The results also suggested that sperm whales might need time to recover from a NSE before engaging in a new foraging dive. Interestingly, the duration of the foraging dive was independent of water depth or the previous surface period (i.e., duration and presence of whalewatching vessels). This means that the occurrence of NSE led to an increase in surface time that was not followed by longer foraging dives. Sperm whales have a low cost of living, low diet quality, and one of the highest diving efficiencies for a diving animal. Their foraging strategies are related to their specific energetic requirements and the behaviour of their prey; therefore, performing longer dives might not be worth the effort. This means that the additional time spent at the surface represents time that will no longer be available for other activities, such as foraging or resting.
The risk-disturbance hypothesis argues that animals perceive human disturbance in a similar manner to nonlethal predation risk, and thus an animal’s response should follow the same economic principles as if encountering a predator, as observed, for example, in elk and birds. Sperm whales do not seem to follow this principle, exhibiting various acoustic and behavioural reactions (and sometimes no reaction at all) to natural and anthropogenic underwater sounds, to the presence of whalewatching platforms and to killer whale presence/sounds (i.e., predators) and attacks. Also, it appears that sperm whales may react less to the presence of tour vessels than other cetacean species, with recent studies only reporting changes in the inter-breath intervals.
This low level of response has also been reported for sperm whales in other areas, such as off Kaikoura, in New Zealand and off the Azores in Portugal. However, the level of exposure should also be considered. In Andenes, under the current level of exposure, the observed short-term effects likely have no biological consequences for the individuals. However, larger number of whalewatching vessels could increase the exposure levels and some individuals may be targeted several times a day by more than one whalewatching vessel, likely increasing the occurrence of the observed short-term effects and potentially leading to long-term consequences.
Near surface events are an easy to identify indicator of likely disturbance, and thus they should be included in regulations or protocols for whalewatching targeting sperm whales. Individuals that show signs of disturbance should be avoided, minimizing or preventing the adverse consequences of cumulative effects. The use of hydrophones as well as increased collaboration between companies, especially with the use of land-based stations to detect whales, can help avoid vessels targeting the same individual. Understanding the occurrence of NSE may well help explain, and avoid, the circumstances under which obvious and subtle responses occur in the presence of whalewatching vessels or other potential stressors.
Ecotourism and you
The International Ecotourism Society defines ecotourism as “Responsible travel to natural areas that conserves the environment and improves the well-being of local people.” (TIES, 1990). Ecotourism is wildlife tourism, such as whalewatching, that minimises human impact, while building environmental and cultural awareness, providing financial benefits for conservation.
Whalewatching trips are offered in almost every country where cetaceans (including river dolphins) are present. In the era of internet and social media, it is easy for you to find information in advance about the company you plan to use to provide you with an experience of a lifetime. Many countries have developed or adopted whalewatching guidelines and best practices (also see IWC) to minimise the impact of the activity. These provide recommendations on the behaviour of the vessels around the animals as well as the number of boats that can be targeting a given animal or group of animals at the same time. Do not hesitate to ask your guide or captain to show you the guidelines they follow and how they apply and comply with them. Your satisfaction depends on it, and remember that the trip has to be good for you and for the animals too!
As a matter of fact, your satisfaction will not be the result of how close you are to the animals but of the overall experience around wild animals. Each trip is different, and as we interrupt their natural behaviour when we approach them, they will not always be willing to interact with us. A good guide and a responsible captain are key for an exceptional experience, both for you and the animals. And how much better if you can learn about the whales’ biology, behaviour, and conservation concerns, as well as about area while helping local communities? Be an ecotourist!