Evidence of Macroalgal Colonization on Newly Ice-Free Areas following Glacial Retreat in Potter Cove (South Shetland Islands), Antarctica

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

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2013

1932-6203

Climate warming has been related to glacial retreat along the Western Antarctic Peninsula. Over the last years, a visiblemelting of Fourcade Glacier (Potter Cove, South Shetland Islands) has exposed newly ice-free hard bottom areas availablefor benthic colonization. However, ice melting produces a reduction of light penetration due to an increase of sedimentinput and higher ice impact. Seventeen years ago, the coastal sites close to the glacier cliffs were devoid of macroalgae. Arethe newly ice-free areas suitable for macroalgal colonization? To tackle this question, underwater video transects wereperformed at six newly ice-free areas with different degree of glacial influence. Macroalgae were found in all sites, even inclose proximity to the retreating glacier. We can show that: 1. The complexity of the macroalgal community is positivelycorrelated to the elapsed time from the ice retreat, 2. Algae development depends on the optical conditions and thesediment input in the water column; some species are limited by light availability, 3. Macroalgal colonization is negativelyaffected by the ice disturbance, 4. The colonization is determined by the size and type of substrate and by the slope of thebottom. As macroalgae are probably one of the main energy sources for the benthos, an expansion of the macroalgaldistribution can be expected to affect the matter and energy fluxes in Potter Cove ecosystem.