Seaweed farming
Encyclopedia
Seaweed farming is the practice of cultivating and harvesting seaweed
. In its most simple form, it consists of the management of naturally found batches. In its most advanced form, it consists of fully controlling the life cycle of the plant.The main food species grown by aquaculture in Japan, China and Korea include Gelidium
, Pterocladia, Porphyra
, and Laminaria
..Seaweed farming has frequently been developed as an alternative to improve economic conditions and to reduce fishing pressure and over exploited fisheries. Seaweeds have been harvested throughout the world as a food source as well as an export commodity for production of agar and carrageenan products.
as early as 1670 in Tokyo Bay
. In autumn of each year, farmers would throw bamboo
branches into shallow, muddy water, where the spores of the seaweed would collect. A few weeks later these branches would be moved to a river estuary
. The nutrients from the river would help the seaweed to grow.
In the 1940s, the Japanese improved this method by placing nets of synthetic material tied to bamboo poles. This effectively doubled the production. A cheaper variant of this method is called the hibi method: simple ropes stretched between bamboo poles.
In the early 1970s there was a recognized demand for seaweed and seaweed products, outstripping supply and cultivation was viewed as the best means to increase productions
seaweed and reef flats at approximately 1m depth at low tide (for what seaweed species?). They also recommended cutting off sea grasses and removing sea urchins prior to farm construction. Seedlings are then tied to monofilament lines and strung between mangrove stakes pounded into the substrate. This off bottom method is still one of the major methods used today.
There are new long line cultivation methods that can be used in deeper water approximately 7m in depth. It uses floating cultivation lines anchored to the bottom and is the primary method used in the villages of North Sulawesi, Indonesia.
Cultivation of seaweed in Asia is a relatively low technology business. Attached plants are placed in the sea and there is a high labour content in the operations. There have been many attempts in various countries to introduce high technology to cultivate detached plants growth in tanks on land in order to reduce labour, but this hasn’t attained commercial viability to date.
from their farming areas. This however is also discouraged as it negatively affects water quality.
Seaweed farming helps to preserve coral reefs by increasing diversity where the algae and seaweed have been introduced and it also provides added niche for local species of fish and invertebrates
Literature pays little attention to the ecological impacts of seaweed farming. Some of the impacts include changes in patterns of sedimentation, water movement, erosion, depletion of nutrients and alteration of water quality prior to planting. Also farming on top or adjacent to coral reefs has ecological impacts due to shading of corals further increasing the threat to coastal ecosystems.
There has been much debate on this topic many saying that farming may be beneficial by increasing the production of herbivorous fishes and shellfish in the area. Pollnac et al (1997b) reported an increase in Siginid population after the start of extensive farming of Eucheuma seaweed in villages in North Sulawesi, Indonesia.
made their living through seaweed farming. Cultivation is also common in all of southeast Asia, Canada, Great Britain, Spain, and the United States.
Seaweed
Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...
. In its most simple form, it consists of the management of naturally found batches. In its most advanced form, it consists of fully controlling the life cycle of the plant.The main food species grown by aquaculture in Japan, China and Korea include Gelidium
Gelidium
Gelidium is a genus of thalloid alga comprising 124 species. Its members are known by a number of common names.Recorded common names are tengusa, makusa, genso, niu mau tsai, japansche scheleiachtige mos, steen-or klipbloem, hay tsay, olus marinus, sajur laut, tschintschau, tschoo-hoae, onikusa,...
, Pterocladia, Porphyra
Porphyra
Porphyra is a foliose red algal genus of laver, comprising approximately 70 species. It grows in the intertidal zone, typically between the upper intertidal zone and the splash zone in cold waters of temperate oceans. In East Asia, it is used to produce the sea vegetable products nori and gim ,...
, and Laminaria
Laminaria
Laminaria is a genus of 31 species of brown algae , all sharing the common name "kelp". This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape, or sea colander, due to...
..Seaweed farming has frequently been developed as an alternative to improve economic conditions and to reduce fishing pressure and over exploited fisheries. Seaweeds have been harvested throughout the world as a food source as well as an export commodity for production of agar and carrageenan products.
History
Seaweed was first consumed in Japan at least 1500 years ago, according to early written records. Seaweed farming began in JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
as early as 1670 in Tokyo Bay
Tokyo Bay
is a bay in the southern Kantō region of Japan. Its old name was .-Geography:Tokyo Bay is surrounded by the Bōsō Peninsula to the east and the Miura Peninsula to the west. In a narrow sense, Tokyo Bay is the area north of the straight line formed by the on the Miura Peninsula on one end and on...
. In autumn of each year, farmers would throw bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....
branches into shallow, muddy water, where the spores of the seaweed would collect. A few weeks later these branches would be moved to a river estuary
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
. The nutrients from the river would help the seaweed to grow.
In the 1940s, the Japanese improved this method by placing nets of synthetic material tied to bamboo poles. This effectively doubled the production. A cheaper variant of this method is called the hibi method: simple ropes stretched between bamboo poles.
In the early 1970s there was a recognized demand for seaweed and seaweed products, outstripping supply and cultivation was viewed as the best means to increase productions
Culture methods
Earliest seaweed farming guides in the Philippines recommended cultivation of LaminariaLaminaria
Laminaria is a genus of 31 species of brown algae , all sharing the common name "kelp". This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape, or sea colander, due to...
seaweed and reef flats at approximately 1m depth at low tide (for what seaweed species?). They also recommended cutting off sea grasses and removing sea urchins prior to farm construction. Seedlings are then tied to monofilament lines and strung between mangrove stakes pounded into the substrate. This off bottom method is still one of the major methods used today.
There are new long line cultivation methods that can be used in deeper water approximately 7m in depth. It uses floating cultivation lines anchored to the bottom and is the primary method used in the villages of North Sulawesi, Indonesia.
Cultivation of seaweed in Asia is a relatively low technology business. Attached plants are placed in the sea and there is a high labour content in the operations. There have been many attempts in various countries to introduce high technology to cultivate detached plants growth in tanks on land in order to reduce labour, but this hasn’t attained commercial viability to date.
Environmental and ecological impacts
Several environmental problems can result from seaweed farming. Sometimes seaweed farmers cut down mangroves to use as stakes for their ropes. This, however, negatively affects the farming since it reduces the water quality and mangrove biodiversity due to depletion. Farmers may also sometimes remove eelgrassZostera
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...
from their farming areas. This however is also discouraged as it negatively affects water quality.
Seaweed farming helps to preserve coral reefs by increasing diversity where the algae and seaweed have been introduced and it also provides added niche for local species of fish and invertebrates
Literature pays little attention to the ecological impacts of seaweed farming. Some of the impacts include changes in patterns of sedimentation, water movement, erosion, depletion of nutrients and alteration of water quality prior to planting. Also farming on top or adjacent to coral reefs has ecological impacts due to shading of corals further increasing the threat to coastal ecosystems.
There has been much debate on this topic many saying that farming may be beneficial by increasing the production of herbivorous fishes and shellfish in the area. Pollnac et al (1997b) reported an increase in Siginid population after the start of extensive farming of Eucheuma seaweed in villages in North Sulawesi, Indonesia.
Societal impact
The practice of seaweed farming has long since spread beyond Japan. In 1997 it was estimated that 40,000 people in the PhilippinesPhilippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
made their living through seaweed farming. Cultivation is also common in all of southeast Asia, Canada, Great Britain, Spain, and the United States.