Fish monitoring requirements of new FERC licenses: are they adequate? Joseph D. Kiernan, Peter B. Moyle and John G. Williams Center for Watershed Sciences University of California, Davis
Trends from recently issued FERC licenses How variable are fish populations over time? Lessons from Martis Ck. - 5, 12 and 3 years Conclusions and recommendations Outline:
Trends in new FERC licenses 92% of new licenses included a change to the flow regime 67% included post-license fish monitoring Annual sampling first 3-5 years Required sampling effort subsequent sampling at 5 year intervals Term of new license: Mean = 38 yrs (range = 3 to 4 yrs) Total # monitoring yrs: Mean = 7 (range = 1 to 12) 5 1 15 2 25 3 35 4 Years after new license
How useful is periodic monitoring likely to be? Natural variability may mask population changes due to dam operation Coefficient of variation (SD/mean; %) 1 9 8 7 6 5 4 3 2 1 Adult trout density (fish/km) 12 4 11 11 12 11 12 11 1 2 3 4 5 6 7 8 Highly fluctuating Moderately fluctuating Moderately stable Highly stable Sample sites on North Fork Middle Fork Tule River Data from Studley et al. 1995
Long-term monitoring of Martis Creek Martis Creek: a 3 year perspective Tributary of Truckee R. 2.9 km segment Martis Dam (USACE; 1972) Pre-dam Q max = 5.9 m 3 /s (1963) Post-dam Q max = 17.3 m 3 /s (26) Martis Dam
Martis Creek: a 5 year perspective Sampled 1979-1983 Fish assemblage 5 native 2 non-native trout Habitat variables Microhabitat use Discharge (m 3 /s) 18 16 14 12 1 8 6 4 2 Food habits Multiple water year types: Normal (1979, ) Dry (1981) Wet (1982, 1983) 1979 1981 1982 1983 Water Year
Martis Creek: a 5 year perspective Ecology: 66(1), 1985, pp. 1-13 Fish assemblage dominated by native species density and biomass Assemblage persistent and stable over time Density (individuals/1 m 2 ) Proportion of total density 1 Total Assemblage Native Fishes 1 1 1 1. 1979 1981 1982 1983.8.6.4.2. Native fishes
Martis Creek: a 5 year perspective Stability maintained by niche diversification Depth Water velocity Substrate size From Moyle and Vondracek 1985
15 1 5 1979 1981 1982 1983 1984 1985 1986 1987 1988 1989 199 Discharge (m 3 /s) Year 1979 1981 1982 1983 1984 1985 1986 1987 1988 1989 Proportion of total density 199 Martis Creek: a 12 year perspective 1 Total Assemblage Native Fishes 1 1 Density (individuals/1 m 2 ) no data Severe spring flooding in 1983 reduced recruitment of native sp. Two distinct equilibria: 1 1..8.6.4.2. Native fishes 1. native sp. (1979-83) Strange EM, Moyle PB, Foin TC. 1993. Environ. Biol. Fish. 36:1-15. 2 b t t (1984 9)
Martis Creek: a 3 year perspective 15 1 5 2 15 1 5 Daily discharge (m 3 /s) Mean max. daily water temperature ( C) 1982 1984 1986 1988 199 1992 1994 1996 1998 2 22 24 26 28 Discharge (m 3 /s) Mean daily discharge WINTER ( ) Water temp ( ) Kiernan and Moyle. Ecol Apps, in revision O N D J F M A M J J A S Month of water year 3 25 2 15 1 5
Martis Creek: a 3 year perspective Basic fish assemblage persistent and resilient Multiple stable states Assemblages dominated by: - native sp. (1979-1983) - brown trout (1984-199) - rainbow trout (1998-28) Populations highly variable over time and space Density (individuals/1 m 2 ) Proportion of total density 1 Total Assemblage Native Fishes 1 1 1 1. Native fishes.8.6.4.2. 1985 199 1995 2 25
Spatial and temporal variability in fish populations 1 A) Brown trout 1 B) Rainbow trout 1 C) Green sunfish 8 8 8 6 6 6 4 4 4 Relative abundance (%) Relative abundance (%) Relative abundance (%) Relative abundance (%) 2 1 8 6 4 2 1 8 1 2 3 4 D) Paiute sculpin 1 2 3 4 G) Speckled dace 2 199 2 199 2 1 8 6 4 2 1 8 1 2 3 4 E) Tahoe sucker 1 2 3 4 H) Lahontan redside 2 199 2 199 2 1 8 6 4 2 1 8 1 2 3 4 F) Mountain sucker 1 2 3 4 I) Mountain whitefish 2 199 2 199 Year Year 6 6 6 4 4 4 2 1 2 3 4 2 199 2 1 2 3 4 2 199 2 1 2 3 4 2 199 Year Sample Site Sample Site Sample site Sample Site
Variability in fish populations (1979-28) 1 Density Biomass 1 1 Highly fluctuating Moderately fluctuating 1 Highly fluctuating Moderately fluctuating Moderately stable Moderately stable Highly stable Highly stable 1 1 Coefficient of variation (%) (%) Lahontan redside Speckled dace Mountain sucker Mountain whitefish Paiute sculpin Tahoe sucker Green sunfish Rainbow trout Brown trout Lahontan redside Speckled dace Mountain sucker Mountain whitefish Paiute sculpin Tahoe sucker Green sunfish Rainbow trout Brown trout Native species Non-native species Native species Non-native species
Population changes are asynchronous Solid circles = downturns Open circles = upturns. 1979 1981 1982 1983 1984 1985 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 25 26 27 28 Species WYT = N N D W W W N W N D N D D D N D W N W N W N D N N N N W D N Native Lahontan redside Mountain sucker Mountain whitefish Paiute sculpin Speckled dace Tahoe sucker Alien (non-native) Brown trout Rainbow trout Green sunfish
Population changes are asynchronous Solid circles = downturns Open circles = upturns. 1979 1981 1982 1983 1984 1985 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 25 26 27 28 Species WYT = N N D W W W N W N D N D D D N D W N W N W N D N N N N W D N Native Lahontan redside Mountain sucker Mountain whitefish Paiute sculpin Speckled dace Tahoe sucker Alien (non-native) Brown trout Rainbow trout Green sunfish Population increases Population decreases
Is streamflow the master variable? Proportion of alien fish 1..8.6.4.2. (A) r s = -.47, P =.1 (B) Winter (C)..5 1. 1.5 2. Mean annual discharge (m 3 /s) r s = -.39, P =.3 Spring r s = -.5, P =.1..5 1. One day max discharge Log 1 (m 3 /s + 1) Winter, P =.31 Spring, P =.4 2 4 6 8 1 Frequency of floods (No./season)
Variables describing fish abundance Brown trout Drought (-) % gravel (-) Winter floods (-) Rainbow trout % boulder (+) mean depth (-) Green sunfish % sand (+) Drought (-) Lahontan redside % boulder (-) % pool (+) Tahoe sucker % boulder (-) Winter floods (-) % pool (+) Paiute sculpin % sand (-) Speckled dace % boulder (-) max. Depth (+) % gravel (-)
Conclusions: Trout populations highly variable CV density = 47-129% CV biomass = 7-131% Population responses to streamflow are complex and context dependent Monitoring programs need to capture the range of environmental variability Extremes may be important Performance criteria based exclusively on abundance may lead to erroneous conclusions
Questions?