National Committee on Marine Sciences (NCMS)
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- Connections and clustering of Paralytic Shellfish Toxin events among coastal embayments in an archipelago partly mediated by advectionPunongbayan, Andalus T.; Wang, Ysabel D.; Villanoy, Cesar L.; Yñiguez, Aletta T. (Elsevier, 2022-01)The potential for advection to influence harmful algal bloom (HAB) spread in adjacent embayments and islands has not been investigated in the Philippines as previous studies have focused on HAB dynamics within specific embayments. Advection of HABs may be relevant in the Samar-Leyte region where adjacent sites are subject to recurrent blooms of Pyrodinium bahamense. We used different analyses to extract the potential role of advection in blooms in the region. First, we used Bayesian and information theoretic approaches applied to historical data on shellfish bans to quantify spatial dependencies in HAB occurrences between sites. Then, to determine whether such dependencies are related to circulation patterns in the region, we analyzed connectivity using a hydrodynamic model coupled with a conservative tracer-based HAB model. The Bayesian network showed that in 7 out of 11 sites, the probability of a shellfish ban depended on the state of an adjacent site. Site pairs with direct dependence relations also shared relatively high similarity in HAB occurrences over time. In the modelled network, bans tend to occur sequentially, spreading from a few sites with relatively high probabilities for ban events. A subset of sites (sources) were found to be informative of future HAB event probabilities in other sites (destinations) over time lags that are generally longer the farther the destination. Modelled surface advection showed high connectivity strengths between sources and destinations associated with circulation features, e.g., an anticyclonic current in Leyte, wind-driven coastal current in western Samar, and tidally-driven flow in the shallow embayments in southwest Samar. High connectivities were correlated with direct dependence relations in the Bayesian network. Connectivity explained up to about 1/3 of the variance in statistical dependencies between ban signals. Our results show that Paralytic Shellfish Toxin events within this region can be due to advection of blooms originating from nearby areas rather than localized cyst dynamics within an embayment. Particular sites were also identified as potential indicator sites within spatial clusters for monitoring since they are typically where blooms originate and spread from.
- Red tide warning up in three provincesJocson, Luisa Maria Jacinta (BusinessWorld Publishing Corporation, 2022-08-24)The Bureau of Fisheries and Aquatic Resources (BFAR) has issued a red tide notice on the coastal waters of Dauis and Tagbilaran City in Bohol
- Shellfish ban up in 10 VisMin areasCariaso, Bella (Philippine Star Printing Co., Inc., 2024-10-01)Ten bodies of water in the Visayas and Mindanao remain affected by the paralytic shellfish poison or red tide toxin, according to the Bureau of Fisheries and Aquatic Resources. The BFAR said a shellfish ban has been imposed on Carigara Bay in Leyte
- No red tide in CLArcellaz, Princess Clea (Sun • Star Publishing, 2024-10-19)The Bureau of Fisheries and Aquatic Resources (BFAR) said shellfish samples collected in Central Luzon are free from the toxic red tide. Based on Shellfish Bulletin No. 26 Series of 2024 issued October 16, 2024, BFAR said the coastal waters of Bataan, Pampanga, Bulacan and Zambales are safe from the water toxin. Alll types of shellfish gathered from these areas are safe for human consumption, the BFAR said.
- Red tide invades Eastern Visayas baysRecuerdo, Elmer (Concept & Information Group, Inc., 2024-01-22)The Bureau of Fisheries and Aquatic Resources regional office here disclosed that two bays in the Eastern Visayas region were declared positive of red tide after shellfish meat samples gathered from the two waters were found to contain toxins that are beyond the regulatory limit. According to the BFAR-8, the San Pedro Bay in Samar and Matarinao Bay in Eastern Samar emerged positive of high levels of toxins that can cause Paralytic Shellfish Poisoning based on the shellfish meat harvested from the area.
- Red tide invades 4 Samar bays anewManuel, Elmer (Concept & Information Group, Inc., 2023-12-02)The Bureau of Fisheries and Aquatic Resources on Friday reported the presence of red tide in Cambatutay Bay in Samar based on the latest examination of meat samples. The agency revealed that seawater samples collected in Cambatutay Bay have tested positive for red tide since 23 Oct 2023 but it was only on 30 November that authorities found the presence of toxins in shellfish meat.
- Red tide invades Samar bays anew(Concept & Information Group, Inc., 2023-10-07)The Bureau of Fisheries and Aquatic Resources on Friday revealed that the red tide phenomenon has recurred in three bays in Samar and Eastern Samar provinces, raising warning not to consume shellfish products in these areas. In a statement, the BFAR identified the bays as Irong-Irong Bay in Catbalogan City, Samar, coastal waters of Calbayog City, Samar; and Matarinao Bay in Eastern Samar province. The bloom of this toxic organism returned in Matarinao after three weeks of red tide absence and in Irong-Irong Bay after nine months. The coastal water of Calbayog City was included in the red tide watch in early 2022.
- 3 bays in Samar placed on red tide alertGabieta, Joey (Philippine Daily Inquirer, Inc., 2023-10-08)The Bureau of Fisheries and Aquatic Resources (BFAR) has warned the public not to consume shellfish products taken from three bays on Samar Island where the red tide toxin was detected. “To safeguard human lives, we are issuing this warning as a precautionary advice to the public to refrain from gathering, selling, and eating all types of shellfish and Acetes sp. locally known as ‘alamang’ or ‘hipon’ from these bays,” said BFAR in its local shellfish bulletin on Friday. According to BFAR, affected by the red tide toxin were the Irong-Irong Bay in Catbalogan City, Samar province
- Red tide remains on two bays(Concept & Information Group, Inc., 2022-12-28)The Bureau of Fisheries and Aquatic Resources revealed on Wednesday that red tide remains in Irong-Irong and San Pedro Bays in Samar province more than a month after the two bays turned positive for paralytic shellfish poisoning toxin. The BFAR — citing latest laboratory results — disclosed that the presence of toxic red tide in both seawater and shellfish meat is still beyond the regulatory limit.