Transcript Human Impacts Relative Contributions and Impacts of Aquaculture and Capture Fisheries James H.

Human Impacts
Relative Contributions and Impacts of
Aquaculture and Capture Fisheries
James H. Tidwell, Ph.D.
Kentucky State University
And
Geoff Allan, Ph.D.
New South Wales Fisheries
Fish is man’s most important source of animal protein
(FAO 2000)
• Fish makes the greatest
contribution where needed
most.
Fish as % animal protein
North America 10%
Africa
17%
Asia
26%
China
22%
The Demand for Fish is Increasing
120
100
80
MMT 60
40
20
0
1970
1998
2010
Why?
• Not really due to increased
rates of consumption
• (15-16 kg/person).
• Primarily due to
population growth.
World Population
Increase
6.5
1.5 MMT additional product
each year!
Billions of people
6
5.5
5
4.5
4
3.5
3
1970
75
80
85
90
95
2000
Where does it come from?
Only Two Sources-Capture or Culture
• Historically – the oceans
• About 80% of our foodfish
supply comes from ocean
capture fisheries.
• If we needed more – we just
fished harder – longer – or
further away.
Today’s Reality
The ocean’s bounty is
NOT limitless.
50% of ocean fisheries
fully exploited.
70% in need of urgent
management.
(FAO 1999).
What We Have Done?
Invest in bigger, faster boats with
longer ranges
•Invest in new technologies to
locate and aggregate the fish
•Mace (1997) estimated that the
“catching capacity” of the fleet
has increased 4-8 X faster than
actual catch rates.
•Increased outlays and decreasing returns create a
financial inertia against reducing fishing pressures.
Why?
• Consumer demand
drives the system
• Not only how much –
but what species are
targeted
Environmental Costs of Capture Fisheries
• Major Issue – By-Catch
• Longline fisheries -billfishes –
pressures on shark species (China)
– slow reproduction and recovery
rates.
• Trawling technologies for ground
fish like flounder-also catch large
numbers of skates and rays.
Shrimp trawls may kill
10 kg finfish /kg of
shrimp
By-Catch
• Other high profile examples
– Shrimp and Sea
turtles
•Driven by
consumer demand
–Tuna and shrimp
are #1 and #2 in
popularity
–Tuna and Dolphins
Current Situation
•The ocean can supply only 2/3
aquaculture
100
million metric tons
of current demand. Significant
increases from capture appear
biologically unsustainable.
114.8
120
97.2
capture fisheries
84.5
80
69.4
60
40
20
0
1980
1985
1990
1995
2000
2005
2010
2015
2020
2025
year
6.5
Billions of people
6
•Population growth continues.
5.5
5
Demands for fish increases
over 1 million tons per year.
4.5
4
3.5
3
1970
75
80
85
90
95
2000
•Where will almost all future supply
increases come from?
Aquaculture is the fastest growing food
production activity in the world.
45
40
35
30
MMT
25
20
15
10
5
0
1984
1986
1990
1994
1998
1999
Projected requirements for food grade fisheries
114.8
120
aquaculture
million metric tons
100
97.2
capture fisheries
84.5
80
69.4
60
40
20
0
1980
1985
1990
1995
2000
2005
year
2010
2015
2020
2025
Growth of Aquaculture
•With a growth rate of 11% per
year – Aquaculture is on a pace
to surpass beef production by
2010.
Not only how much but where.
While 80% of beef
production is in
industrialized nations
–Aquaculture is growing
6X faster in developing
countries than in
developed countries
Aquaculture Production:
Developed vs Developing countries
40
91% omnivores
or filter feeders
million metric tons
35
30
25
20
Developed
Developing
15
10
5
0
1984 1986 1988 1990 1992 1994 1996 1998 2000
Year
FAO States that:
“As an inexpensive source of highly nutritious animal
protein, aquaculture has become an important factor for
improving food security, raising nutritional standards,
and alleviating poverty, particularly in the world’s
poorest countries.”
Food Security
• Production already increased
400% between 1984 and 1998.
–FAO 2001 predicts
significant increases in
small-scale aquaculture
production in Africa.
There are not too few fish - there are
too many people
If terrestrial agriculture had not
developed, we could never support
the current human population.
A similar juncture has been reached
or passed in fish supplies.
Aquaculture Too Has Its Costs
• The very rapid growth of aquaculture has led, in some cases,
to environmental impacts and conflicts over limited
resources.
45
40
35
30
MMT
25
20
15
10
5
0
1984
1986
1990
1994
1998
1999
• You cannot produce 40 Billion kg of anything without leaving
an “environmental footprint”.
• However, let us base our analyses on facts and fairly compare
these impacts to other sources.
Painting with a broad brush. Don’t say
aquaculture when discussing one species!!
“Aquaculture
Industry a
failure”,
study claims
The Down Side of
Fish Farming
Shrimp and Salmon =/ Aquaculture
35
30
25
20
MMT
15
10
5
6%
9%
0
Shrimp
Salmon
Total Aqua
Environmental Costs of Aquaculture
• Mangrove Destruction
• Fact: As much as 50-60% of the
historic resource has been lost.
• The World Wildlife Fund
reported < 5% of mangrove
losses due to shrimp farms.
• Most to urbanization, fuel,
pulp…
Issue: Fish Meal in Aquaculture Diets
• Naylor et al (2000) reported that aquaculture is “a
contributing factor to the collapse of fish stocks
worldwide”.
• “ever increasing amounts of small pelagic fish would be
caught for use in aquaculture feeds”
• An analysis of these data indicates no statistical
relationship between aquaculture production and pelagic
fish landings or fish meal production (P values > 0.80)
World Aquaculture
Production
35
25
World Landings
of Pelagic Fish
20
15
el nino
10
World Fishmeal
Production
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
0
1985
5
1984
Million Metric Tons
30
What has occurred is a market driven reallocation of how this
fixed amount is used.
30 MMT
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
20
17
29
55
48
17
23
1988
1998
24
35
2000
Others
Swine
Poultry
Aqua
Fish Meal Use vs. Total Production in U.S. Catfish
350000
300000
6.9X
Return
250000
200000
MMT
150000
100000
50000
0
Fish Meal
Live Wt. of fish
meal fish
Catfish
Produced
• Naylor et al pointed out that certain species are “net
consumers” of fish.
• Specifically salmon and shrimp requiring 3Kg of fish to
produce 1Kg of fish on the farm. (actually less)
>4X Return
33.31
35
29.94
30
25
1999 Fishmeal consumption (MMT)
20
1999 Live weight of fish species used in making fishmeal (MMT)
15
10
9.32
1999 Aquaculture production volume (MMT)
5
2.79
0.67
1.39
1.97 1.13
0.47
0.45
1.89
2.67
0.85
2.22
0.64
0
Salmons and Trouts
Shrimps, Prawns
Marine Fish
Others
Total
OK- What if we get that same fish from the
wild??
30-35%
100%
Kg of Forage Fish Required to Produce 1 Kg of Salmon or
Shrimp
KG
By-Catch +
Wastes
16
14
12
10
8
6
4
2
0
Trophic
Conversion
Aquaculture
Wild Capture
30
25
20
MMT 15
10
5
0
Wt. of fish discarded by
capture fisheries
Wt. of fish used in
aquaculture
Nutrition Research
• Just as other livestock
industries have reduced fish
meal inclusion – so will
aquaculture – as nutritional
requirements of culture
species are identified.
Poultry 2 species
Aquaculture 167 species
Fish Meal Use in Poultry
18
16
14
12
MMT
10
8
6
4
2
0
1988
1998
2000
• Naylor et al. 1999 – “due to a reliance on fish meal,
aquaculture of these species is being subsidized by the
marine ecosystem.”
• If we source these same products from capture
fisheries, they are ENTIRELY “subsidized” by the
marine ecosystem.
• Species identified as net producers
do not convert food to flesh with
more metabolic efficiency – They
are just subsidized by a different
ecosystem – freshwater or
terrestrial.
These have their own
environmental costs
Why is Aquaculture More Efficient?
• Less waste – In capture fisheries as much as 40% of the
total catch may be wasted or discarded (Howgate
1997).
• In aquaculture there is a shorter chain, with more
control , from production to harvest to processing and
distribution.
Today’s Reality
• We need Capture Fisheries AND Aquaculture working
together to meet human demand.
Soon they must each supply half of
the worlds fish supply.
Percentage of Total World Seafood Supplied by
Aquaculture
%
40
35
30
25
20
15
10
5
0
1990
1992
1994
1996
1998
2000
• “The divisions between aquaculture
and capture fisheries will rapidly
fade, and in many regions, have
already gone” (Coates 1996).
• In Alaska aquaculture is
“outlawed” but “wild harvest”
salmon and oyster industries rely
heavily on aquacultured seedstock.
• Rational growth of aquaculture production is necessary to
meet basically ALL future increases in the world’s fish
supplies.
114.8
120
aquaculture
million metric tons
97.2
capture fisheries
100
84.5
80
69.4
60
40
20
0
1980
1985
1990
1995
2000
2005
2010
2015
2020
year
• Simplistic, unbalanced assessments of aquaculture multiplied through the popular media - can impede
responsible aquaculture development.
2025
• This could negatively
impact food security in
regions where high
quality protein is needed
most.
It could actually
increase pressures on
marine stocks to
supply the shortfall.
FAO (2001):
“ Irrespective of whether inaccurate information is
generated deliberately to promote a specific cause, or
inadvertently through ignorance, it can have a major
impact on public opinion and policy making that may not
be in the best interest of either sustainable use of fisheries
resources or the conservation of aquatic systems.”
Table 17.02
Table 17.03