Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

12
Average Mutual Information and fisheries impacts Manuel Zetina Rejón

description

Impact evaluation Time Relative Biomass 0 10% -10% Biomass MC TR Resilience= (R) Persistence (P) Recovery time (TR) Magnitude of change (MC) Disturbance Δ F’s

Transcript of Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Page 1: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Average Mutual Information and fisheries impacts

Manuel Zetina Rejón

Page 2: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Simulation scenarios

0

0.5

1

1.5

2

2.5

0 5 10 15 20 25 30 35 40 45 50Years of simulation

Rel

ativ

e fis

hing

effo

rt

• Campeche sound– Shrimp– Demersal– Pelagic– Beach seine– Octopus

• Terminos Lagoon– Finfish– Oyster– Blue crab

• All fisheries

Page 3: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Impact evaluation

Time

Rela

tive

Bio

mas

s

0

10%

-10%

Biomass

MC

TRResilience=

(R)

Persistence(P)

Recovery time(TR)

Magnitudeof change

(MC)

Disturbance

Δ F’s

Page 4: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Effects of fisheries

AllShrimp

Demersal

Pelagic

Beach seine

OctopusFinfish

-10-8-6-4-20246810

-10 -8 -6 -4 -2 0 2 4 6 8 10Axis 1 (49 %)

Axi

s 2

(20

%)

Persistence

AllShrimp

Demersal

PelagicBeach seine

Octopus

Finfish

-15

-10

-5

0

5

10

15

-15 -10 -5 0 5 10 15Axis 1 (72 %)

Axi

s 2

(9 %

)

Magnitude of Change

AllShrimp

Demersal

PelagicBeach seine

Octopus

Finfish

-15

-10

-5

0

5

10

15

-15 -10 -5 0 5 10 15Axis 1 (70 %)

Axi

s 2

(10

%)

Recovery time

AllShrimp

Demersal

PelagicBeach seine

Octopus

Finfish

-10-8-6-4-20246810

-10 -8 -6 -4 -2 0 2 4 6 8 10Axis 1 (57 %)

Axi

2 (1

6 %

)

Resilience

Page 5: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Time

Rela

tive

Biom

ass

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Time

Rela

tive

Biom

ass

Resilience indicator:Area of change (AC)

),()( tit MaxBBMax

),()( tit MinBBMin

dtBMinBMaxACfin

ini

t

ttt )( )()(

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Time

Rela

tive

Biom

ass

Low Impacts = Low ACHigh Impacts = High AC

Page 6: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Area of Change

0.20.40.60.81.01.21.41.61.82.0

0.20.40.60.81.01.21.41.61.82.0

2 6 10 14 18 22 26 30 34 38 42 46 50 2 6 10 14 18 22 26 30 34 38 42 46 50 2 6 10 14 18 22 26 30 34 38 42 46 50

Years of Simulation

0.20.40.60.81.01.21.41.61.82.0

ShrimpSC

Rel

ativ

e B

iom

ass

DemersalSC

PelagicSC

Beach seineSC

FinfishLT

OctopusSC

OysterLT

Blue crabLT

All

AC=102.8 AC=43.3 AC=201.3

AC=22.8 AC=37.0 AC=77.9

AC=0 AC=0 AC=258.4

Page 7: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

AllPelagic

Finfish

Shrimp

Demersal

Octopus

Beach seine

R 2 = 0.97

1

21

41

61

81

101

121

141

161

50 100 150 200 250 300AC

MA

GN

ITU

DE

OF

CH

AN

GE

AllPelagic

Finfish

Shrimp

Demersal

Octopus

Beach seine

R2 = 0.96

1

6

11

16

21

26

31

36

REC

OVE

RY

TIM

E

Page 8: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Information Theory (Ulanowicz, 1986)Average Mutual Information ( I ) measures the probability that a unit of energy flows to certain destination.

When uncertainty of the destination is high, I is bigger, quantifies degree of articulation in network/models.

Measure of organization, higher in mature and complex systems.

The I is higher while more complex trophic links.

I = Lower I = Higher

Page 9: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Hypothesis

When a fishery catch or remove biomass of group of species with simple trophic links, the impact of this fishery could be more severe, making ecosystem's stability and resilience vulnerable when high biomasses are extracted from the system

Page 10: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Average Mutual Information ( IF )

n

ii

t

iF I

CCI

1

Page 11: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

AC vs. IF

Oyster Blue crab Beach seine

Octopus Demersal

Shrimp Finfish

Pelagic All

R 2 = 0.6

-

0.5

1.0

1.5

2.0

2.5

3.0

- 1.0 2.0 3.0 4.0 5.0 6.0 7.0

I F

log

AC

Page 12: Average Mutual Information and fisheries impacts Manuel Zetina Rejn.

Realistic Model

Simulation scenarios

(changes in fishingintensity)

Evaluationof Impacts

ModelValidation

Research strategy

0.20.40.60.81.01.21.41.6

Time seriesObserved data

0.5

1.0

1.5

2.0

2.5

3.0

1984 1988 1992 1996