CAN CHAETOGNATH FECAL PELLETS CONTRIBUTE SIGNIFICANTLY TO CARBON FLUX

The high abundance of chaetognaths and the relatively large size of their fecal pellets suggest that these planktonic predators might make a substantial contribution to vertical carbon flux in some regions. Although fecal pellets of the epipelagic species Parasagitta euneritica and the mesopelagic species Solidosagitta zetesios and Pseudosagitta maxima had high sinking speeds, 27 to 1313 m d-1, they sank 5 to 10 times more slowly than comparably sized herbivore fecal pellets. Chaetognath fecal pellets had densities around 1.035 g CM-3. Estimates using published pellet production rates and animal abundances, and measured pellet carbon content show that chaetognath fecal pellets could contribute modestly (4 to 6 %) to carbon flux in the euphotic zone and substantially (6 to 60 %) at depth.