mixed-fisheries and ecosystem based management · 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 1990 2000 2010...

Mixed-fisheries and Ecosystem Based Management trade-offs and the importance of climate

Christopher Lynam and Steven Mackinson

S12 Linking climate change to marine management objectives Tuesday 24th March 2015

PICES Symposium on ‘Effects of climate change on the world’s oceans’

The issue

MULTIPLE USES

MULTIPLE IMPACTS

FISHERIES NOT INDEPENDENT

POLICY

CLIMATE

COD

COD

WHITING

Lynam + Mackinson: Mixed fisheries + EBM 2

ENVIRONMENT

Policy arena Management for European seas required to meet aims of policy: 1. Common Fisheries Policy (CFP; EC 2013) 2. Marine Strategy Framework Directive (MSFD; EC 2010) Objectives: 1) to achieve maximum sustainable yield for all commercial

species by 2020

2) to achieve Good Environmental Status (GES) of marine waters by 2020


Climate is explicitly mentioned … MSFD Descriptor 1: Biodiversity “The quality and occurrence of habitats and the distribution and abundance of species are in line with prevailing physiographic, geographic and climatic conditions.” MSFD Descriptor 4: Food Webs ”All elements of the marine food webs, to the extent that they are known, occur at normal abundance and diversity and levels capable of ensuring the long-term abundance of the species and the retention of their full reproductive capacity”


Activity (fishing effort)

Pressure (fishing mortality)

Species indicator

(stock biomass)

Community indicator

(in line with prevailing climatic conditions)


Additional management

for GES?

Fisheries management

Extended management cycle

Fisheries and Environmental objectives CFP: Fisheries management have adopted maximum sustainable yield (MSY) targets for fishing mortality on commercial species MSFD: GES by 2020, assessment based on ecological indicators, including indicators of Biodiversity and Food webs


Q How might fisheries management measures contribute

towards the attainment of GES? Q How important are the prevailing climatic conditions?

Which ecological indicators respond to fishing pressure? What management measures might alter fishing pressure? Will climate change mean that we can not meet our aims?

Considered by OSPAR and ICES responsive to fisheries impacts: Food webs • Mean trophic level of surveyed species • Abundance of trophic guilds

(piscivores, planktivores, benthivores, bentho-piscivores) • Large Fish Indicator (all fish and elasmobranches) Biodiversity • Large Fish Indicator (demersal fish and elasmobranchs) • Mean Maximum Length of demersal fish and elasmobranchs


MSFD state indicators

8

• ICES (2012) approved “key-run” of North Sea model

• Driven by time series of fishing mortality for assessed stocks and fishing effort for 8 fleets

Includes environmental drivers Direct forcing of phytoplankton Direct forcing on some fish (e.g. cod) following literature Indirect effects on higher levels [see Mackinson (2013)]

e.g. plaice caught by multiple gears

Multi-fleet

multi-species

Scenario developments

• Benefit of the optimisation approach is that we final a single set of effort for 3 fleets (using ICES F targets for 8 stocks)

• Incorporating the effort strategy in EwE we can model the expected F on 43 species in a consistent way

Lynam + Mackinson: Mixed fisheries + EBM

Fishing strategy (for wider effects)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1990 2000 2010 2020 2030

Herr

ing

fishi

ng m

orta

lity

0

0.2

0.4

0.6

0.8

1

1.2

1990 2000 2010 2020 2030

Nor

way

pou

t fis

hing

mor

talit

y0

0.2

0.4

0.6

0.8

1

1.2

1.4

1990 2000 2010 2020 2030

Cod

fishi

ng m

orta

lity

0

0.2

0.4

0.6

0.8

1

1.2

1990 2000 2010 2020 2030

Hadd

ock

fishi

ng m

orta

lity

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1990 2000 2010 2020 2030

Saith

e fis

hing

mor

talit

y

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1990 2000 2010 2020 2030

Whi

ting

fishi

ng m

orta

lity

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1990 2000 2010 2020 2030

Sole

fish

ing

mor

talit

y

Fishing mortality target

Baseline fishing (2007 mortality value)

Optimised fishing strategy

F (stock assessment)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1990 2000 2010 2020 2030

Plai

ce fi

shin

g m

orta

litycod haddock plaice

saithe whiting sole

herring N. pout

Fishing mortality target

Baseline fishing (2007 mortality value)

Optimised fishing strategy

F (stock assessment)

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Nor

th S

ea S

ST re

lativ

e to

199

0

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Nor

th S

ea S

ST re

lativ

e to

199

0

12

14

16

18

20

22

24

26

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Tota

l bio

mas

s (to

nnes

per

km

2 )12

14

16

18

20

22

24

26

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Tota

l bio

mas

s (to

nnes

per

km

2 )


Baseline fishing and constant climate

Optimised fishing strategy with constant climate

Baseline fishing plus climate scenario

Optimised fishing plus climate scenario

Temperature scenario

Scenario

Biomass (constant climate)

Biomass (+SST variable)

SST constant

SST variable

Total biomass of system follows temperature trajectory

12





hindcast period

6

8

10

12

14

16

18

20

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Biom

ass o

f sur

veye

d sp

ecie

s (t

per

km

2 )

3.7

3.75

3.8

3.85

3.9

3.95

4

4.05

4.1

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Trop

hic l

evel

of s

urve

yed

spec

ies

(fish

and

ela

smob

ranc

hes)

Total biomass of fish less sensitive than biomass of entire system Yet small change in trophic level…

Temperature – little effect on fish ?

Biomass of fish and elasmobranchs Trophic level of fish and elasmobranchs

Survey

ΔF by species

-1.00 -0.50 0.00 0.50 1.00 1.50

SoleCod (adult)

PlaiceSealsSprat

Saithe (adult)Spurdog

MonkfishLarge piscivorous sharks

Catfish (Wolf-fish)Herring (adult)

Large demersal fishHaddock (adult)

Squid & cuttlefishFlounder

Herring (juvenile 0, 1)Mackerel

Other gadoids (large)Witch

Lemon soleJuvenile Haddock (0-1, 0-20cm)

Whiting (adult)Shrimp

SandeelsMiscellaneous filterfeeding pelagic…

DabSmall demersal fish

Turbot and brillSkate + cuckoo ray

NephropsOther gadoids (small)

Small sharksJuvenile Saithe (0-3, 0-40cm)

Juvenile raysThornback & Spotted ray

Horse mackerelHake

GurnardsJuvenile Cod(0-2, 0-40cm)

Juvenile Whiting (0-1, 0-20cm)Starry ray + others

HalibutDragonets

Large crabsBlue whiting

SeabirdsLong-rough dab

MegrimNorway pout

% change in biomass at equilibrium (2030)

-0.30 -0.20 -0.10 0.00

SoleCod (adult)PlaiceSealsSpratSaithe (adult)SpurdogMonkfishLarge piscivorous sharksCatfish (Wolf-fish)Herring (adult)Large demersal fishHaddock (adult)Squid & cuttlefishFlounderHerring (juvenile 0, 1)MackerelOther gadoids (large)WitchLemon soleJuvenile Haddock (0-1, 0-20cm)Whiting (adult)ShrimpSandeelsMiscellaneous filterfeeding pelagic…DabSmall demersal fishTurbot and brillSkate + cuckoo rayNephropsOther gadoids (small)Small sharksJuvenile Saithe (0-3, 0-40cm)Juvenile raysThornback & Spotted rayHorse mackerelHakeGurnardsJuvenile Cod(0-2, 0-40cm)Juvenile Whiting (0-1, 0-20cm)Starry ray + othersHalibutDragonetsLarge crabsBlue whitingSeabirdsLong-rough dabMegrimNorway pout

Difference in F

Without change in climate Winners and losers decreases in F or no change for every group

Winners

losers

ΔF % change in biomass

-1.00 -0.50 0.00 0.50 1.00 1.50

SoleCod (adult)

PlaiceSealsSprat
















Horse mackerelHake



HalibutDragonets



MegrimNorway pout


% change in biomass -1.00 -0.50 0.00 0.50 1.00 1.50

SoleCod (adult)

PlaiceSealsSprat
















Horse mackerelHake



HalibutDragonets



MegrimNorway pout


% change in biomass

ΔF and ΔSST

With variability in climate Losers worse off decreases in F or no change for every group

Winners

losers

% change in biomass

0

0.5

1

1.5

2

2.5

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Biom

ass o

f pis

civo

res

(t p

er k

m2 )

0

1

2

3

4

5

6

7

8

9

10

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Biom

ass o

f pla

nktiv

ores

(t

per

km

2 )

ΔF and ΔSST: food webs

Biomass by trophic guild

Planktivores

Piscivores





Survey

ΔF and ΔSST: biodiversity

Size structure indicators for demersal guild

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Larg

e Sp

ecie

s Ind

icat

or(d

emer

sal

fish

and

elas

mob

ranc

hes)

55

65

75

85

95

105

115

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Mea

n m

axim

um le

ngth

(cm

)(d

emer

sal f

ish

and

elas

mob

ranc

hes)

Mean Maximum Length

Large Species Indicator





Survey

ΔF and ΔSST: food webs

Size structure indicators for all species Less sensitive to climate than the demersal guild

45

50

55

60

65

70

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Mea

n m

axim

um le

ngth

(cm

) (al

l su

rvey

ed fi

sh a

nd e

lasm

obra

nche

s)

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

2027

2029

Larg

e Sp

ecie

s Ind

icat

or (a

ll su

rvey

edfis

h an

d el

asm

obra

nche

s)Baseline fishing and constant climate




Mean Maximum Length

Large Species Indicator

Survey

18

Reduced fishing effort will lead to increases in • size-based indicators and • biomasses of piscivores, planktivores and benthivores • however, predation by piscivores will depress bentho-

piscivore biomass

• Fisheries management measures will contribute to improvements in the biodiversity of the fish community, but food web interactions will mediate changes

Lynam + Mackinson: Mixed fisheries + EBM

Summary: fishing impacts

Climate warming may • increase indicators of size and trophic level • increase the biomass of planktivores and benthivores • decrease the biomass of piscivores

• Community indicators are less sensitive to climate as the number of species included in the indicator increase


Summary: climate impacts

• Targets for ecological indicators + targets for fishing mortality

(revised to reflect fleet/species interactions) must be set in a coherent manner

• Climate change must be considered such that management

targets set are achievable


Implications

‘Effects of climate change on the world’s oceans’ Santos City, Brazil, 23-27 March 2015 S12 Linking climate change to marine management objectives

mixed-fisheries and ecosystem based management · 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 1990 2000 2010...

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