Seasonal variability of water quality around patch reefs inside a lagoon from its interaction with outer sea

抄録

This work presents some field data analyses of two long-term sensor deployments, obtained from a coastal lagoon named “Puerto Galera,” in the Philippines. The lagoon ecosystems compose of coral reef patches, seagrass beds and mangroves. Due to the topographic features of the lagoon, the water exchange between it and the outer sea is limited by tidal driven currents. However, it is found that the exchange is maintained by the lagoon’s interaction with the outer sea through massive intrusions of outer sea water. There are two different proposed triggering mechanisms of the intrusion in the present study. The mechanisms are related to mainstream fluctuating strong tidal currents and the upwelling of deep cool water brought about by a prevailing east wind. The latter factor has strong seasonality and therefore affects the water quality of the inner-most part of the lagoon as evidenced by apparent seasonal differences in overall chlorophyll-a and dissolved oxygen concentrations.