Glassy Sweeper

Photo: pleahy · © all rights reserved

Glassy sweepers school in enormous numbers inside El Planchón's hold and beneath the deck plates, their translucent copper bodies creating shifting walls of light that part and reunite around entering divers. They are nocturnal feeders that use the wreck as a daytime refuge, emerging after dark to feed on zooplankton in the water column above the reef. Their sheer abundance — thousands of individuals in a single hold — demonstrates how rapidly artificial structures can concentrate life and become productive focal points for the surrounding reef ecosystem.