Summary of Abstract Submission

Abstract Submission No. IO50-09-0042PresentationPoster

RELATIONSHIP BETWEEN THE DISTRIBUTIONS OF THE INDIAN OIL SARDINE (SARDINELLA LONGICEPS) AND CHLOROPHYLL CONCENTRATION IN THE NORTHERN INDIAN OCEAN

Maria Paul Thottan*1, Muhammad Shafeeque1, Trevor Platt2, Shubha Sathyendranath2, Grinson George1

1 Central Marine Fisheries Research Institute, Kochi-682018, India, India
2 PML, Prospect Place, Plymouth, Devon PL1 3DH, UK, UK

ABSTRACT :

The study evaluates the inter-annual fluctuations of S. longiceps populations in the Northern Indian Ocean using landings data from the FAO (Food and Agricultural Organisation) and the CMFRI (Central Marine Fisheries Research Institute, Kochi) databases. Maps of chlorophyll persistence on a yearly basis are created using satellite-derived chlorophyll data (Ocean Colour ┐Climate Change Initiative merged chlorophyll product, see www.oceancolour.org/) to identify regions in the ocean that show consistently high chlorophyll. The areal extent of the patches of high persistence are studied on a yearly basis. A comparison of the maps of persistence and the landings data established that the areas of high persistence correspond with areas from where high landings of sardines are recorded, especially in the upwelling region off Kerala coast. This relationship aided in understanding the inter-annual variability in sardine landings.Also, it is known that the survival of sardines recruited to the fishery the same year are highly dependent on the timing of blooms of specific species of phytoplankton (diatoms). Therefore, variability in landings is also compared with regional variations in micro-phytoplankton, using satellite algorithms for mapping phytoplankton size classes applied to the northern Indian Ocean. The role of additional factors such as upwelling intensity; sea-surface temperature; and river runoff patterns in modulating sardine landings was also evaluated.