Monitoring of Harmful Algal Bloom Toxins using Biotoxin Adsorption Tracking Technique Joshua Allen C. Canlas (a*), Michelle Marie T. Ochoa (a), and Lilibeth A. Savador-Reyes (a)
(a) The Marine Science Institute, College of Science, University of the Philippines-Diliman, Quezon City, Philippines
Abstract
Harmful algal blooms (HABs) are an increasing concern worldwide due to the significant threats they pose to marine ecosystems, human health, and local economies. The increasing occurrence and wider distribution of HAB events in the coastal waters of the Philippines highlight the need to strengthen monitoring efforts. Traditional monitoring activities that rely on shellfish tissue analysis and phytoplankton monitoring require substantial sampling effort and often provide only a snapshot of bloom conditions. In this study, the passive sampling method Biotoxin Adsorption Tracking Technique (BATT) was used to monitor dissolved HAB toxins. This method is based on the adsorption of toxins from surrounding waters onto polymeric resins, allowing compounds to accumulate over the deployment period until retrieval. Deployments were conducted across shellfish farms in the Philippines. Physicochemical parameters, phytoplankton, and shellfish samples were also collected to examine their relationship with the occurrence of toxins. Extracted samples were analyzed using high-performance liquid chromatography with fluorescence detector (HPLC-FLD) and Liquid Chromatography-Mass Spectrometry (LCMS) for the detection of toxins. This study enabled assessment of dissolved toxins and provided baseline information on toxin dynamics across different mariculture areas. Our findings serve as a foundation for strengthening early warning strategies and improving monitoring frameworks for shellfish safety.
