In contrast to temperate Harmful Algal Blooms (HABs), knowledge on the mechanisms driving tropical HABs are less well studied. The interaction of a seasonal temperature window, cysts (for certain species) and large-scale transport are some of the key processes in temperate HABs. In the Philippines, HABs occur not along long open coastlines, but in embayments that are highly influenced by run-off and stratification. These embayments are typically also the sites of cultured or wild harvest shellfish and other aquaculture activities. Sorsogon Bay in the northeastern Philippines has experienced prolonged shellfish-harvesting bans due to blooms by Pyrodinium bahamense var. compressum severely affecting the fisheries industry in this area, as well as leading to Paralytic Shellfish Poisoning illnesses and fatalities. A novel integrated model was developed that mechanistically captures the interactions between hydrodynamic conditions, nutrients, the life history (cells and cysts) of Pyrodinium, as well as the cultured shellfish within the bay and their ensuing toxicities due to ingestion of toxic Pyrodinium cells and cysts. This is the second model developed for HABs in the Philippines, and the first to integrate different components of Pyrodinium bloom dynamics. The model is modularly composed of a watershed nutrient and diffusion model, a 3D hydrodynamic model, a Pyrodinium population model and a shellfish toxin model. It was able to capture the observed temporal variations of Pyrodinium and shellfish toxicity. It was also able to represent some aspects of the spatial distribution in Sorsogon Bay though there were discrepancies. To explore the dynamics of blooms, the linkages between the bloom and decline of the Pyrodinium population with shellfish toxicity as affected by temperature, salinity and nutrients were investigated. Comparisons with field results showed the seasonality of blooms in Sorsogon Bay is driven by increased rainfall. The timing of these conditions is important in facilitating Pyrodinium excystment and reproduction. Model results showed as well the potential significance of shellfish grazing and dinoflagellate cell mortality in influencing the decline of the bloom, and toxicity levels. This approach is promising in helping to understand mechanisms for HABs more holistically, and the model can be further improved to provide more precise quantitative information.

与温带有害藻华（HABs）相反，对驱动热带HABs机理的知识研究较少。温带HAB的关键过程包括季节性温度窗口，囊肿（某些物种）和大规模运输的相互作用。在菲律宾，HAB不在漫长的开放海岸线上发生，而是在受径流和分层高度影响的隔离区内发生。这些巢穴通常也是养殖或野生收获贝类和其他水产养殖活动的地点。菲律宾东北部的索索贡湾（Sorsogon Bay）由于巴哈热霉（Pyrodinium bahamense var）的开花而经历了长时间的贝类捕捞禁令。压缩物严重影响了该地区的渔业，并导致麻痹性贝类中毒引起的疾病和死亡。建立了一个新颖的综合模型，该模型以机械方式捕获了水动力条件，养分，吡咯鎓的生活史（细胞和囊肿）以及海湾内的养殖贝类以及由于摄入有毒吡咯鎓细胞和囊肿而引起的毒性之间的相互作用。。这是在菲律宾针对HAB开发的第二个模型，也是第一个整合了Pyrodinium Bloom动态的不同组成部分的模型。该模型由分水岭的营养物和扩散模型，3D流体动力学模型，纵火场组成。种群模型和贝类毒素模型。它能够捕获所观察到的吡啶鎓和贝类毒性的时间变化。尽管存在差异，但它也能够代表索索贡湾空间分布的某些方面。为了探究水华的变化，研究了吡yr虫种群水华和衰落与贝类毒性受温度，盐度和养分的影响之间的联系。与实地结果的比较表明，索索贡湾（Sorsogon Bay）水华的季节性受降雨增加的驱动。这些条件的时机对促进吡啶鎓很重要囊肿和繁殖。模型结果还显示了贝类放牧和鞭毛藻细胞死亡率在影响水华下降和毒性水平方面的潜在意义。这种方法有望有助于从整体上更全面地了解HAB的机制，并且可以进一步改进该模型以提供更精确的定量信息。