State of the Marine Environment

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Transcript State of the Marine Environment

State of the Marine
Environment
Rainer Froese
Leibniz Institute of Marine Sciences, Kiel
IfM-GEOMAR
[email protected]
Acknowledgements
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Sea Around Us provided data
FishBase provided data
EEA provided data
Daniel Pauly, Boris Worm and Ian Payne
shared slides
• DG Development and DG Research
supported previous research
Overview
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Major Threats to European Seas
Paradox of Fishing
Myths about Fishing
Common Sense Fisheries Policy
Europe‘s Regional Seas
Major Threats to Europe‘s Seas
1. Fishing (NE, North Sea, Mediterranean,
Baltic, Black Sea)
Fishing Down Marine Food Webs
Pauly et al. 1998 Science 279:860-863
Trophic Level
5
4
3
2
Watson and Pauly In: Atlas of the Ocean
Fishing Down the Food Web
in the North Sea
(Source: Froese and Pauly 2003)
3.5
4
3.5
3
Trophic Level
2.5
3.3
2
3.2
1.5
Catch
1
3.1
0.5
3
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
Years
Trends in mean trophic level of annual landings from the North Sea
0
2000
Million Tonnes / year
Mean Trophic Level
3.4
Major Threats to Europe‘s Seas
1. Fishing (NE, North Sea, Mediterranean,
Baltic, Black Sea)
2. Pollution (North Sea, Baltic, Black Sea)
Pollution
Regional trends of hazardous substances in fish from north-east
Atlantic and Baltic regions (Source: EEA)
Major Threats to Europe‘s Seas
1. Fishing (NE, North Sea, Mediterranean,
Baltic, Black Sea)
2. Pollution (North Sea, Baltic, Black Sea)
3. Eutrophication (Black Sea, Baltic, North
Sea)
Eutrophication
Chlorophyll-a concentrations in transitional,
coastal and marine waters (Source: EEA)
Major Threats to Europe‘s Seas
1. Fishing (NE, North Sea, Mediterranean,
Baltic, Black Sea)
2. Pollution (North Sea, Baltic, Black Sea)
3. Eutrophication (Black Sea, Baltic, North
Sea)
4. Climate change (NE, North Sea)
Climate change
Observed European annual average
temperature deviations (Source: EEA)
Major Threats to Europe‘s Seas
1. Fishing (NE, North Sea, Mediterranean,
Baltic, Black Sea)
2.
3.
4.
5.
6.
Pollution (North Sea, Baltic, Black Sea)
Eutrophication (Black Sea, Baltic, North Sea)
Climate change (NE, North Sea)
Invasive species (Black Sea, Mediterranean)
Local threats: Coastal developments, Mariculture,
Shipping accidents
Paradox of Fishing
• Reducing pollution, eutrophication, green house
gases, and ballast water introductions are
‚common sense‘ solutions that seem to work.
• Fishing less to get more fish is not ‚common
sense‘
• Fishers and boats are less but fishing effort has
increased
• Focus only on reducing fishing effort has not
worked in the past 100 years and is unlikely to
work in the future.
Time Series of Abundance and Fishing
Mortality
Trends from
‘Working Group’
reports by fisheries
scientists in
government agencies
(NMFS, DFO,
DIFMAR,
IFREMER, etc.),
compiled by R. A.
Myers.
Myths about Fishing
• There are enough fish...
FAO Marine Catches 1951-1998
(Source: Froese and Pauly 2003)
100%
Percent of World Fisheries
26%
22%
5.1 years
31%
80%
Collapsed
4.1 years
Overfished
5.0 years
Fully exploited
60%
38%
Developing
4.3 years
40%
20%
0%
1951
Undeveloped
?
1956
1961
1966
1971
1976
Years
1981
1986
1991
1996
The Northeast Atlantic, ICES
(Source: Froese and Pauly 2003)
100%
Collapsed
Percent of ICES Fisheries
28%
5.1 years
75%
43%
3.9 years
50%
Overfished
Fully exploited
Developing
25%
Undeveloped
0%
1974
1978
1982
1986
Years
1990
1994
1998
Geographic expansion of fisheries
(Source: Sea Around Us)
Years at and after maximum catch in half-degree cell
Myths about Fishing
• There are enough fish...
• It is the climate...
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Source: Myers and Worm 2003.
Nature 423: 280-283
Myths about Fishing
• There are enough fish...
• It is the climate...
• It is the pollution...
(t/km2)
Biomass of table fish in 1900 (Christensen et al. 2003, Fish & Fisheries)
and in 2000….
Myths about Fishing
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There are enough fish...
It is the climate...
It is the pollution...
Size does not matter...
Size Does Matter!
1. Size at first maturity: fish caught below that
size could not spawn;
2. Size at maximum yield: fish caught below
that size have not yet reached optimum
weight;
3. Mega-spawner size (many eggs, high egg
survival, good genes): fish caught below that
size have no chance to become Megaspawners
EC Minimum Size Limits
Council Regulation No 2555/2001
Species
EC
Minimum
Size
Atlantic cod 41 cm
Size at first Size at
maturity
maximum
yield
60 cm
85 cm
American
plaice
Yellowtail
flounder
Greenland
halibut
25 cm
20 cm
25 cm
25 cm
26 cm
29 cm
30 cm
58 cm
72 cm
Myths about Fishing
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There are enough fish...
It is the climate...
It is the pollution...
Size does not matter...
Recruitment can be predicted...
Stocks will recover...
Aquaculture is the solution...
Aquaculture is Part of the Problem
• 3-4 kg of wild fish to culture 1 kg of salmon
• 5 kg of wild fish for 1 kg of cod
• 20 kg of wild fish for fattening of 1 kg of
tuna
• More Aquaculture means less wild fish for
human consumption
Three Simple Steps from CFP to
Common Sense Fisheries Policy
1. Let them spawn
– Size at first maturity is known for all stocks
2. Let them grow
– Size of maximum yield per recruit is known for all
stocks and is slightly beyond size at maturity
3. Let some live
– Old, large fish produce more eggs, have better
genes, and provide an insurance against recruitment
failures
CSFP
Commercial Landings of Nile perch in 1982
100
90
80
Numbers
70
60
50
40
30
20
10
0
0
20
40
60
80
100
120
Length (cm)
140
160
180
200
220
CSFP
Commercial Landings of Nile perch in 1982
100
Lm
90
Lopt
Linf
80
Numbers
70
60
50
40
30
20
10
0
0
20
40
60
80
100 120
Length (cm)
140
160
180 200
220
CSFP
Common Sense Fisheries Policy
• Agree on biology of stock: maturity, spawning
time and area, productivity
• Agree on percentage of first-time spawners to be
caught (10 – 50 %)
• Determine annual number of first time spawners
by survey on spawning grounds
• Allow fishing of first-time spawners after
spawning season
• Provide strong incentives for catching only fish
of the desired size (mix of Policy Instruments)
• Only import mature fish
Don‘t Eat Babies
Rainer Froese
IfM, Düsternbrooker Weg 20
24105 Kiel, Germany
[email protected]
As a result of overfishing, most fishes are now caught before they had a chance to
reproduce. This results in low catches (growth overfishing) and very small spawning
stocks (recruitment overfishing). We suggest that fish of a given suitable stock are only
caught after the first and before the second spawning in order to obtain maximum
biomass and at the same time rebuild and maintain strong spawning stocks including
large, fit ‘mega-spawners‘. The percentage to be taken from this cohort will depend on
the species and on the status of the stock, and should be agreed between all parties
involved. As the size of the cohort can be easily determined through surveys before and
during first spawning, the total allowed catch in a given year can be determined quite
accurately and transparently. We suggest that such simple regulations can be easier
communicated and enforced than traditional management tools. Preliminary size at first
maturity can be obtained from www.fishbase.org for all commercial fishes of the world.
This size is shown below for some commercial fishes of the North Sea. Similar posters
can be used to educate fishers, fish dealers, and consumers.
European Sprat, Sprattus sprattus, Lm = 10 cm TL
Herring, Clupea harengus, Lm = 24 cm TL
Atlantic cod, Gadus morhua, Lm = 50 cm TL
Atlantic mackerel, Scomber scombrus, Lm = 30 cm FL
European plaice
Pleuronectes platessus
Lm = 28 cm TL
Thank You
More information:
• Froese, R. 2004. Keep it simple: three indicators to deal
with overfishing. Fish and Fisheries 5:86-91
• Froese, R. 2004. Keep fishery management simple.
ICES Newsletter 41:9-10
Copies available from
[email protected]