Transcript Kentucky State University Aquaculture Program KSU`s Program of

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
Tidwell’s Theory of Fisheries
Relativity
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
Billions of people
6
5.5
5
1.5 MMT additional
product each year!
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
– slow reproduction and
recovery rates.
•
• Trawling technologies for
ground fish like flounderalso catch large numbers of
skates and rays.
Shrimp trawls may kill
10 kg of juvenile finfish
for each kg of shrimp
By-Catch
• Other high profile
examples
– Shrimp and Sea
turtles
–Tuna and Dolphins
•Driven by
consumer demand
–Tuna and shrimp
are #1 and #2 in
popularity
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
25
MMT
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
25
MMT
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%
Shrimp
Salmon
0
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
100
97.2
capture fisheries
84.5
80
69.4
60
40
20
0
1980
• Simplistic, unbalanced assessments of
1985
1990
1995
2000
2005
2010
2015
2020
2025
year
aquaculture - multiplied through the popular
media - can impede responsible aquaculture
development.
• 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.”