Effects of anthropogenic activities on the distribution, abundance and behavior of southern right whales in Golfo Nuevo, Chubut
M.B. Argüelles
The southern right whale is a protected species, one of four to be declared a National Natural Monument in Argentina. It is a cultural icon and an opportunity for sustainable ecotourism economies. Understanding the effects of human activities on these whale populations is therefore a priority for their conservation and management. This project compared whale abundance, distribution and behavior between a marine protected area (Doradillo), a large urban coastal area with port activity, recreation and tourism (Puerto Madryn), and a small rural coastal area where boat-based whale watching is concentrated (Puerto Pirámides).
Given that southern right whales use the study area as seasonal calving grounds, the whales were present at Doradillo and Puerto Pirámides (protected and whale-watching areas, respectively) as expected: numbers were low in June, building steadily through the August-October peak season and then declining again. At Puerto Madryn (urban port), whale abundance was lower and more erratic over the course of the season. Mother-calf pairs represented almost 90% of the whales using Doradillo, while over 60% of whales near Puerto Pirámides were solitary individuals. This may suggest that many mother-calf pairs are finding refuge in the fully protected marine reserve area. However, approximately 50% of whales sighted near Puerto Madryn were also mother-calf pairs. Whale distributions were overlaid with sightings of boat traffic and records from the Puerto Madryn Port Authority, illustrating that the whales in the Puerto Madryn area overlap heavily with vessels both in space and time (peak vessel traffic was in October). While there is a shipping lane designated for vessels coming into the larger gulf region, there are no restrictions in the immediate bay of Puerto Madryn and collisions with whales are not uncommon. This study provides specific whale distribution information that was presented to the Port Authorities and that will hopefully inform the management of vessel traffic in areas frequented by whales. ($8,082)