Tackling the Coral-Killing Sponge
In partnership with BKKPN Kupang Satker Banda

Terpios hoshinota, often called the "black disease sponge," is a fast-spreading encrusting sponge that poses a serious threat to coral reefs. First described in Guam in the 1970s, it has since been recorded across the Indo-Pacific, including Taiwan, Okinawa, Indonesia, the Great Barrier Reef, and the Indian Ocean. This sponge aggressively overgrows live corals, smothering them and leaving behind barren reef structures.

Outbreaks of T. hoshinota have been observed more frequently in degraded reef environments, particularly in areas affected by high sedimentation, eutrophication, and warming waters. Its ability to colonize various coral species and expand across different environments makes it a growing concern for reef resilience.

While research continues to better understand its ecology and potential control measures, the increasing spread of T. hoshinota highlights the urgent need to protect and restore coral ecosystems to reduce their vulnerability to such threats.

In December 2022, we identified T. hoshinota at a reef site in the Banda Islands, near a former aquaculture platform. We suspect that excess nutrients from fish food may have contributed to the sponge’s proliferation. To counter its spread, we began testing a shading technique in January 2023, using recycled event banners to block sunlight—a method previously found to halt the sponge’s growth.

While the sponge disappeared beneath the covers, it continues to reappear in new locations, suggesting that by the time it was discovered, it had already spread to nearby reefs. So far, it seems to only start overgrowing corals when it becomes large and well established, reinforcing the idea that reducing stressors, particularly nutrient pollution, is the most effective management approach.

This initiative is a collaborative effort with BKKPN Kupang Sakter Banda, KKP Banda, and Uni Banda Naira (UBN) to protect the region’s reefs from further impact.