Boat Interactions Research Articles

Short-beaked common dolphins of Dilek Peninsula National Park, South Aegean Sea: Preliminary results on group structure, spatial distribution, behavioural patterns, whistle characteristics and behavioural context

Basic knowledge about populations of short‐beaked common dolphins (Delphinus delphis) in the eastern part of the Mediterranean Sea is still lacking. Classified as ‘Endangered’ in an IUCN assessment released in 2022, it is necessary to gain baseline knowledge to understand the species’ population status and develop impactful conservation measures. The current study conducted boat surveys, employing visual and acoustic techniques between January 2019 and July 2022 in the Dilek Peninsula National Park, central Aegean Sea. Results revealed the continuous coastal presence of common dolphins, with subadults recorded during every sighting in low group sizes. Travelling‐related activities made up 58% of observed behaviour while resting comprised just 1%. Whistles were produced in the range of 1.83–48kHz with a peak frequency of 10.4kHz and median duration of 0.54s. Concave whistles were the most frequently recorded whistle type. Whistles were found to be generated when dolphins were interacting with boats and diving/travelling fast, forming 53% and 31% of whistle production respectively. The continuous presence of common dolphins, particularly subadults, emphasises the importance of the Dilek Peninsula. Whistle parameters show similarities with other common dolphin populations of the Mediterranean and Black Sea, albeit with shorter durations. The high whistle presence during boat interactions requires investigation to assess whether whistles carry avoidance or predatory messages, or whether there are potential consequences for the species’ energy budget. The current study presents preliminary information on the behavioural context of acoustic patterns. Further research is essential to understand the click and whistle characteristics within the biological, environmental and anthropogenic variables of their surroundings.

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

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.

CFD-based predictions of hydrodynamic forces in ship-tug boat interactions

ABSTRACTThis paper presents numerical investigations on the ship-ship interaction between a large oil tanker and a tug boat by means of Reynolds Averaged Navier-Stokes method. Prior to the systematic simulations for predicting the hydrodynamic interactions between the ships, a grid convergence study is performed to estimate the numerical error and uncertainty in ship resistance predictions. The grid convergence results indicate that the numerical error caused by the grid discretization is small, from which an appropriate grid density is selected for the systematic investigations. In the systematic computations, the ship-tug boat interaction forces are predicted in terms of the effects from several aspects: relative positions between the two ships and drift angle of the tug boat. In comparison with previous studies on the interaction effects between two large ships with comparable sizes, the forces acting on the tug boat are more considerably influenced by the ship-tug boat interaction effects since the scale of the tug boat is much smaller than the large ship. The predicted pressure distributions further verify this phenomenon. From the systematic computations, it is suggested that in practical operations the effects on the hydrodynamic performance of the tug boat resulted from the ship-tug boat interaction should be carefully taken into account.

Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006–2013. Our results demonstrated that tourist boat interactions affected dolphins’ behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity.

Estimating cumulative exposure of wildlife to non‐lethal disturbance using spatially explicit capture–recapture models

ABSTRACTImpact assessments often focus on short‐term behavioral responses of animals to human disturbance. However, the cumulative effects caused by repeated behavioral disruptions are of management concern because these effects have the potential to influence individuals’ survival and reproduction. We need to estimate individual exposure rates to disturbance to determine cumulative effects. We present a new approach to estimate the spatial exposure of minke whales to whalewatching boats in Faxaflói Bay, Iceland. We used recent advances in spatially explicit capture–recapture modeling to estimate the probability that whales would encounter a disturbance (i.e., whalewatching boat). We obtained spatially explicit individual encounter histories of individually identifiable animals using photo‐identification. We divided the study area into 1‐km2 grid cells and considered each cell a spatially distinct sampling unit. We used capture history of individuals to model and estimate spatial encounter probabilities of individual minke whales across the study area, accounting for heterogeneity in sampling effort. We inferred the exposure of individual minke whales to whalewatching vessels throughout the feeding season by estimating individual whale encounters with vessels using the whale encounter probabilities and spatially explicit whalewatching intensity in the same area, obtained from recorded whalewatching vessel tracks. We then estimated the cumulative time whales spent with whalewatching boats to assess the biological significance of whalewatching disturbances. The estimated exposure levels to boats varied considerably between individuals because of both temporal and spatial variations in the activity centers of whales and the whalewatching intensity in the area. However, although some whales were repeatedly exposed to whalewatching boats throughout the feeding season, the estimated cumulative time they spent with boats was very low. Although whalewatching boat interactions caused feeding disruptions for the whales, the estimated low cumulative exposure indicated that the whalewatching industry in its current state likely is not having any long‐term negative effects on vital rates. © 2015 The Wildlife Society.

Behavioural effects of tourism on oceanic common dolphins, Delphinus sp., in New Zealand: the effects of Markov analysis variations and current tour operator compliance with regulations.

Common dolphins, Delphinus sp., are one of the marine mammal species tourism operations in New Zealand focus on. While effects of cetacean-watching activities have previously been examined in coastal regions in New Zealand, this study is the first to investigate effects of commercial tourism and recreational vessels on common dolphins in an open oceanic habitat. Observations from both an independent research vessel and aboard commercial tour vessels operating off the central and east coast Bay of Plenty, North Island, New Zealand were used to assess dolphin behaviour and record the level of compliance by permitted commercial tour operators and private recreational vessels with New Zealand regulations. Dolphin behaviour was assessed using two different approaches to Markov chain analysis in order to examine variation of responses of dolphins to vessels. Results showed that, regardless of the variance in Markov methods, dolphin foraging behaviour was significantly altered by boat interactions. Dolphins spent less time foraging during interactions and took significantly longer to return to foraging once disrupted by vessel presence. This research raises concerns about the potential disruption to feeding, a biologically critical behaviour. This may be particularly important in an open oceanic habitat, where prey resources are typically widely dispersed and unpredictable in abundance. Furthermore, because tourism in this region focuses on common dolphins transiting between adjacent coastal locations, the potential for cumulative effects could exacerbate the local effects demonstrated in this study. While the overall level of compliance by commercial operators was relatively high, non-compliance to the regulations was observed with time restriction, number or speed of vessels interacting with dolphins not being respected. Additionally, prohibited swimming with calves did occur. The effects shown in this study should be carefully considered within conservation management plans, in order to reduce the risk of detrimental effects on common dolphins within the region.

Sex differences in risk perception in deep‐diving bottlenose dolphins leads to decreased foraging efficiency when exposed to human disturbance

Summary Individuals make behavioural decisions by weighing potential advantages and costs (e.g. increased food intake vs. increased risk of predation). When animals change their activities in response to a perceived threat, their energetic input may decline. Marine ecotourism, including whale and dolphin watching, is growing globally and cetaceans perceive interactions with tour vessels as a form of risk. Observable behavioural changes need to be linked to bioenergetic effects to determine the potential population consequences of this disturbance. We developed a theoretical optimal dive model for bottlenose dolphins under three potential types of perceived risk resulting from human interactions at the surface (decreasing instantaneous risk, increasing instantaneous risk and no risk). We compared the predictions of these theoretical models to observed dive cycles of foraging male and female dolphins in the presence and absence of tour vessels. We used mixture models to classify dive types and mixed effects models to analyse changes in the interbreath interval of surface and bottom dives and the frequency of estimated bottom dives. Males significantly increased bottom time and performed fewer bottom dives when boats were present, matching predictions of our theoretical model for perceived decreasing instantaneous risk. In contrast, females significantly decreased bottom times and increased the frequency of bottom dives, matching predictions from the model for perceived increasing instantaneous risk. Therefore, our empirical results suggest differences in the perception of risk between sexes. Synthesis and applications. By comparing theoretical predictions with observed dive data, our study suggests that boat interactions during foraging can cause decreased net energy gain over a foraging bout for both sexes, with females being more impacted. The population under study is currently listed as critically endangered. Understanding whether these predicted energetic impacts affect an individual's vital rates will provide a link to the population‐level consequences of this disturbance. Previous analytical approaches have failed to capture the costs associated with disturbance during foraging, leading to management recommendations that only protect animals from increased energetic expenditure. We suggest that the current management scheme should be revised to include foraging areas in order to secure the energy intake of animals.

Inferring energy expenditure from respiration rates in minke whales to measure the effects of whale watching boat interactions

Quantifying the energetic costs of human induced behavioral disturbance on wildlife is a crucial step to evaluate the potential long-term effects of disturbance on individual vital rates. Standard methods cannot be used for estimating energetic cost of transport because of the large size of most cetaceans, and instead energetic costs are inferred from respiration rates. We quantified the added energetic costs of avoidance to whale watching boats for minke whales (Balaenoptera acutorostrata) in Faxaflói bay, Iceland, by comparing minke whale movement tracks and respiration in the presence (impact) and absence (control) of whale watching boats. Energy expenditure was inferred from respiration rates, using published bioenergetic models for minke whales and mass-specific cost of transport (COT) was estimated for different swimming speeds. The sensitivity of the COT estimate to model assumptions was investigated using resampling methods. ANCOVA was used to investigate the effects of swimming speed and whale watching boats on minke whale respiration rate. Respiration rate increased linearly with swimming speed, while COT decreased nonlinearly with increased speed up to an optimal speed between 2.5 and 7.0ms−1. Respiration rates were higher during interactions with whale watching boats at any given speed, suggesting that boat presence elicited a stress response in the animals, resulting in a 23.2% increase in estimated energy expenditure. Swimming speed also increased during whale watching interactions from 1.62 to 2.64ms−1, resulting in an additional 4.4% increase in estimated energy expenditure during whale watching interactions. Thus, whale watching boat interactions resulted in an overall increase in estimated energy expenditure of 27.6%, from 56.54 to 72.16Jkg−1min−1. During interactions with whale watching boats, minke whales swam at speeds that were within the lower range of the optimal COT. This suggests that minke whales employ similar avoidance strategies towards whale watching boats as towards natural predators.

Inferring activity budgets in wild animals to estimate the consequences of disturbances

Activity budgets can provide a direct link to an animal's bioenergetic budget and is thus a valuable unit of measure when assessing human-induced nonlethal effects on wildlife conservation status. However, activity budget inference can be challenging for species that are difficult to observe and require multiple observational variables. Here, we assessed whether whalewatching boat interactions could affect the activity budgets of minke whales (Balaenoptera acutorostrata). We used a stepwise modeling approach to quantitatively record, identify, and assign activity states to continuous behavioral time series data, to estimate activity budgets. First, we used multiple behavioral variables, recorded from continuous visual observations of individual animals, to quantitatively identify and define behavioral types. Activity states were then assigned to each sampling unit, using a combination of hidden and observed states. Three activity states were identified: nonfeeding, foraging, and surface feeding (SF). From the resulting time series of activity states, transition probability matrices were estimated using first-order Markov chains. We then simulated time series of activity states, using Monte Carlo methods based on the transition probability matrices, to obtain activity budgets, accounting for heterogeneity in state duration. Whalewatching interactions reduced the time whales spend foraging and SF, potentially resulting in an overall decrease in energy intake of 42%. This modeling approach thus provides a means to link short-term behavioral changes resulting from human disturbance to potential long-term bioenergetic consequences in animals. It also provides an analytical framework applicable to other species when direct observations of activity states are not possible.

Whale watching disrupts feeding activities of minke whales on a feeding ground

Human disturbances of wildlife, such as tourism, can alter the activities of targeted individuals. Repeated behavioural disruptions can have long-term consequences for individual vital rates (survival and reproduction). To manage these sub-lethal impacts, we need to understand how activity disruptions can influence bioenergetics and ultimately individual vital rates. Empirical studies of the mechanistic links between whale-watching boat exposure and behavioural variation and vital rates are currently lacking for baleen whales (mysticetes). We compared minke whale Balaenoptera acutorostrata behaviour on a feeding ground in the presence and absence of whale-watching boats. Effects on activity states were inferred from changes in movement metric data as well as the occurrence of surface feeding events. Linear mixed effects models and generalised estimation equations were used to investigate the effect of whale-watching boat interactions. Measurement errors were quantified, and their effects on model parameter estimates were investigated using resampling methods. Minke whales responded to whale-watching boats by performing shorter dives and increased sinuous movement. A reduction in the probability of observing longer inter-breath intervals during sinuous movement showed that whale-watching boat interactions reduced foraging activity. Further, the probability of observing surface feeding events also decreased during interactions with whale-watching boats. This indicates that whalewatching boats disrupted the feeding activities of minke whales. Since minke whales are capital breeders, a decrease in feeding success on the feeding grounds due to whale-watching boats could lead to a decrease in energy available for foetus development and nursing on the breeding grounds. Such impact could therefore alter the calving success of this species.

Vessel traffic affects bottlenose dolphin (Tursiops truncatus) behaviour in waters surrounding Lampedusa Island, south Italy

Since 2003, as part of the LIFE project ‘Del.Ta.’ (NAT/IT/000163) a bottlenose dolphin community has been studied in order to assess the impact of increasing boat traffic in the Pelagie Archipelago (Sicily, Italy). During the summer of 2006 and 2008, land-based surveys were carried out at Lampedusa, one of the Archipelago's Islands, at set hours from 6 locations (7 in 2008) in standard weather conditions. Continuous horizon scanning and focal group sampling methods were used to study dolphin presence and behaviour. Dolphin–boat interactions were recorded for each sighting. A total of approximately 559 hours were spent monitoring and 83 sightings were recorded. With regard to the different types of vessels, interaction with sailing boats was always neutral, whereas fast boats caused the interruption of all activities and avoidance behaviour. Positive interaction occasionally occurred with bottom trawling fishing boats. Interactions recorded when fishing and powered engine boats approached within 200 m predominantly resulted in a negative reaction from the dolphins (approximately 70%) and dolphin behaviour was affected in terms of occurrence and patterns. Behavioural analysis showed that the animals reduced the frequency of behaviours related to feeding, social and relaxing activities. The dolphins also increased information-gathering behaviour such as spyhopping. The use of Markovian chain models revealed evidence of disruptions in sub-sequences made up of behaviours often associated with feeding. After boat departures, the animals rarely restarted their previous activity and persistence of this effect could have long-term consequences as a result of non-habituation. Sighting duration also decreased in the presence of vessels. The possible negative long-term effect of the presence of boats may be indicated by the lower mean sighting duration in 2008, when the highest presence of powered engine boats was recorded. In view of the scenario outlined above, local authorities need to enforce the requirement of maintaining a distance of over 200 m away from the animals for all types of boat and also promote regular land-based surveys of vessel impacts for tourist boats and dolphin watching cruises.

Does whale watching in Southern New England impact humpback whale ( Megaptera novaeangliae) calf production or calf survival?

There is growing concern about the effects of wildlife tourism on biologically important parameters in target species and/or populations. We tested whether whale watch vessel exposure affected either the calving rates or calf survival to age 2 in humpback whales ( Megaptera novaeangliae) on their feeding grounds off of southern New England, where individually identified whales have been studied intensively for decades and whale watch pressure is intense. Whale watch exposure did not correlate with either the calving rate (# of calves/# of years sighted) or calf production and survival of individual females, although a breakpoint analysis showed a slight negative trend up to 1649 min (or 20 boat interactions). In some comparisons, whales with more exposure were significantly more likely to produce calves and to have those calves survive. Logistic regressions including exposure and prey variables also failed to show negative effects of exposure in predicting calf productivity or survival. A limited comparison of calves seen only in an alternate habitat without whale watching showed similar return rates to those in the exposed area. Our data include limited suggestions that some animals (i.e., females alive when whale watching started) might be more susceptible to impacts than others. However, we found no direct evidence for negative effects of whale watch exposure, and suggest that short-term disturbance may not necessarily be indicative of more meaningful detrimental effects on either individuals or populations.

Tourism affects the behavioural budget of the common dolphin Delphinus sp. in the Hauraki Gulf, New Zealand

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 355:287-295 (2008) - DOI: https://doi.org/10.3354/meps07386 Tourism affects the behavioural budget of the common dolphin Delphinus sp. in the Hauraki Gulf, New Zealand Karen A. Stockin1,*, David Lusseau2, Vicky Binedell1, Nicky Wiseman3, Mark B. Orams1 1Coastal-Marine Research Group, Institute of Natural Resources, Massey University, Private Bag 102-904, North Shore MSC, New Zealand 2Biology Department, Dalhousie University, Halifax, Nova Scotia B3H 4JI, Canada 3Laboratory of Molecular Biology and Evolution, University of Auckland, Private Bag 92019, Auckland, New Zealand *Email: k.a.stockin@massey.ac.nz ABSTRACT: Common dolphins Delphinus sp. are frequently targeted by tourism operations in New Zealand waters, yet there is a paucity of data on potential impacts faced by this species. Transition matrix models, used widely in population ecology, have recently been applied to behavioural transitions in order to provide successful management guidelines. We detail the use of Markov chain models to assess the impact of tourism activities on the behavioural state of common dolphins in the Hauraki Gulf, New Zealand. First-order time discrete Markov chain models were used to describe transition probabilities in both control and impact scenarios. The effect of boat interactions was quantified by comparing transition probabilities of both control and impact chains. Foraging and resting bouts were significantly disrupted by boat interactions to a level that raises concern about the sustainability of this impact. Both the duration of bouts and the overall time spent in these 2 behavioural states decreased. Foraging dolphins took significantly longer to return to their initial behavioural state in the presence of the tour boat. There was also an increased preference to shift behaviour to socialising or milling after tour boat interactions. Impacts identified in the present study are similar to those previously reported for bottlenose dolphins, a coastal species typically considered to be more susceptible to cumulative anthropogenic impacts. KEY WORDS: Markov-chain models · Dolphin tourism · Common dolphin · Delphinus sp. · Disturbance · Foraging · New Zealand Full text in pdf format PreviousNextCite this article as: Stockin KA, Lusseau D, Binedell V, Wiseman N, Orams MB (2008) Tourism affects the behavioural budget of the common dolphin Delphinus sp. in the Hauraki Gulf, New Zealand. Mar Ecol Prog Ser 355:287-295. https://doi.org/10.3354/meps07386 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 355. Online publication date: February 26, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research.

Unsustainable Dolphin-watching Tourism in Fiordland, New Zealand

Bottlenose dolphins are a key resource of the tourism industry in Fiordland and are used on a daily basis by the tour operators offering cruises on the fiords. Recent studies have shown that the current levels of dolphin–boat interactions in this region cannot be sustained by bottlenose dolphins. Interactions have both short- and long-term effects on both individuals and their populations. Population models indicate that these effects may be affecting the viability of the three bottlenose dolphin populations living in Fiordland. We are currently observing drastic changes in the bottlenose dolphin population living in Doubtful Sound, which can be linked to the level of boat interactions to which they are currently exposed. The creation of a multilevel marine mammal sanctuary would help minimize dolphin–boat interactions and still allow for some further growth in the tourism sector in Fiordland.

The Human Dimensions of Whale Watching: An Analysis Based on Viewing Platforms

Visitor perceptions of the impacts of cetacean-based tourism from land-based and boat-based platforms are not well understood. Data from on-site surveys (n=633) and observational data were obtained at boat and land-based whale viewing platforms in the San Juan Islands, USA during the summer of 2000. Whale watchers at both platforms expressed concerns regarding adverse impacts on whales due to whale watching activities. Land-based whale watchers, however, were significantly more concerned about the presence of boats disturbing not only the whales, but also their own experiences. In particular, the noise and maneuvering of whale-watching boats were identified as issues of concern. The findings suggest that site-specific strategies for managing whale watching are necessary. Possible strategies include limiting the number of boats and the frequency and duration of boat interactions with whales. Furthermore, platform-specific visitor education programs may be useful for helping to address viewers’ concerns.

The Hidden Cost of Tourism: Detecting Long-term Effects of Tourism Using Behavioral Information

Increasingly, whales and dolphins are the focus of tourism activities in many coastal locations. Although these activities can affect individuals and populations of cetaceans, the biological significance and hence the cost of these impacts are as yet largely unknown. This study assessed the effects of boat interactions on the behavioral budget of two populations of bottlenose dolphins (Tersiops truncatus) living in similar fjords but exposed to different levels of tourism activities. This comparison makes it possible to assess the costs of short-term avoidance strategies and the threshold at which those strategies are no longer effective. The effects of boat

Effects of Tour Boats on the Behavior of Bottlenose Dolphins: Using Markov Chains to Model Anthropogenic Impacts

Abstract: Nature‐based tourism activities have been developing over the last decade, but it is still difficult to manage these activities sustainably. This sector is increasingly focusing on whales and dolphins in coastal communities, but the exact effects of these tourism activities are unclear. Markov chain modeling may help researchers assess the effects of tourism activities on the behavioral budget of small cetaceans. Matrix models have been used widely in population ecology to provide successful management guidelines. From June 2000 to August 2001, I collected information on the behavioral state of bottlenose dolphin ( Tursiops spp.) schools from a population residing in Doubtful Sound, Fiordland, New Zealand. In addition, I recorded the occurrence of boat and dolphin interactions. I then calculated the transition probabilities of passing from one behavior to another by using a first‐order, time‐discrete Markov chain model. Behavioral transitions during which a boat‐dolphin interaction occurred were compiled in an “impact” chain. All other transitions were tallied in a control chain. I then quantified the effect of boat‐dolphin interactions during behavioral transitions by comparing the behavioral transition probabilities of both chains. Socializing and resting behaviors were disrupted by interactions with boats to a level that raises concern. Both the duration of bouts and the total amount of time spent in both these behavioral states were substantially decreased. Dolphins were significantly more likely to be traveling after an interaction with a boat. However, the overall behavioral budget of the population was not significantly affected. Therefore, the bottlenose dolphin population seems to be able to sustain the present level of boat interactions because of its low intensity. More effort is needed to develop prognosis analyses in order to understand how the effect of boat interactions on dolphins changes with variations in intensity.

Managing the impacts of dolphin-based tourism through the definition of critical habitats: the case of bottlenose dolphins (Tursiops spp.) in Doubtful Sound, New Zealand

Marine ecotourism in New Zealand presents a challenging tourism-environment management context. This is demonstrated in the case of Doubtful Sound (New Zealand) where the recent proliferation of tour operators has brought pressures to bear upon a population of bottlenose dolphins resident in the sound. Strict methodologies are necessary to objectively interpret responses to tourism-induced anthropogenic impacts upon cetaceans. Previous research in this field has established that boat interactions with dolphins in Doubtful Sound affect the behavioural budget of the dolphin population, and that dolphins are more sensitive to interactions with boats when they are resting and to a lesser extent when they are socialising. This article reports on a programme of research that employed observational data to explore the applicability of tourism management techniques grounded in spatial ecology. The data provided scientific evidence that determining critical habitat through spatio-ecological analysis is a powerful tool to protect marine mammals in New Zealand, and elsewhere, from biologically significant tourism-induced impacts. The delineation of multi-levelled marine sanctuaries may, therefore, be an effective approach to managing the impacts of tourism upon marine mammals.