About Rock Fish
Tasty rock fish is the dish of must for every banquet. Starting from 2000, Yongan Siang Office has been holding the annual "Rock Fish Cultural Festival" with industrial features of Yongan prepared rock fish banquet for visitors around the island.
Rock fish is sea water fish with demersal habit, living in reef area or dark rock and preying other fish and shrimps as food, a ferocious one nicknamed as the "King of the Rock Undersea." Growing in tropic sea, rock fish mostly are cultivated at the suitable temperature between 22-28 on the area south to Tainan Coast. In 1976, one of the residents of Yongan Siang, Mr. Ciou Nan-zuo, introduced 6,000 rock fish from Penghu had began rock fish farming on Southwest Coast of Taiwan. Along with the change of agricultural fanning and the advancement of farming technology, farming of rock fish has became fanning of professionally diversified division and Yongan Siang has been known as the best rock fish breeder in both quantity and quality. Yongan does not supply rock fish only to domestic markets in Taiwan, but oversea markers in Hong Kong, Macao, and Vietnam, that accounts 60% of the total sales, more than that of domestic markets. Accordingly, rock fish is regarded as the star industry here in Yongan Siang.
Professionally Diversified Division of Aquaculture Farming
Yongan has the farming area of scale of rock fish of more than 300 hectares and the annul production volume of about 8,000 tons, good in both quality and quantity; Yongan, thus, is known as the home of rock fish. Due to the suitable climate and stable water quality on Southwest Coast of Taiwan as well as farming of professionally diversified division, the yield rate of rock fish fanning increases gradually and the production period is lasted to about six months a year. Rock fishing farming is a very important economic support for Yongan Siang. It is also because of the professional and divers ified division, spawning, breeding, and raising are operated in different sites to form a specialized production line.
Spawning
Rock fish has the characteristics of being hermaphroditism and the female ones need to be raised for three years for spawning and eight years for male fish. In other words, most young adults are females and elder ones are males. The spawning period is from March to October when rock fish swim in pairs and females begin ovulation and males reject sperm to conduct insemi- nation on the water. Fishermen collect fish egg floating to the pond sides.
The collection of fish egg is done on the sides of ponds or using net. It has to been conducted carefully without any damages done to the eggs. Collected eggs are then put in the tank filled with oxygen and covered with fine net to avoid floating out. After one night's floating screening, those without insemination will float down and those with insemination will float on the surface in transparent color like a ball. These eggs with insemination are put in spawning tank for three to four days for hatching. Fries then grow wing-like fins and fins that will disappear at first 14 days and 24-30days respectively. The fully grown fries has the length of two cm, nicknamed "the whitty."
It takes about a month to grow rock fish from insemination, spawning, to "the whitty," and climate and water quality are the influential factors. The yield rate is about 30%.
Breeding
Breeding is an industry of high profit, high risk and high technology. Besides the factors of water quality and climate, there is the threat of virus infection. Sometimes, the yield rate is as high as 90% and other times, it may be as low as 20%. "The whitty" needs to go through several stages before selling to the market. Normally, the market price is calculated by the size of fries, three inches for about NT$30 and four for NT$40. The larger the size of fries, the lower the death rate will become.
The health condition of fries directly influence the growth and quality of rock fish. Healthy fries have a good appetite, grow fast, survive better, and turn in better yield rate. Thus, it is essential to judge the health condition of a fry by its appetite.
Season is another influential factor to decide on the price of fries. "Crossing- winter Fries" are sold around the period from Chinese New Year to Tomb-Sweeping Day at higher price and they can be harvested by the end of that year; "Yearly Fries" are sold around the period from April to August in Chinese lunar calendar at lower price when the temperature is high good for growth and fires have higher yield rate, but they need to be raised to the next year before harvesting.
Adult Fish
It takes about eight months to raise a 8-cm fry to 0.6 kg adult fish, 16 months for 1.2 kg, and one year for 1.2-2.4kg.
The fish pond for adult fish is about 0.3-0.4 Fen with the population density of 60,000 fish per hectare. In general, fish ponds are equipped with water mills and feeders. Because rock fish is accustomed to the dark area, fish cages are put around the feeder to allow them to shield from the sun light.
The key factors to the farming of rock fish are temperature and water quality. Fish being raised in good water quality have better appetites, are less likely to be infected, and require lower cost. Water quality depend on the color as well as the composition of nitrite, ammonia, and ph value and water quality management is a big issue for fishermen to address. In addition, fanners are concerned of the control of fish infection and once fish show bad appetites and rest often on the pond side, they will be at the high alert of the virus that might bring high death rate.
Under the promotion of Yongan Fishermen's Association, a doctor from Animal Disease Control Center, Kaohsiung City Govern- ment comes to Yongan to offer his professi- onal help each week and on that day, fishermen will bring their fish there for diagnosis.
Fish farming in Yongan depends on the pumping of surface water of filtering layer; thus, the water supply is stable. In the long term, there is no concem over the over- pumping of underground water.
Good Taste and Quality; 60% of Adult Fish Export
Due to the comfortable climate, good water quality, and advanced accumulated fishing experience and technology, milk fish, the largest production amount, rock fish, and perch have good performance in both quantity and quality to supply both domestic and oversea markets.
When growing to 2.4-4.2 kg, rock fish are sold to domestic and oversea markets in either frozen, mostly exported to Japan, or in fish fillet form to European and American countries.
Due to the comfortable climate, rock fish dish is available around the year in Taiwan. The demand for rock fish grows explosively, in particular, in the high seasons from September to April of Chinese lunar calendar when most people like to have their weddings held during this time. More than a dozen of rock fish farms in Yongan area have passed the standard tests of water quality, drug residual, and so on and are certified by the Economic Association of Fishery Development of National Taiwan Ocean University as qualified fishing farm facilities to ensure the improved overall quality of fishing products.