Sea cucumbers, often appearing as alien-looking, leathery animals on the ocean floor, are a delicacy in many parts of the world, valued for their use in soups and their perceived health and libido benefits. But a boom in demand since the 1980s has led to overfishing and population collapses in parts of the Pacific, including remote Australian reefs.
Now, a new genetic study published in the journal iScience suggests that at least one species, the black teatfish (Holothuria whitmaei), may live much longer than previously thought. Study lead author Dr Sven Uthicke, a molecular ecologist at the Australian Institute of Marine Science, said the fish could reach 100 years of age. He said the finding meant fishery management needed to revise whether current catch limits were sustainable, noting: "They're currently assuming that these animals are replaced, basically, 10 times more than they are likely to be."
The age at which a marine species reaches maturity is a key factor in calculating a fishery's environmental sustainability. Dr Uthicke said the sustainable catch limit for black teatfish and similar species might be lower than currently assumed.
Sea cucumbers play an important role in reef and seagrass health. CSIRO marine ecologist John Keesing said that while much remained unknown about the ecological services they provide, "we do know that they are very important in aerating sediment."
Illegal fishing has also been identified as a key culprit in the disappearance of entire sea cucumber species from some Australian reefs, compounding concerns about the long-term viability of legal fisheries.