scholarly journals Western Fisheries Research Center--Forage fish studies in Puget Sound

Fact Sheet ◽  
2012 ◽  
Author(s):  
Theresa L. Liedtke
Keyword(s):  
Puget Sound ◽  
Research Center ◽  
Forage Fish

Contributions of adult mortality to declines of Puget Sound Pacific herring

2017 ◽  
Vol 75 (1) ◽  
pp. 319-329 ◽  
Author(s):  
Margaret C Siple ◽  
Andrew O Shelton ◽  
Tessa B Francis ◽  
Dayv Lowry ◽  
Adam P Lindquist ◽  
...  
Keyword(s):  
Age Structure ◽  
Puget Sound ◽  
Adult Mortality ◽  
Forage Fish ◽  
Pacific Herring ◽  
Natural Mortality ◽  
Structured Population Model ◽  
Adult Age ◽  
Age Structured

Abstract Forage fish undergo dramatic changes in abundance through time. Long-term fluctuations, which have historically been attributed to changes in recruitment, may also be due to changes in adult mortality. Pacific herring, a lightly exploited forage fish in Puget Sound, WA, have exhibited shifts in age structure and decreases in spawning biomass during the past 30 years. Here, we investigate changes in adult mortality as a potential explanation for these shifts. Using a hierarchical, age-structured population model, we indicate that adult natural mortality for Puget Sound Pacific herring has increased since 1973. We find that natural mortality has increased for every age class of adult (age 3+), especially age 4 fish, whose estimated mortality has doubled over the survey time period (from M = 0.84–1.76). We demonstrate that long-term shifts in mortality explain changes in age structure, and may explain biomass declines and failure to reach management thresholds for two spawning sites in Puget Sound (Cherry Point and Squaxin Pass). Temporal shifts in natural adult mortality could have negative implications for herring and herring predators. We demonstrate that adult mortality, in addition to recruitment variation, is an important driver for forage fish, which face exceptionally high natural mortality compared with other fishes.

Variable prey consumption leads to distinct regional differences in Chinook salmon growth during the early marine critical period

2020 ◽  
Vol 640 ◽  
pp. 147-169
Author(s):  
MJ Davis ◽  
JW Chamberlin ◽  
JR Gardner ◽  
KA Connelly ◽  
MM Gamble ◽  
...  
Keyword(s):  
Growth Rates ◽  
Chinook Salmon ◽  
Critical Period ◽  
Pacific Salmon ◽  
Puget Sound ◽  
Foraging Strategies ◽  
Forage Fish ◽  
San Juan ◽  
San Juan Islands ◽  
Marine Habitats

Growth during the early marine critical period is positively associated with survival and recruitment for Pacific salmon Oncorhynchus spp., so it is important to understand how certain foraging strategies may bolster growth in estuarine and marine environments. To elucidate how spatiotemporal and demographic differences in diet contribute to growth rate variability, we analyzed stomach contents in tandem with morphometric and hormonal indices of growth for subyearling Chinook salmon O. tshawytscha captured in Puget Sound, Washington, USA. Regional dietary patterns indicated that fish caught in northern Puget Sound ate insects in the estuarine and nearshore habitats, followed by decapod larvae, euphausiids, or forage fish in the offshore zone. In southern Puget Sound, fish ate insects in the estuary but were more likely to eat mysids and other crustaceans in the nearshore zone. In the marine habitats adjacent to the San Juan Islands, subyearlings ate forage fish, and their stomachs were as much as 1.4 to 3 times fuller than salmon captured in other regions. Scale-derived growth rates and insulin-like growth factor-1 levels showed distinct growth advantages for San Juan Islands fish which were strongly associated with the early adoption of piscivory. However, consumption of larger crustaceans such as mysids and euphausiids was also associated with greater relative growth regardless of where individuals were captured. These findings highlight how spatiotemporal differences in prey quantity, prey profitability, and individual foraging strategies result in variable growth rates among salmon populations. Specifically, they emphasize the role of piscivory in promoting early marine growth for out-migrating Chinook salmon.

Persistent organic pollutants in forage fish prey of rhinoceros auklets breeding in Puget Sound and the northern California Current

2014 ◽  
Vol 86 (1-2) ◽  
pp. 367-378 ◽  
Author(s):  
Thomas P. Good ◽  
Scott F. Pearson ◽  
Peter Hodum ◽  
Daryle Boyd ◽  
Bernadita F. Anulacion ◽  
...  
Keyword(s):  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Puget Sound ◽  
California Current ◽  
Forage Fish ◽  
Northern California ◽  
Fish Prey ◽  
Northern California Current

Studying Multilingualism and Group Differences in Adult Communication

2010 ◽  
Vol 17 (3) ◽  
pp. 59-64
Author(s):  
Loraine K. Obler
Keyword(s):  
Older Adults ◽  
Research Center ◽  
Group Differences ◽  
Aging Brain

The focus of this article is on the study of bilingual and multilingual adults at the Howard Goodglass Aphasia Research Center and the Language in the Aging Brain Laboratory by Drs. Obler and Albert along with former students and colleagues. Summaries of studies examining research in healthy bilingual adults, healthy monolingual older adults, and monolingual and bilingual individuals with aphasia are presented.

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