Aerial surveys of southern right whales Eubalaena australis in the neighbourhood of Península Valdés during the period 1999-2008

CRESPO, ENRIQUE ALBERTO; PEDRAZA, SUSANA NOEMÍ; DANS, SIVANA LAURA; COSCARELLA, MARIANO ALBERTO; SVENDSEN, GUILLERMO

Puerto Madryn

Workshop; SOUTHERN RIGHT WHALE DIE-OFF WORKSHOP; 2010

International Whaling Commission

this programme is designed to monitor trends in numbers, seasonal changes within and through years, changes in distribution and seasonal patterns of arrival and departure of whales in the area. Twelve aerial surveys were conducted between May 1999-December 2000 and 29 between October 2004-November 2008, flying parallel to the coastline at an altitude of 500 feet with a strip width of 1500 m, from the mouth of Chubut River (42°30´) to Puerto Lobos (42°) for a total coastal strip length of 620 km. Whales were classified as: a) mother-calf pairs, b) solitary individuals or c) breeding groups considered as one female and n-1 males. Around 95% of the whales were within the strip and the number of whales in the strip can be considered a measure of relative abundance. The interval between flights ranged from 45-50 days