DENR 4-A responds to COTS outbreak in Verde Island Passage

by Ruth Quinto, Pia Laguna April 19, 2022 COTS  (Photo by DENR CALABARZON) TINGLOY, Batangas (PIA) — The Department of Environment and Natu...

by Ruth Quinto, Pia Laguna
April 19, 2022

COTS (Photo by DENR CALABARZON)

TINGLOY, Batangas (PIA) — The Department of Environment and Natural Resources (DENR) CALABARZON leads the extraction and collection of crown-of-thorns starfish (COTS) — a large sea stars that feeds upon head or stone coral polyps, within the Mabini-Tingloy area of the Verde Island Passage.

The extraction conducted recently was supported by the Calaca and Lipa CENR Offices and local government units of Mabini and Tingloy.



The reported outbreak of COTS in Verde Island Passage (VIP) in Batangas caused the authorities to commence the collection and extraction.

The DENR CALABARZON said the extreme aggregation of COTS can strip a reef 90% of its coral tissues, and this can affect fish populations.



According to the Great Barrier Reef Marine Park (GBRMPA), having 15 COTS per hectare can already be considered an outbreak.

During the collection operation, there were estimated 1,500 COTS collected equivalent to 6 80-liter drums. These COTS measure 15-70 cm in diameter with 10-18 thorney arms.



Among the causes behind the COTS outbreak include the loss of its natural predators such as the Triton’s trumpet, Napoleon wrasse, white-spotted pufferfish, and titan triggerfish that keep its population in check.

The DENR CALABARZON added that the continuous rise in sea surface temperature due to climate change exacerbated by various anthropogenic activities including improper waste management, deforestation, agricultural land run-off, and overfishing also caused the COTS outbreak. — Ruth Quinto, PIA Laguna (with reports from DENR CALABARZON)