Behavioural responses of spinner dolphins to human interactions

Abstract

There is increasing evidence that whale and dolphin watching activities have detrimental effects on targeted cetacean populations. In Egypt, spinner dolphins regularly occur in the resting areas of Samadai, Satayah and Qubbat'Isa reefs. In-water human interactions with dolphins are regulated with a time-area closure system at Samadai, unregulated at Satayah and non-existent at Qubbat'Isa. This provided an ideal experimental setting to advance our understanding of the effects of tourism on a species highly sensitive to disturbances. Our study confirmed that the intensity and duration of interactions, and therefore, dolphin exposure to tourism, differed among the study sites. Compared with the Qubbat'Isa control site, behavioural reactions to boats and swimmers at the two tourism sites suggested that dolphin rest was disrupted, especially around the middle of the day and especially at Satayah, where dolphin tourism is unregulated. Our results indicate also that the dolphin protection measures at Samadai reduce the level of disturbance. We recommend that similar measures be implemented at other dolphin tourism locations, and that no new operations be initiated until the long-term impacts on dolphin populations are better understood. Our experience emphasizes the need to adopt precautionary approaches in research and management of whale and dolphin watching.

Population ecology and the management of whale watching operations on a data‐deficient dolphin population

“…This study advanced previous knowledge of the potential disruptive nature of WW on this population (Fumagalli et al, ) by showing that operations target‐sensitive segments in a habitat regularly used as a resting and calving ground. We strongly recommend intervention to mitigate disturbance of the population by (a) reducing interactions and exposure rate at Satayah and other resting sites with a time–area closure plan, similar to the one successfully implemented at Samadai Reef, that would best suit spatially and temporally constrained populations (Lusseau, ); (b) supporting further research to test the patterns in our results and to monitor population‐level impacts; and (c) devising ways to integrate site‐specific management efforts in a fully developed regional network for the protection of the species.…”

“…This species is particularly vulnerable to WW activities (Johnston, ; Tyne et al, ) because of its exposure in critical resting areas (Norris et al, ), sensitivity to associated disturbances (Courbis & Timmel, ; Fumagalli et al, ; Heenehan et al, ; Lammers, ; Timmel et al, ), and lack of resilience to disruptions (Tyne et al, ). In the Egyptian Red Sea, the rapid growth of a commercial WW industry at Samadai Reef in the early 2000s (O'Connor et al, ) generated serious concern among the local stakeholders, resulting in the prompt implementation of a precautionary, site‐specific management plan (Notarbartolo di Sciara et al, ), and dedicated research efforts (Cesario, ; De Montpellier, ; Fumagalli, ; Fumagalli et al, ; Notarbartolo di Sciara et al, ; Ponnampalam, ; Shawky & Afifi, ; Shawky et al, ). The management plan in Samadai Reef substantially reduces behavioral disruptions caused by human interactions, which are instead documented as pervasive and severe at the nonmanaged resting area at Satayah Reef (Fumagalli et al, ).…”

“…In the Egyptian Red Sea, the rapid growth of a commercial WW industry at Samadai Reef in the early 2000s (O'Connor et al, ) generated serious concern among the local stakeholders, resulting in the prompt implementation of a precautionary, site‐specific management plan (Notarbartolo di Sciara et al, ), and dedicated research efforts (Cesario, ; De Montpellier, ; Fumagalli, ; Fumagalli et al, ; Notarbartolo di Sciara et al, ; Ponnampalam, ; Shawky & Afifi, ; Shawky et al, ). The management plan in Samadai Reef substantially reduces behavioral disruptions caused by human interactions, which are instead documented as pervasive and severe at the nonmanaged resting area at Satayah Reef (Fumagalli et al, ). There, in 2009, tourism was reported as “opportunistic” with a potential for further development (O'Connor et al, ).…”

“…Whale watching (WW), or the viewing of free-ranging cetacean in the wild (Parsons et al, 2006), is a popular activity worldwide (Hoyt, 2018). WW operations have associated socio-ecological benefits (Corkeron, 2004;Curtin, 2009;Orams, Forestell, & Spring, 2014), but can detrimentally affect the behavior of the target animals (Christiansen, Lusseau, Stensland, & Berggren, 2010;Fumagalli et al, 2018;Lundquist, Gemmell, & Würsig, 2012;Lusseau, 2003;Stockin et al, 2008) and can lead to long-term population-level effects, including displacement and decline (Bejder et al, 2006;Lusseau & Bejder, 2007). International organizations concerned with WW are now taking a precautionary stance and urging the adoption of appropriate mitigation measures (Convention on Migratory Species, 2017), while encouraging research on robust predictive models (e.g., LaWE, International Whaling Commission, 2009;MAWI, International Whaling Commission, 2018).…”

“…This research presents a case study on a reef-associated population of spinner dolphin (Stenella longirostris) in the Egyptian Red Sea (Figure 1). This species is particularly vulnerable to WW activities (Johnston, 2014;Tyne et al, 2017) because of its exposure in critical resting areas (Norris et al, 1994), sensitivity to associated disturbances (Courbis & Timmel, 2009;Fumagalli et al, 2018;Heenehan et al, 2017;Lammers, 2004;Timmel et al, 2008), and lack of resilience to disruptions . In the Egyptian Red Sea, the rapid growth of a commercial WW industry at Samadai Reef in the early 2000s (O'Connor et al, 2009) generated serious concern among the local stakeholders, resulting in the prompt implementation of a precautionary, site-specific management plan (Notarbartolo di Sciara et al, 2009), and dedicated research efforts (Cesario, 2017;De Montpellier, 2007;Fumagalli, 2016;Fumagalli et al, 2018;Notarbartolo di Sciara et al, 2009;Ponnampalam, 2005;Shawky & Afifi, 2008;Shawky et al, 2015).…”