Marine scientists warn of overfishing risk for century-old sea cucumbers

Marine scientists have discovered that the black‑teatfish sea cucumber can live for more than a century, a finding that could upend current fishing limits and put the species at greater risk of overexploitation. The breakthrough came from a genetic mark‑recapture study led by Dr Sven Uthicke, senior principal research scientist at the Australian Institute of Marine Science, published this week. The research tracked individual animals over decades and identified several specimens that were over 100 years old.

The revelation arrives as commercial demand for sea cucumbers has surged worldwide, driven by their value in Asian cuisine and traditional medicine. In Australia, the black‑teatfish is one of the most heavily harvested species, supporting a multi‑million‑dollar fishery. Until now, managers assumed the animal’s lifespan was measured in decades, not centuries, and set catch limits based on that shorter life expectancy. The new data suggest the species recovers far more slowly than previously thought, meaning current quotas may be too high.

Uthicke’s team collected tissue samples from hundreds of sea cucumbers across the Great Barrier Reef and used DNA markers to identify which individuals were the same across multiple years. The genetic fingerprints showed that some individuals had been alive for more than a hundred years, far exceeding the 30‑ to 40‑year lifespan that earlier studies estimated. “If a single animal can live that long, the population turnover is far slower,” Uthicke said. The study also found that recruitment – the addition of new, young animals to the population – is limited, further slowing recovery after heavy fishing. Fisheries officials have been warned that the existing catch limits could be depleting a resource that cannot bounce back quickly.

The findings are prompting calls for tighter management of the black‑teatfish fishery. Regulators are expected to review quotas and may introduce more conservative limits or seasonal closures to give the species a chance to replenish. Conservation groups argue the data underscore the need for precautionary approaches to marine resources that have long lifespans. As scientists continue to monitor the population, the study highlights how new genetic tools can reveal hidden aspects of marine life that are crucial for sustainable harvesting.