Tour boats affect the activity patterns of bottlenose dolphins (Tursiops truncatus) in Bocas del Toro, Panama

Abstract

Bottlenose dolphins (Tursiops truncatus) of the Bocas del Toro archipelago are targeted by the largest boat-based cetacean watching operation in Panama. Tourism is concentrated in Dolphin Bay, home to a population of resident dolphins. Previous studies have shown that tour boats elicit short-term changes in dolphin behavior and communication; however, the relationship of these responses to the local population’s biology and ecology is unclear. Studying the effects of tour boats on dolphin activity patterns and behavior can provide information about the biological significance of these responses. Here, we investigated the effects of tour boat activity on bottlenose dolphin activity patterns in Bocas del Toro, Panama over 10 weeks in 2014. Markov chain models were used to assess the effect of tour boats on dolphin behavioral transition probabilities in both control and impact scenarios. Effect of tour boat interactions was quantified by comparing transition probabilities of control and impact chains. Data were also used to construct dolphin activity budgets. Markov chain analysis revealed that in the presence of tour boats, dolphins were less likely to stay socializing and were more likely to begin traveling, and less likely to begin foraging while traveling. Additionally, activity budgets for foraging decreased and traveling increased as an effect of tour boat presence. These behavioral responses are likely to have energetic costs for individuals which may ultimately result in population-level impacts. Boat operator compliance with Panamanian whale watching regulations is urgently needed to minimize potential long-term impacts on this small, genetically distinct population and to ensure the future viability of the local tourism industry.

Cashing in on Spinners: Revenue Estimates of Wild Dolphin-Swim Tourism in the Hawaiian Islands

“…Common-pool resources such as dolphins can easily become overly exploited through tourism if not managed appropriately (Heenehan et al, 2015). If growth continues without any additional protection or enforcement serious impacts will be placed on the dolphin population, leading to possible decline of the population or shift of habitat (Tyne et al, 2018;Kassamali-Fox et al, 2020). This would not only be a worst-case scenario for the genetically distinct Hawaiian spinner dolphin population, but would potentially crash the dolphin tourism industry as well, adding to the long list of species that have succumbed to the tragedy of the commons.…”

Tourist Knowledge, Pro-Conservation Intentions, and Tourist Concern for the Impacts of Whale-Watching in Las Perlas Archipelago, Panama

“…However, there are growing concerns about the negative impacts the whale-watching industry may exert on cetacean populations (Orams, 2004;Parsons, 2012;Cressey, 2014;Sitar et al, 2016;Kassamali-Fox et al, 2020). Direct impacts, such as vessel collisions can injure whales (Nielson et al, 2012;Guzman et al, 2013).…”

Dolphin Watching and Compliance to Guidelines Affect Spinner Dolphins’ (Stenella longirostris) Behaviour in Reunion Island

“…Identifying and quantifying the impacts of cetacean watching have become a growing concern for conservation management and are the prerequisite to actioning a reduction in any short- and long-term consequences it may have on cetaceans [ 10 , 11 , 12 ]. Changes in cetacean behavioural states are easily measured in the field and are frequently used to evaluate short-term disturbances resulting from dolphin-watching vessels on the targeted species [ 11 , 12 , 13 , 14 , 15 , 16 ]. Dolphins react to the vessels’ presence by showing short-term antipredator behavioural responses, such as forming tighter groups [ 10 , 17 , 18 ], altering their swimming speed and direction [ 18 ] or displaying more erratic surface movements [ 13 , 15 , 19 ].…”

“…Dolphins often display avoidance reactions before a vessel arrives, as they can detect the underwater noise produced by engines from a distance [ 18 , 19 , 21 , 22 , 23 ]. Avoidance responses can include increasing the depth and duration of dives [ 18 , 19 , 21 , 24 ] and reducing socialisation such as resting and feeding activities with conspecifics in favour of travelling [ 11 , 14 , 16 , 20 ]. Such alterations in behavioural budgets have great energetic costs for the dolphins, increasing their physical demand [ 11 , 13 , 19 , 21 ], which over the long term can contribute to reduced reproductive success and population decline [ 10 , 21 , 25 , 26 , 27 ].…”