«Prepared for Environment Southland Paul Sirota Department of Geography University of Otago 20-02-2006 Contents Summary 3 1.0 Introduction 4 1.1 ...»
The effects of commercial sea-surface activity in
Milford Sound: An initial scoping and
information gathering report
Prepared for Environment Southland
Department of Geography
University of Otago
1.0 Introduction 4
1.1 Annotated bibliography 4
2.0 Ecology of Milford Sound 4 5
2.1 Marine Mammals 5 2.1.1 Dolphins 7 2.1.2 New Zealand Fur Seals 8 2.1.3 Whales
3.0 Other Marine Biota 8 8
3.1 Black Coral (Antipathes fiordensis) 10
3.2 Sea Urchin (Evenchinus chloroticus) and Sea Star (Coscinasterias muricata) 10
3.3 New Zealand Rock Lobster, Crayfish 11
3.4 Fish Species 11 3.4.1 Blue Cod 11 3.4.2 Terakihi 11
3.5 Penguins and other bird species 12
4.0 Perceptions from Stakeholders and Visitors 12 12
4.1 Perceptions of stakeholders 13
4.2 Visitor Perceptions 18 4.2.1 Travel web logs (blogs) 19
4.3 Maori perspective
5.0 Commercial Tourist Cruise Vessels 20
5.1 International Cruise Boats 20
5.2 Possible inputs from local tourist boats to water
2 Summary The major attraction that draws visitors to experience Milford Sound is the natural and seemingly unspoilt character of a coastal marine wildlife association combined with a native wilderness landscape. Through the increasingly rare combination of these elements Milford Sound has become iconic to tourism in New Zealand. As a tourist destination, Milford Sound is relatively accessible and is also considered to be safe, while at the same time spectacular. It is these additional features that may explain the general demographic and types of tourists that tend to visit the destination at present. Wildlife that inhabits Milford Sound and the other fiords in the Fiordland Coastal Marine Area (FCMA) is becoming an increasingly major draw-card for international tourism in the area. Dolphins that visit, or are resident within the fiords, are probably the second major attraction after the outstanding scenery of the FCMA.
Research conducted from within the University of Otago, some of which is now beginning to be published in peer reviewed journals, indicates that increases in commercial and tourist activity in the area are likely to bring the associated wildlife and marine biota under increasing pressure. A general decline in the population of some aquatic species has already been noted, as well as signs of pressure on some marine mammals. The current state of the ecology of Milford Sound can be attributed to current and historical commercial and recreational activity within the area.
The perceptions regarding natural character and landscape values of the area may also be deleteriously affected by any further increase in motorised commercial vessel activity in Milford Sound. Perceptions of natural landscape and wilderness values are attenuated when synergies are formed between commercial tourist vessels, air traffic, high road usage and large influxes of visitors within a confined area. Research concerning the sustainability of tourism in Milford Sound has shown that from an academic perspective, at present, unsustainable indicators appear to out-weigh those of sustainable indicators for the destination. The current carrying capacity for Milford Sound appears to have been reached, if not slightly exceeded. It is recommended that a full and integrated Cumulative Effects Assessment (CEA) be conducted for Milford Sound. The CEA should include cross-boundary jurisdictional activities and therefore address synergies between the variety of activities currently practiced within the fiord and surrounding area. Utilising a multi-method approach, the CEA should address the combined effects of aircraft, road usage, visitor numbers and commercial and recreational sea-surface activities on landscape and natural character perceptions of visitors.
1.0 Introduction This report is an initial scoping study regarding the possible effects associated with any increases in commercial boating activity in Milford Sound located within the FCMA. Some of the information within this report is unpublished postgraduate research from the University of Otago that has relevance to issues involving commercial boating in Milford Sound and the wider FCMA. Other research available from the internet and from peer-reviewed publications is included where appropriate.
Sustainability is one of the major goals and also one of the major challenges facing future management of the developing tourist industry in New Zealand at present.
Milford Sound is often referred to as one of the jewels in the crown of New Zealand tourism, and as such it is appropriate that the management of such a treasure takes steps to ensure that this jewel does not become tarnished. In contrast, Milford Sound has also been described as ‘the sacrificial lamb to the tourist dollar’ in some of the ‘grey literature’ that has been surveyed during the course of this research. An obvious tension is therefore identified in the current perception of Milford Sound as a scenic and natural wilderness area. Resolution of these contrasting perceptions will affect the future management and possible outcomes for Milford Sound.
Each subsection has the reviewed literature associated with the subject matter included at the end of the section. This format is adopted for ease in identification of the cited literature for each subsection. A full bibliographic reference section is included at the end of the report. Reference sections of each work cited in this report have not been duplicated due to redundancy, but it should be noted that an extensive body of information may be accessed through these references.
1.1 Annotated bibliography:
The annotated bibliography is intended to act as a resource for an investigation by Environment Southland (ES) involving possible effects associated with increases in commercial sea-surface activity in Milford Sound. This section addresses a variety of topics, both biophysical and social, that are relevant to commercial boating activity in the FCMA. The Department of Conservation (D.o.C) already retains much of the ecological information regarding marine flora and fauna of the FCMA in a Southland Marine Database, therefore the focus of this report is to identify any gaps or new, or as yet unpublished, research relevant to Milford Sound. Any research that will help ascertain perceptions of the natural character and landscape values associated with Milford Sound, or how these may change due to an increase in commercial boating activity in the fiord, is also included.
2.0 Ecology of Milford Sound:
ES in conjunction with D.o.C already have a body of information regarding the ecology of FCMA and Fiordland National Park used for compliance monitoring (Environmental Compliance Monitoring Report, 2001/2002, Southland Marine Database). The research reviewed in this section should be used in conjunction with information already held by D.o.C.
42.1 Marine Mammals
Research on bottlenose dolphins (Tursiops spp.) has been conducted in Milford Sound and Doubtful Sound. The dolphins that visit Milford Sound appear to be directly affected by the presence of high numbers of tourist boats operating in the fiord. Residence times of bottlenose dolphins within Milford Sound appear to be shortening as a response to an increase in vessel numbers. Dolphins that do visit Milford Sound appear to stay near the entrance and occupy the zones less frequented by vessels (Lusseau, 2005). However, a recent reconnaissance excursion on one of the larger commercial tourist vessels showed that in calmer conditions the tourist boats cover the entire fiord perimeter leaving few areas of the fiord free of boating activity.
High speeds are attained in areas not regulated by speed restrictions within the fiord by recreational and charter vessels used for fishing or those used for the crayfish industry. High speed vessels also have the potential to harm dolphins due to collisions, especially if dolphins are trying to avoid tourist vessels. The general evidence presented below indicates that the bottlenose dolphin populations of both Milford Sound and Doubtful Sound require ongoing monitoring so as to ensure a sustainable population in both fiords. Ecological monitoring of the dolphins is needed along with compliance monitoring of tourist boat operators to the Voluntary Code of Practice (COP) and Code of Conduct for Marine Mammal Watching issued by D.o.C.
Interviews conducted with Doubtful Sound tourist boat operators by Fairbairn (2003), indicated that operators in Doubtful Sound occasionally pursue dolphin pods within the fiord in order to allow clients to observe them. The interviews revealed that selfregulation does not appear to be favoured by all of the operators in Doubtful Sound.
The Code of Conduct for Marine Mammal Watching appears to be accepted in theory but not necessarily adhered to by all operators. Operators appear to alert each other as to the location of the pods within the fiord. This results in operators deviating from the agreed route for vessels within the fiord in order to intercept the pods. This practice appears to gain greater client satisfaction on the respective tourist boats.
Fairbairn, N. (2003) Bottlenose Dolphin Tourism in Doubtful Sound: An analysis of Sustainable Tourism Management in Doubtful Sound, unpublished Post Graduate Diploma in Tourism dissertation, Department of Tourism, University of Otago, New Zealand.
------------------------------------------------------------------------------------------------------Statistical analysis of residency times for bottlenose dolphins (Tursiops spp.), in Milford Sound by Lusseau (2005), has indicated that commercial sea-surface activities have an effect on the time spent by pods of dolphins in Milford Sound.
These conclusions are resultant from a study between Dec. 1999 and Feb. 2002.
During times of intense tourist traffic, visiting dolphins tend to stay near the entrance to the fiord out of the reach of the tourist boats. It appears that dolphins tend to spend less time in Milford Sound when traffic is heavy. Cetaceans (whales and dolphins), move away from boats when interactions become intrusive or too lengthy, possibly due to acoustic disturbance or risk of personal injury.
5 During the period of the study by Lusseau, four individuals from a population between 45 and 55 dolphins had propeller marks from collisions with boats. Two of the four had collided with boats over the study period, one of which (a two week old calf) disappeared after being hit and is presumed dead. Horizontal avoidance strategies by dolphins become ineffective when boat traffic is high, as these strategies generally just tend to bring the dolphins into contact with another boat. It is considered that this may lead to abandonment of the fiord by the dolphins. Avoidance of vessels could have long-term implications for the demography of the dolphin population in the FCMA.
Lusseau, D. (2005) Residency pattern of bottlenose dolphins Tursiops spp. in Milford Sound, New Zealand, is related to boat traffic. Marine Ecology Progress Series Vol.
295, pp. 265-272.
------------------------------------------------------------------------------------------------------Research by both Lusseau authors indicates that dolphins are reliant on in-fiord fish species as well as pelagic fish species. Tourist operators involved in commercial seasurface activity appear to be placing the dolphin population under pressure. Diesel engines that propel larger tourist vessels operating within Milford Sound transmit significant noise and vibration into the water column. In areas where the fiord narrows, such as near the entrance where dolphins are more commonly observed, noise may also be reflected between the walls of the fiord. Significant noise volumes may hinder the ability for dolphins to communicate in synchronised diving efforts for in-fiord species.
Marine mammals are generally believed to have a major impact on the structure and function of marine communities. The study by the second Lusseau author, during 2002, found that bottlenose dolphins in Doubtful Sound are dependent on in-fiord species, especially demersal species and those associated with the shallow reef zone along the rock walls. Some ephemeral pelagic species do however subsidise their diet during the summer months. This species of dolphin is therefore particularly vulnerable to changes in the availability of local food sources.
The present dolphin population, having not significantly varied in size for the past 12 years, indicate that the dolphin population is at carrying capacity with its environment. Breeding of dolphins has been linked to periods of sufficient resources being available to support pregnant and lactating females. Changes to the availability of prey fishes, either through direct competition with fisheries, or through environmental change, could have detrimental effects on the viability of the bottlenose dolphin population as well as other predators relying on production generated inside the fiord.
Lusseau, S. (2002) Diet of bottlenose dolphins in Doubtful Sound, New Zealand;
Evidence from stable carbon and nitrogen isotope analysis, unpublished Master of Science dissertation, Marine Science, University of Otago, New Zealand.
Lusseau, D. (2004). The state of the scenic cruise industry in Doubtful Sound in relation to a key natural resource: bottlenose dolphins. In: Nature-based tourism in peripheral Areas: Development or disaster? (M. Hall and S. Boyd eds.) Channelview Publications.
-----------------------------------------------------------------------------------------------------Research by Orchiston (2004) is considered more closely within the section regarding operator perceptions of tourist and other operator activity. However, in relation to the effects of tourist operations regarding dolphins, the study indicated that operators recognised that tourist operations are likely to significantly impact the dolphins in Doubtful Sound. Operators are also aware of potential impacts of tourism on marine species. Forty percent of the operators interviewed agreed that there will be increasing disturbance of marine mammals over the next five to ten years. Interviews with operators also indicated that a number of unpermitted operators have been observed behaving inappropriately around dolphins by other operators.