Unusual blooms of Noctiluca miliaris in the Arabian Sea during the Northeast Monsoon
Abstract
Until the late 1990's Noctiluca miliaris Suriray (synonym Noctiluca scintillans Macartney), a large heterotrophic dinoflagellate was a minor component of phytoplankton populations in the Arabian Sea, appearing in bloom form only sporadically in coastal regions predisposed to upwelling and deep slope water intrusions during the Southwest monsoon. Since then however, N. miralis blooms have increased in frequency and intensity, but with the majority of blooms being observed following the Northeast monsoon (NEM) and at times, in association with the well known blooms of the diazotroph Trichodesmium sp. Microscopy and chemotaxonomy from HPLC analysis of phytoplankton pigments undertaken in 2003-2004. as well as satellite ocean color data suggest that N. miralis blooms are becoming more intense and widespread in the Arabian Sea. Large blooms of these organisms have started appearing in the Gulf of Oman and off the coast of Oman. This study uses recent, merged SeaWiFS and MODIS-Aqua ocean color datasets to investigate the temporal evolution and spatial extent of these taxonomically validated blooms. Aqua-MODIS SST and altimetry data suggest that mesoscale eddies that populate the Western Arabian Sea during the NEM may be playing a significant role in the production and dispersal of these blooms from the Gulf of Oman into the Central Arabian Sea.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2007
- Bibcode:
- 2007AGUSMOS34A..07G
- Keywords:
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- 4223 Descriptive and regional oceanography;
- 4275 Remote sensing and electromagnetic processes (0689;
- 2487;
- 3285;
- 4455;
- 6934);
- 4858 Population dynamics and ecology