Phytoplankton chlorophyll-breakdown pathway: Implication in ecosystem assessment.

摘要: The chlorophyll-breakdown to pheophorbide is determined by biotic factors such as grazing (via chlorophyllide) or senescence pheophytin). So far, much of the information on available from sediments, but water column limited. This study addressed chlorophyll-breakdown-pathways (Chl-BP) a seasonal basis eight major ports (18-30 stations/port) representing freshwater, estuarine, and marine ecosystems. distribution chlorophyll its breakdown fractions (pheophytin, pheophorbide) exhibited distinct spatial variations. Fresh-water (except Haldia-port) estuarine are characterized high-biomass, high-pheophytin, low-pheophorbide, whereas marine-ports low-biomass Mangalore-port), low-pheophytin, high-pheophorbide. Pheophytin were biomass independent dependent, respectively. pheophorbide: pheophytin ratio indicated potential proxy for determining dominant pathway, i.e., herbivory (>1) not (<1). However, CHl-BP taxa-specific grazer's feeding habits. ratios apparent differences between different ecosystems, higher in (up 11.2) followed 0.9) freshwater 0.4; except Haldia) systems. diatoms (preferred grazer diet) contribution total phytoplankton was more low high suggested prevalence via mode, We proposed that scaling will have implications ballast management - BWM (ballast tank conditions (eg. dark) during voyages, post-voyage discharge including treated using approved systems, nature ports, point) algal bloom research (e.g. understanding fate control measures).