Assessing the impact of tourism on New Zealand fur seals (Arctocephalus forsteri) (2001)
AuthorsBoren, Laura J.show all
Marine mammal viewing and encounters are significant tourist activities in some areas of New Zealand - it was estimated in 1992 that at least 300,000+ tourists took part in marine related tourism in New Zealand annually (Robertson, 1992), and the industry has grown considerably since then. While eco-tourism can have positive outcomes (e.g. generating revenue and increasing environmental awareness), if it is not managed effectively, it can also have a negative impact on the target species and their environment. Effective management requires an understanding of how the target species react to tourist activities. We need to know: • If the animals are modifying their behaviour and if so how can we measure the changes in behaviour? • Are the changes in behaviour biologically significant? • How can we prevent or mitigate any negative effects of eco-tourism on marine mammals? New Zealand fur seals, Arctocephalus forsteri, are the only marine mammal found regularly ashore on accessible sections of the New Zealand coastline and are therefore the target of both land and sea-based tourism. The time that fur seals come ashore to breed (Nov-Feb) coincides with the peak tourist season making it important that we understand the implications of tourist/seal interactions on the behaviour as well as the reproductive success of the species. Three study sites were chosen to reflect a spectrum of visitor density, type of tourism, and anticipated fur seal sensitivity. Two experimental sites, the Kaikoura coastline and Tonga Island in Abel Tasman National Park both attract a large number of tourists for viewing by boat, and kayak, and by land in Kaikoura. A control site, Whakamoa, on the Banks Peninsula, which receives no tourist traffic, was used to compare responses of seals to various approach types. Data were collected during the Austral summer seasons 1999/2000 and 2000/2001. Behaviour was observed using focal animal and instantaneous scan sampling (Altmann, 1974), while attributes of tourist approaches were tested experimentally via controlled approaches. Approaches were broken into land, kayak and boat approaches, and the following factors were manipulated: distance, noise, frequency of approach, and size of group approaching. In the first field season (1999-2000), Focal Animal observations were carried out on 277 individual seals representing five different gender/age classes: adult male, adult female, sub-adult male, juvenile and pup. In the second field season (2000-2001), Focal Animal data were collected on 124 mother/pup pairs. Over both field seasons 162 hours of Instantaneous Scan data were collected. Controlled Approaches by land, kayak, and boat were carried out during both seasons and data were collected on 3525 seals. Frequency approach data were collected by land (n=13 seals), and by kayak (n=55 seals) in the first field season. Also in the first field season, the impact of group size was tested on 97 seals by land. Seals' responses to tourist approaches were recorded during both seasons, on land and at sea in both boats and kayaks (n=3699 seals approached). Data were collected on 327 seals approached by a commercial guided walk in the second field season. A total of 33 commercial swim with- seal programmes were observed during the second season. A mark-recapture experiment was carried out at Ohau Point and Tonga Island breeding colonies both seasons (n=167 pups sampled) to assess pup productivity and condition at these sites. The results from this study indicate that fur seals are changing their behaviour in response to tourist activities. Chapter 3 of this thesis details the results of the behavioural sampling. Focal Animal data collected on all gender/age groups suggests that there are significant differences in the behavioural repertoire of seals based on site and gender/age differences. Focal Animal data collected on mother/pup pairs suggests that time spent 'Nuzzling' was significantly less at Tonga Island (p<0.019) although no significant differences were observed in mother/pup association time between sites. Instantaneous scans showed significant changes in seals' behaviours in response to tourist disturbance. They also show significant differences in colony behaviour between sites (p<0.0001), as well as behavioural changes within the colonies over the two seasons (p<0.042). The experimental data including controlled approaches are presented in Chapter 4. The results from the controlled approach aspect indicate that fur seals respond more strongly to. land-based approaches than sea-based approaches (p<0.0001). Response to different approaches also varied by site with more avoidance responses displayed at the control site (p<0.005). There was no significant correlation between group size and fur seal response or the frequency of approach and seal response. Results from the guided walk showed that seals' responses varied significantly based on the distance of approach, and the size of the group approaching. The responses of seals to the guided walk were also compared to responses of seals approached by tourists without a guide; the presence of a guide reduced the number of avoidance responses by as much as 15%. No significant difference was found in seals' responses to swims organised by different companies, however, particular human behaviours were observed to increase the likelihood of seals avoiding the swimmers. The data presented here have shown that seal responses vary based on a large number of factors, and that seals may habituate over time in areas of high tourist activity. This study indicates that current management guidelines are not preventing negative impacts in tourist/seal interactions. In Chapter 5, strategies are recommended to lessen the overall impact of eco-tourism activities on fur seals including (See Chapter 4 for calculation) new minimum approach distances (land approaches - 30 m at nonbreeding sites, prohibited at breeding sites; kayak approaches 20 m at breeding sites; boat approaches - 30 m at all locations). Long-term monitoring is required to assess the possible impacts of tourism on the reproductive success of the species.