Is
the cultivation of aquatic organisms, such as fish, shellfish,
algae and other aquatic plants. Mariculture is specifically
marine aquaculture, and thus is a subset of aquaculture. Some
examples of aquaculture include raising catfish and tilapia
in freshwater ponds, growing cultured pearls, and farming
salmon in net-pens set out in a bay. Fish farming is a common
kind of aquaculture.
History
Aquaculture was used in China circa 2500 BC. When the waters
lowered after river floods some fishes, namely carps, were
held in artificial lakes. Their brood were later fed using
nymphs and feces from silkworms used for silk production.
The Romans were quite adept in breeding fish in ponds-piscinae
in latin.In Europe it became common again in monasteries during
the Middle Ages, since fish was scarce and thus expensive.
The 19th century's transportation improvements made fish easily
available and inexpensive, even far from the seas, causing
a decline in aquaculture.
The current boom started in the 1960s after overfishing caused
another price rise. Today, commercial aquaculture exists on
a huge scale previously unknown, causing controversy because
of its effects on the public waters beyond the boundaries
of the pens.
Benefits
Aquaculture has been one of the fastest growing segments of
global food production in recent decades, and has been hailed
as an answer to declining wild fish stocks caused largely
by overfishing.
Tuna farming in Australia, as well as of other species, has
had immense success.
Salmon farming in the Tenth Region of Chile has, for the first
time, brought a stable (yet not sustainable) industry to many
depressed backwater towns and started a cash flow; previously,
the only employment options had been leaving home, relying
on the government, subsistence farming, or fishing.
In an unusual arrangement in Hawaii in the United States,
aquaculture is carried out with various combinations of Deep
Ocean Water (DOW), and Surface Ocean Water (SOW) which is
drawn to the surface by the Natural Energy Laboratory of Hawaii
as part of research into OTEC renewable energy. This allows
fish which require clean cold water to be raised on shore
in water drawn from the ocean depths.
Challenges
In countries like the U.K., Canada, Norway, and Chile, salmon
and trout farming are one of the fastest-growing forms of
agriculture. Salmon farming is not increasing in the United
States because of heavy competition from other countries,
and higher environmental standards for fish farms in the US.
Salmon farming, like other food producing operations such
as beef, wheat or tomatoes can impact the environment.
However, the difference between shore farming and fish farming
is that shore farming takes place on private land, while fish
farming often takes place on the public waters. Organic wastes
from fish cages can have a significant effect on water quality
and the population structure of organisms, beyond the boundaries
of the fish pens, increasing the occurrence of toxic algal
blooms. Scotland, as well as Chile and China, has had serious
toxic algae blooms. Algal blooms can cause the death of huge
numbers of wild fish and other species, and great harm to
wild fisheries. However, even a month of fallow time can return
the area to pristine condition.
Like other agriculture production, aquaculture must stand
up to a rigorous evaluation of any environmental impact. Salmon
aquaculture has come under increasing scrutiny from environmental
nongovernmental organizations (ENGO's). In Canada, salmon
farming sites occupy a small portion of the coastal zone areas
where they are located. The total area occupied by Canadian
salmon farms in British Columbia and the Bay of Fundy in New
Brunswick is about 8,900 acres (36 kmð) which is less than
0.01% of the coastal area where these sites are located. Still,
even though salmon farms occupy only a small percentage of
the public waters, scientists have found a significant degradation
of the areas where they exist, with lowered oxygen levels,
replacement of native seaweeds with invasive seaweeds, increased
algal blooms, reduction of wild species, and loss of nursery
habitat for wild fish.
Wild Pacific and Atlantic salmon stocks have seen significant
declines over the last several decades, before salmon farming
operations started. These declines were caused by a combination
of factors including climate change, overfishing and freshwater
habitat destruction. However, rivers with fish farms have
experienced accelerated decline of wild stocks caused by spread
of diseases such as infectious salmon anemia, and parasites
such as sea lice from farmed to wild salmon.
Concerns have been raised on the East coast that wild Atlantic
salmon may interbreed with and catch disease from salmon that
escape from farms. Canadian salmon farmers have significantly
reduced the escape of their salmon. The evidence shows that
the escape of farmed salmon on Canada's west coast poses low
risk to Pacific salmon. However, young wild salmon swimming
down river to the ocean are free of sea lice parasites before
they swim past the salmon farms, and laden with sea lice after
they pass the farms. Most die from these sea lice.
Many farmed fish species are carnivorous, meaning that other
wild fish species must be harvested to maintain the fish farm.
For example, herring are used to make salmon feed. Since herring
are the backbone of the North Atlantic food chain, increased
fishing pressure on their numbers is a serious threat to all
other fish species which depend on herring for food. Fish
farms, far from removing the pressure on wild fish stocks,
increase it.
The fish farm industry is trying to decrease its reliance
on fish for fish feed. A portion of the fish meal used in
fish feeds comes from the trimmings and discards of commercial
species. More studies are being done concerning shifts in
feed composition using poultry and vegetable oils as substitutes
for fish protein & oil. This use of land based feeds in
turn may result in a decrease of the Omega 3 fish oils in
the farmed fish.
Other problems with aquaculture include the potential for
increasing the spread of unwanted invasive species, as farmed
species are often not native to the area in which they are
farmed. When these species escape, they can compete with native
species and damage ecosystems. Another problem is the spread
of introduced parasites, pests, and diseases.
See also:
fishery
• Shrimp
Farm
Resources:
Aquaculture
Resources Alternative Farming Systems Information Center
web page providing links to associations, specialists, state
contacts, the U.S. Subcommittee and Internet sites related
to aquaculture. Alternative
www.nal.usda.gov/afsic/afsaqua.htm
Aquaculture
Magazine online: FISH FARMING and PROCESSING. The aquaculture
industry's leading international publication. Information
about raising, growing, breeding and selling tilapia, trout,
salmon, shrimp, catfish, oysters, shellfish.
www.aquaculturemag.com
AquaNIC Gateway
to the world's electronic aquaculture resources. Aquaculture
Network Information Center
www.aquanic.org
Sites found related
to Agriculture > Aquacluture Education - contains aquaculture
instructional materials from the National Council of Seafood
and Aquacultre - provides seafood and aquaculture marketing
materials.
dir.yahoo.com/Science/Agriculture/Aquaculture
Department
of Commerce Aquaculture Policy. National Aquaculture Act
of 1980 Draft Code of Conduct for Responsible Aquaculture
Development in the U.S. Exclusive Economic Zone (.PDF)
www.nmfs.noaa.gov/aquaculture.htm
Online directory of information and resources.
Common typo errors:
aquaculutre, aquacutlure, aquacluture, aquauclture, aqucaulture,
aqauculture, auqaculture, aquacultur, aquacultue, aquacultre,
aquaclture, aqaculture, auaculture, quaculture, aquacuture,
aquacultuer, aquacultrue, aquaulture, aquculture,
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