Juvenile Chinook Salmon Mortality in a Snake River Reservoir: Smallmouth Bass Predation Revisited

2018 ◽  
Vol 147 (2) ◽  
pp. 316-328 ◽  
Author(s):  
John M. Erhardt ◽  
Kenneth F. Tiffan ◽  
William P. Connor
Keyword(s):  
Chinook Salmon ◽  
Smallmouth Bass ◽  
Snake River ◽  
Juvenile Chinook Salmon ◽  
River Reservoir ◽  
Juvenile Chinook

Effects of surgically and gastrically implanted radio transmitters on swimming performance and predator avoidance of juvenile chinook salmon (Oncorhynchus tshawytscha)

1998 ◽  
Vol 55 (4) ◽  
pp. 781-787 ◽  
Author(s):  
Noah S Adams ◽  
Dennis W Rondorf ◽  
Scott D Evans ◽  
Joseph E Kelly ◽  
Russell W Perry
Keyword(s):  
Body Weight ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Swimming Performance ◽  
Smallmouth Bass ◽  
Control Fish ◽  
Entire Study ◽  
Juvenile Chinook Salmon ◽  
Surgical Implants ◽  
Juvenile Chinook

Radiotelemetry data are often used to make inferences about an entire study population; therefore, the transmitter attachment method should be the one that least affects the study animal. Juvenile chinook salmon (Oncorhynchus tshawytscha) <120 mm in fork length (FL) with either gastrically or surgically implanted transmitters had significantly lower critical swimming speeds than control fish 1 and 19-23 days after tagging. For fish >120 mm FL, fish with gastric implants swam as well as controls 1 day but not 19-23 days after tagging. In contrast, fish with surgical implants swam as well as controls 19-23 days but not 1 day after tagging. During predation trials, fish with gastric or surgical implants were eaten by smallmouth bass (Micropterus dolomieu) in significantly greater numbers than controls. We do not recommend implanting transmitters (representing 4.6-10.4% of the fish's body weight) in fish <120 mm FL. Furthermore, surgical implants (representing 2.2-5.6% of the fish's body weight) may be the preferred method for biotelemetry studies of juvenile chinook salmon >120 mm FL.

Vulnerability to predation and physiological stress responses in juvenile chinook salmon (Oncorhynchus tshawytscha) experimentally infected with Renibacterium salmoninarum

1998 ◽  
Vol 55 (7) ◽  
pp. 1599-1606 ◽  
Author(s):  
Matthew G Mesa ◽  
Thomas P Poe ◽  
Alec G Maule ◽  
Carl B Schreck
Keyword(s):  
Stress Responses ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Physiological Stress ◽  
Smallmouth Bass ◽  
Control Fish ◽  
Infection Level ◽  
Renibacterium Salmoninarum ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

We experimentally infected juvenile chinook salmon (Oncorhynchus tshawytscha) with Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease (BKD), to examine the vulnerability to predation of fish with differing levels of Rs infection and assess physiological change during progression of the disease. Immersion challenges conducted during 1992 and 1994 produced fish with either a low to moderate (1992) or high (1994) infection level of Rs during the 14-week postchallenge rearing period. When equal numbers of treatment and unchallenged control fish were subjected to predation by either northern squawfish (Ptychocheilus oregonensis) or smallmouth bass (Micropterus dolomieui), Rs-challenged fish were eaten in significantly greater numbers than controls by nearly two to one. In 1994, we also sampled fish every 2 weeks after the challenge to determine some stressful effects of Rs infection. During disease progression in fish, plasma cortisol and lactate increased significantly whereas glucose decreased significantly. Our results indicate the role that BKD may play in predator-prey interactions, thus ascribing some ecological significance to this disease beyond that of direct pathogen-related mortality. In addition, the physiological changes observed in our fish during the chronic progression of BKD indicate that this disease is stressful, particularly during the later stages.

Costs of living for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an increasingly warming and invaded world

2012 ◽  
Vol 69 (10) ◽  
pp. 1621-1630 ◽  
Author(s):  
Lauren M. Kuehne ◽  
Julian D. Olden ◽  
Jeffrey J. Duda
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Multiple Stressors ◽  
Freshwater Ecosystems ◽  
Smallmouth Bass ◽  
Interactive Effects ◽  
Physiological Indicators ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Rapid environmental change in freshwater ecosystems has created a need to understand the interactive effects of multiple stressors, with temperature and invasive predators identified as key threats to imperiled fish species. We tested the separate and interactive effects of water temperature and predation by non-native smallmouth bass ( Micropterus dolomieu ) on the lethal (mortality) and sublethal (behavior, physiology, and growth) effects for juvenile Chinook salmon ( Oncorhynchus tshawytscha ) in seminatural stream channel experiments. Over 48 h trials, there was no difference in direct predation with warmer temperatures, but significant interactive effects on sublethal responses of juvenile salmon. Warmer temperatures resulted in significantly stronger and more variable antipredator responses (surface shoaling and swimming activity), while physiological indicators (plasma glucose, plasma cortisol) suggested suppression of physiological mechanisms in response to the combined stressors. These patterns corresponded with additive negative growth in predation, temperature, and combined treatments. Our results suggest that chronic increases in temperature may not increase direct predation over short periods, but can result in significant sublethal costs with negative implications for long-term development, disease resistance, and subsequent size-selective mortality of Pacific salmon.

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