The Use of Data from a Platform of Opportunity (Whale Watching) to Study Coastal Cetaceans On the Southwest Coast of South Africa

Abstract

Effective conservation management requires information on wildlife abundance and distribution. Platforms of opportunity, including whale-watching vessels (WWV), can provide inexpensive and valuable information particularly in data deficient areas. This study analyzed over 5,500 cetacean encounters from more than 2,500 trips over 10 years by a WWV in the Western Cape, South Africa. Results were twofold: 1) providing spatial and temporal distribution patterns of the five main cetacean species for the area (southern right, humpback, and Bryde's whales, Indo-Pacific bottlenose and Indian Ocean humpback dolphins) and the first long-term, year-round data for this area; 2) showing that regularly recorded opportunistic encounters from a WWV constitute an important source of baseline information. Caveats and limitations of data from WWV are discussed and advice regarding data collection from platforms of opportunity is provided. Particularly, the lack of effort data and of clearly defined behavioral categories is emphasized and standardization of guidelines for data collection methods worldwide is suggested.