TAIPEI (AFP) - Taiwan is to set up its first turtle sanctuary, officials said on Sunday, after the second seizure within weeks of more than 2,000 of the protected creatures, bound for dinner plates in China.

Taiwan's coastguard discovered on Saturday 2,439 Asian yellow pond and yellow-lined box turtles in a fishing boat in Tungkang, a port in the southern region of Pingtung.

The skipper of the boat, bound for China, and three Indonesian crew were arrested. They could face jail terms of up to five years plus a fine of up to NT$1.5 million (S$64,000), according to Taiwan's wildlife protection law.

The coastguard seized 2,626 rare turtles on board another boat last month as they were being taken off the island, in what the authorities said was their biggest ever seizure of smuggled turtles.

The reptiles were to be eaten by wealthy Chinese or used as an ingredient in China for traditional medicine, officials said.

The new sanctuary will open in October on the Feitsui reservoir outside the capital Taipei.

"The preservation of rare turtles in the (reservoir) area is already relatively better (than other areas of Taiwan)," Kuan Li-hao, an official of the forestry bureau, told AFP. "Once the sanctuary is set up, patrols will be stepped up there to deter poaching.

"As winter approaches, the demand for turtles in China, especially in the south, is rising," Mr Kuan said.

Because the number of wild turtles is in sharp decline in China, market prices have surged to about five times those of Taiwan, which is separated by a 200-kilometre strait from the Chinese mainland.

The two types of turtles seized in the past three weeks are in the second tier of Taiwan's national three-category wildlife protection list, meaning they are deemed rare and valuable. The first category is for endangered species.