INCREASED AVOIDANCE OF SWIMMERS BY WILD BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) DUE TO LONG‐TERM EXPOSURE TO SWIM‐WITH‐DOLPHIN TOURISM

Abstract

The responses of wild, non‐provisioned bottlenose dolphins (Tursiops truncatus) to swim attempts from commercial swim‐with‐dolphin tour boats were systematically observed during two research periods: 1994–1995 and 1997–1998. A total of 255 groups of dolphins was encountered during boat‐based surveys and 36% (n= 93) were exposed to at least one swim attempt. The operators' success with swim attempts, defined as at least one dolphin milling within 5 m of at least one swimmer, decreased from 48% in 1994–1995 to 34% in 1997–1998, and avoidance responses to swimmers increased from 22% to 31%. Dolphin response was found to vary according to swimmer placement. The greatest increase in avoidance occurred when swimmers were placed in the dolphins' path of travel. Based on sighting records of 266 individually identified dolphins, it was estimated that an average dolphin was exposed to 31 swim attempts per year. This level of exposure suggests that individual dolphins have, with cumulative experience, become sensitized to swim attempts. When a swim attempt was successful, on average it involved 19% of the group. Age‐class differences in interaction rates showed that juveniles were significantly more likely to interact with swimmers than adults. This study highlights the importance of longitudinal studies in evaluating human impact and suggests the urgent need for similar studies of potential human impact on other toothed cetaceans.

Comportamento do boto-cinza, Sotalia guianensis (Van Bénédén) (Cetacea, Delphinidae) na presença de barcos de turismo na Praia de Pipa, Rio Grande do Norte, Brasil

“…Suas características estruturais, mecânicas e tipo de abordagem podem, em maior ou menor grau, causar alterações comportamentais nos indivíduos alvo em curto e longo prazo (WATKINS 1986, BEDJER et al 1999, CONSTANTINE 2001 Comparação das médias das freqüências de deslocamento (± EP), para as situações de controle, experimental e pós-exposição, durante interações com embarcação de com aproximação lenta e direcional; (3) média de comportamentos aéreos (± EP) para cada um dos tipos de composição de grupo nas interações com barcos isolados; (4) média de socialização (± EP) para cada um dos tipos de composição de grupo nas interações com barco isolado; (5) Média de deslocamento (± EP) para cada um dos tipos de composição de grupo nas interações com barco isolado. (*) Composição de grupo com diferenças significativas, p < 0,05 pelo teste U de Mann-Whitney.…”

Effect of Spinner Dolphin Presence on Level of Swimmer and Vessel Activity in Hawai'ian Bays

“…Marine mam-2 COURBIS Courbis, 2004;Lusseau, 2003;Ng & Leung, 2003;Ross, 2001), changes in swimming speed (Kruse, 1991;Nowacek & Wells, 2001;Ross, 2001), changes in surfacing patterns (Hastie, Wilson, Tufft, & Thompson, 2003;Janik & Thompson, 1996), changes in vocalizations (Lesage, Barrette, Kingsley, & Sjare, 1999;Scarpaci, Bigger, Corkeron, & Nugegoda, 2000), shifts in habitat preference (Allen & Read, 2000;Bejder, 2005), and reduction in distance between animals (Bejder, Dawson, & Haraway, 1999;Nowacek & Wells, 2001). Constantine (2001) found that bottlenose dolphins (Tursiops truncatus) in swim-with-the-dolphins programs in the Bay of Islands, New Zealand showed a significant increase in avoidance of swimmers across years. Dolphin avoidance of vessels has also been documented (Blane & Jackson, 1994).…”

“…Many studies have addressed the impacts of tourism on marine mammals in a variety of locations (Barr & Slooton, 1999;Blane, 1990;Blane & Jackson, 1994;Constantine, 2001;Duffus & Deardon, 1993;Lusseau, 2003;Orams, 1997). Marine mam-2 COURBIS Courbis, 2004;Lusseau, 2003;Ng & Leung, 2003;Ross, 2001), changes in swimming speed (Kruse, 1991;Nowacek & Wells, 2001;Ross, 2001), changes in surfacing patterns (Hastie, Wilson, Tufft, & Thompson, 2003;Janik & Thompson, 1996), changes in vocalizations (Lesage, Barrette, Kingsley, & Sjare, 1999;Scarpaci, Bigger, Corkeron, & Nugegoda, 2000), shifts in habitat preference (Allen & Read, 2000;Bejder, 2005), and reduction in distance between animals (Bejder, Dawson, & Haraway, 1999;Nowacek & Wells, 2001).…”

Managing Wildlife-based Tourism: Edging Slowly Towards Sustainability?

“…The interactions of wildlife populations with tourists have, rather belatedly, become acknowledged for their complexity (e.g. in reference to tourist engagements with cetaceans, see Beale & Monahan, 2004;Bejder et al, 1999Bejder et al, , 2006cConstantine, 2001;Corkeron, 2004;Gill et al, 2001;Williams et al, 2002). Herein lies a critical test for tourism sustainability.…”