Polychlorinated Biphenyl Concentrations in Adult Chinook Salmon (Oncorhynchus tshawytscha) Returning to Coastal and Puget Sound Hatcheries of Washington State

2005 ◽  
Vol 39 (18) ◽  
pp. 6944-6951 ◽  
Author(s):  
Brian R. Missildine ◽  
Roger J. Peters ◽  
Gerardo Chin-Leo ◽  
Douglas Houck

2017 ◽  
Vol 74 (8) ◽  
pp. 1173-1194 ◽  
Author(s):  
Brandon Chasco ◽  
Isaac C. Kaplan ◽  
Austen Thomas ◽  
Alejandro Acevedo-Gutiérrez ◽  
Dawn Noren ◽  
...  

Conflicts can arise when the recovery of one protected species limits the recovery of another through competition or predation. The recovery of many marine mammal populations on the west coast of the United States has been viewed as a success; however, within Puget Sound in Washington State, the increased abundance of three protected pinniped species may be adversely affecting the recovery of threatened Chinook salmon (Oncorhynchus tshawytscha) and endangered killer whales (Orcinus orca) within the region. Between 1970 and 2015, we estimate that the annual biomass of Chinook salmon consumed by pinnipeds has increased from 68 to 625 metric tons. Converting juvenile Chinook salmon into adult equivalents, we found that by 2015, pinnipeds consumed double that of resident killer whales and six times greater than the combined commercial and recreational catches. We demonstrate the importance of interspecific interactions when evaluating species recovery. As more protected species respond positively to recovery efforts, managers should attempt to evaluate tradeoffs between these recovery efforts and the unintended ecosystem consequences of predation and competition on other protected species.



2019 ◽  
Vol 77 (4) ◽  
pp. 1503-1515 ◽  
Author(s):  
William H Satterthwaite ◽  
Kelly S Andrews ◽  
Brian J Burke ◽  
Jennifer L Gosselin ◽  
Correigh M Greene ◽  
...  

Abstract Preseason abundance forecasts drive management of US West Coast salmon fisheries, yet little is known about how environmental variability influences forecast performance. We compared forecasts of Chinook salmon (Oncorhynchus tshawytscha) against returns for (i) key California-Oregon ocean fishery stocks and (ii) high priority prey stocks for endangered Southern Resident Killer Whales (Orcinus orca) in Puget Sound, Washington. We explored how well environmental indices (at multiple locations and time lags) explained performance of forecasts based on different methods (i.e. sibling-based, production-based, environment-based, or recent averages), testing for nonlinear threshold dynamics. For the California stocks, no index tested explained >50% of the variation in forecast performance, but spring Pacific Decadal Oscillation and winter North Pacific Index during the year of return explained >40% of the variation for the sibling-based Sacramento Fall Chinook forecast, with nonlinearity and apparent thresholds. This suggests that oceanic conditions experienced by adults (after younger siblings returned) have the most impact on sibling-based forecasts. For Puget Sound stocks, we detected nonlinear/threshold relationships explaining >50% of the variation with multiple indices and lags. Environmental influences on preseason forecasts may create biases that render salmon fisheries management more or less conservative, and therefore could motivate the development of ecosystem-based risk assessments.



2021 ◽  
Vol 78 (1) ◽  
pp. 68-77
Author(s):  
Catherine S. Austin ◽  
Timothy E. Essington ◽  
Thomas P. Quinn

Median timing of reproduction in salmonid populations is generally consistent among years, reflecting long-term patterns of natural selection from characteristics of the local environment. However, altered selection from factors related to climate change or human intervention might shift timing over generations, with implications for the population’s persistence. To study these processes, we modeled median timing of redd (nest) counts as an index of spawning timing by natural-origin Chinook salmon (Oncorhynchus tshawytscha) in the Skagit River system in Washington State, USA. Over the last 2–6 decades, natural-origin salmon have been spawning later by 0.03–0.52 days·year–1, while a naturally spawning group that is influenced by strays from a hatchery has been spawning earlier by 0.19 days·year–1. Trends in the spawning timing of hatchery-origin strays may reflect opposing selection from the hatchery, where egg take for propagation has become earlier by 0.58 days·year–1. As mean August river temperatures have risen over the period of record, hatchery timing trends may be moving in the opposite direction from the plastic or adaptive patterns expressed by natural-origin fish.



1991 ◽  
Vol 48 (9) ◽  
pp. 1685-1690 ◽  
Author(s):  
Gerald T. Ankley ◽  
Donald E. Tillitt ◽  
John P. Giesy ◽  
Paul D. Jones ◽  
David A. Verbrugge

Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), derived via the H4IIE rat hepatoma cell bioassay, were measured in polychlorinated biphenyl (PCB) containing extracts of flesh (dorsal muscle) and egg samples from 10 spawning chinook salmon (Oncorhynchus tshawytscha) from Lake Michigan. There was a marked maternal transfer of both TCDD-EQ and PCBs, and potency of the PCB mixture (expressed as picograms of TCDD-EQ per microgram of PCB) in eggs was 2.5 times greater than potency of the PCB mixture in dorsal muscle of the fish. There was a statistically significant, inverse relationship between the total concentration of PCBs in eggs and hatching success of the fish, with an effect concentration that corresponded to approximately 100 pg TCDD-EQ/g egg. Our results, based on a relatively small sample size, suggest that PCBs, in particular those with TCDD-type activity, may have influenced reproductive success of the fish.



Orca ◽  
2018 ◽  
Author(s):  
Jason M. Colby

The call came by ship-to-shore radio from a Washington State ferry. The skipper on the Seattle-Bremerton route had just spotted killer whales headed south, and he thought Ted Griffin should know. Shouting his thanks, the aquarium owner raced down the dock, leapt into Pegasus, and tore off in the direction of the sighting. Clocked at sixty miles per hour, the shallow-draft runabout may have been the fastest boat on Puget Sound, and it overtook the orcas near Vashon Island. But as Griffin throttled down, he realized to his disbelief that someone else was already chasing them. There, clear as day, was a blue helicopter hovering over the whales. Incensed, Griffin steered Pegasus closer, until he could almost touch the helicopter’s pontoons. Looking up, he spotted a burly man leaning out the cabin door and eying the pod. “Get away from my whales!” Griffin shouted. “Your whales?” the man laughed. “You’ll have to catch them first.” It was the first time Griffin had met Don Goldsberry, ex-fisherman and animal collector for the Point Defiance Aquarium (formerly the Tacoma Aquarium). The two men’s shared pursuit of orcas would soon bind them together. On this day, however, Griffin left feeling a bit embarrassed, having behaved, as he put it, “like a rancher possessive of his herd.” Some part of him knew his quest to capture and befriend a killer whale was becoming unhealthy. He had a struggling aquarium in Seattle and a growing family on Bainbridge Island. Orcas were his obsession, but they weren’t paying the bills. At home, he still talked and laughed with Joan and played with his little sons, Jay and John. But he had whales on the brain. He dreamed of them when asleep and sometimes mumbled about them when awake. With each reported sighting, he dropped everything—to Joan’s increased annoyance. In time, Griffin had come to see patterns in the animals’ migrations and behavior. He noted that they appeared when chinook salmon were running and that they seemed to cling to the west side of Puget Sound when headed south and to the east side when swimming north.



2011 ◽  
Vol 68 (2) ◽  
pp. 232-240 ◽  
Author(s):  
Elisabeth J Duffy ◽  
David A Beauchamp

We examined the effect of early marine entry timing and body size on the marine (smolt-to-adult) survival of Puget Sound Chinook salmon ( Oncorhynchus tshawytscha ). We used data from coded wire tag release groups of hatchery Chinook salmon to test whether hatchery release date, release size, and size in offshore waters in July and September influenced marine survival. Marine survival was most strongly related to the average body size in July, with larger sizes associated with higher survivals. This relationship was consistent over multiple years (1997–2002), suggesting that mortality after July is strongly size-dependent. Release size and date only slightly improved this relationship, whereas size in September showed little relationship to marine survival. Specifically, fish that experienced the highest marine survivals were released before 25 May and were larger than 17 g (or 120 mm fork length) by July. Our findings highlight the importance of local conditions in Puget Sound (Washington, USA) during the spring and summer, and suggest that declines in marine survival since the 1980s may have been caused by reductions in the quality of feeding and growing conditions during early marine life.



2004 ◽  
Vol 61 (9) ◽  
pp. 1756-1770 ◽  
Author(s):  
Gregory T Ruggerone ◽  
Frederick A Goetz

We tested for competition between pink salmon (Oncorhynchus gorbuscha) and chinook salmon (Oncorhynchus tshawytscha) originating from rivers in the Puget Sound area using coded-wire-tagged subyearling hatchery chinook salmon. Following a 2-year life cycle, many juvenile pink salmon enter Puget Sound in even-numbered years, whereas few migrate during odd-numbered years. During 1984–1997, juvenile chinook salmon released during even-numbered years experienced 59% lower survival than those released during odd-numbered years, a trend consistent among 13 chinook salmon stocks. Lower even-numbered-year survival of chinook salmon was associated with reduced first-year growth and survival and delayed maturation. In contrast, chinook salmon released into coastal streams, where few pink salmon occur, did not exhibit an alternating-year pattern of survival, suggesting that the interaction occurred within Puget Sound and the lower Strait of Georgia. Unexpectedly, the survival pattern of Puget Sound chinook salmon was reversed prior to the 1982–1983 El Niño: chinook salmon survival was higher when they migrated with juvenile pink salmon during 1972–1983. We hypothesize that chinook salmon survival changed as a result of a shift from predation- to competition-based mortality in response to recent declines in predator and prey abundances and increases in pink salmon abundance. Alternating-year mortality accounted for most of the 50% decline in marine survival of chinook salmon between 1972–1983 and 1984–1997.



2014 ◽  
Vol 71 (1) ◽  
pp. 162-180 ◽  
Author(s):  
James P. Meador

This study examined the rate of survival for hatchery-reared, ocean-type juvenile Chinook salmon (Oncorhynchus tshawytscha) to the adult life stage in relation to contamination status for estuaries where they temporarily reside. The hypothesis tested here is that juvenile Chinook from Puget Sound (Washington, USA) area hatcheries exhibit differential survival as categorized by the state of contamination in their respective natal estuaries. Data were examined from 20 hatcheries that released fish to 14 local estuaries in the Greater Puget Sound area over 37 years (1972–2008). A parallel analysis was also conducted for coho salmon (Oncorhynchus kisutch) outmigrating from many of the same hatcheries. For all years combined, juvenile Chinook transiting contaminated estuaries exhibited an overall rate of survival that was 45% lower than that for Chinook moving through uncontaminated estuaries, which was confirmed when tested year by year. The results for coho originating from the same hatcheries and sharing a similar marine distribution indicated no substantial differences among estuaries. These observations have important implications for wild juvenile Chinook that spend more time in the estuary compared with hatchery-reared fish.



2017 ◽  
Vol 115 (4) ◽  
pp. 544-555 ◽  
Author(s):  
Anna N. Kagley ◽  
Joseph M. Smith ◽  
Kurt L. Fresh ◽  
Kinsey E. Frick ◽  
Thomas P. Quinn


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