Seaweed is used for rice, sushi and cropped from sea
before sunrise. The quality is affected in sun so the weed is cropped early
before sunlight. Farmers brave open sea, cold winter winds to maintain crop quality,
freshness. Grown on long lines cultivation season starts autumn to spring.
High demand of seaweed have provided good economic value
and societal impact on local communities. Annual income is estimated 5 times
more for seaweed farmers in comparison with agriculturists.
In some countries where the demand is high there is a
huge local market and export opportunities. In the Philippines it is estimated
that 40,000 people make a living farming the weed.
Algaculture- Seaweed
Cultivation
Seaweed farming is a form of aquaculture sub grouped
under algaculture. Other industries in algaculture are micrologal bacterial flocks,
seaweed, and raceway pond. Others are Giant kelp farming, Photo bioreactor,
microalgae.
Top
Producers
Top producers of seaweed is Japan with annual production
value exceeding US $2 billion. Other producers are Philippines, United States
of America and Spain. More include Korea, China, UK and Canada.
Japan
Philippines
United States of America
Spain
United Kingdom
Asia
Canada
Seaweed
Cultivation in Japan
Japan is the top consumer and producer of seaweed. History
goes back early 1670 with an estimated consumption of 9 billion pieces.
Cultivation of ‘Undaria pinnatifida’ nutritious farming is
standardized with a range from dried to salted seaweed.
Environmental
impact
Some farming practiced by the farmers have adverse effect
both negatively and positively on the ecology. Beneficial effects include
preservation of coral reefs increase shellfish and local fish species. However
fishing practice of cutting mangroves depletes mangrove biodiversity while
eelgrass removal affects water quality.
Equipment
Equipment used in the process are longlines, subsurface lines,
headrope lines , grit system hook and pole. Others are blanching bath, plastic
crates, salting drum, spiral dryer, staged machine, concrete anchor, seawater
baths, net bags, storage freezer
Cultivation
and Harvesting
Most popular cultivated species are Laminaria, Gelidium,
Porphyra and Pterocladia and Undaria pinnatifida’. At 1 meter
depth low tide sea urchins, seagrass is remove to accommodate reef flats. They
tie seedlings to 180 m monofilament lines between mangrove poles/stakes.
In
deeper water 7 meters depth cultivation involves floating lines fixed to
bottom. To harvest long of surface mounted lines are cropped. Whilst harvesting
the farmer separates sporophyll, frond and stripe.
Processing is done on the pier close to harvested crop. Processing involves blanching proceeded by seawater baths then lightly pressed and salted. Another round of pressing is done in 24 hours before frozen. Mechanized operation involve staged machine to remove grit material while drying is done with spiral dryers at 80-120 degrees centigrade.
