THE Bureau of Fisheries and Aquatic Resources (BFAR)-Davao Region held a two-day crown of thorns cleanup last week, April 17 to 18 off the Island Garden City of Samal.
The first cleanup was done at the waters off the village of Linosotan in Kaputian District last Monday with a team from BFAR-Davao Region, the field office in Penaplata, and members of the village area's bantay dagat.
A total of 305 crown of thorns were picked, which weighed 83 kilos, in a coral reef that's less than a hectare. A crown of thorns outbreak is when there are more than 15 starfish per hectare or more than one starfish spotted per 20-minute swim.
Having a total of 305 in less than a hectare is a disturbing number. The crown of thorns starfish or Acanthaster planci feed on corals.
On any normal coral reef, the crown of thorns help contain the proliferation of staghorn and plate corals, which are the fastest-growing corals, to allow the slower growing ones, like the brain corals, to grow.
But in an outbreak, like having more than 300 in less than a hectare of coral cover, crown of thorns threaten coral reefs as they not only decimate the fast-growing corals but also feast on the slow-growing ones.
Outbreaks become more often with the warmer waters as the species that help contain the crown of thorns have become scarce. These are the giant triton snail, the humphead Maori wrasse, starry pufferfish, titan trigger fish, and the harlequin shrimp.
With the predator-prey balance tilted in favor of the crown of thorns, the corals are placed at higher risk of decimation.