Wild Taiwan

A lady of leisure writes about wildlife in Taiwan.

Thursday, December 22, 2005

seafood in Taiwan

Taiwan has a lot of marine fish cultures, eels, groupers, small abalone (or nine holes Haliotis diversicolor), shrimps etc. See http://www.roc-taiwan.org/taiwan/5-gp/yearbook/2002/chpt12-6.htm

The Japanese eel, Anguilla japonica, or unagi, is the one that's cultured in Taiwan. Eel culture in Taiwan can be in the form of a nursery operation, raising newly transformed elvers of Anguilla japonica to fingerlings, in the form of a production operation, raising fingerlings to market size eels, or a combination of the two.
Eels have an interesting life cycle, half in the sea and half in freshwater. Eels spend their growing period in freshwater but breed in the sea. They become sexually mature after the adult eels migrate back from the rivers into the sea. In nature, the larvae feed on small crustaceans, worms, insects. They spend anywhere from 5 to 20 years in freshwater and grow to a size of about 45cm or longer before reaching sexual maturity. Then they go into the sea toward their spawning ground. After hatching, the transparent leaf-like larvae drift with the Kuroshio current along the Western Pacific coast up to Japan. They are believed to spend 5-6 months as pelagic swimmers before metamorphosing into elvers and migrate upriver. They are totally transparent but have the body shape of an eel and are called glass eels. The glass eels are carried by tides into the estuaries of coastal rivers where they undergo further development to become elvers (up to 1-3 years of age), which are similar to the adult form except for size. The elvers then undertake a more active secondary migration into the freshwater, upper reaches of the catchment where they grow and develop into sexually mature adults before returning to the sea to spawn (average 10-25 years of age, although this varies with species and location).
The Japanese eel are endemic only in waters of China, Korea, Japan, and Taiwan. With a total dependence on natural sources, the supply of glass eel is limited, very unpredictable, and is the bottleneck in the development of eel culture. Many people thus place their hope for the future for eel farming on artificial propagation. Induction of ovulation through hypophysation, artificial fertilization of eggs, and hatching of such fertilized eggs has been carried out successfully in Japan and Taiwan. The cultivation of such larvae to the elver stage for the farming industry, however, will probably not be possible in the near future.

In order to culture eels in the freshwater environment, a lot of groundwater is pumped thus causing land subsidence. source: http://www.american.edu/projects/mandala/TED/eelfarm.htm
Eels are commonly sold as fresh or already smoked with teriyaki source.

There are many grouper species but the most common grouper species cultured in Taiwan is the orange-spotted (Epinephelus coioides). They are fed with trash fish or artificial feed (dry formulation). Seed, which is usually fry or fingerling, can be wild-caught or hatchery-bred. In the former, supply is usually seasonal and unpredictable but are however more robust and hardy as they would already have undergone pre-selection by nature. In the case of hatchery-bred seeds, supply is more predictable, and, depending on whether the parent stocks were wild-caught or farm raised, could be produced on schedule in batch-operation sequence. More information available on http://www.redlist.org/search/details/44674.pdf

Another is the small abalone

In 1998 it has suffered bacterial disease from Vibrio parahaemolyticus (Letters in Microbiology (2000)31:433-437). Eventhough some abalone may fall sick, they were still considered safe for human consumption provided they were cooked properly. More information available on http://www.fishtech.com/facts.html