Montipora grisea

Montipora grisea is a colonial stony coral in the family Acroporidae, typically forming encrusting to plate-like or branching colonies depending on local conditions. Like other scleractinian corals, it builds a calcium carbonate skeleton and hosts symbiotic zooxanthellae, algae that supply the coral with energy through photosynthesis while the coral provides shelter and nutrients in return. Colonies extend polyps to capture plankton, particularly at night, supplementing their symbiotic energy intake.

As a reef-building species, it contributes to the structural complexity of reef systems, providing habitat for numerous invertebrates and fish.

The species occupies marine neritic (shallow coastal) waters across a broad Indo-Pacific range, spanning countries including the Marshall Islands, Papua New Guinea, Solomon Islands, New Caledonia, Madagascar, Micronesia, Seychelles, Australia, Mauritius, Maldives, Thailand, Vanuatu, Vietnam, Taiwan, China, Japan, Palau, and Fiji.

Its decline stems from a combination of pressures rather than a single cause. Fishing and harvesting activities damage colonies directly, while recreational activities such as diving and anchoring cause physical breakage. Coral disease and outbreaks of problematic native species, such as crown-of-thorns starfish, further degrade colonies.

Land-based pollution—domestic wastewater, agricultural runoff, and effluents from non-timber crop production—reduces water quality and promotes algal overgrowth. Habitat alteration and invasive species add further stress, compounding the effects of warming-driven bleaching events.

Conservation efforts include the species' listing under the IUCN Red List as Endangered, inclusion in regional marine protected areas across its range, and broader reef management and water-quality initiatives in affected countries. No population figures are available. Given the persistence of multiple concurrent threats and the ongoing decreasing population trend, the species' outlook remains poor without substantial improvements in coastal water quality and reef protection.