Living along the shores of Manila Bay from the 1940s to 1960s, we never had to pay for clams, mussels, oysters, and other seafood. The bay was clean and shellfish was free for the taking.

Almost all the bivalves were cooked like tinola, or briefly grilled until their shells barely opened.

All, except for blood cockles called batotoy in Tagalog, which our parents insisted we had to eat well-cooked.

Reading about blood cockles recently gave me the chills. It has caused many deaths and illnesses, causing it to be banned in many places.

Allegedly, if they come from parts of China they can hold hepatitis A.

There are many other articles insisting blood clams are a dangerous food to eat. In addition, all seafood and shellfish carry their own risk of eating (mercury).

Clams and other bivalves can have clear blood, but their blood contains hemoglobin, which is found in many other organisms. As a result, it is vulnerable to the blood diseases that affect humans. Blood clams from China were discovered to be contaminated with hepatitis, which resulted in their ban.

Blood clams are so dangerous they spread viruses such as hepatitis A and dysentery. In 1988, 31 people died from eating these clams. Fifteen percent of people who consume blood clams gain some sort of infection.

Are blood clams safe to eat or not? Blood clams are a type of shellfish that is harvested from coastal waters around the world. The clams are filter feeders and their diet consists mostly of plankton and other small organisms. When the clams are harvested, they are often cooked and eaten whole.

The main concern with eating blood clams is that they may contain high levels of toxins and bacteria that can cause food poisoning. In addition, the clams may also harbor viruses that can cause serious illness. For these reasons, it is important to make sure that blood clams are properly cooked before they are consumed.  

Red tide alert in Vismin 

The public is warned against consuming seafood caught in the coastal waters of Bohol, Zamboanga del Sur, Capiz, Iloilo and Aklan. The Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR) warned shellfish collected and tested from coastal waters of Dauis and Tagbilaran City in Bohol; and Dumanquillas Bay in Zamboanga del Sur are still positive for Paralytic Shellfish Poison (PSP) or toxic red tide that is beyond the regulatory limit.

Moreover, Saplan Bay (Ivisan and Saplan in Capiz; Mambuquiao and Camanci, Batan in Aklan); coastal waters of Panay; President Roxas, Roxas City in Capiz; coastal waters of Gigantes Islands, Carles in Iloilo; and coastal waters of Altavas, Batan and New Washington in Batan Bay, Aklan are now positive for PSP.

“All types of shellfish and Acetes sp. or alamang gathered from the areas shown above are not safe for human consumption,” it said.

“Fish, squids, shrimps, and crabs are safe for human consumption provided that they are fresh and washed thoroughly, and internal organs such as gills and intestines are removed before cooking,” it added.

On the other hand, the areas that are free from toxic red tide include the coastal waters of Cavite, Las Piñas, Parañaque, Navotas, Bulacan, and Bataan (Mariveles, Limay, Orion, Pilar, Balanga, Hermosa, Orani, Abucay, and Samal) in Manila Bay; mariculture areas in Infanta, coastal waters of Bolinao, Anda, Alaminos, Sual, and Wawa, Bani in Pangasinan; mariculture areas in Rosario, and Sto.Tomas in La Union; coastal waters of Pampanga; Masinloc Bay in Zambales; Pagbilao Bay, Pagbilao, and coastal waters of Walay, Padre Burgos in Quezon; Honda and Puerto Princesa Bays, Puerto Princesa City and coastal waters of Inner Malampaya Sound, Taytay in Palawan.

The areas that have not been detected with the red tide are the coastal waters of Milagros and Mandaon in Masbate; Sorsogon Bay, Juag Lagoon and Matnog in Sorsogon; coastal waters of Borongon, San Dionisio in Iloilo; coastal waters of E.B. Magalona, Talisay City, Silay City, Bacolod City, Hinigaran and Victorias City in Negros Occidental; Tambobo and Siit Bays in Siaton; and Bais Bay in Negros Oriental; coastal waters of Daram and Zumarraga, Cambatutay, Irong-irong, Maqueda, San Pedro and Villareal Bays in Samar; coastal waters of Guiuan in Eastern Samar; coastal waters of Lete, Calubian, Ormoc, Sogod, Carigara Bay and Cancabato Bay, Tacloban City in Leyte.

Also cleared from red tide are coastal waters of Biliran Island; Tantanang Bay in Zamboanga Sibugay; Murcielagos Bay in Zamboanga del Norte and (Sapang Dalaga, and Baliangao) in Misamis Occidental; Panguil Bay, Tangub City, and coastal waters of Ozamiz City in Misamis Occidental; coastal waters of Baroy in Lanao del Norte; Taguines Lagoon, Benoni, Mahinog in Camiguin; Balite, and Pujada Bays, Mati City in Davao Oriental; Malalag Bay in Davao Occidental and Davao del Sur; coastal waters of Nasipit in Agusan del Norte; Litalit Bay in Surigao del Norte; and coastal waters of Hinatuan, Cortes, Lianga and Bislig Bays in Surigao del Sur.