The Bureau of Fisheries and Aquatic Resources (BFAR) warned the public anew against eating and catching shellfish in six coastal waters in the Visayas found positive for paralytic shellfish poison or red tide toxin.

BFAR Shellfish Bulletin No.7-16 said that the coastal waters of Dauis in Bohol; Daram Island in Daram, Irong-Irong Bay and Cambatutay Bay in Western Samar; Leyte; Naval, Biliran Island Province; and Pilar in Capiz are still positive for red tide.

The agency said that all types of shellfish and acetes (alamang) gathered and collected from these areas are not safe for human consumption.

BFAR, however, said that several species—including fish, shrimps and crabs—are safe to eat provided that they are fresh and washed thoroughly, and internal organs such as gills and intestines are removed before cooking.

Meanwhile, the bulletin added that Balite Bay in Mati, Davao Oriental and the coastal waters of Gigantes Islands in Carles, Iloilo are now free of the toxic red tide.

Other major fishing grounds in the country continued to be unaffected by the toxins.

Red tide occurs when algae rapidly increase in numbers to the extent that it dominates the local planktonic or benthic community. Blooms are caused by environmental conditions that promote explosive growth.

Such high abundance can result from explosive growth caused by a metabolic response to a particular stimulus or from the physical concentration of a species in a certain area due to local patterns in water circulation, warm sea surface temperatures and high nutrient content.