Registros y abundancia relativa de mamíferos marinos durante el crucero oceanográfico insular B/I Orión (CO-II-2000) en las Islas Galápagos y sus alrededores

Abstract

En el presente trabajo se dan a conocer los resultados de las observaciones de campo de mamíferos marinos realizado en el segundo semestre del año 2000 en las Islas Galápagos y sus alrededores, durante un crucero oceanográfico del Instituto Oceanográfico de la Armada del Ecuador.

A total of 32 species of marine mammals have been recorded waters of the Galapagos Islands (including two species of sea lions and a sigthing of the southamerican sea lion, Otaria flavescens). This paper presents records of marine mammals collected during an oceanographic cruise (B/I ORION-CO-II-2000) around Galapagos Islands. The cruise was carried out between transects 089° W and 092° W from August 1 to August 16 (2000); along 2557 nautical miles. The work also included observations made from eighteen oceanographic stations. A total of 637 individuals and 5 species of marine mammals were recorded. In order of abundance these were: Common dolphins, Delphinus delphis and Pantropical spotted dolphins, Stenella atenuatta (n=400); Galapagos sea lions, Zalophus wollebaeki (n=130); Bottlenose dolphins, Tursiops truncatus (n=106); and Bryde's whales, Balaenoptera edeni (n=1). The relative abundance was 0.25 ind./ nautical mile and the daily abundance was 39,81 ind./ day. Most of the individuals were recorded between 00° 30' N; 92° 00 W (n=203) and 00° 10' S; 91° 34 W (n=204). Individuals were sighted primarily in areas considered to be high productivity such as upwelling areas.