Impact of Global Fisheries and Global Warming on Marine Ecosystems and Food Security Daniel Pauly...
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Impact of Global Fisheries and Global Warming on Marine Ecosystems and Food Security Daniel Pauly Sea Around Us Project Fisheries Centre, UBC A Future for Fisheries? Toward Effective Strategies for Sustainability KU Leuven, February 5, 2008
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Transcript of Impact of Global Fisheries and Global Warming on Marine Ecosystems and Food Security Daniel Pauly...
Impact of Global Fisheries and Global Warmingon Marine Ecosystems and Food Security
Daniel PaulySea Around Us ProjectFisheries Centre, UBC
A Future for Fisheries?Toward Effective Strategies for Sustainability
KU Leuven, February 5, 2008
This graph, illustrating a Canadian tragedy, leads to several questions. One of them is: how typical is the story of the Northern cod fishery? Can we generalize?
And it goes on!
We can define…
Now let’s apply these definitions to the global FAO catch statistics…
Fully exploited
Developing
Underdeveloped… Over-exploitedCrashed
Sto
cks
(%)
Our first generalization is bleak indeed.
Developing
Fully exploited
Over-exploited
Crashed
Underdeveloped
Also, it is tempting to project these trends…
Sto
cks
(%)
2048 ?
Our next generalization relies on maps. We don’t really know where most fisheries operate, but when we have global FAO catch statistics, we can infer the distribution of fisheries (and of catches) by using a filtering approach…
Taxon (what) FAO Area (where)Country (who)
Taxon Distribution Database
Spatial ReferenceDatabase
Fishing AccessDatabase
Common Spatial Cells?
Assign catch rates to cells
YES
Over 99.9% of the global marine catch can be assigned to ½ degree spatial cells, and we are steadily improving the underlying databases …
No; improve underlying databases
This is the first map we got. It was not very exciting, except for the anomalies (red)….
0
We had no problem with Peruvian and Chilean waters being extremely productive. But China?
Thus, global fisheries landings, despite (or because of ) increasing effort, have been declining since the late 1980s, a fact long hidden by over-reporting from China:
Watson and Pauly (Nature), 2001.
40
45
50
55
60
65
70
75
80
85
90
1970 1975 1980 1985 1990 1995 2000
Glo
ba
l c
atc
h (
t ·1
06 )
Uncorrected
Corrected
Corrected, no anchoveta
El Niño event
(a)El Niño events
0
20
40
60
80
100
120
1975 1980 1985 1990 1995 2000
Year
Wit
hd
raw
als
(mil
lion
t)
A
E
D
C
B
In fact, the decline is even stronger if one considers discarded fish. This was generally overlooked when FAO’s last estimate of discards (dot E; 7-8 million t) was released.
Zeller and Pauly (Fish & Fisheries, 2005)
Peruvian anchoveta
Other landed fishes and invertebrates
Discarded fishes and invertebrates
Back to basics: ecosystem fluxes move up ‘trophic pyramids’…
Tro
ph
ic le
vel
Phytoplankton
Top predators
Prey fish
Zooplankton
. . ... .. .. .. .. .. .. .. *.*. .. .... . ..*.*.*.*.*.*.
*.*. *.*.*.*.*.*.
. . . . . . 10% 10%
10% 10%
10% 10%
*.*.
4
3
2
1
and each species tends to have its own trophic level…
3.2
3.3
3.4
3.5
3.6
1950 1955 1960 1965 1970 1975 1980 1985 1990 1995
Year
Tro
ph
ic le
vel
Global coastal
North Atlantic
2000
Another generalization emerges when we compute the mean trophic level of world catches. This shows a global decline…
Pauly et al. (Science, 1998)
In fact, ‘fishing down’ is so widespread that the Convention on Biological Diversity (CBD) now uses mean trophic levels as an index of biodiversity, the “Marine Trophic Index”.
Trophic level change (1950-2000)
>1 0.5 to 1.0 no change /no data
And this means that ‘fishing down’ is
everywhere
We can see from space how trawlers stir up sediment…
Photo courtesy of Dr. Kyle van Houten (Duke University)
Here: shrimp trawlers off the Texas Coast, Gulf of Mexico
The Benguela Current may be the first system where jellyfish became dominant, but it won’t be the last…
Grenadier, snoek,seabream
Hake
HakeHake
FlatfishPollock
Flounder
Cod
Cod, saithe, plaice, redfish, haddockDemeral Fishes
Consumers in the ‘North’ have not noticed this, nor similar trends: while most seafood is traded between the EU, the USA and Northeast Asia, the ‘South’ has so far met the shortfall in the ‘North’….
We’ll need to get out of the vicious circle of contemporary fisheries management.
We can do things right, as illustrated by Georges Bank haddock
200-MileLimit
EmergencyClosure
Now turning to subsidies
MEY
MSY Bionomic equilibrium (BE)
Total cost of fishing effort (TC)
Total Revenue (TR)
Fishing effort (E)
TR & TC ( $)
E1 E2 E3
Max. rent
TC1
TC2
BE2
BE1
TR
TR& TC ($)
E3 E4 Fishing effort (E)
Cost-reducing subsidies
Let’s assume a Gordon-Schaefer bioeconomic model How subsidies induce overfishing
Non fuel
Fuel
0
5
10
15
20
25
30
35
World Bank This study
Subs
idy
amou
nts
in b
illion
USD
Global subsidy comparisons
Sumaila and Pauly (2006)
Subsidies come in different flavors…
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Asia
Europe
Lat. America & Caribbean
North America
Sub Saharan Africa
North Africa & Mediterranean
Oceania
Subsidy amount (billion USD)
Good subsidies Bad subsidies Ugly subsidies
Sumaila and Pauly (2006)
Marine Protected Areas are part of the solution. There are many, but most of them are tiny…
0
500
1000
1500
2000
2500
3000
3500
4000
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Year
Cu
mu
lati
ve A
rea
('00
0 sq
km
)
International sites
National sites
1% of world ocean area (growth rate ~ 5% year-1)
Wood et al. (in press)
As a result, the growth of the global MPA network is so slow that we will miss all the targets…
Wood et al. (in press)
0
5
10
15
20
25
30
35
40
1970 1975 1980 1985 1990 1995 2000
0
5
10
15
20
25
30
35
40
1970 1975 1980 1985 1990 1995 2000
The worldwide aquaculture production - by countries (10^6 tonnes)
China
However, all the optimistic projections forget that aquaculture is mainly a Chinese enterprise (2/3 of production), devoted mainly to freshwater fishes…
Aquaculture has grown to a production of 40 millions t in the last decades , and some believe it is solution to our fish supply problem…
Freshw. fishes
But a major trend in aquaculture is what may be called ‘farming up the food web’, which occurs in major producing countries …
Note absence of an increasing trend for the USA, due to a high production of (low trophic level) catfishes(Pauly et al. 2001. Conservation Biology in Practice 2(4): 25).
The farms’ impacts on coastal ecosystems are, besides pollution, that they tend to increase the ‘fishing down’ effects…
Jacquet, J. and D. Pauly. 2007. The rise of consumer awareness campaigns in an era of collapsing fisheries. Mar. Pol. 31: 315-321.
One approach much talked about are market-based mechanisms, see e.g., www.seafoodguide.org. Another approach is illustrated here…
Pho
to (
?) b
y Je
nnif
er J
acqu
et
Source: Watson, Alder & Pauly, 2006
However, over 1/3 of the world’s fish catch is currently wasted, i.e., turned into animal feeds…
36%
…which is a tremendous waste of good food
Meanwhile, thing are heating up…
Al Gore & IPCC: Nobel Prize 2007
………..
Probability of occurrence by water temperature
Temperature-abundance profile
Small yellow croaker (Larimichthys polyactis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
0.00
0.05
0.10
0.15
0.20
2 4 6 8 10 12 14 16 18 20 22 24 26 28
Temperature (degree C)
Pro
ba
bili
ty o
f o
cc
urr
en
ce
Small yellow croakerYear 0
Year 30
Small yellow croaker
Year 0
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 2
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 4
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 6
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 8
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 10
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 12
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 14
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 16
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 18
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 20
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 22
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 24
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 26
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 28
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Year 30
Barndoor skate(Dipturus laevis)
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Year 0
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 2
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 4
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 6
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 8
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 10
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 12
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 14
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 16
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 18
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 20
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 22
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 24
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 26
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 28
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Year 28
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Greenland shark(Somniosus microcephalus)
Original (static) distribution
Relative abundance
0
0 - 0.00015
> 0.0015 - 0.0038
> 0.0038 - 0.0062
> 0.0062 - 0.0095
> 0.0095 - 0.012
> 0.012 - 0.016
> 0.016 - 0.023
> 0.023 - 0.030
> 0.030 - 0.040
> 0.040
Low
High
Relative abundance
Distribution after 30 years
Antarctic toothfish (Dissostichus mawsoni)
…as an example of a species predicted to go extinct
Acknowledgements… • Thanks to the Pew Charitable Trusts,
Philadelphia;
• Fisheries Centre, University of British Columbia;
• Members of the Sea Around Us project,and many others...
visit us at www.seaaroundus.org
