 Members of the genus "Synechococcus" contribute ~25% to photosynthetic primary productivity in the ocean, having significant bottom-up effect on higher trophic levels.The dissolved organic matter (DOM) released from viral lysis by cyanophages can be shunted into the microbial loop where it is recycled or rejected by heterotrophic bacteria to form recalcitrant matter that is eventually buried in sediment.This is an important step in atmospheric carbon sequestration, commonly referred to as the biological pump, and maintenance of other biogeochemical cycles.