Time filter

Source Type

Bellingham, WA, United States

Hershberger P.K.,U.S. Geological Survey | Gregg J.L.,U.S. Geological Survey | Hart L.M.,U.S. Geological Survey | Moffitt S.,Alaska Department of Fish and Game | And 8 more authors.
Journal of Fish Diseases | Year: 2016

The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE Pacific. An exception to this zoographic pattern occurred among a group of juvenile, age 1+ year Pacific herring from Cordova Harbor, AK in June 2010, which demonstrated an unusually high infection prevalence of 35%. Reasons for this anomaly were hypothesized to involve anthropogenic influences that resulted in locally elevated infection pressures. Interannual declines in infection prevalence from some populations (e.g. Lower Cook Inlet, AK; from 20-32% in 2007 to 0-3% during 2009-13) or from the largest size cohorts of other populations (e.g. Sitka Sound, AK; from 62.5% in 2007 to 19.6% in 2013) were likely a reflection of selective mortality among the infected cohorts. All available information for Ichthyophonus in the NE Pacific, including broad geographic range, low host specificity and presence in archived Pacific herring tissue samples dating to the 1980s, indicate a long-standing host-pathogen relationship. © 2016 John Wiley & Sons Ltd. Source

Losee J.P.,Fish Program | Fisher J.,Oregon State University | Teel D.J.,National Oceanic and Atmospheric Administration | Baldwin R.E.,Fish and Wildlife | And 2 more authors.
Journal of Fish Biology | Year: 2014

The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (SR) in a salmonid host; second, to identify whether SR differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower SR than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between SR and ocean growth and condition of juvenile O. kisutch salmon. © 2014 The Fisheries Society of the British Isles. Source

Williams G.D.,National Oceanic and Atmospheric Administration | Andrews K.S.,National Oceanic and Atmospheric Administration | Farrer D.A.,Fish Program | Levin P.S.,National Oceanic and Atmospheric Administration
Transactions of the American Fisheries Society | Year: 2010

The bluntnose sixgill shark Hexanchus griseus is a wide-ranging marine predator and the largest predatory shark in Puget Sound. Biological characteristics of the Puget Sound bluntnose sixgill shark population remain largely undocumented, despite a recent escalation in recreational angling for the species. Standardized longline sampling, supplemented with other opportunistic collections, was used to collect size, sex ratio, and relative catch rate data at three locations during 2006-2008. Fishing trials were also used to examine the effect of soak time, fishing depth, and time of day on catch rates. Captured bluntnose sixgill sharks were exclusively subadults (175-315 cm total length) found in approximately equal sex ratios in all seasons. Catch rates were highest in Elliott Bay, the urbanized port of Seattle, Washington, and were not affected by sampling season. Catch information derived from hook timers implies that the sharks locate and encounter baited hooks relatively rapidly (<2 h); diel fishing trials suggest some trend toward lower catch rates at shallower sites during the day. Data collected in this study provide some basic context for informing management decisions associated with a large marine predator in the Puget Sound-Georgia Basin ecosystem and improve our basic understanding of bluntnose sixgill shark biology in the region. © American Fisheries Society 2009. Source

Yoo J.-W.,Korea Institute of Coastal Ecology Inc | Lee Y.-W.,Fish Program | Ruesink J.L.,University of Washington | Lee C.-G.,Korea Institute of Coastal Ecology Inc | And 8 more authors.
Environmental Monitoring and Assessment | Year: 2010

The coast of the Korean peninsula experiences a range of human impacts, including pollution, shipping, reclamation, and aquaculture, that have motivated numerous local studies of macrobenthic organisms. In this paper, 1,492 subtidal stations were compiled from 23 studies (areas) to evaluate environmental quality on a broader scale. A common index in biomonitoring, Shannon-Wiener evenness proportion (SEP), could not incorporate azoic or single-species samples. This shortcoming was overcome by developing an inverse function of SEP (ISEP), which was positively correlated with independent measures of water quality available for nine sites and was not biased by the size of the sampling unit. Additionally, at Shihwa Dike, where samples were collected before and after reinstating a tidal connection with the ocean, ISEP values improved over time, as expected. Thus, it is now possible to assign Korean subtidal sites to seven ISEP "grades" and to use their values and trends to guide coastal management. © 2009 Springer Science+Business Media B.V. Source

Williams G.D.,Pacific States Marine Fisheries Commission | Andrews K.S.,National Oceanic and Atmospheric Administration | Katz S.L.,Channel Islands National Marine Sanctuary | Moser M.L.,National Oceanic and Atmospheric Administration | And 3 more authors.
Journal of Fish Biology | Year: 2012

The detailed movements of 32 acoustically tagged broadnose sevengill shark Notorynchus cepedianus were documented in and around north-east Pacific Ocean estuarine embayments from 2005 to 2007. Arrangements of passive acoustic receivers allowed analysis of movement at several spatial scales, with sex and size examined as possible factors influencing the pattern and timing of these movements. Notorynchus cepedianus exhibited a distinctly seasonal pattern of estuary use over three consecutive years, entering Willapa Bay in the spring, residing therein for extended periods of time during the summer and dispersing into nearshore coastal habitats and over the continental shelf during the autumn. Notorynchus cepedianus within Willapa Bay showed spatio-temporal patterns of segregation by size and sex, with males and small females using peripheral southern estuary channels early in the season before joining large females, who remained concentrated in central estuary channels for the entire season. Individuals displayed a high degree of fidelity not only to Willapa Bay (63% were documented returning over three consecutive seasons), but also to specific areas within the estuary, showing consistent patterns of site use from year to year. Cross-estuary movement was common during the summer, with most fish also moving into an adjacent estuarine embayment for some extent of time. Most winter and autumn coastal detections of N. cepedianus were made over the continental shelf near Oregon and Washington, U.S.A., but there were also examples of individuals moving into nearshore coastal habitats further south into California, suggesting the feasibility of broad-scale coastal movements to known birthing and nursery grounds for the species. These findings contribute to a better understanding of N. cepedianus movement ecology, which can be used to improve the holistic management of this highly mobile apex predator in regional ecosystems. © 2012. Source

Discover hidden collaborations