The sperm whale, Physeter macrocephalus, was the most captured great whale in the Azores Archipelago by land-based whaling and nowadays is the most appealing species for whale watching, one of the archipelago's principal sources of tourism. Our objective was to compare number of sightings during whaling and whale watching activities. Our main question to address the possible impact of past whaling in recent whale watching is: does a present-day eco-tourist sight more or fewer sperm whales than a whaler could sight in the past? For that, a compilation of data resulting both from past whaling records and recent whale watching records was conducted. We obtained a total of 727 independent sightings of sperm whales during a total of 280 different days of sperm whaling between 1947 and 1973. A total of 1767 sperm whale sightings were made during 1133 days of whale watching activities, between 1997 and 2008. The sperm whale sighting per unit of effort average was significantly higher in the past (35.68) than in the present (12.06). In the Azores, captures over the decades greatly decreased the number of sperm whales in the region and twenty years after the end of sperm whaling a reduced number of recent sightings were found.

The present work uses daily checklist data from whale-watching to study basic aspects of cetacean ecology. Data in the Azores consists of a simple daily list of all species sighted by boats, with no additional information. The Azorean whale-watching activity is described and sources of variation related to data collection are debated. A data-set from one whale-watching company is analysed from 2001 to 2006, from April to October (tourism season). The first four years were used to describe frequencies in the area, and maximum and minimum regional sea surface temperatures for nineteen cetacean species, based on remote sensed data. Several species were present throughout the season, while for others, results indicate transient habits in the study area (Balaenopterids, Globicephala sp., Pseudorca crassidens, Orcinus orca and Hyperodoon ampullatus). Reservations were made relative to small size and evasive species. Sighting frequencies on temperature classes in 2005 and 2006 were used successfully in an experimental approach to study delphinid simpatry. The simplicity of data was overcome by the diversity of sighted species and the dimension of the time scale. Daily checklist is a low cost useful source of information mainly for large cetaceans that should keep being registered.

Johnstone Strait provides important summer habitat for the northern resident killer whales Orcinus orca of British Columbia. The site is also an active whale-watching area. A voluntary code of conduct requests that boats do not approach whales closer than 100 m to address perceived, rather than demonstrated, effects of boat traffic on killer whales. The purpose of the study was to test the relevance of this distance guideline. Relationships between boat traffic and whale behaviour were studied in 1995 and 1996 by shore-based theodolite tracking of 25 identifiable focal animals from the population of 209 whales. Individual killer whales were repeatedly tracked in the absence of boats and during approaches by a 5.2 m motorboat that paralleled each whale at 100 m. In addition, whales were tracked opportunistically, when no effort was made to manipulate boat traffic. Dive times, swim speeds, and surface-active behaviours such as breaching and spy-hopping were recorded. On average, male killer whales swam significantly faster than females. Whales responded to experimental approaches by adopting a less predictable path than observed during the preceding, no-boat period, although males and females used subtly different avoidance tactics. Females responded by swimming faster and increasing the angle between successive dives, whereas males maintained their speed and chose a smooth, but less direct, path. Canonical correlations between whale behaviour and vessel proximity are consistent with these conclusions, which suggest that weakening whale-watching guidelines, or not enforcing them, would result in higher levels of disturbance. High variability in whale behaviour underscores the importance of large sample size and extensive experimentation when assessing the impacts of human activity on killer whales.