Catbalogan city: A local red tide warning has been issued for Irong-Irong Bay in Samar after seawater samples collected there tested positive for red tide toxins, the Bureau of Fisheries and Aquatic Resources (BFAR) reported on Tuesday. The bay in Catbalogan City, the capital of Samar province, is the fourth area in the region included in the latest red tide warning issued by the fisheries bureau.

According to Philippines News Agency, 'filtered seawater samples collected from Irong-Irong Bay remain positive for pyrodinium bahamense, a dinoflagellate that produces red tide toxin,' BFAR said in a statement. The public is advised to refrain from gathering, selling, and eating all types of shellfish and Acetes sp., locally known as "alamang" or "hipon," from the bay to prevent possible paralytic shellfish poisoning.

Fish, squid, shrimp, and crab from these waters are safe to eat as long as they are fresh and their internal organs, such as intestines and gills, are removed and thoroughly washed. Other shellfish ban areas include waters around Biliran Island, Daram Island in Samar, and Matarinao Bay in General MacArthur, Quinapondan, Hernani, and Salcedo in Eastern Samar.

A shellfish ban is imposed in an area if both shellfish and seawater samples from the area tested positive for red tide based on examination by the BFAR main office laboratory. Other bays in the national shellfish bulletin include Dumanquilas Bay (Zamboanga del Sur), Bolinao and Anda (Pangasinan), Panguil Bay (Misamis Occidental and Lanao del Norte), and Tantangan Bay (Zamboanga Sibugay).

BFAR said red tide cysts recur due to frequent rains that cause runoff of organic-rich sediments, which fertilize the cysts.