Abundance, composition and distribution of phytoplankton in Mindoro Strait

Abstract

Phytoplankton in Mindoro Strait, north of Palawan, were investigated from the samples taken last April-May 2007. Twenty stations were selected from over 40 stations surveyed. Samples were collected by filtering 50L of surface waters through 20 micrometer mesh plankton net using a 10L bucket. Phytoplankton assemblage was grouped into four major taxa. Diatoms dominated the area. It recorded the highest mean density of 314.9indivL-1. It was followed by blue green algae that noted a mean density of 165.69indivL-1. The next most abundant was dinoflagellates that recorded a mean density of 51.59indivL-1 and then the group of silicoflagellates. It recoded 35.69indivL-1 mean density. The top three species were <i>Trichodesmium, Thalasiothrix</i> and <i>Isthmia</i>. <i>Protoperidinium</i> represented the dinoflagellates among the top genera while <i>Eutintinnus</i> recorded the highest silicoflagellate. Higher concentrations were found in the midst of the oceanic region where water currents mainly pass. Overall abundance is lower than other nearby waters. This is maybe due to the effect of water currents.