March 21, 2005

 

Seaweed aquaculture is big business for small farmers
 

An eFeedLink^® Exclusive Report

 

SEAWEED is now a growing big business to small farmers, whether in China, Africa or Europe.

 

All along the East African Tanzanian coast, for example, and around its many islands, thousands of farmers are supplementing their meagre income from their vegetable-and-fruit farms by cultivating seaweed which is being used as an important ingredient in many products, from animal feed to cheeses, and fertilisers to shampoos.

 

In the west coast of Ireland, seaweed-harvesting companies are sending their staff out to pick the seaweed on beaches, cutting the plants with a short-bladed knife to allow them to re-grow.

 

The seaweed industry in Ireland alone is worth up to 20 million euros, according to a BBC News Online report last year.

 

Seaweed makes you look young
 

 

Seaweed (or marine algae) has a substance called Fucoidan, which helps in preserving your skin, and so you don't look old and wrinkled before your time. Cosmetic companies require this substance for their various anti-aging creams.

 

Worldwide, seaweed is sold mainly for food. It has also been used for fertiliser, animal feed supplements, and food and pharmaceutical additives.

 

As the market for seaweed grows, many people have become concerned about the effects of foraging, as in Ireland where large quantities of seaweed are removed from rocky shores, thus upsetting the balance of plant and animal communities there. It may also cause rapid erosion of the shore.

 

Aquaculture of seaweed
 

 

The more economically efficient method of harvesting is to culture seaweed in suspended structures away from rocky shores, so that the existing ecosystem is not substantially altered. Harvesting cultured seaweed is much simpler and safer too. If seaweeds are cultured on nets or ropes strung horizontally on the surface of protected bays, harvesters do not have to wait for the proper tides and risk dangerous wave action to gather the crop.

 

In Tanzania, the farmers cultivate seaweed by driving two wooden pegs into the seabed 10 metres apart. A rope joins the two pegs, and seeds are attached to the rope.

 

It is not difficult, but it is hard work, said the farmers. Production is also low and high winds and strong currents could wash the weed to sea, they added.

 

The seaweed takes about two months to grow. When it is harvested, it is laid out in the sun to dry. Traders then buy the seaweed and export it to major producer countries such as China and the Philippines.

 

China itself is the world's no.1 seaweed producer, with 292.4 million tonnes and more than 50-percent market share. The Philippines is no.5 with 36.7 million tonnes (1997 FAO figures). See table below.

 

Seaweed World Production (in tonnes)

 

Year	1993	1994	1995	1996	1997	% Share	Growth
							(1993-97)
World production	36,566,591	71,624,400	141,389,256	280,902,907	559,888,073	100	-
China	18,511,176	36,821,085	73,346,026	146,377,635	292,441,630	52.23	99.37
North Korea	3,594,446	7,166,892	14,316,784	28,618,568	57,221,136	10.22	99.75
South Korea	3,352,172	6,464,342	12,650,014	25,098,883	50,027,596	8.94	96.57
Japan	3,411,847	6,453,944	12,418,978	24,426,747	48,476,658	8.66	94.18
Philippines	2,704,308	5,031,093	9,606,416	18,666,506	36,720,567	6.56	92
Chile	1,241,142	2,403,421	4,702,937	9,243,340	18,325,732	3.27	96.03
Norway	904,545	1,809,090	3,618,180	7,236,360	14,472,720	2.58	100
Indonesia	673,951	1,229,507	2,348,576	4,585,577	9,009,611	1.61	91.29
US	405,972	811,944	1,623,888	3,247,572	6,494,882	1.16	99.99
India	437,800	831,500	1,617,900	3,190,700	6,334,700	1.13	95.06
others	1,329,232	2,601,582	5,139,557	10,211,019	20,362,841	3.64	97.84
Source: FAO

 

Note:

 

Seaweed (Eucheuma) is a growth of marine algae, which unlike other land and aquatic plants, has no true roots, stems and leaves. It is widely distributed in the ocean, occurring from the tide level to considerable depths. It attached itself to floating trees or sand, mud, rocks, shells and coral.

 

There are four main groups of marine seaweeds: red algae, brown algae, green algae and blue green algae. The most important variety is red algae which grows on sandy bottom of marine waters in inter-tidal or sub-tidal zones where the water is very salty, clear and fast moving. Its soft body is light brown to light green with erect or prostate branches.

 

The red algae are the source of carrageenan, a valuable substance used in gelling, suspending, thickening or waterholding in various products. Carrageenan is a white, yellowish powder that is odorless. It has the unique ability to form an almost infinite variety of gels at room temperature, rigid or compliant, tough or tender with high or low melting point. The gels require no refrigeration and can be made stable through repeated freeze-thaw cycles.

 

Carrageenan serves mainly as an additive in food processing. It is stabilizer, binder and emulsifier for many food products, such as chocolate. It is also a medicinal ingredient in the preparation of surgical jellies, demulcents and anti-acid tablets.