Number of southern right whales Eubalaena australis and population trend in the neighbourhood of Península Valdés during the period 1999-2011 by means of aerial and boat surveys

ENRIQUE A. CRESPO; SUSANA N. PEDRAZA; SILVANA L. DANS; MARIANO A. COSCARELLA; GUILLERMO M. SVENDSEN; DEGRATI MARIANA

Buenos Aires

Workshop; IWC SOUTHERN RIGHT WHALE ASSESSMENT WORKSHOP; 2011

Based on the need of having a quick and cheap methodology to estimate relative abundance and population trend we developed a method based on direct counts of whales on the coastal zone. Therefore, the objectives of this work were: 1) to develop the method, 2) to estimate relative abundance in the monitoring zone every year, 3) to estimate rate of increase, 4) to document changes in the distribution of whales through time, and 5) to study the seasonal pattern of arriving and departing of whales in the area. Given that not all the whales are located in the coastal zone, additional objectives were: 6) to estimate density out of the coastal zone, 7) to have an idea of the total number of whales circulating in the area every year.Based on the need of having a quick and cheap methodology to estimate relative abundance and population trend we developed a method based on direct counts of whales on the coastal zone. Therefore, the objectives of this work were: 1) to develop the method, 2) to estimate relative abundance in the monitoring zone every year, 3) to estimate rate of increase, 4) to document changes in the distribution of whales through time, and 5) to study the seasonal pattern of arriving and departing of whales in the area. Given that not all the whales are located in the coastal zone, additional objectives were: 6) to estimate density out of the coastal zone, 7) to have an idea of the total number of whales circulating in the area every year.