Tropical Sea Cucumbers in Trouble – Critics for Ocean Ecosystem Health

White teatfish in the southern Great Barrier Reef. Credit: Steve Purcell

Sea cucumbers are essential to the health of ocean ecosystems.

Researchers call for better protection of tropical sea cucumbers in the Great Barrier Reef whose numbers are declining due to persistent and growing overexploitation.

New research reveals that overexploitation has put tropical sea cucumber populations in the Great Barrier Reef at risk, with high demand for the delicacy from East and Southeast Asia.

Several kinds of sea cucumbers are harvested, mainly for Chinese consumption. The global market for sea cucumbers is estimated at over US$200 million per year.

Posted in Biological Conservation, the research was carried out by a team from the University of Sydney and the University of Queensland.

“Known as the earthworms or the vacuum cleaners of the sea, sea cucumbers are vital to reef health, helping to keep the seabed clean and productive,” said biology professor Dr Maria Byrne. Marine at the School of Life and Environmental Sciences at the University of Sydney.

“Abundant populations of sea cucumbers on unfished reefs process tons of lagoon sediment through their bodies every year – they are the clean sand solution.

“These animals are globally endangered and their harvest on the Great Barrier Reef is of serious concern.

“Fishing data collected along Australia’s main reef sea cucumber fishing ground has shown the need for caution and regulatory change.

“The Great Barrier Reef is home to 10 of the world’s 16 threatened or vulnerable sea cucumber species. Data shows that populations of some of the most prized species have declined due to increasing and persistent global overexploitation.

The udder in particular in danger

Of particular concern is a rapidly disappearing group of tropical sea cucumbers known as the teatfish.

Udders are listed under CITES (Convention on International Trade in Endangered Species), which provides a solid basis for restricting their harvest and export. Yet two of these species, the white teatfish and the black teatfish, accounted for more than 20 percent of the Queensland fishery’s recent total catch.

Udder populations are the most endangered due to their high market value and poor reproduction. Individuals that remain on the reef fail to find a mate due to fishing withdrawal.

“Black udder numbers have not recovered since their fishery closed in 1999 due to overfishing – although the fishery reopened in 2019,” said Dr Kenny Wolfe of the University of Queensland.

“In December 2021, we saw a silver lining when Federal Environment Minister Sussan Ley supported CITES listing and, in recognition of their perilous state, determined that harvesting black teats would not be allowed.

“This is a big win for one of our 10 endangered or vulnerable sea cucumbers, but further policy interventions are needed to ensure other sea cucumber populations don’t start to falter. towards extinction,” he said.

More government protection is needed

Professor Byrne said effective legal regulation was essential to protect sea cucumbers.

“The Great Barrier Reef sea cucumber fishery has a long history of operating under what is known as a non-regulatory – and therefore non-binding – performance measurement system.

“This system recommended regular assessment of sea cucumber stocks, but this has not been done, so the industry has been operating for decades without any real idea of ​​the impact of their harvests on the sustainability of the stocks.

“Going forward, it will be essential to have a regulated and legally enforced policy framework for regular, independent stock assessments of all tropical sea cucumber species harvested from the Great Barrier Reef.

“Only then will we be able to assess what a sustainable harvest is and identify species-specific interventions, hopefully avoiding local extinction of these sea cucumber species. ecologically important on the Great Barrier Reef.

“This is essential for the health of the reef and makes an important contribution to achieving the Australian and Queensland governments’ Reef 2050 plan, ensuring that the UNESCO ‘at risk’ status of the Great Barrier Reef is avoided, and for the Queensland Department of Agriculture and Fisheries to respond to its latest Sustainable Fisheries Strategy.

Reference: “Overview of the Great Barrier Reef Sea Cucumber Fishery with a Focus on Vulnerable and Threatened Species” by Kennedy Wolfe and Maria Byrne, 29 January 2022, Biological conservation.
DOI: 10.1016/j.biocon.2022.109451