Overview of herring related findings of NCEAS Portfolio Effects - PowerPoint PPT Presentation

Overview of herring related findings of NCEAS Portfolio Effects Working Group Northwest Eric Ward, Rich Brenner eric.ward@noaa.gov September 8, 2017 richard.brenner@alaska.gov

Acknowledgments • Thanks to S. Moffitt and J. Rice for help with data / synthesis

Background: other oil spill responses • Deepwater Horizon (2010) in Gulf of Mexico • Synthesized long term monitoring data from LDWF • 3 gears, 12 species, data from 1968 – present • Monthly sampling, environmental covariates • Lack of anomaly or state change following DWH event (Ward et al. in review)

BUT we see clear responses in lab settings • Incardona et al. (2015) – herring and pink salmon associated with EVOS • Incardona (2014) – Deepwater Horizon response • Why are clear responses in the lab not mirrored in wild populations? U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 4

Lab vs Population Responses (Fodrie et al. 2014) • Exposure • Intrinsic factors • Life history variation (overlapping generations) • Spatial variation in timing • Environmental variation • Hurricanes, warm blob • Human adjustments • Management changes, fisheries closures, dispersants U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 5

Summary of group’s work 1. Summarize long term trends in herring catches and fisheries 2. Evaluate patterns of changing growth rates 3. Identify single factors associated with productivity in herring, salmon populations 4. Why are there more male herring? 5. Meta-analysis comparing SEAK populations to PWS U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 6

Long history of exploitation in Alaska and PWS 50000 Reduction Seine Bait Catches (1000 kgs) Pound 30000 Gill 10000 0 1940 1950 1960 1970 1980 1990 • Reid (1971) and Funk & Sandone (1989, 1990) U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 7

1970s: emerging fishery, new products • Herring roe harvested for Japanese export • Demand / prices peaked ~ 1986-1996 Average ex-vessel roe herring price paid in select roe herring purse seine fisheries, nominal dollars $2,500 $2,000 $1,500 Price/ton $1,000 $500 $0 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Southeast Prince Wm. Sound Cook Inlet Kodiak Alaska Pen-Aleutian Is Bristol Bay • (Carlson 2005, CFEC) U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 8

How have these changes affected fishers? • Rise of the single permit holder (Anderson et al. 2017) • People who specialize (hold 1 permit) tend to have greater variability in income than people with 2+ permits • Despite closures, PWS herring permits continue to be bought / sold • Like other fisheries in AK that have been closed / experienced restrictions, many individuals have stopped fishing (Beaudreau et al. in review) U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 9

Identifying single drivers associated with salmon / herring productivity • Modeled after Deriso et al. (2008), for herring and salmon in PWS • Covariates organized by ‘hypothesis’ • Model selection used to evaluate relative data support of various covariates • What this analysis isn’t: • exhaustive model selection to find single ‘best’ model • Comprehensive analysis of every potential driver U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 10

Hypotheses • 1. Productivity most strongly affected by EVOS • 2. Density dependence (SSB) • 3. Environmental covariates (discharge, SST, etc) • 4. Competition and / or predation with other species (including hatchery salmon) U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 11

What we found • Herring don’t have strong effect of Ricker density dependence Copper River Chinook Coghill Lake sockeye 1985 1.5 1990 2 1995 1.0 2000 1 log (R/S) log (R/S) 2005 0.5 0 0.0 − 1 − 0.5 − 2 10000 20000 30000 40000 50000 50000 100000 150000 Spawners Spawners Eshamy Lake sockeye Copper River sockeye 2.5 1.6 1.5 1.2 log (R/S) log (R/S) 0.5 0.8 − 0.5 0.4 10000 20000 30000 40000 50000 5e+05 6e+05 7e+05 8e+05 9e+05 Spawners Spawners PWS pink PWS herring − 4 1.5 log (age 3 recruits / SSB) − 6 1.0 − 8 log (R/S) 0.5 − 12 0.0 − 0.5 − 16 2.0e+06 6.0e+06 1.0e+07 1.4e+07 2e+04 4e+04 6e+04 8e+04 1e+05 Spawners Spawning biomass (mt) U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 12

But some negative effect of discharge • High discharge = low recruitment ● (a) 350000 Total discharge m 3 s − 1 ● ● ● ● ● ● ● 300000 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 250000 ● ● ● ● ● 1980 1985 1990 1995 2000 2005 2010 (b) 0 log (age 3 recruits / SSB) ● ● ● − 5 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● − 10 ● ● ● ● ● ● − 15 ● ● 1980 1985 1990 1995 2000 2005 2010 U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 13

Interestingly, discharge also record low / volatile in 1930s 400000 350000 Total freshwater discharge m 3 s − 1 300000 250000 200000 1940 1960 1980 2000 U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 14

More on discharge • Where’s it coming from? • Approximately 50% glaciers (Beamer et al. 2016; Hill et al. 2015) • What’s it doing? • Altering timing / quality of plankton bloom (= food for herring) • Similar patterns seen in Europe U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 15

Why are there more male herring? • More male herring in research vessels over time during spawning 0.6 Percent male 0.5 1990 2000 2010 Year U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 16

Lots of potential reasons • Was it EVOS? • Other change in population? • Nutritional stress? • Change in sampling? • Other regions (Puget Sound) don’t show much variation in sex ratios • Implications for management, assessment models U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 17

No clear effect of EVOS • Contrasted ‘oiled’ versus ‘un-oiled’ sampling sites in PWS to identify effects (or oiled:year interactions) • No significant effect found explaining the trend U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 18

But large changes over time in sampling gears • Cast and purse seines are dominant gear types 7500 5000 Gear Samples Cast net Purse seine 2500 0 1990 2000 2010 Year U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 19

Sex ratio trend driven by gear change • Increased trend in males = Increased cast nets + Cast nets selecting more males 0.65 0.60 Predicted proportion of males Gear Cast net Purse seine 0.55 0.50 5.0 7.5 10.0 Age U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 20

Implications for assessment models • Cast / seine samples occur in different places • May capture different portions of spawn • Modeling changes: sex- and gear- specific selectivities • Future research: could we include time-varying selectivity over duration of spawn U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 21

Summary • Multiple factors responsible for herring not recovering • Limitations of monitoring data • Synthesis paper (Marshall et al.) • Future work: comparisons across spatial locations • Do SEAK populations share response to discharge? • Questions? U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 22