life-history strategies of fishes and their relevance to ecosystem-based fisheries management rainer...
TRANSCRIPT
![Page 1: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/1.jpg)
Life-history Strategies of Fishes and their
Relevance to Ecosystem-Based Fisheries Management
Rainer Froese
![Page 2: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/2.jpg)
Content
• What are life-history strategies?– Choice of key traits– Correlation of traits– Dealing with bias
• Exploring life-history space
• Ecosystems and life-history strategies
• Implications for ecosystem-based fisheries management
![Page 3: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/3.jpg)
Key Trait: Size
0
1000
2000
3000
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Length (log; cm)
Fre
qu
en
cy
Small< 6.6 cm
Medium6.6 - 46
Large46 - 323
very large> 323 cm
23,603 speciesgeom. mean 17.4 cm
![Page 4: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/4.jpg)
Size Distribution is Multi-ModalCumming and Havlicek (2002)
0
500
1000
1500
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Length (log; cm)
Fre
qu
en
cy
![Page 5: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/5.jpg)
Key Trait: Trophic Level
0
500
1000
1500
2.0 2.5 3.0 3.5 4.0 4.5 5.0
Trophic level
Fre
qu
en
cy
7,161 species
herbi-vore
omnivore low-level predator mid-levelpredator
top-predator
![Page 6: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/6.jpg)
Key Trait: Productivity(modified after Musick 1999)
Parameter High Medium Low Very low
rmax (1/year) > 0.5 0.16 – 0.50 0.05 – 0.15 < 0.05
td (years) <1.4 1.4 - 4.4 4.5 - 14 > 14
Interest rate (%) > 65 17 – 65 5 - 16 < 5
K (1/year) > 0.3 0.16 – 0.30 0.05 – 0.15 < 0.05
Fecundity (1/year) > 10,000 100 – 1000 10 – 100 < 10
tm (years) < 1 2 – 4 5 – 10 > 10
tmax (years) 1 – 3 4 – 10 11 – 30 > 30
![Page 7: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/7.jpg)
Key Traits: Productivity
Productivity Species Percent r’ max
Very low 263 10.5 0.025
Low 1016 40.5 0.1
Medium 879 25.0 0.23
High 353 14.0 0.75
2,511 species
![Page 8: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/8.jpg)
Productivity is a Proxy for Metabolism
(routine metabolism of 175 species)
10
100
1000
10000
1 High 2 Medium 3 Low 4 Very low
Productivity
Oxy
ge
n c
on
sum
ptio
n (
mg
/kg
/h)
![Page 9: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/9.jpg)
Trait Correlation: Size vs Troph
1
10
100
1000
10000
1 Herb 2 Omni 3 Low 4 Mid 5 Top
Trophic groups
Le
ng
th (
cm)
![Page 10: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/10.jpg)
Trait Correlation: Size vs Productivity
1
10
100
1000
10000
1 Very low 2 Low 3 Medium 4 High
Productivity groups
Le
ng
th (
cm)
![Page 11: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/11.jpg)
Trait Correlation: Trophic Level vs Productivity
2.0
3.0
4.0
5.0
1 Very low 2 Low 3 Medium 4 High
Productivity groups
Tro
ph
ic le
vel
![Page 12: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/12.jpg)
Available Data are Biased
• Combined available data for 1,880 species are biased towards large, commercial, northern-hemisphere, temperate species
• Solution: Use modelling approach to expand data base
![Page 13: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/13.jpg)
Expanding the Database: Trophic Level
2
2.5
3
3.5
4
4.5
5
1 10 100 1000
Length (cm)
Tro
ph
ic l
evel
Trophic level of 97 species of Genus Epinephelus as a function of their body length.
Top
Medium
Low
![Page 14: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/14.jpg)
Residuals of Modelled Troph
0
500
1000
1500
2000
2500
-2 -1 0 1 2 3
Species (log; n)
Fre
qu
en
cy
Residual Troph
![Page 15: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/15.jpg)
Expanding the Database: Productivity (K)
.01
.1
1
10
1 10 100 1000
Length (cm)
K (
1/y
ea
r)
Von Bertalanffy growth parameter K plotted over maximum length for Family Serranidae
High
Medium
Low
Very low
![Page 16: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/16.jpg)
Modelled vs Observed K
0.0
0.1
1.0
10.0
0.01 0.10 1.00 10.00
K observed (1/year)
K p
red
icte
d (
1/y
ea
r)
![Page 17: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/17.jpg)
Life-History Strategies
• The extended data set contains 20,480 species, nearing a census
• Bias towards large northern species has disappeared
• Of 80 possible combinations of traits only 50 are used
• Three strategies are used by 60% of the species
![Page 18: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/18.jpg)
Occupation of Size-Troph Space
Small Medium LargeVerylarge
Herb
OmniLow
MidTop
0
2000
4000
6000
8000
10000
12000
![Page 19: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/19.jpg)
Occupation of Size-Productivity Space
Small MediumLarge
Verylarge
Very low
Low
MediumHigh
0
2000
4000
6000
8000
10000
![Page 20: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/20.jpg)
Occupation of Troph-Productivity Space
HerbOmni
LowMid
Top
Very low
Low
MediumHigh
0
2000
4000
6000
8000
10000
![Page 21: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/21.jpg)
Goals of Ecosystem-based Fisheries Management
• Sustainable and productive fisheries
• Minimum impact on the ecosystem
• Ecosystem as close to unfished state as possible
![Page 22: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/22.jpg)
Interrelationship of Ecosystems andLife-history Strategies (I)
Selectiontheory
Environment Number of species
Size Productivity Trophic diversity
r-K variable small high
stable large low
Succession less mature low small high low
mature high large low high
Temperature high temp. high small high
low temp. low large low
![Page 23: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/23.jpg)
Interrelationship of Ecosystems and Life-history Strategies (II)
• No relationship between fecundity and reproductive success in highly-fecund bony fishes (Froese and Luna 2004)
• Fecundity balances typical pre-adult mortality in the respective environment (Beverton 1991)
• Longevity has evolved to survive periods unfavourable for recruitment (Longhurst 2002)
• Abundance increases with productivity and decreases with size (Froese 2005)
![Page 24: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/24.jpg)
Impact of Fishing
• Fishing strongly alters the size spectrum of ecosystems (and populations) (Froese et al. 2000)
• Fishing reduces trophic diversity (fishing down the food web) (Pauly et al. 1998)
• Fishing strongly alters relative abundances, with collapse of previously abundant species, ‘outbreak’ of rare species (Bakun 2005)
![Page 25: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/25.jpg)
Fishing Down the Food Web
![Page 26: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/26.jpg)
Goals of Ecosystem-based Fisheries
• Minimize direct impact on the environment• Rebuild & preserve size spectrum• Rebuild & preserve trophic diversity• Rebuild & preserve productivity• -- Don’t catch juveniles• -- Protect Mega-spawners• -- Only catch proportion of fish with
optimum size, after first and before second spawning
![Page 27: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/27.jpg)
How ?
• Establish no-take zones
• Use non-destructive gears
• Use size-selective gears
• Use knowledge and technology
• Create incentives for ‘good’ fishing
• Involve stakeholders in monitoring and management
![Page 28: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/28.jpg)
Thanks to the FishBase Team
![Page 29: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/29.jpg)
Thanks to our Donors
![Page 30: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/30.jpg)
Reality Check
DG Fish recommendation for TAC 2006: 28,400 tons (+ 15%)
![Page 31: Life-history Strategies of Fishes and their Relevance to Ecosystem-Based Fisheries Management Rainer Froese IfM-GEOMAR rfroese@ifm-geomar.de](https://reader036.vdocuments.mx/reader036/viewer/2022070413/5697bfdb1a28abf838cb085b/html5/thumbnails/31.jpg)
Thank You
• Comments?
• Questions?