Abstract:
Most data used to assess the distribution and abundance of whales are derived from scientific surveys that are designed carefully to minimize sources of variation and reduce the potential for bias. Gathering data in this fashion tends to be both time consuming and costly. Similar data, however, can be collected from platforms of opportunity, including commercial vessels, ecotourism operations and whale watch vessels. The goal of the current project was to make recommendations for data collection procedures aboard whale watch vessels so that such observations are as comparable as possible to data collected from scientific surveys. To accomplish this goal, a sightings data set was obtained from three whale watch companies on Stellwagen Bank, Massachusetts during summer 2007. Vessel and sightings data were obtained via GPS for the duration of whale watches out of Gloucester and Boston, Massachusetts. Whale sightings data were combined with vessel trackline data to calculate species-specific sightings-per-unit-effort (SPUE). These SPUE values were then compared to similar data derived from scientific surveys conducted in the same area. Additionally, sightings data from whale watches from 1994-2006 were analyzed for long-term trends in abundance and distribution. Whale watch vessels offer a large, valuable and largely untapped source of data on the distribution and abundance of whales. Whale watch data collected in a standardized fashion could contribute significantly to scientific and conservation efforts.
