Herring Common tern
Predator models Sarah Gaichas, NEFSC Herring MSE workshop #2 December 7-8, 2016
Herring’s role as forage: summary Predator Class Groundfish Marine mammals Humans (Fishery) Tuna/billfish Birds
Consumption of herring Highest Intermediate Intermediate Lowest Lowest
Dependence on herring as prey Moderate-low Moderate-low High High* Moderate-high
Predators in the Northeast US have many prey options. Herring is a high energy option which migrates seasonally throughout the shelf. Herring prey on zooplankton, which also vary. *Herring size may be more important than herring abundance
Herring MSE design Herring operating model
Herring N at age, Weight at age, Unfished N at age
Stock status (Error added to operating model output)
Alternative control rules
Groundfish predator model
Status relative to Bmsy, abundance, condition
Tuna predator model
Status relative to Bmsy, abundance, condition
Bird predator model
Reproductive success
Whale predator model
Abundance, condition Herring surplus production, status relative to Bmsy, condition
Alternative Herring allowable catches
Herring catch Economic interactions model
Herring and lobster fishery revenues & profits
Aydin’s Modelling Yield Curve
Insights gained
Models, uncertainty, and complexity
“Realist”
“Non believer”
“Believer”
Belief in model
Summary Predator and overlap • Tuna Forage throughout North Atlantic, seasonally in GOM
• Terns Forage seasonally near island breeding colonies in GOM
• Groundfish Forage through same range as herring most of the year
• Marine mammals
Modeled herring relationship Herring average weight affects tuna growth Herring total biomass affects tern reproductive success (productivity) Herring total abundance affects dogfish survival Food web model
Tuna condition
Herring biomass
0.0230
Herring size, Gulf of Maine
“The decline in bluefin tuna condition, 0.0220 despite high prey biomass in the Gulf of 0.0215 Maine, suggests that managing for high 0.0210 abundance at middle trophic levels does 0.0205 not guarantee the success of all top 0.0200 predators. In fact, it suggests that for 0.0195 0.0190 some upper level predators, the quality 0.0185 of the prey may be more important than 0.0180 the 0overall 0.05 abundance.” 0.1 0.15 0.2 0.25 0.3
Growth Intercept
0.0225
Herring Avg Wt
Tuna Biomass
Tuna Numbers
Growth Intercept
Tuna Average Weight 0.0230 0.0225 0.0220 0.0215 0.0210 0.0205 0.0200 0.0195 0.0190 0.0185 0.0180 0
0.1 0.2 Herring Avg Wt
0.3
MAP OF REGION AND COLONIES
Herring Common tern
1.10
Predator Recruit Multiplier
1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94 0.92 0.90
0
500000
1000000
1500000
Herring Abundance
2000000
2500000
Top groundfish predators of herring
1980 1981 1982 1983 1984 1985 1986 1987
1980 1981 1982 1983 1984 1985 1986 1987
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1979
1979
1988
1978
0
1978
10
1977
20
1977
30
1976
40
1976
50
1975
60
1974
70
1975
80
1974
90
1973
100
1973
100
90
80
70
60
50
40
30
20
10
0
Herring Dogfish
Predator Annual Natural Mortality
0.100 0.090 0.080 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 0
1000000
2000000
3000000
4000000
5000000
6000000
Herring Abundance
Simulated dogfish with fishing
Simulated dogfish with no fishing
Mass balance food web model parameters System of linear equations For each group, i, specify: Biomass (B) [or Ecotrophic Efficiency (EE)] Population growth rate (P/B) Consumption (Q/B) Diet composition (DC) Fishery catch (C)
Biomass accumulation (BA) Im/emigration (IM and EM)
Solving for EE [or B] for each group
P Q Bi * EE i IM i BAi B j * * DCij EM i Ci B i Bj j
Data uncertainty rating distributions for parameters
Good OK Bad Ugly
Incorporating uncertainty 50 45 40 35 30 25 20 15 10 5 0
% change from base biomass
1
20 10 0
4
7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Perturbation: change in survival for one group
.......
-10 -20
Effects on each group in the food web
Increase GOM herring survival 10% High uncertainty Herring up 10% increase in production No change in production
Other forage down
Groundfish
Marine mammals
Small Pelagics− anadromous
Small Pelagics− squid
Small Pelagics− other
Sea Birds
Odontocetes
Baleen Whales
Pinnipeds
HMS
Sharks− pelagics
Demersals− piscivores
Demersals− omnivores
Demersals− benthivores
Medium Pelagics− (piscivores & other)
Species Small Pelagics− commercial
Larval−juv fish− all
Shrimp_etc
Megabenthos−other
Megabenthos−filterers
Macrobenthos−other
Macrobenthos−molluscs
Macrobenthos−crustaceans
Macrobenthos−polychaetes
Micronekton
Gelatinous Zooplankton
Large Copepods
Small copepods
Microzooplankton
Bacteria
Phytoplankton−Primary Producers
−0.5 0.0
0.5
1.0
1.5
Proportional Difference from Base 2.0
Decrease GOM herring biomass 50% vul, herring down 50%, B
High uncertainty
Is forage quality changing?
Beyond Biomass
Is forage quality changing?
Slide courtesy Tim Sheehan, NEFSC
Possible improvements? • Consider multiple forage species of a predator together or “forage base” as a whole • Consider integrated two way feedbacks between predators and prey where possible • Consider changes in forage quality
Herring’s role as forage: summary Predator Class Groundfish Marine mammals Humans (Fishery) Tuna/billfish Birds
Consumption of herring Highest Intermediate Intermediate Lowest Lowest
Dependence on herring as prey Moderate-low Moderate-low High High* Moderate-high
Predators in the Northeast US have many prey options. Herring is a high energy option which migrates seasonally throughout the shelf. Herring prey on zooplankton, which also vary. *Herring size may be more important than herring abundance
Herring MSE design Herring operating model
Herring N at age, Weight at age, Unfished N at age
Stock status (Error added to operating model output)
Alternative control rules
Groundfish predator model
Status relative to Bmsy, abundance, condition
Tuna predator model
Status relative to Bmsy, abundance, condition
Bird predator model
Reproductive success
Whale predator model
Abundance, condition Herring surplus production, status relative to Bmsy, condition
Alternative Herring allowable catches
Herring catch Economic interactions model
Herring and lobster fishery revenues & profits
Aydin’s Modelling Yield Curve
Insights gained
Models, uncertainty, and complexity
“Realist”
“Non believer”
“Believer”
Belief in model
Summary Predator and overlap • Tuna Forage throughout North Atlantic, seasonally in GOM
• Terns Forage seasonally near island breeding colonies in GOM
• Groundfish Forage through same range as herring most of the year
• Marine mammals
Modeled herring relationship Herring average weight affects tuna growth Herring total biomass affects tern reproductive success (productivity) Herring total abundance affects dogfish survival Food web model
Tuna condition
Herring biomass
0.0230
Herring size, Gulf of Maine
“The decline in bluefin tuna condition, 0.0220 despite high prey biomass in the Gulf of 0.0215 Maine, suggests that managing for high 0.0210 abundance at middle trophic levels does 0.0205 not guarantee the success of all top 0.0200 predators. In fact, it suggests that for 0.0195 0.0190 some upper level predators, the quality 0.0185 of the prey may be more important than 0.0180 the 0overall 0.05 abundance.” 0.1 0.15 0.2 0.25 0.3
Growth Intercept
0.0225
Herring Avg Wt
Tuna Biomass
Tuna Numbers
Growth Intercept
Tuna Average Weight 0.0230 0.0225 0.0220 0.0215 0.0210 0.0205 0.0200 0.0195 0.0190 0.0185 0.0180 0
0.1 0.2 Herring Avg Wt
0.3
MAP OF REGION AND COLONIES
Herring Common tern
1.10
Predator Recruit Multiplier
1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94 0.92 0.90
0
500000
1000000
1500000
Herring Abundance
2000000
2500000
Top groundfish predators of herring
1980 1981 1982 1983 1984 1985 1986 1987
1980 1981 1982 1983 1984 1985 1986 1987
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1979
1979
1988
1978
0
1978
10
1977
20
1977
30
1976
40
1976
50
1975
60
1974
70
1975
80
1974
90
1973
100
1973
100
90
80
70
60
50
40
30
20
10
0
Herring Dogfish
Predator Annual Natural Mortality
0.100 0.090 0.080 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 0
1000000
2000000
3000000
4000000
5000000
6000000
Herring Abundance
Simulated dogfish with fishing
Simulated dogfish with no fishing
Mass balance food web model parameters System of linear equations For each group, i, specify: Biomass (B) [or Ecotrophic Efficiency (EE)] Population growth rate (P/B) Consumption (Q/B) Diet composition (DC) Fishery catch (C)
Biomass accumulation (BA) Im/emigration (IM and EM)
Solving for EE [or B] for each group
P Q Bi * EE i IM i BAi B j * * DCij EM i Ci B i Bj j
Data uncertainty rating distributions for parameters
Good OK Bad Ugly
Incorporating uncertainty 50 45 40 35 30 25 20 15 10 5 0
% change from base biomass
1
20 10 0
4
7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Perturbation: change in survival for one group
.......
-10 -20
Effects on each group in the food web
Increase GOM herring survival 10% High uncertainty Herring up 10% increase in production No change in production
Other forage down
Groundfish
Marine mammals
Small Pelagics− anadromous
Small Pelagics− squid
Small Pelagics− other
Sea Birds
Odontocetes
Baleen Whales
Pinnipeds
HMS
Sharks− pelagics
Demersals− piscivores
Demersals− omnivores
Demersals− benthivores
Medium Pelagics− (piscivores & other)
Species Small Pelagics− commercial
Larval−juv fish− all
Shrimp_etc
Megabenthos−other
Megabenthos−filterers
Macrobenthos−other
Macrobenthos−molluscs
Macrobenthos−crustaceans
Macrobenthos−polychaetes
Micronekton
Gelatinous Zooplankton
Large Copepods
Small copepods
Microzooplankton
Bacteria
Phytoplankton−Primary Producers
−0.5 0.0
0.5
1.0
1.5
Proportional Difference from Base 2.0
Decrease GOM herring biomass 50% vul, herring down 50%, B
High uncertainty
Is forage quality changing?
Beyond Biomass
Is forage quality changing?
Slide courtesy Tim Sheehan, NEFSC
Possible improvements? • Consider multiple forage species of a predator together or “forage base” as a whole • Consider integrated two way feedbacks between predators and prey where possible • Consider changes in forage quality
