Forty years of change in forage fish and jellyfish abundance across greater Puget Sound, Washington (USA): anthropogenic and climate associations

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.

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

Marine Ecology Progress Series ◽

10.3354/meps13279 ◽

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.

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

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2014.06.042 ◽

2014 ◽

Vol 86 (1-2) ◽

pp. 367-378 ◽

Cited By ~ 16

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

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Summary of project NR-106 activity at CVE Precommissioning School, Puget Sound Navy Yard, Bremerton, Washington. (OSRD, 1945; Publ. Bd., No. 4449.).

PsycEXTRA Dataset ◽

10.1037/e422062004-001 ◽

1946 ◽

Cited By ~ 1

Author(s):

B. J. Covner ◽

M. S. Viteles

Keyword(s):

Puget Sound

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VA Puget Sound HCS Shakes as Earth Quakes

PsycEXTRA Dataset ◽

10.1037/e511162006-007 ◽

2001 ◽

Author(s):

Joe Barison

Keyword(s):

Puget Sound

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Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

Case Studies in the Environment ◽

10.1525/cse.2019.002147 ◽

2019 ◽

Vol 3 (1) ◽

pp. 1-9

Author(s):

Robert M. Anderson ◽

Amy M. Lambert

Keyword(s):

Ecological Restoration ◽

Native Species ◽

Puget Sound ◽

A Value ◽

The Social ◽

Remote Island ◽

Scientific Truth ◽

Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

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