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

Overview of herring related findings of NCEAS Portfolio Effects Working Group

Eric Ward, Rich Brenner eric.ward@noaa.gov richard.brenner@alaska.gov

Northwest September 8, 2017

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

• Reid (1971) and Funk & Sandone (1989, 1990)

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 7

1940 1950 1960 1970 1980 1990 10000 30000 50000 Catches (1000 kgs) Reduction Seine Bait Pound Gill

1970s: emerging fishery, new products

• Herring roe harvested for Japanese export
• Demand / prices peaked ~ 1986-1996
• (Carlson 2005, CFEC)

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 8

Average ex-vessel roe herring price paid in select roe herring purse seine fisheries, nominal dollars

$0 $500 $1,000 $1,500 $2,000 $2,500 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Price/ton Southeast Prince Wm. Sound Cook Inlet Kodiak Alaska Pen-Aleutian Is Bristol Bay

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

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 12

10000 20000 30000 40000 50000 −0.5 0.0 0.5 1.0 1.5

Copper River Chinook

Spawners log (R/S)

1985 1990 1995 2000 2005

50000 100000 150000 −2 −1 1 2

Coghill Lake sockeye

Spawners log (R/S) 10000 20000 30000 40000 50000 −0.5 0.5 1.5 2.5

Eshamy Lake sockeye

Spawners log (R/S) 5e+05 6e+05 7e+05 8e+05 9e+05 0.4 0.8 1.2 1.6

Copper River sockeye

Spawners log (R/S) 2.0e+06 6.0e+06 1.0e+07 1.4e+07 −0.5 0.0 0.5 1.0 1.5

PWS pink

Spawners log (R/S) 2e+04 4e+04 6e+04 8e+04 1e+05 −16 −12 −8 −6 −4

PWS herring

Spawning biomass (mt) log (age 3 recruits / SSB)

But some negative effect of discharge

• High discharge = low recruitment

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 13

• 1980

1985 1990 1995 2000 2005 2010 250000 300000 350000 Total discharge m3 s−1 (a) 1980 1985 1990 1995 2000 2005 2010 −15 −10 −5 log (age 3 recruits / SSB) (b)

• ●
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• ●
• ●
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Interestingly, discharge also record low / volatile in 1930s

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 14

1940 1960 1980 2000 200000 250000 300000 350000 400000 Total freshwater discharge m3 s−1

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

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 16

0.5 0.6 1990 2000 2010

Year Percent male

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

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 19

2500 5000 7500 1990 2000 2010

Year Samples Gear

Cast net Purse seine

Sex ratio trend driven by gear change

• Increased trend in males = Increased cast nets +

Cast nets selecting more males

U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 20

0.50 0.55 0.60 0.65 5.0 7.5 10.0

Age Predicted proportion of males Gear

Cast net Purse seine

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