Vermetid Snails Can Reduce Coral Growth Across Pacific Reefs

Researchers discovered that a little-studied snail called Dendropoma maximum severely damages reef-building corals, reducing their growth by up to 81% and survival by up to 52%. This overlooked species could be reshaping coral reef communities across the Indo-Pacific. The researchers conducted field surveys on 90 coral reefs in Moorea, French Polynesia, documenting the relationship between vermetid presence and coral health. They then performed controlled field experiments, transplanting coral fragments to reefs where they either removed all vermetids or left them at natural densities, measuring coral growth and survival over 7 months. Vermetids reduced coral skeletal growth by up to 81% and survival by up to 52% across four coral species. The presence of vermetids was strongly associated with flattened, stunted coral growth forms on natural reefs. Different coral species showed varying susceptibility to vermetid damage, suggesting these snails could alter coral community composition. Vermetid densities were positively correlated with dead coral substrate for three of four coral species studied. The research shows that an overlooked species may be a significant driver of coral reef decline at a time when reefs are already under severe stress from climate change and human activities. The finding that vermetids affect different coral species differently suggests they could be reshaping entire reef communities, potentially making some reefs less diverse or resilient.

Citation

Shima, Jeffrey S.; Osenberg, Craig W.; Stier, Adrian C. (2010). The vermetid gastropod Dendropoma maximum reduces coral growth and survival. Biology Letters.

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