Monitoring tourism schooners observing estuarine dolphins (<i>Sotalia guianensis</i>) in the Estuarine Complex of Cananéia, south‐east Brazil

Filla, Gislaine de Fatima; Monteiro‐Filho, Emygdio L. A.

doi:10.1002/aqc.1034

Cited by 27 publications

(19 citation statements)

References 20 publications

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“…; Bejder et al 2006a), appear to avoid dolphin-watching boats at similar approach distances. This was also the case for estuarine dolphins (Sotalia guianensis) in south-eastern Brazil (Filla and Monteiro-Filho 2009). Bottlenose dolphins (T. aduncus and truncatus) in other areas show movement away from the source of disturbance within 100 m (Nowacek et al 2001;Lemon et al 2006).…”

Section: Discussionmentioning

confidence: 56%

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

2011

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Context. Potential impacts of human disturbance on animal populations can be measured as behavioural responses and may affect the survival and fecundity of animals. In areas where human-wildlife interactions occur, conservation management needs to be in place to secure both a viable tourism industry and the sustainability of the targeted species.Aims. We sought to evaluate whether different approach distances by boat have effects on the behaviour and group cohesion of dolphins that are targeted by Australia's largest dolphin-watching industry.Methods. The effects of different approach distances of boats on the behavioural states of dolphins, group dispersal and direction of movement were investigated in this area by controlled boat experiments conducted between August 2008 and December 2009.Key results. Results showed that there was significantly less feeding when boats approached dolphin groups to a distance of 50 m than when they did to a distance of 150 m, or with controlled approaches. Resting was also observed significantly less when boats approached to a distance of 50 m than when they approached to a distance of 150 m. The dispersal of dolphin groups was significantly tighter (less dispersed) when boats approached to 50 m than that with 150-m-distance or controlled approaches. Furthermore, the dolphins' direction of movement was less neutral when the experimental boat approaches were carried out at a distance of 50 m than when they were carried out at a distance of 150 m, or with controlled approaches. Similar results were also obtained for dolphin groups including calves.Conclusions. On the basis of the results from this study, we recommend that the existing New South Wales regulations, which stipulate that dolphin-watching boats keep a distance of 50 m to groups with adults only and 150 m to groups with calves, are maintained within the Port Stephens-Great Lakes Marine Park (PSGLMP).Implications. Management plans whose stated goals include both sustainability of a dolphin-watching industry and longer-term viability of a dolphin population may reconcile conflicting objectives and improve their decision making by using these empirical measures rather than best guesses.

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Section: Discussionmentioning

confidence: 56%

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

2011

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“…Among the baleen whales, humpback whales showed the most dramatic changes from negative to positive responses after whale watching was initiated, whereas minke whales went from approaching vessels to not being interested in them (Watkins, 1986). Therefore, humpback whales, like some populations of gray whales, Eschrichtius robustus (Lilljeborg, 1861), and belugas, Delphinapterus leucas (Pallas, 1776) (Filla & Monteiro-Filho, 2009), may develop a tolerance towards anthropogenic stimuli that could also explain the lack of overt responses in the present study.…”

Section: Results Inmentioning

confidence: 99%

Effects of whale watching on the activity budgets of humpback whales,Megaptera novaeangliae(Borowski, 1781), on a feeding ground

Clemente

Christiansen

Pirotta

et al. 2018

Aquatic Conservation

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Whale watching can affect cetacean behaviour, and can in some cases lead to long‐term negative effects on survival and reproduction. The waters of Juneau (Alaska) represent a summer feeding ground for the Central North Pacific stock of humpback whales, Megaptera novaeangliae (Borowski, 1781). The recent dramatic expansion of the local whale‐watching industry has raised concerns over the potential negative impact of such activity on the whales. The aim of this study was to understand the impact of whale‐watching vessels on humpback whale behaviour in Juneau. From June to September 2015, land‐based observations were conducted to record whale behaviour in the presence and absence of vessels. Markov chains and model simulations showed that the presence of vessels was not associated with a reduction in the time spent feeding. Whales exhibited more surface‐active behaviour and travelled less in the presence of vessels. The lack of an overt response of feeding whales to whale‐watching disturbance could result from the importance of the Southeast Alaska study region as a feeding ground, which could make the whales less apt to interrupt feeding under disturbance; however, The high proportion of travelling observed may indicate that the study area represents a travelling corridor between other, localized feeding areas. The increase in surface‐active behaviour may represent a response to vessel presence that could potentially lead to energetic consequences. The large number of whale‐watching vessels operating could lead to the increased tolerance of whales towards whale‐watching activities. The lack of responses in this study may suggest that the reactions of whales are context specific, depending on their previous experience with vessels and their foraging behaviour, for example. Subtler negative effects could still occur, however, and a prolonged monitoring programme is required to assess less overt behavioural responses of whales over time.

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“…In some areas of Brazil, tourism involving small cetaceans is not perceived by the local community as a positive activity (FILLA & MONTEIRO-FILHO 2009, ZAPPES et al 2011, because since there are no regulations, those activities end up infringing on the existing environmental laws as well as on cultural mores.…”

Section: Discussionmentioning

confidence: 99%

Conflicts between river dolphins (Cetacea: Odontoceti) and fisheries in the Central Amazon: a path toward tragedy?

Alves

Zappes

Andriolo

2012

Zoologia (Curitiba)

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Monitoring tourism schooners observing estuarine dolphins (Sotalia guianensis) in the Estuarine Complex of Cananéia, south‐east Brazil

Cited by 27 publications

References 20 publications

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

Effects of whale watching on the activity budgets of humpback whales,Megaptera novaeangliae(Borowski, 1781), on a feeding ground

Conflicts between river dolphins (Cetacea: Odontoceti) and fisheries in the Central Amazon: a path toward tragedy?

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