What If Gone

Species → Sandfish Sea Cucumber

Sandfish Sea Cucumber

Holothuria scabra

A decline of more than 90% recorded across at least half of its…
Extinction risk Endangered
Ecosystem engineerCoral reefOverfishingMarine environment
Sandfish Sea Cucumber (Holothuria scabra)
Photo: Alexander Green, Wikimedia Commons (CC BY 4.0)

What if it disappeared?

Impact Moderate
Over 22 years, Philippines

Fished for the Asian dried bêche-de-mer market, the species has declined by more than 90% across at least half its range — in the Philippines, annual catches fell from 3,000-4,000 tonnes in the 1980s to just 600-800 tonnes by the late 1990s and early 2000s.

Documented
Detail

UICN, Liste rouge — Holothuria scabra, évaluation 2013 (Hamel et al.).

The species' slow growth and irregular recruitment make it especially vulnerable to overfishing, unable to rebuild at the rate it is being harvested — a classic fishery-collapse pattern, documented here through the direct drop in landed tonnage rather than a single population estimate.

Over 6 months, Fiji

What this decline concretely means for the seafloor has been measured experimentally: by excluding sandfish from sediment plots for six months, sediment oxygen consumption doubled within the first month, and oxygen penetration depth fell by 63% during a water-warming episode — a collapse absent from plots where the species remained present at high density.

Documented
Detail

Lee, S., Ford, A.K., Mangubhai, S., Wild, C. et Ferse, S.C.A. (2018). Effects of sandfish (Holothuria scabra) removal on shallow-water sediments in Fiji. PeerJ, 6, e4773.

By continuously burrowing through and filtering sediment to feed, the sandfish maintains the aerobic conditions the seafloor community depends on. Without it, sediment becomes markedly more vulnerable to heat stress — a buffering effect against water warming that the removal experiment makes visible in just six months.

Documentation

Last verified: August 14, 2026