Aquaculture in Korea: Gil Ha Yoon

Seaweed culture
Aquaculture in Korea
Seaweed culture in Korea is mainly concentrated on the south western coast where
almost 90% of cultivation takes place. Undaria dominates production constituting 42%
of the total wet weight. However, Porphyra is the most valuable species totalling 65% of
overall value. Porphyra cultivation in Korea reached a turning point in the 1960s when
Gil Ha Yoon
South Korea is peninsula with a 2,413 km coast line.
The total land mass of the country is 98,480 km 2 ,
(including 290 km 2 of inland water) but usable land
AQUACULTURE IN KOREA
is only 20% of the total and the population is thus
South Korea is peninsula with a 2,413 km line. The total land mass of the
concentrated around the coast. Not surprisingly
country is 98,480 km
Koreans obtain 2 , (including 290 km
more protein 2 of inland water) but usable land is only 20%
from fishery products
of the total and the population is thus concentrated around the coast. Not surprisingly
than red meat. The Korean Food Year Book
2007 Koreans reported obtain more protein that from fishery annual products than per red meat. capita The Korean sea Food food Year
consumption Book 2007 reported that was annual 48.1 per capita kg sea in food 2005. consumption Because was 48.1 kg of in 2005. the
high Because of the high consumption of of fishery products, products, the industry the is recognized industry as an
is important recognized national industry, as although an important it contributes only 1% national of Korean GDP. industry,
although it contributes only 1% of Korean GDP.
Extensive aquaculture has been practiced in Korea for several hundred years, but modern
Extensive aquaculture has been practiced in Korea for several
intensive culture (mainly of sea weed and shellfish) did not emerge until the 1960's.
hundred years, but modern intensive culture (mainly of sea weed
and However, shellfish) production did was not less emerge than 100,000 until metric the 1960’s. tons in this However, period. From production
the 1970's
was
aquaculture
less than
production
100,000
increased
metric
year on
tons
year from
in this
around
period.
147,000
From
metric tons
the
in
1970’s
1971,
aquaculture production increased year on year from around 147,000
metric to reach tons more in than 1971, 700,000 to metric reach tons more in 1981 than and over 700,000 1.2 million metric tons in 2006. 1981
and over 1.2 million metric tons in 2006.
Table 1. Contribution of capture fisheries and aquaculture to Korean fishery
production (1971-2006)
(unit:1,000 tonnes)
Year
Capture
Culture Total
Coastal Offshore
1971 766 159 147 1,073
1976 1,257 724 410 2,407
1981 1,528 542 701 2,811
1986 1,726 930 947 3,660
1991 1,304 874 775 2,952
1996 1,623 715 874 3,214
2001 1,252 739 656 2,647
2006 1,109 639 1,259 3,007
Table 1. Contribution of capture fisheries and aquaculture to Korean fishery production
(1971-2006) 1. Mariculture
Mariculture makes up 99% of aquaculture production. Production is dominated by
Mariculture
seaweeds and followed by molluscs and finfish.
Mariculture makes up 99% of aquaculture production. Production is
dominated by seaweeds and followed by molluscs and finfish.
Table 2. Production of different aquaculture products in Korea 2006
Fishery products Tonnes %
Seaweed 764,913 60.7
Shellfish 391,060 31.1
1616
Seaweed culture
Finfish 91,123 15.2
Others 12,128 0.9
Total 1,259,274 100
Table 2. Production of different aquaculture products in Korea 2006
Seaweed culture
Seaweed culture in Korea is mainly concentrated on the south western coast where
Seaweed culture in Korea is mainly concentrated on the south
western
almost 90%
coast
of cultivation
where almost
takes place.
90%
Undaria
of cultivation
dominates production
takes
constituting
place. Undaria
42%
dominates of the total wet production weight. However, constituting Porphyra is the 42% most valuable of the species total totalling wet weight. 65% of
However, Porphyra is the most valuable species totalling 65% of
overall value. Porphyra cultivation in Korea reached a turning point in the 1960s when
Porphyra cultivation in Korea reached a turning point
in the method 1960s of seeding when changed the method from natural of seeding to artificial changed using oyster from shells. natural Since the to
artificial using oyster shells. Since the early 1980s, the previously used
early 1980s, the previously used floating system was replaced by a rack system, and
frozen, seeded nets are commonly used. Production has also been boosted by the
transplanting of new species and expansion of the culture areas.
the method of seeding changed from natural to artificial using oyster shells. Since the
early 1980s, the previously used floating system was replaced by a rack system, and
Table 3. Production of cultured seaweeds in Korea in 2006
Seaweed Tonnes %
Porphyra 217,559 28.4
Undaria 322,371 42.1
Laminaria 201,919 26.4
Hiziki 21,125 2.8
Others 1,939 0.3
Total 764,913 100
Table 3. Production of cultured seaweeds in Korea in 2006
floating system was replaced by a rack system, and frozen, seeded
nets are commonly used. Production has also been boosted by the
transplanting of new species and expansion of the culture areas.
Porphyra production from aquaculture is currently estimated to be
217,559 tons (wet wt.) which is equivalent to more than 10 billion
sheets of dried laver. Porphyra needs to be exposed to the air from
time to time. On ground that is unsuitable for racks, floating rafts are
used. These consist of frames of plastic tubing to which up to 100m of
nets can be attached. The frames are arranged in such a way that the
nets are exposed to the air for 3-4 h every day. Undaria and Laminaria
are cultured using a long-line method in which culture ropes are laid
in parallel with the main water flow. The ropes are checked every
month to thin the plant densities and to remove trapped debris and
fouling organisms. The plants are kept approximately 1~2m below
the surface.
Mollusc culture
Production of molluscs reached 391,060 MT in 2006, making up 31.1%
of the total mariculture production. The major species cultured are
oysters (Crassostrea gigas, Pinctada fucata), mussels (Mytilus coruscus),
Manila clams (Ruditapes philippinarum), ark shells (Anadara satowi,
A. broughtonii), cockles (A. granosabisenensis, A. subcrenata), scallop
(Patinopecten yessoensis), and abalone (Haliotis discushannai). Oysters
dominate production. In 2006, oyster production was 283,296 MT,
accounting for 72.4% of the total yield of cultured invertebrates.
Table 4. Production of cultured mollusc species in Korea 2006
Molluscs Tonnes %
Oyster 283,296 72.4
Mussel 81,617 20.9
Manila clam 14,327 3.7
Arkshell 7,127 1.8
Abalone 3,050 0.8
Others 1,643 0.4
Total 391,060 100
Table 4. Production of cultured mollusc species in Korea 2006
Culture of oysters, mussels and pearl oysters is based on the long line system. In this
Culture system, the of oysters, floating lines mussels are laid on and the pearl water surface oysters The is long based lines are on 100m the long in length line
system. In this system, the floating lines are laid on the water surface
The and long laid 510m lines are apart. 100m Vertical in ropes length are hung and from laid the 5 ~ long 10m line apart. at intervals Vertical of
ropes are hung from the long line at intervals of 50 ~ 70cm and seed
5070cm and seed collectors are attached to these ropes at intervals of 30 50cm.
collectors are attached to these ropes at intervals of 30 ~ 50cm.
Bottom culture is employed for molluscs such as arkshells and Manila clams. The
parameters affecting site selection include water depth, water temperature, algal foods

Rainbow trout farm
was 91,123 tonnes, 15% of total marine production, but because of
trends in consumption in Korea, finfish culture is the most valuable
aquaculture production. The highest production of cultured fish
was from olive flounder (48.1%), followed by black rockfish (30.2%),
sea breams (9.6%) and grey mullet (6.2%). Although culture of olive
flounder started only in the late 1980s, Korean production exceeded
that of Japan by 1997.
Olive flounder is reared in land-based raceway culture systems where
water is pumped ashore.
Farms are usually located on the south and west coasts and each farm
usually produces on average about 110 tonnes per year with mean
stocking densities of 20kg/m 3 . Other fish species such as sea breams
or mullet are grown in floating cages or enclosures. Cage cultures
are more common. The cages are 5m x 5m or 10m x 10m in size and
stocked with 700-1000 juveniles per m 3 at a length of 4cm to 5cm.
Cage farms for finfish culture near the shore
Cage farms for finfish culture near the shore
Bottom culture is employed for molluscs such as arkshells and Manila
clams. and Acanthopagrus The parameters schlegeli, affecting and grey mullet, site selection Mugil cephalus, include have been water important depth,
water
marine
temperature,
finfish cultured since
algal
the
foods
late 1980s.
and
Finfish
bottom
production
substrate.
in 2006 was
Normally,
91,123
water depths for bottom culture are less than 20m for most species
but
tonnes,
arkshells
15% of total
are
marine
cultured
production,
below
but
the
because
intertidal
of trends in
zone
consumption
down
in
to
Korea,
40m
depth.
finfish culture is the most valuable aquaculture production. The highest production of
cultured fish was from olive flounder (48.1%), followed by black rockfish (30.2%), sea
Finfish
With breams the (9.6%) development and grey mullet of (6.2%). advanced Although aquaculture of olive flounder technology, started only olive in
flounder, the late 1980s, Paralichthys Korean production olivaceus, exceeded together that of Japan with by black 1997. rockfish, Sebastes
schlegeli, sea breams, Pagrus major and Acanthopagrus schlegeli,
and grey mullet, Mugil cephalus, have been important marine
finfish cultured since the late 1980s. Finfish production in 2006
Table 5. Production of cultured finfish in Korea 2006
Finfish Tonnes %
Olive flounder 48,852 48.1
Rock fish 27,517 30.2
Sea breams 8,777 9.6
Grey mullet 5,651 6.2
Freshwater culture
Freshwater culture represents only 1% of total Korean aquaculture
production. Eel ponds were first constructed in 1924 near Busan,
but the operation was discontinued in the 1940’s. A further attempt
was made in 1966 in Noksan, Kimhae, near Busan, using wild elvers.
The rainbow trout was first introduced into Korea in 1965, but the
annual production remained negligible (below 10 tonnes) until
1980. Production then increased reaching 704 tonnes in 1987 and
more than 5000 tonnes in 2006. The main area of trout production is
Gangwon-do, where relatively large amounts of upland cool spring
water are available. In some sites ground water is used.
Korea has traditionally been a seafood exporter but increasing
domestic demand and decreased local production means Korea
currently imports $ 1.7 billion more seafood products than it exports.
It is unlikely that Korean capture fisheries will be increased due to
stock depletion and that aquaculture will be increasingly important.
However, the Korean aquaculture industry also faces problems such
as natural disasters (typhoons and red tides), low price imported
products and lack of highly skilled manpower. To circumvent these
problems there will be expansion of offshore culture sites, and
increasing use of automated management systems.
Sea bass 1,571 1.7
Others 4,090 4.5
Total 91,123 100
Table 5. Production of cultured finfish in Korea 2006
Olive flounder is reared in land-based raceway culture systems where water is pumped
ashore.
Farms are usually located on the south and west coasts and each farm usually produces on
average about 110 tonnes per year with mean stocking densities of 20kg/ m3 . Other fish
species such as sea breams or mullet are grown in floating cages or enclosures. Cage
cultures are more common. The cages are 5m x 5m or 10m x 10m in size and stocked with
Rainbow trout farm
Rainbow trout farm
17
Submerged nets for sea weed culture
Aquaculture News 34 / May 2008 17
Submerged nets for sea weed culture