Macroalgal communities on new ice-free areas in Potter Cove, South Shetland, Antarctica

DOLORES DEREGIBUS; MARIA LILIANA QUARTINO; GABRIELA LAURA CAMPANA; GUSTAVO EDGAR JUAN LATORRE

Oslo

Congreso; International Polar Year Oslo Scientific Meeting 2010; 2010

Environmental changes associated with the rapid warming have recently been detected, both on land and in the sea, and these changes will have a strong influence on the structure and function of marine communities in the region (Smale and Barnes 2008). Climate warming has specially been associated to retreating of ice fronts and increased melt water production in the Westerrn Antarctic Peninsula (WAP) (Cook et al., 2005). An effect of glacial retreat along WAP is the opening of newly ice-free areas for benthic colonization and also alter the water column properties increasing sediment input and salinity changes and ice disturbance processes (Schloss et al., 2008; Smale and Barnes, 2008). One notorious example of the warming changing is Potter Cove (62º 14? S, 58º 38? W), a tributary inlet close to the entrance of Maxwell Bay, one of the two big fjords at King George Island. During the last 18 years an effort has been performed to achieve a deeper knowledge of the benthic system of this Cove including studies of the macroalgae communities. Over the last years a visible melting in Fourcade glaciar is observed showing several rock free ice areas. In 1993 the sublittoral vegetation of the Cove was documented by subaquatic video transects providing a valuable information of the vertical distribution at the different sites of the cove (Kloser et al 1996). Soft bottom of the inner cove was devoid of macroalgae and notable exceptions were boulders and stones of moraine deposits, which occur in front of glacier cliffs north of the cove. In this new warming scenario moraine deposits provide a hard bottom suitable for the early algae colonization. Since December 2007 up to August 2008 fourteen underwater video transects were taken in six different new free ice areas. The aim of the study is to analyze the vertical and spatial distribution of the macroalgae in the new free ice areas along the time.