Planktivorous damselfish support significant nitrogen and phosphorus fluxes to Mediterranean reefs

In an ecosystem, which is apparently very limited in N and P, the planktivorous damselfish Chromis chromis acts as an important vector in transferring nutrients from the pelagic into littoral food webs. C. chromis are more efficient at absorbing nutrients from their diet than herbivorous Pomacentridae, and excrete more faeces in the spring when their plankton food is more abundant. Faeces released in the water column sink rapidly to the substratum and are consumed by herbivorous and omnivorous fish. Faeces released into night-shelters are rapidly consumed by invertebrate detritivores, and particularly mobile scavengers, such as shrimps and hermit crabs. Night-time accrual of Chromis faeces represents a very important flux of N and P. Such fluxes are predictable in time and space and have thus far been ignored in studies of the western Mediterranean.