Impact of "el niño 1997-98" on larval settlement of some benthic marine invertebrates of independencia bay, pisco-Peru

The changes and magnitlJde of "El Niño" (EN) impact, on larval settlement mechanisms, of some benthic marine invertebrates, on artificial lilamentous substrates (nylon fiber) were monthly evaluated, lrom January 1996 to July 1998, in a 10m depth station located eastern of Independencia Island in Independencia Bay. During 1996, in "La Niña" (LN) warm phase, the number 01 species showed a peak in April and the density showed one in June, The total density and species number showed a firsl peak in March 1997, then, a second peak in February and July 1998 in the warm phase EN 1997-98, respectively. The bivalve Hiatel/a solida, turbellaria Notoplana sp., and gastropod Caecum chilense constituted a first group 01 species that intensilied its settlement during cold phase LN 1996. The second group intensified lts settlement in earlier warm phase of EN 1997-98, and its was conformed by the brachiopod Discinisca lamel/osa, echinoderm Ophiactís kr6yeri, and the bivalves 01 Mytilidae family. At the beginning 01 1998, a third group showed an intensiflcation 01 larval settlement in later phase 01 the EN 1997-98 warm phase, and il was lormed by the bivalve Argopec/en purpura/us, and a turrilorm gastropod, The appearance 01 recently settlemenl larvae 01 tropical species as the bivalve Pteria stema, and the gastropod Epitonium sp. appeared in later warm phase 01 ENSO 1997-98.