Sea Cucumbers Offer Hope for Shrimp Farmers

ABC reports that a growing number of shrimp ponds are being abandoned because waste from the crustaceans is building up, becoming toxic and causing disease.

But Australian scientist Dr Dave Mills, who works for the WorldFish Centre, an international scientific body that aims to reduce poverty, says sea cucumbers can clean the ponds.

"They have this ability to eat organic material out of the sediments, so this is beneficial for the ponds because you don't get this horrible build-up of organic material and the farmers can just put the sea cucumbers in the ponds and they don't have to feed them," he said.

While wild sea cucumber stocks are running low because of over-fishing, the farmed species is starting to take off.

After a decade of research, Viet Nam's government-owned hatchery north of Nha Trang is producing reliable batches of juveniles.

Dr Mills says the slow movers, which can fetch more than $200 a kilogram when dried, are now winning over commercial investors.

"There's a small number of farmers involved," Dr Mills said.

"At the moment there's around 15 between a couple of provinces in central Viet Nam.

"Some of them have been involved for up to five years; those farmers have been quite successful.

"So there's quite a high demand for juvenile sea cucumbers to grow in ponds now."

Pham Van Hoan was one of the first farmers to swap from shrimp to the more sedate species.

He says his income has increased significantly.

"Before I farmed them, I didn't have enough money to build a house, but after changing to sea cucumbers I was able to," he said.

"I also bought a bed, a wardrobe, a washing machine, a fridge and a motorbike," he said.

Tran Van Huu, a 30-year veteran of the shrimp industry, has taken up sea cucumber farming more recently.

But instead of replacing the crustacean, which he says he can earn more money from, he has decided to farm both.

"Sea cucumbers eat the waste from shrimp and clean the sediment, so if we have one crop of sea cucumbers and then one crop of shrimp, we'll definitely make a profit," he said.

Dr Mills and leading local researcher Nguyen Dinh Quang Duy are now testing whether they can take things one step further and grow both at the same time.

Early experiments in tanks found it was not exactly a marriage made in heaven.

"What we found in these tank trials we conducted was largely that when the shrimp get very big they will physically attack the sea cucumbers... we had low survival and low growth rates," Dr Mills said.

However, by adding fewer shrimp in the new trial, he is optimistic this odd couple can co-exist.