5 th RiSCC Workshop Terra Antartica Reports 2005, 11, 57-62 Measuring Impacts on Soils by Human Activity in an Antarctic Special Protected Area P. TEJEDO 1 *, A. JUSTEL 2 , E. RICO 1 , J. BENAYAS 1 & A. QUESADA 3 1 Dpt. Ecología. Universidad Autónoma de Madrid. 28049 Madrid - Spain 2 Dpt. Matemáticas. Universidad Autónoma de Madrid. 28049 Madrid - Spain 3 Dpt. Biología. Universidad Autónoma de Madrid. 28049 Madrid - Spain *Corresponding author (pablo.tejedo@uam.es) Abstract - We report an environmental impact study, conducted by the LIMNOPOLAR expedition at Byers Peninsula, Livingston Island, South Shetland Islands, designated as Antarctic Special Protection Area No. 126 (SCAR, 2003). The main objective is to test the effectiveness of SCAR recommendations for minimizing the environmental impact of Antarctic expeditions, by using new tentative models for prediction and minimization of human activity impacts on Antarctic protected areas. We analyzed physical soil degradation on the camp surface and on the paths created by the researchers to access the sampling areas. Several quantitative and semiquantitative indicators are applied in the study, such as a penetration index, the apparent density (used to obtain the soil compression), or the use level. The first data collected show empirical evidence that even low human activity affects on the soil at the surface layer. INTRODUCTION The Byers Peninsula (62º 34’35” S, 61º 13’07” W) is the largest ice-free area in the South Shetland Islands (see Fig. 1), approximately 60,6 km 2 in extent, and one of the largest in the Antarctic Peninsula Region (Richard et al., 1994). It was originally designated as Antarctic Specially Protected Area (ASPA) Nº 10 through Recommendation IV-10 in 1966; in 1975, designation as an ASPA was terminated through Recommendation VIII-2 and redesignation as a Site of Special Scientific Interest (SSSI) Nº 6 was made through Recommendation VIII-4. Actually, it forms ASPA Nº 126, Livingston Island, South Shetland Islands (Harris, 2001). Values protected under the original designation included the diversity of plant and animal life, a substantial population of southern elephant seals (Mirounga leonina), small colonies of Antarctic fur seals (Arctocephalus gazella) and many invertebrates. In this way, the first detailed study of the terrestrial invertebrate fauna of the Byers Peninsula recorded fourteen micro-arthropod taxa (ten Acari, four collembola) and two Diptera (Convey et al., 1994). In addition, the outstanding scientific interest associated with such a large variety of plants and animals within a relatively small area (Cesari et al., 1999) and a special geological (Thomson & López-Martínez, 1996) and archaeological importance were considerate. With over 60 lakes, numerous freshwater pools and a great variety of often extensive streams, it is the most significant limnological site in the South Shetland Islands and perhaps the Antarctica Peninsula region. This place has not been subjected to significant levels of human disturbance (Bonner & Lewis, 1985).