WDFW Monitoring and Management of Fish in the East Fork Lewis River
Tom Wadsworth WDFW Region 5 District Fish Biologist Salmonid Populations in the East Fork (EF) Lewis River and ESA Status
• Chinook (fall run) – Lower Columbia evolutionarily significant unit (ESU), listed in 1999 as ‘threatened’ in Endangered Species Act (ESA) • Coho – Lower Columbia ESU listed in 2005 as ‘threatened’ in ESA • Chum (fall) – Lower Columbia ESU listed in 1999 as ‘threatened’ in ESA • Steelhead (summer and winter runs) – Lower Columbia distinct population segment listed in 1998 as ‘threatened’ in ESA • Rainbow trout – contribute genetics to steelhead populations • Cutthroat trout – not ESA listed, include anadromous life history • Other native and non-native fish species – not ESA listed WDFW Region 5 Salmonid Monitoring Strategy
• Lower Columbia Salmon Recovery and Fish & Wildlife Subbasin Plan - Lower Columbia Fish Recovery Board (2010) • Defines priority populations for recovery of listed ESUs (Primary, Contributing, Stabilizing) • Sets targets for recovery • Helps guide monitoring priorities
• Conduct annual monitoring of adult and juveniles to track recovery of ESA listed ESUs, hatchery-origin spawners, etc.
• EF Lewis River – spawning ground surveys, no recent juvenile monitoring Salmonid population trends in EF Lewis Fall Chinook
4,000 3,500 3,000 - Primary recovery population 2,500 - Tule Chinook population 2,000 includes NF and EF Lewis 1,500 - Natural-origin abundance 1,000 above target recovery goal 500 in recent years (LCFRB 2010) 0 2010 2011 2012 2013 2014 2015 2016 2017 - EF Lewis component of population is fairly large NF and EF Abundance EF Lewis Abundance - Return late-summer when Target Abundance Historical Abundance river is warm/low Salmonid population trends in EF Lewis Coho
3,500 - Primary recovery population 3,000 - Trend unclear but 2,500 relatively low recently 2,000 - Below target recovery 1,500 goal in most years (LCFRB 1,000 2010) 500
0 2010 2011 2012 2013 2014 2015 2016 2017
EF Lewis NOR Coho Target Abundance Historical Abundance Salmonid population trends in EF Lewis Summer steelhead
1200
1000
800
600 - Primary recovery population - Increasing population trend 400 - Above target recovery goal 200 in most years (LCFRB 2010) 0 - Catch-and-release fishery, harvest of hatchery strays
Natural spawners Historical Abundance Target Abundance - Return in summer months when river can be low/warm Salmonid population trends in EF Lewis Winter steelhead
1400 1200 1000 - Primary recovery 800 population 600 - Stable or increasing 400 population trend 200 0 - Recent years above target recovery goal (LCFRB 2010) - Catch-and-release fishery, Natural spawners Historical Abundance Target Abundance harvest of hatchery strays EF Lewis Wild Steelhead Gene Bank
• Statewide Steelhead Management Plan requires gene banks in each Major Population Group (MPG) • EF Lewis in Cascade MPG • One of two wild steelhead gene banks established for the Cascade MPG in 2014 • Chosen with assistance from a steelhead workgroup • With designation, hatchery steelhead cannot be released • Regulations structured to protect Boundaries of Lower Columbia River Major Population Groups wild steelhead Salmonid population trends in EF Lewis Fall Chum
• Population monitoring has been difficult due to low population size
• Lewis River population (EF Lewis and NF Lewis) • Historical abundance: 125,000 • Current: unknown (likely <100) • Target: 1,300
Photo: Chum salmon by Tony Overman (The Olympian) Freshwater Temperatures and Salmonids
• Migration can be impaired by maximum stream temperatures above 18-20°C (64-68°F)* • Adult mortalities can occur starting at 16°C (60°F), increased chance of mortality above 24-25°C (75-77°F)* • Spawning success can be impaired by maximum temperatures above 14-16°C (57-60°F)* • Eggs require daily maximum temperature below 13-15°C (55-59°F) to ensure survival success* • Salmon will look for refugia to avoid warmer waters, hard to find in some areas, especially at low flows
*WA DOE. 2002. Evaluating Standards for Protecting Aquatic Life in Washington's Surface Water Quality Standards - Temperature Criteria WDFW Temperature Monitoring in SW Washington
• In 2015, summer drought conditions raised concerns for fish • Thousands of sockeye salmon died in Columbia River – likely due to temperatures well above 70°F • Stream flows very low throughout SW WA • Began actively monitoring stream temperatures to guide fishing regulations and better understand conditions • Used online data from DOE and USGS stations • Deployed dozens of small HOBO data loggers • 2015 summer monitoring showed warm, cool areas in region EF Lewis River Water Temperature Monitoring
• LCFRB (2010) Limiting Factors analysis showed temperature as a primary or secondary factor for fall Chinook and steelhead in EF Lewis
• Three sites in 2015: Lewisville Park, Heisson Bridge, above Sunset Falls • Two sites in 2016 and 2018: above Lewisville Park, near confluence with NF Lewis River Water Temperatures Near Lewisville Park 2015, 2016, 2018
Maximum daily temperatures, 2015-2018 2016, 2018 Mean daily temperatures 85 80 80 75 70 75 65 70 60 65 55 60 50 55 45 40 50 20-Jun 20-Jul 20-Aug 20-Sep 45
Temperature (Degrees Fahrenheit) Temperature 2018 2016 2015 40 20-Jun 20-Jul 20-Aug 20-Sep Temperatures Near Confluence with NF Lewis River 2016 and 2018
85 Daily Maximum Temperatures - Tidally influenced area made 80 for high variability within days 75 70 - Overall pattern similar to 65 Lewisville Park area 60 55 50
45 2016 2018 Temperature (Degrees Fahrenheit) (Degrees Temperature 40 20-Jun 20-Jul 20-Aug 20-Sep Temperatures Above Sunset Falls 2015
Above Sunset Falls daily temperatures - 2015 - Temperatures were cooler in August than 70.0 lower river 65.0
60.0 - Fishing not allowed in this area all year 55.0
50.0
45.0 Minimum daily temps Maximum daily temps 40.0 1-Aug-2015 1-Sep-2015 1-Oct-2015 Recent Changes to EF Lewis Sport Fishing Regulations
• 2015 summer regulations due to warm/low water • From mouth to top boat ramp at Lewisville Park: Closed • From top boat ramp at Lewisville Park upstream Horseshoe Falls: Closed from 2 PM to one hour before official sunrise (‘hoot owl’ closure)
• 2018 changes - WDFW/public review of fishing regulations statewide • Closed to fishing July 16 and Sept. 15 due to warm/low water conditions • Trout: release cutthroat trout and wild rainbow trout, can harvest 2 hatchery rainbows/steelhead (remove hatchery fish to benefit wild fish) • Salmon: Sept. 16 – Dec 31, daily limit 2 adult hatchery Chinook or Coho • Maintain fishing closure from 400 feet below Horseshoe Falls upriver