DISTRIBUTION, SIZE AND BACTERIAL-COLONIZATION OF TRANSPARENT EXOPOLYMER PARTICLES (TEP) IN THE OCEAN

The distribution, abundance, and size spectra of transparent exopolyme r particles (TEP) generated from excretion products of phytoplankton w ere investigated. TEP was found at all stations studied, but abundance and total quantity of TEP varied by 4 orders of magnitude among coast al, slope and oceanic environments. Abundance and size distributions o f TEP appeared to be related to plankton composition. Abundance tended to be higher in coastal and shallow waters compared to oceanic and de ep waters respectively. The average size of TEP was appreciably larger at stations where diatoms dominated phytoplankton. Size distributions of TEP generally followed a power-law function, except when aggregati on dominated interaction of particles. The type of size distribution o f TEP may allow us to predict the tendency of a plankton community to aggregate. General differences in the shape of size spectra of TEP ind icate TEP generated by diatoms to be stickier and more fractal compare d to TEP generated by non-diatom plankton. All TEP were colonized by b acteria, but no correlation was found between numbers of attached bact eria on individual TEP and the respective size of TEP. Bacteria densit y on TEP, however, decreased with increasing size of TEP exponentially . Between 2 and 25% of the total bacterial population were attached to TEP. Total number of bacteria were not correlated with total quantity of TEP, suggesting that no simple overall relationship exists between TEP and bacteria.