Transcript Aquaculture - University of San Diego

Allain, Brooke, Amanda, Alexandra
Introduction
 “Seafood is one of the healthiest and most popular
sources of protein worldwide. Almost half of the
seafood we eat comes from farms, making aquaculture
- seafood farming - the fastest growing food
production system in the world…Despite a steep
learning curve for this growing industry – learning in
just 30 years what land farmers have garnered over
6,000 years – positive changes in the industry already
are visible.” –worldwildlife.org
 Total U.S. production is about $1 billion annually,
compared to a $70 billion world market
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Shellfish Farming
 Shellfish including
mussels, clams, and
oysters are filter feeders.
 They filter food and
nutrients out of the
water, including the
nutrients that cause
eutrophication and
algae blooms.
 One oyster can filter
about 50 gallons of
water per day.
Example: Chesapeake Bay Oysters
 It is estimated that at their historic population peak,
oysters filtered all of the Bay’s water in less than one
week. It takes about one year for the current
population to do so.
 Farming the native oyster species has a threefold
effect: it takes fishing pressure off native populations,
helps filter the bay’s water, and the female farmed
oysters that reach maturity can disperse 25-85 million
offspring!
Example: Swedish Mussels
 Nutrient emissions from agriculture and other diffuse
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sources were causing blooms of algae and phytoplankton
off the coast of Sweden depleting water quality.
Mussels use these as food sources.
Farming mussels moves these problem nutrients from the
sea back to land in the form of edible protein.
One kg of live mussels will remove 8.5 to 12 g of nitrogen,
0.6 to 0.8 g of phosphorous, and about 40 to 50 g of
carbon.
Source Dr. Odd Lindahl, Kristineberg Marine Biological
Station, Sweden.
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Freshwater aquaculture
 Catfish, tilapia, and trout are the most commonly
farmed freshwater fish.
 Tilapia are particularly good for the environment
because they are herbivores and require no fishmeal to
eat.
 Freshwater fish farming has fewer environmental
problems associated with it because it is usually self
contained in manmade ponds.
 According to the NOAA 70% of aquaculture in the
United States is freshwater.
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Coastal Aquaculture (Mariculture)
 Aquaculture is often conducted in coastal environments and
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operations can be located on land with a nearby water source
or in bays, estuaries, or marine waters.
Marine coasts are used because of high biological
productivity and easy accessibility
Finfish, Shrimp, Shellfish, and Algae are grown and used for
human consumption, pharmaceuticals and feed.
Aquaculture operations help meet consumer demand for
seafood and generate jobs and income.
In Hawaii, the value of aquaculture products produced has
increase from $13 million in the year 1995 to $28 million in
2003.
Coastal Aquaculture Authority Act, 2005 (India) – Large
production of shrimp
 Regulation of activities connected with coastal
aquaculture in coastal areas
 Mandates the Central Government to take all such
measures for regulation of guidelines
 Ensures that coastal aquaculture does not cause any
harm to the coastal environment
 Protection of the livelihood of various sections of people
living in the coastal areas
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Off-Shore Aquaculture (Mariculture)
 Aquaculture moves off-shore because of
less competition for space and the
natural characteristics of offshore
waters — deeper water, stronger current
flow and superior water quality
 The National Offshore Aquaculture
Act of 2005 (U.S.)
 Issuing of offshore aquaculture permits and
environmental requirements
 Not subject to fishing regulations that
restrict size, season and harvest methods
 Require the Secretary of Commerce to work
with other federal agencies to develop and
implement a coordinated permitting
process and enforce policy to protect wild
stocks and the quality of marine ecosystems
 Establishment of a research and
development program
 Provide for enforcement of the Act.
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Off-Shore Aquaculture… an ecosystem?
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What is overfishing?
 Overfishing occurs when fish
and other marine species are
caught at a rate faster than
they can reproduce
 It can lead to depletion or
extinction of fish populations
 Most problems associated
with overfishing have been
caused in the last 50 years by
the growing human
population demanding food
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Why is overfishing a problem?
 Developing countries
depend on fish
 Marine biodiversity is
in danger
 Food chain diversity
is severely affected
 Shifts in ecosystem
from large fish to
smaller fish
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How bad is it?
 Scientists predict that if current
trends continue, world food
fisheries could collapse entirely by
2050 (Dr. Worm)
 70% of the world’s fish stocks are
either fully exploited or depleted
(FAO)
 3/4 of the world’s fish stocks are
being harvested faster than they can
reproduce (Dr. Worm)
 One in five people on this planet
depends on fish as their primary
source of protein (FAO)
 90% of all large predatory fish including tuna, sharks, swordfish,
cod, and halibut - are gone.
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How can aquaculture help?
 Gives people more control of
conditions
 Restores depleted species of
fish & shellfish
 Boosts commercial catches
and sports fishing
 Complements wild catches to
meet growing demand
 Improvements of fishmeal
 Nat’l Offshore Aquaculture
Act of 2007 requires abidance
of existing water quality laws
and other pertinent laws
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Damaging Fishing Techniques and
Their Subsequent Effects
• Sensitive habitats, endangered species, and marine
food chain
• 28.7 million tons of by-catch annually associated
mainly with:
• Trawling
• Long Lining
• Drift Nets
Factory Trawling
 Every pound of commercial catch has 10-20 pounds of
by-catch associated with it
 Captures sea creatures that were not intended and
clear-cuts everything in its path
 May be the cause of recent collapse of ground fish
stock
 Stirs up sediments placing a lot of suspended solids
into the water column
Trawling
Destroys everything in its
path
May be the most detrimental
fishing technique to the
environment, but is used
most frequently
Long Lining
 Thousands of baited
hooks up to 80 miles
long
 Frequently catch nonintended species
 180,000 birds die on long
lines each year
 Sharks are severely
impacted ,detrimental
because they have slow
reproductive rates
Drift Nets
 Free Floating 29-49 feet
deep and as long as 55
miles long
 Largest amount of bycatch associated with
drift nets
 Great lengths of drift
nets are lost every year
(storms)- “ghost nets”
creating problems
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Final Thought
 “It is vital that the United States further develop its
own sustainable aquaculture industry, both to reduce
its annual $9 billion annual seafood import deficit and
to keep pace with the growing demand for seafood.”
-National Oceanic and Atmospheric Administration
References
 http://www.magazine.noaa.gov/stories/mag202.htm
 http://coastalmanagement.noaa.gov/aquaculture.html
 http://columbianewsservice.com/2010/04/awaiting-legislation-eco-friendly-fish-farmsin-federal-waters/
 http://www.akvagroup.com/index.cfm?id=319215
 http://aquaculture.tn.nic.in/
 http://www.encyclopedia.com/topic/aquaculture.aspx
 http://fishery.about.com/od/BenefitsofAquaculture/a/Aquaculture-What-IsAquaculture_2.htm
 http://www.csmonitor.com/Environment/2010/0224/Recirculating-aquaculturesystems-The-future-of-fish-farming/(page)/2
 http://www.bayoyster.com/eat.html
 http://news.mongabay.com/2007/0709-interview_mike_sutton.html
 http://www.theglobaleducationproject.org/earth/fisheries-and-aquaculture.php
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How to avoid environmental impact
 To better manage possible impacts from this growing industry, coastal
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managers can address the siting and management of aquaculture in a
comprehensive manner. For example:
New policies, laws, and/or regulations can provide a mechanism to
balance the needs of different marine resource users and protect the
health of coastal and ocean resources;
Siting tools can help identify areas to site aquaculture facilities that
will minimize conflicts with existing resource users;
Coordination mechanisms between regulatory agencies at the local,
state and federal level can improve and speed decision making;
Accurately assessing environmental impacts can improve decision
making.
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How to Sustain Aquaculture
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Recirculation Aquaculture Systems
 This new technology eliminates many of the
environmental issues associated with aquaculture.
 About 99.75 percent of the water in each unit is
continuously cleaned and returned to the fish tanks,
greatly reducing the water footprint.
 These self contained systems prevent any possibility of
fish, fish waste, antibiotics, or other chemicals to get
out into the natural environment.
 The excess nutrients in the waste can be used as
fertilizer in local agriculture.
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Future Technology
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Replacing Fish Meal
 Fish meal is traditionally used to feed carnivorous fish such as
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trout and salmon.
This fishmeal is attained by using fish by products and baitfish
that is caught in the wild.
These baitfish are key to the health of wild ecosystems and they
can also contain heavy metals which can be transferred to the
farmed fish and then to humans.
Recently the USDA has developed a plant based fish feed using
protein from soybeans, barley, and corn, with no fish or fish oil.
Studies have shown that this new food preforms as well or better
than traditional fish feed using fish meal.
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