Meeting Abstract

P3.62  Sunday, Jan. 6  Abundance and distribution of echninoderms in nearshore hard-bottom habitats near Anvers Island, Antarctic Peninsula MCCLINTOCK,, J.B*; WHITE, BA; AMSLER, CD; MAH, CL; AMSLER, MO; WHITE, S; QUETIN, LB; ROSS, RM; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; National Museum of Natural History; Univ. of Alabama at Birmingham; Univ. of California, Santa Barbara; Univ. of California, Santa Barbara; Univ. of California, Santa Barbara mcclinto@uab.edu

Echinoderms are well represented in nearshore hard-bottom habitats along the Antarctic Peninsula where they are presumably important contributors to benthic productivity, carbon flow, and determinants of community structure. Remarkably, very few quantititive studies exist on their patterns of abundance. The present study assesses the densities of echinoderms at shallow depths (2-15 m) at five sampling sites near Anvers Island on the central western Antarctica Peninsula. Four of five classes of the Echinodermata were present. Mean total echinoderm densities were high (34.9 individuals per meter square) and ranged from 21.9 individuals per meter square for asteroids and 2.7 individuals per meter square for holothuroids. With the exception of a positive relationship between the abundance of the regular sea urchin Sterechinus neumayeri and the biomass of the brown alga Himanthothallus grandifolius, no significant relationships were found between the abundance of asteroids, ophiuroids, or holothuroids and two species of brown algae or three algal ecotypes. The present study indicates nearshore hard-bottom echinoderms along the Antarctic Peninsula are important in the carbon cycle. Moreover, their inherent vulnerability to ocean acidification and climate warming in a rapidly changing environment makes these baseline data important metrics for future comparison.