Importance of water temperature in the management of American river Chinook Salmon and steelhead: How cool does it really need to be and when? Rob Titus California Department of Fish & Wildlife Fisheries Branch, Sacramento Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW Save the American River Association Effie Yeaw Nature Center December 6, 2014
Periods of flow and temperature management on the lower American River Pre-Folsom Project: up to about 1950 Spring-run Chinook still in the system Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Spring-run Chinook salmon still in the system prior to construction of the Folsom Project Spring run Fall run Possibly the last spring run to ascend the American River above Folsom
Periods of flow and temperature management on the lower American River Pre-Folsom Project: up to about 1950 Era of USBR control: 1950s c. 1990 SWRCB Water Right Decision D-893 500 cfs from mid-september through December 250 cfs from Jan. 1 through September 15 Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Periods of flow and temperature management on the lower American River Judge Hodge Era: 1990s Formation of American River Operations Group (AROG) Court mandated studies to reduce uncertainty ESA listing of Central Valley steelhead: 1997 Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Periods of flow and temperature management on the lower American River Recent temperature management: 2000s 2001 studies on juvenile steelhead oversummering 2004 discovery of rosy anus in juvenile steelhead 2007 Flow Management Standard 2009 OCAP Biological Opinion for the CVP/SWP Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Importance of water temperature Question: How does temperature affect salmon and steelhead in the lower American River? Juvenile Chinook salmon, Dry Creek, Placer Co. Photo: Bill Snider
Fish are ectotherms! Chinook salmon (Oncorhynchus tshawytscha) Steelhead rainbow trout (Oncorhynchus mykiss) Original watercolors by Detlef Buettner, ADFG
Life is split between fresh and salt water anadromous life cycle Eggs Embryos Adults Spawning Rearing Fry Parr Sub-adults Ocean entry & rearing Emigration Smolts Salmon trollers off Point Ross, Sonoma Co. Photo: Rob Titus
Basic habitat needs of salmon & steelhead in fresh water 1. Sufficient flow of cool, well-oxygenated water 2. Clean gravels for redds Flow and water temperature limit Chinook salmon and steelhead production on the American River Lower Sunrise Bar at 1,500 cfs. Photo: Rob Titus
Competing temperature demands between Chinook salmon and steelhead Juvenile steelhead oversummering Need daily mean water temperature of 65 F or lower Chinook salmon spawning in fall Water temperature below 60 F (58 F or less for eggs) Limited coldwater pool in Folsom Lake Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Steelhead Temperature Requirements 80 F Acute effects Lethal temp for steelhead with chronic exposure 1 76 72 68 Preferred temp for steelhead growth 3 Steelhead immune system at peak function 4 64 60 Preferred temp for steelhead spawning & incubation 1 56 1 Moyle (2002) 2 Present study 3 Myrick and Cech (2000) 4 W. Cox, DFG, pers. comm.
Assessment of juvenile steelhead on the lower American River: 2001 and onward Sampling juvenile steelhead at Lower Sunrise Bar in 2004 with average daily water temperatures above 65 F Photo: Sacramento Bee
300 250 200 150 100 2001 Mean individual growth rates of PIT-tagged steelhead 0.82 mm / day n = 9 50 0 Mean ± SD FL (mm) 300 250 200 150 100 50 0 300 250 200 150 100 50 2002 2004 1.07 mm / day n = 47 1.02 mm / day n = 38 Generally, juvenile steelhead grow very quickly on the lower American River 0 12 Apr 16 20 Jun 24 28 32 Aug 36 40 Oct 44 Julian Week
Juvenile steelhead with high condition factor K = 1.37 Juvenile steelhead in poor condition, Secret Ravine (Dry Creek drainage), 12 Nov 2004 K = 0.78
In August 2004, we began to observe signs of disease among wild steelhead sampled in the lower American River Anal vent inflammation in juvenile steelhead at Arden Bar, 24 Aug 2004
State of California Department of Fish and Game Location FISH PATHOLOGIST REPORT Date Lower American River October 6, 2004 Species Steelhead Holding Area NA wild fish Parasites and Disease Condition Fish presented with rosy anus. Internally, fish showed inflammation of the posterior intestine. Moderate to high numbers of mixed, motile bacteria were observed in scrapes of inflamed areas. Aside from the rosy anus, the steelhead appeared to be in excellent body condition. Comments The bacteria infection is the likely cause of the rosy anus. Steelhead may be more susceptible to bacteria infection due to stress from higher than optimal water temperatures. Fish were ~8 inches in length. Submitted By Joe Maret, DVM, Senior Fish Pathologist, CDFG Anal prolapse Photos: Rob Titus, CDFW
Temperature, in 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 Annual thermograph on the lower American River 2001 2002 2003 2004 2005 Operations group temperature target Mar-01 May-01 Aug-01 Nov-01 Feb-02 May-02 Aug-02 Nov-02 Feb-03 May-03 Aug-03 Nov-03 Feb-04 May-04 Aug-04 Nov-04 Feb-05 May-05 Aug-05 Nov-05 Date Source: Russ Yaworsky, USBR Hazel Avenue Bridge William Pond Park Watt Avenue Bridge
Steelhead Temperature Requirements 80 F Acute effects Lethal temp for steelhead with chronic exposure 1 76 72 Chronic effects Bacterial infection in steelhead > rosy anus 2 68 Summer temperature standard for steelhead Preferred temp for steelhead growth 3 Steelhead immune system at peak function 4 Preferred temp for steelhead spawning & incubation 1 64 60 56 1 Moyle (2002) 2 Present study 3 Myrick and Cech (2000) 4 W. Cox, DFG, pers. comm.
Protective regulations for wild steelhead Barbless hooks Zero bag limit Facilitate catch-and-release fisheries Source: www.flyguysoutfitting.com/barbless.html
Post-release mortality of steelhead/rainbow and cutthroat trout* Post-release mortality (%) Hooking mortality increases sharply above 64 F 60 50 40 30 20 10 0 40 50 60 70 80 Water temperature (F) * Fish captured with artificial lures and flies
Steelhead Temperature Requirements 80 F Acute effects Lethal temp for steelhead with chronic exposure 1 76 72 Chronic effects Bacterial infection in steelhead 2. Sharp increase in hooking mortality 5 Summer temperature standard for steelhead Preferred temp for steelhead growth 3 Steelhead immune system at peak function 4 Preferred temp for steelhead spawning & incubation 1 68 64 60 56 1 Moyle (2002) 2 Present study 3 Myrick and Cech (2000) 4 W. Cox, DFG, pers. comm. 5 Titus & Vanicek (1988), others
Rearing space in bar complex habitats decreases with drop in flow 1,500 cfs in October 2004 Riffle at Arden Bar Are steelhead displaced into deeper water habitats where predators are abundant? 1,000 cfs in September 2004 Photos: Mike Brown, DFG
Large (30-40 species), complex warmwater fish community with high predation risk Steelhead Temperature Requirements Acute effects Lethal temp for steelhead with chronic exposure 1 80 76 Upper limit for striped bass rearing 1 86 Temp range for adult largemouth bass growth 1 72 Temp range for pikeminnow rearing 1 Chronic effects Bacterial infection in steelhead 2. Sharp increase in hooking mortality Summer temperature standard for steelhead Preferred temp for steelhead growth 3 68 64 Temp range for striped bass spawning: Apr- Jun 1 Temp range for largemouth bass spawning: Apr- Jun 1 Temp range for pikeminnow spawning: Apr- May 1 Small (4-5 species), simple coldwater fish community with low predation risk Steelhead immune system at peak function 4 Preferred temp for steelhead spawning & incubation 1 60 56 1 Moyle (2002) 2 Present study 3 Myrick and Cech (2000) 4 W. Cox, DFG, pers. comm. 5 Titus & Vanicek (1988), others
Temperature effects on Chinook salmon spawning on the lower American River Aerial view of Chinook salmon redds at Upper Sunrise Photo: CDFW
Chinook salmon initiate spawning when mean daily water temperature falls below 60 F No. of Redds (thousands) Chinook salmon redd counts by flight, 1991-1995 6 80 4 Mean flow: 1000 cfs 60 2 40 0 20 6 80 4 600 cfs 60 2 40 0 20 6 80 1750 cfs 4 60 2 40 0 20 6 80 1250 cfs 4 60 2 40 0 20 6 80 2500 cfs 4 60 2 40 0 20 01-Sep 01-Oct 01-Nov 01-Dec 01-Jan 01-Feb Water temp. (F) TOTAL REDDS WATERTEMP (F)
High pre-spawning mortality of Chinook at low flow and high temperature In 2001, about two-thirds of adult females died before spawning Very large spawner population (over 150,000 adults) Suitable spawning conditions ~2,500 cfs to accommodate ~70,000 adults Water temperature below 60 F (58 F or less for eggs) Salmon anglers on the American River at Sailor Bar. Photo: Terry Linton, CDFW
Bottom-line temperature considerations Daily mean water temperature of 65 F or less at Watt Avenue to protect steelhead Regulatory connections ESA recovery, Fish and Game Code 5937 Steelhead catch on the lower American River
Bottom-line temperature considerations Enhance coldwater pool in Folsom Lake to maintain biodiversity of Chinook salmon on the American Balance temperature needs of Chinook salmon and steelhead Salmon troller off Point Ross, Sonoma Co. Photo: Rob Titus, CDFW