Fishway passage, water diversion and warming temperatures: Factors - PowerPoint PPT Presentation

Fishway passage, water diversion and warming temperatures: Factors limiting successful spawning migration of Seton-Anderson watershed sockeye salmon Scott Hinch David Roscoe Pacific Salmon Ecology and Conservation Laboratory

Background • Research by the IPSFC in the 70s / 80s found that sockeye were attracted to powerhouse tailrace on the Fraser River. • Their experiments suggested potential dilution with Cayoose Ck for Gates (20%) and Portage (10%) sockeye would maximize attraction into Seton River (these dilution rates used today). • Still, migration mortality rates were ~ 10% and 30% for these stocks respectively with these dilution levels.

Background • First thorough evaluation of fishway attraction and passage in 2005 by UBC • Found 23% failure to enter fishway, but ~ 0% failure to ascend fishway • Found 33% of fish that exited fishway disappeared before reaching spawning grounds; another 13% that exited were reported captured in fisheries • Thus, previous work suggests cumulative mortality may be high in the Seton Anderson watershed (~50% of fish that approach tailrace on Fraser do not reach spawning grounds). • Needed was a study to examine relative levels of mortality throughout the Seton system in a single year

Objectives of UBC 2007 study • Quantify mortality along the migratory route in the Seton-Anderson watershed • Evaluate fishway effectiveness • Assess impact of fishway on migration success • Identify needs for management experiments and future research

Seton dam fishway – capture locale at top pool Seton River Fish water sluice To Seton Entrance Lake Exit metres N 0 10 5

Methods • Captured 88 sockeye from top of Seton dam fishway • Sockeye transported by truck to release site and held for recovery in river • Blood sampling (ions, lactate, glucose, hormones) • Energy sampling (microwave fat meter) • Implant acoustic telemetry transmitter, temperature data logger

Methods • Fish release sites • Acoustic telemetry receiver array (lower section) = release site Fraser River 2 6-8 10 Power Fishway Seton Dam 4,5 house Seton Creek 3 Seton Lake 1 9 Cayoosh Creek Hydro canal Cayoosh 1000 m Diversion Dam N

• Acoustic telemetry receiver array (upper section) 12 13 Seton Lake Anderson Lake Lillooet, B.C. 11 14 10 15 Fraser River Seton Dam 16 17 Gates Stock Spawning Area N 20 km

Results – Physiological Stress Indices 10 Glucose ( m m ol/ L) Lactate ( m m ol/ L) 3 9 2.5 8 7 2 6 1.5 5 4 1 C R C R 3 C R C R 0.5 2 0 1 0 Males Females Males Females 450 Osm olality ( m m ol/ L) 320 400 Cortisol ( ng/ m L) 310 350 300 300 250 290 200 280 C R C R 150 C R C R 270 100 260 50 250 0 Males Females Males Females • Sockeye not physiologically stressed or exhausted after fishway ascent or transport (same as 2005 results). • Mortalities and successful migrants did not differ in terms of most physiological measures.

Results: Mortality along the migratory route Fish released downstream of dam Fate # % Successful migrant 27 48 Failed in Lake 10 18 Failed at dam/fishway 10 18 Total loss = 52% Did not reach dam 8 14 Fishery removal 1 2 Total 56 Survival to spawning grounds was greater for males (71% of 17 fish) than females (40% of 38 fish; P =0.03). Fish released upstream of dam Fate # % No significant difference in survival between fish held Successful migrant 26 93 for recovery and those Failed in Lake 2 7 released immediately. Total 28

Results: Fishway evaluation • 20% of tagged fish that reached the dam failed to pass fishway in 2007. • Failure largely due to ‘attraction’ to entrance rather than passage through fishway. 100% 93% 100 86% 90 77% 80 Efficiency ( % ) 70 60 50 40 n=30 n=51 n=23 n=44 30 20 10 2005 2007 2005 2007 0 Attraction Passage

Results Delay at different discharges in 2005 and 2007

Results Attraction efficiency at different discharges in 2005 and 2007

Results 70 100 6 90 48 60 Below dam delay (hrs) 80 13 Attraction efficiency (% ) 50 70 4 8 60 40 50 30 5 40 30 20 6 20 5 36 10 10 10 0 0 0 10 20 30 40 50 60 70 Dam spill discharge (m 3 / s) • Lowest attraction and longest delay at highest discharge • Not a simple relationship between discharge and attraction

60 cms 35 cms 12.7 cms

Results Temperature profiles of sockeye 20 22 Portage Creek 18 Anderson Lake Portage Creek 20 16 18 14 Temperature (oC) 16 o C) 14 12 Temperature ( 12 10 10 8 Release into 8 Seton Lake 6 6 Arrival at spawning Release 4 Anderson grounds 4 into Seton Lake Arrival at spawning grounds Lake 2 2 0 0 21-Aug 23-Aug 25-Aug 27-Aug 29-Aug 31-Aug 20-Aug 22-Aug 24-Aug 26-Aug 28-Aug 30-Aug 1-Sep • No thermal data for mortalities Seton • Very high and stressful Lake Anderson F temperatures rarely experienced r Lake R a Portage s i v e e r Creek r Seton • Thermal refuges utilized by some Dam Spawning individuals grounds N

Summary • Sockeye were in good physiological conditions after fishway and ascent and transport. • 48% of fish released downstream, and 93% of fish released upstream of the dam reached spawning grounds. • Mortality was higher for females (71%) than males (40%). • 20% of sockeye unable to pass fishway and most of failure associated with attraction to the entrance. • Attraction into fishway and delay affected by discharge. • Some fish (n = 5) were attracted to tailrace after falling back out of lower Seton River. Could be related to seeking an alternate route or a cool water refuge.

Recommendations 1) Temporary blockage in fishway could have serious consequences for populations of migrating sockeye. When fishway was temporarily blocked in 2007, some tagged sockeye (n = 3) moved out of the fishway and downstream to the Fraser River, and never returned to the fishway. The fishway exit should be monitored and maintained frequently (daily) during migration. Previous resistivity counter did not accurately count fish and may have impeded migration (UBC 2005 study). Managers should carefully consider effects of fish enumeration devices on passage and validate counts with videography and spawning escapement.

Recommendations 2) Some (n=5) fish in our study were attracted to the powerhouse tailrace on the Fraser River. 13% of tailrace ‘releases’ never made it to dam. Research is needed to quantify delay when sockeye initially encounter the powerhouse tailrace on the Fraser River.

Recommendations 3) Relationship between attraction and discharge is complex. High spill discharges (~60cms) from dam were associated with poor passage efficiency and long delays, small sample size. Management experiments are needed to examine relationships between discharge, flow patterns, attraction and delay. Entrance Important questions to study: • How do different discharges affect Attraction hydraulics and attraction? flow - use Acoustic Doppler Current Profiler Siphons Can flow patterns (hence migration cues) be favourably altered via changes in water release at siphons? • What are consequences of delay?

Recommendations 4) Annual population assessments needed downstream of dam. These data should be used in conjunction with fishway counts, spawning ground escapements and telemetry experiments. We specifically recommend that research: • use “fishway-naïve” individuals caught downstream of the dam • minimize handling and capture stress (use trap-net / weir approach)

Gates Creek sockeye 120,000 2004 cycle 2005 cycle 100,000 2006 cycle 2007 cycle 80,000 # of spaw ners 60,000 40,000 2008 20,000 0 1950 1960 1970 1980 1990 2000 2010

•IUCN Report on sockeye salmon to be released next week •First ever global assessment of endangerment status for a Pacific salmon species

Fraser sockeye stock status Gates • 51 populations assessed Portage • 21 least concern • 6 vulnerable • 10 endangered • 14 critically endangered Least Concern (no decline) Vulnerable (30% decline 3 generations) Endangered (50% decline) Critically Endangered (80% decline) Extinct in Wild Extinct

IUCN Conclusions • Gates Creek (“critically endangered”) and Portage Creek (“vulnerable”) sockeye populations have had declining escapements in recent cycles (Salmonid Specialist report for IUCN)

Thanks to … David Patterson, Jayme Hills Northern St’at’imc Fisheries Bonnie Adolph, Elijah Michel, Terry Adolph UBC Pacific Salmon Ecology & Conservation group: Lucas Pon, Marika Gale, Steve Cooke - Carleton University Glenn Crossin,Ken Jeffries, Andrew Lotto