Yesterday I was standing on the bright blue shores of Gerupuk Bay in South Lombok, watching seaweed farmers carry their harvest from sea to land. I was meeting with their foreman, a nice chap who allowed me to take some pictures of Lombok seaweed for our forthcoming agri-catalogue. The seaweed was about to be trucked to Sumbawa, so I caught them at a nice moment.
The farmers were a happy bunch, all smiley and talkative with me. I guess the seaweed harvest was looking good and the market is right.
In Bahasa Indonesia seaweed means “rumput laut” (seagrass; rumput=grass, laut=sea) which in English translates to seagrass. Technically speaking that's the wrong word. Because seaweed is an algae form, they are NOT plants.
In English there is seagrass and seaweed. Seagrass denotes the species of marine organisms that ARE plants and, like plants, have different sexes, produce flowers, fruits and seeds. They enhance the ecosystems they live in by providing food and shelter to many animals and organisms.
One of the animals heavily dependent on seagrass for food is the dugong (also known as sea cow), the only strictly-marine herbivorous mammal.
Dugongs also live in Indonesia. There were probably populations of dugongs in Lombok not too long ago, but I haven’t heard of any now. They do still live not too far east of Lombok actually, for example near the island of Flores. They are listed as a “vulnerable to extinction” species by the IUCN, due to hunting, habitat degradation, and fishing-related fatalities (such as mutilations on their bodies from being hit by ships).
Anyways. Back to seaweed. Seaweed, unlike seagrass, reproduces via spores (not seeds) and serves fewer bio-functions in its environment. In an evolutionary sense, seaweed is less developed and more primitive than seagrass.
Seagrass and algae beds together form an important ecosystem, and both should be maintained. But the balance has been tipped in favor of algae of late. Seaweed and seagrass in fact have a non-symbiotic relationship; in areas where seagrass dies and decays - often through human disturbances like eutrophication, mechanical destruction of habitat, and overfishing – algal blooms occur. These are free-floating micro and macro algae, which obscure the water, weakening the sunlight infiltration and making photosynthesis for watergrass difficult. As this happens, the algal blooms accelerate and have a positive feedback effect on seagrass loss, and a complete regime shift from seagrass to algal dominance may occur.
Lombok has both seaweed and seagrass areas, but the areas of seagrass I’ve seen weren’t real meadows but just patches of seagrass. In the shallow areas of Tanjung’an Bay I’ve directly swum over many of these. But they are very limited. I am guessing the seagrass areas have been shrinking more and more in Lombok, just as elsewhere.
But for the marine farmers of Gerupuk Bay, seaweed is an important commodity. Seaweed is highly prized for the extraction of its gelatinous substances, like carrageenan, which is used in the food and pharma-industry. Most seaweed from Indonesia, which this year has surpassed the Philippines as the largest seaweed producer in the world, is shipped to Hong Kong and Taiwan to my knowledge.
Seaweed in Gerupuk, Lombok, grows on long lines. Typically, seaweed does not grow a real root system like seagrass (plants), but has “holdfasts” to attach itself to hard substrates like rocks and shells. But the farmers here attach short seaweed sections by rope to the long lines, so they just float at sea anyways. I’ve seen two types of seaweed harvested here yesterday: one is a large, thick and brown-green variety called “Maumere” (because it stems from said area in East Indonesia) and another is a variety from the Philippines called Tambalang, which occurs both in red and green color.
When the individual sections have grown to about 100 grams the transplanting begins.
Seaweed in Lombok is actually “transplanted” to waters in Sumbawa, where it is allowed to mature fully. An individual seaweed section there may grow to about 1.5kg. One long line with its multiple nodes will carry a total of about 25kg of seaweed for its final harvest before sale.
And that concludes my seaweed post for today. Apologies if this was a little technical. This stuff is more interesting to see in person. If you rent a boat to take you out to one of the surf breaks in Gerupuk Bay you will actually drive right past the floating structures in the water there. There are many more out at sea; I was windsurfing zig-zag through a field of them once. Or they were lobster farms. I forget. I was paying attention to other things, like how to get back to shore.
