Prof.

BIOLOGICAL CONSERVATION

Biological Conservation 118 (2004) 609–617 www.elsevier.com/locate/biocon

~ El Nino induced local extinction of coral reef bryozoan species from Northern Bahia, Brazil
Francisco Kelmo b a,b

, Martin J. Attrill

a,*

, Rilza C.T. Gomes c, Malcolm B. Jones

a

a School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK Brazilian Research Council, CNPq Brazil & Departamento de Zoologia, Instituto de Biologia, Universidade Federal da Bahia, Campus Universitrio de Ondina, Salvador, Bahia 40210-340, Brazil a c Regional Council for Protection of the Environment, CRA, Bahia, Brazil

Received 25 March 2003; received in revised form 25 September 2003; accepted 12 October 2003

Abstract The 1997–1998 El-Ni~o Southern Oscillation was the most severe on record and dramatically impacted corals worldwide. n However, the effect of this event on the associated community of reef organisms has received much less attention. The composition of the bryozoan assemblage from the coral reefs of Northern Bahia, Brazil were monitored annually from 1995 to 2000, allowing the investigation of the effects of this large-scale stressor on an important, diverse, yet understudied component of the coral reef system. Bryozoan samples (35 replicates/reef) were collected during April/May from four shallow bank reefs (10–40 m depth) located a few kilometres off the coast, together with measurements of the associated environmental parameters. Currently 157 species have been recorded from the study area, but significant reductions in density and diversity were apparent between pre- and post El-Ni~o n Southern Oscillation (ENSO) years, multivariate analysis denoting significant changes in assemblage composition. A total of 61 species were unrecorded following the 1997–1998 ENSO event (22 species from 1997; 25 further species from 1998 and 14 more from 1999). These included several species endemic to Brazil, suggesting that the