Gracilaria spp.

Gracilaria or Gracilariopsis are red seaweeds that occur in both temperate and tropical environments. Some Gracilaria species have very important economic value and are farmed primarily for agar extraction or abalone feed. Gracilaria spp. make up the third largest farmed seaweed in terms of production volumes globally and have experienced the  strongest growth over the last decade. 

Common name:
Irish moss, Gracilaria, ogonori

Scientific name of main commercial species:
Gracilariaopsis lemaneiformis, Gracilaria chilensis, Gracilaria gigas and Gracilariopsis longissima

Red seaweeds (Rhodophyta)

There are 284 identified species worldwide. The main commercially cultivated Gracilaria species are known to be fairly robust crops, that can cope with a wide range of temperatures and tolerate salinity fluctuations from 15 to 50 ppt comparatively well. The most common species used for agar extraction is the high temperature-resistant strain of Gp. lemaneiformis.



Aquaculture feed
Gracilaria species are used for feed by the continuously growing abalone industry, especially in China, since they have been shown to improve the relative growth and survival rate of abalone.

Hydrocolloids (Agar)
Gracilaria are responsible for over 90% of the global production of agar, a hydrocolloid which has multiple uses in the food, pharmaceutical and cosmetic industries; including as a gelling agent, thickener, stabiliser and emulsifying agent. 

For example, agar can replace animal gelatin in  dairy products and pharmaceuticals or serve as a source of dietary fibres for weight management, edible packaging and biodegradable packaging.  

Direct food
Gracilaria have been consumed for millennia in China, Japan and the Republic of Korea as food for human consumption, due to their high nutritional value. Today, the major consumers are Indonesia, Japan, Malaysia, the Philippines, Thailand and Vietnam.


The Chinese Fishery Statistical Yearbook stated a production volume of 368,967 tonnes dry weight in 2020 and a conversion factor of 10% was applied to get to the FAO volume of 3.7 million tonnes wet weight. 

Industry experts suggest that this figure might be too inflated, but it is difficult to comprehensively quantify the real production volume, since production area varies greatly every year and a major part of the fresh biomass is directly sold as abalone feed without record.

Production Outlook:
continuous growth may slow down. With increasing government restrictions on cultivation areas, farmers tend to opt for more valuable species (sea cucumber or abalone). In turn, since 70% of farmed Gracilaria is sold as abalone feed, the production is highly dependent on the development of the abalone industry.


According to government statistics, production in Indonesia only started in the early 2000s and had reached 1.9  million tonnes wet weight in 2021 (Ministry of Marine Affairs and Fisheries – DKP). Industry experts suggest that this figure might be too inflated.

Industry Estimates: 1 – 1.2 million tonnes wet in 2021 

Production Outlook:
Gracilaria production in Indonesia will continue to grow, as long as demand and prices keep at the current level or increase. The production area in ponds is limited (and decreasing), however sea cultivation has large potential to expand.

The high-level supply chain overview for Gracilaria in Indonesia

Disclaimer: Region-level differences do exist and the individual networks impact the production.

Input suppliers: pond-based Indonesian Gracilaria farmers typically don’t have many material needs. They get the seedlings from their own harvest or other farmers or the local collectors. Once in a while they might purchase fertiliser from a local agri-inputs trader.

Farmers: these are almost exclusively smallholders from coastal communities who farm seaweed either full-time or part-time to earn a living. Learn more about the farming process in our farm insights chapter.

Local collectors: well connected local actors who will buy the seaweed from the farmers and aggregate volumes to further trade. The prerequisites are a vehicle for the transport of the seaweed and a warehouse. Some handle only small volumes and are seaweed farmers themselves, others are fully dedicated to the trade activity and have several employees. Activities of local collectors include buying semi-dried seaweed, bringing it to a warehouse, cleaning, sorting, sun drying to bring the moisture content to a percentage that meets the requirements of the exporters and processors, packaging and transportation to a regional trader.

Regional traders: often located in the major port cities, they can be independent or work for a processor or exporter. They often dry the seaweed again (redrying), remove  impurities, pack it manually, store it in the warehouse and transport raw dried seaweed to Indonesian domestic processors or to the exporters. 

Exporters: the exporters primarily supply dry seaweed in compressed 50 kg bales to foreign markets and a smaller amount to domestic processors. They often pay local collectors and regional traders in cash (bank transfer), and provide down payments and working capital to local collectors and regional traders.

In 2021 almost 50% of all Gracilaria produced in Indonesia (37.000 tonnes dry weight, equivalent to 353.000 tonnes wet weight) was exported according to official statistics. China is by far the main importer of dried seaweed from Indonesia. 

Processors: almost all processors of Gracilaria currently produce agar. For this process seaweed is washed to remove sand, salts and other foreign matter before several processing steps are applied for extracting the agar. In 2021 a little over 50% was processed domestically in Indonesia (47.200 tonnes dry weight, equivalent to 600.000 tonnes wet weight) according to the Indonesian Seaweed Industry Association. China is by far the main importer of dry seaweed from Indonesia.

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