain divergent trends in 3 populations of black-legged kittiwakes Rissa tridactyla, a surface-feeding piscivore, in the eastern Bering Sea....
In 2013, the California current was dominated by
strong coastal upwelling and high productivity. Indices
of total cumulative upwelling for particular coastal
locations reached some of the highest values on record.
Chlorophyll a levels were high throughout spring and
summer. Catches of upwelling-related fish species were
also high. After a...