Jelly-falls are primarily made up of the decaying corpses of Cnidaria and Thaliacea (Pyrosomida, Doliolida, and Salpida). Several circumstances can trigger the death of gelatinous organisms which would cause them to sink. These include high levels of primary production that can clog the feeding apparatuses of the organisms, a sudden temperature change, when an old bloom runs out of food, when predators damage the bodies of the jellies, and parasitism. In general, however, jelly-falls are linked to jelly-blooms and primary production, with over 75% of the jelly falls in subpolar and temperate regions occurring after spring blooms, and over 25% of the jelly-falls in the tropics occurring after upwelling events.
With global climates shifting towards creating warmer and more acidic oceans, conditions not favored by non-resilient species, jellies are likely to grow in population sizes. Eutrophic areas and dead zones can become jelly hot spots with substantial blooms. As the climate changes and ocean waters warm, jelly blooms become more prolific and the transport of jelly-carbon to the lower ocean increases. With a possible slowing of the classic biological pump, the transport of carbon and nutrients to the deep sea through jelly-falls may become more and more important to deep ocean.