Patterns of seasonal abundance of harbor seals at Netarts and Tillamook Bays, Oregon, were documented by recording numbers of seals hauling out on tidally exposed sand flats in both bays. Harbor seal abundance at Tillamook Bay peaked during pupping (May-June) and molting (August) periods, while peak abundance at Netarts Bay...
Lithothamnion rnuelleri is reported for the first time as one of the main components of rhodolith beds along the Eastern Pacific Ocean based on samples from Washington State (USA), Pacific Baja California (Mexico), southern Nicaragua, and Costa Rica. Individual rhodoliths ranged from fruticose to lumpy in morphology, and bi-sporangial, tetrasporangial,...
What do you say when you have only a minute to explain to a municipal official why keeping track of the number of bird species found in a park may help make decisions about park management? Talk of significant differences among treatments or testing theory will likely meet with glazed...
During July 1970, albacore boats trolling surface jigs (jig boats) had record catches in an area off the mouth of the Columbia River. The jig fishery declined suddenly in late July and was poor throughout the remainder of the summer. No obvious oceanographic changes were correlated with these drastic changes...
Ecological interactions between natural and
hatchery juvenile salmon during their early marine
residence, a time of high mortality, have received little
attention. These interactions may negatively influence
survival and hamper the ability of natural populations to
recover. We examined the spatial distributions and size
differences of both marked (hatchery) and...
Requirements are growing for peer review of the science used for governmental management decisions. This is particularly true for fisheries science, where management decisions are often controversial. The National Oceanic and Atmospheric Administration's National Marine Fisheries Service instituted the Center for Independent Experts (CIE) in 1998 as a national peer-review...
We examined the incidental catches of American shad (Alosa sapidissima) taken during research cruises and in commercial and recreational landings along the Pacific coast of North America during over 30 years of sampling. Shad, an introduced species, was mainly found over the shallow continental shelf, and largest catches and highest...
For widely distributed species at risk, such as Pacific salmon (Oncorhynchus spp.), habitat monitoring is both essential and challenging. Only recently have widespread monitoring programs been implemented for salmon habitat in the Pacific Northwest. Remote sensing data, such as Landsat images, are therefore a useful way to evaluate trends prior...
El ano 2006 representa en dos sentidos una fecha critica para la cuenca del Rio Columbia y para los esfuerzos de recuperacion del salmon y la trucha arcoiris en la region Pacifico Noroeste: el 25 aniversario de la creacion del Consejo para la Conservacion y Poder del Noroeste y el...
The coded wire tag (CWT) database contains detailed information on millions of Pacific salmon
Oncorhynchus spp. released from hatcheries or smolt traps and recovered in the north Pacific Ocean and its tributaries. I used this data set to examine the spatial and temporal variation in the marine distributions of 77...
The fisheries literature embodies critical assumptions about fisherman attitudes and motivations. Common assumptions are that populations of fisherman are homogeneous in motivation and decision making and that they behave in a myopic fashion, ignoring the effects of their fishing activities on the fishery resource. The results of a survey of...
The introduced Asian parasitic bopyrid isopod, Orthione griffenis, was first discovered on the Pacific coast of North America in Washington in 1988 and next in California in 1992. The range of Orthione presently extends from British Columbia to Baja California, where it infests at least two species of the native...
Saltwater-adapted juvenile chinook salmon Oncorhynchus tshawytscha exposed to aromatic and chlorinated compounds, representative of contaminants found in urban estuaries in Puget Sound, have a higher susceptibility to vibriosis than do fish exposed only to the solvent vehicle. Susceptibility to vibriosis was assessed by examining the percent cumulative mortality of the...
One aspect of diadromy that has received little attention is buoyancy regulation in fish moving between freshwater and marine environments. Because of density differences between the two water types, fish must alter their whole-fish density (WFD) or they will become positively (float) or negatively (sink) buoyant as they change environments....
The operation of the Federal Columbia River Power System (FCRPS) has negatively affected threatened and endangered salmonid populations in the Pacific Northwest. Barging Snake River spring Chinook salmon Oncorhynchus tshawytscha through the FCRPS is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. However, little is...
The bivalve Pacific geoduck (Panopea generosa) has been used in the eastern North Pacific Ocean to create proxies for environmental factors such as temperature and oceanographic conditions. This type of research depends upon accurate age determination of Pacific geoducks, which historically was based on shell growth-increment counts. A recent study...
In the California Current coastal boundary zone, the spring transition between downwelling and upwelling conditions, along with the fluctuating structure of the Columbia River plume, creates highly dynamic interactions. In this study, we investigated whether the surface distribution of brachyuran larvae and ichthyoplankton would track the dynamics of the Columbia...
We combine high-resolution bathymetry acquired using the Autonomous Underwater Vehicle ABE with digital seafloor imagery collected using the remotely operated vehicle ROPOS across the axial valley of the Southern Explorer Ridge (SER) to infer the recent volcanic and tectonic processes. The SER is an intermediate spreading ridge located in the...
Although the adverse impact of pathogens on salmon populations in the Pacific Northwest is often discussed and recognized, little is currently known regarding the incidence and corresponding significance of delayed disease-induced mortalities. In the study reported herein, we surveyed the presence and prevalence of selected micro- and macroparasites in out-migrant...
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...