LEGAZPI CITY – The Bureau of Fisheries and Aquatic Resources (BFAR) is heightening its monitoring of Masbate’s Milagros Bay after laboratory results confirmed samples collected in the area are positive for paralytic shellfish poison (PSP) or red tide toxin.

The PSP toxin level in shellfish samples collected from Milagros Bay recorded 60.99 to 127.06 micrograms of saxitoxin, BFAR 5 (Bicol) information officer, Nonie Enolva, said on Saturday.

An area is considered positive for red tide when the PSP level exceeds 60 micrograms.

"Latest results indicated the paralytic shellfish poison is beyond the regulatory limit," she said in an interview.

Enolva reiterated the warning to prevent the gathering, transport, selling, buying, and eating of all types of shellfish and alamang (small shrimp) from affected coastal waters.

Violators will be fined between PHP1,000 and PHP10,000 or imprisoned for two months to one year, or both.

Meanwhile, the shellfish sample collected from Sorsogon Bay tested negative for PSP toxin, said Nelson Bien, BFAR-5 director.

The confirmatory test was conducted by the National Fisheries Laboratory Division.

"This revokes the previous local red tide advisory dated Oct. 6, 2022. The public is hereby informed that the shellfish and acetes sp. (shrimp species) gathered from Sorsogon Bay are now safe for human consumption," Bien said in an advisory.

The gathering, harvesting, and marketing of shellfish from the area of Sorsogon Bay are now allowed.

Experts said shellfish are prone to red tide because when they eat the poison-producing algae, the toxin can accumulate in their tissues.

Biotoxins do not harm shellfish so the level in their tissues will rise until the algae bloom subsides.

It takes days or months for shellfish to eventually flush the toxin out.

The usual symptoms of PSP are tingling, numbness of the mouth and extremities, and gastrointestinal discomforts, such as vomiting and diarrhea.

In severe cases, difficulty in swallowing, speech paralysis with respiratory arrest, and death may occur. (PNA)