Summary of Abstract Submission

Abstract Submission No. IO50-05-0012PresentationPoster

ANNUAL VARIABILITY OF ABSORPTION CHARACTERISTICS OF PHYTOPLANKTON, COLOURED DISSOLVED ORGANIC MATTER, DETRITUS ALONG THE SOUTHEASTERN ARABIAN SEA

Souda V P*1, Minu P 1, Shaju S S1, Ashraf P M1, B. Meenakumari2

1 ICAR-Central Institute of Fisheries Technology, Kochi, India
2 ICAR, Krishi Anusandhan Bhawan - II, New Delhi - 110 012, India, India

ABSTRACT :

Optical properties of natural water is an important factor for primary production, species composition of the phytoplankton, the heat budget of water bodies , for monitoring of water quality and interpretation of optical remote sensing data. Objective of this study is to measure the spatial and temporal variations of absorption spectra of optically active substances (phytoplankton, coloured dissolved organic matter and detritus) from estuary and off shore stations along Southeastern Arabian Sea since 2010. Absorption by phytoplankton at 440 nm (Aph (440)) has shown 2 peaks, during May- June and September- October in offshore stations while estuarine station give zigzag trend with high absorption coefficients greater than 1m-1. August 2010 and April 2014 have exceptionally high Aph (440) at two offshore stations. Absorption by detritus (Ad (440)) is very much comparable with Aph (440) spatially and seasonally. CDOM absorption at 440 nm (A¬CDOM (440)) showed less variation throughout the year and the absorption coefficients were <0.3m-1 in the offshore stations with a surprising hike during June 2010 in one station. Percentage of contribution to total absorption by each component is varied with time and station. In estuary, percentile contribution of phytoplankton and detritus is comparable. However, frequency is more for detritus. Phytoplankton frequency is raised along with CDOM in off shore stations. Absorption coefficients at 440 nm suggests particulate matter is more contributing towards the absorption than CDOM, out of detritus is the major fraction in this area with seasonal instability