BOAT-RELATED BEHAVIOURS OF CETACEANS AS A TOOL FOR THE DEVELOPMENT OF SPECIES-SPECIFIC WHALE WATCHING GUIDELINES
Off La Gomera (Canary Islands), a variety of cetacean species is abundant year round, making it possible to conduct comparative studies in the context of whale watching. From 01 September 1995 until 31 December 2001, behavioural interactions of cetaceans with whale watching boats were studied. Observations were made from whale watching vessels operating in the South of the island, using the behavioural sampling method. Eight behavioural events were defined as boat-related, including e.g. bowriding, approaches, scoutings, etc.. In addition, each encounter was categorized into one of four sighting categories: avoidance, no response, proximity and interaction. From a total of 2134 sightings, 268 sightings of six species (1680 samples) were analysed. The occurrence of boat-related behaviours differed significantly between species with the Atlantic spotted dolphin being the most interactive cetacean and beaked whales, on the other side of the spectrum, predominantly performing avoidance behaviours. Different species thus could be ranked according to their affinity to whale watching boats. In three species (bottlenose dolphin, pilot whale and Atlantic spotted dolphin), the frequency of boat-related behaviours differed in relation to behavioural states, with social and feeding related behaviours generally being more susceptible to disturbance than milling or travel. The results have been transformed into species-specific whale watching guidelines that acknowledge both the inter-species behavioural differences and the intra-species variation of responsiveness according to behavioural states. Other implications for a sustainably managed whale watching tourism include the production and distribution of educative material incorporating species-specific guidelines. Finally, a model of a marine protected area in the south of La Gomera specially designed for the regulation off whale watching activities is presented.