OCEANOGRAPHIC EVENTS AT NORTHERN BORNEO AND THEIR RELATIONSHIP TO HARMFUL ALGAL BLOOMS

The west coast of Northern Borneo is strongly influenced by Asian monsoon. Present research using the satellite ocean color (OC) remote sensing has identified some interesting oceanographic phenomena in this area that could be related to the harmful algal blooms (HAB). Occurrence of seasonal upwelling event was noticed off the northern tip of Borneo Island that could be related to the northeast monsoon wind. Harmful algal blooms by Pyrodinium bahamense var. compressum occurred since 1976. Subsequently, during December 2003, there was a report of new HAB by Cochlodinium polykrikoides in Northern Borneo. Analysis of OC images revealed that the Cochlodinium bloom had very high chlorophyll a signal and strong absorption characteristics. Results showed that the Baram River plume and upwelling at Northern Borneo were the source of nutrient for the Cochlodinium bloom in the offshore region. Ocean color images of 2004 showed that the bloom from Northern Borneo had crossed the Balabac Straits, reaching Palawan Island in Philippine. Due to the possibility of transboundary HAB problem, we propose a regional HAB monitoring network for an effective HAB management.