POTENTIAL IMPACTS OF UTILISATION

Environmental Impacts of Wild-harvesting

Harvesting of native animals can affect ecosystem functioning as a result of a number of actions. These include:

a) the removal of individuals, eggs or (for plants) fruit, seeds or parts of the individual;

b) the removal of nutrients through biomass;

c) causing physical damage to non-target species;⁸⁵

d) changing the genetic makeup and diversity of natural populations through removal of the `best' individuals; and

e) spread of pathogens, weeds and pests.⁸⁶

Wild-harvesting may have little or large impact on the target population. The Committee recognises that the impacts of consumptive use of native animals will depend on the size of the activity, how it is managed and characteristics of the particular species, as well as on the type of production method used.

The Committee notes that sustainable harvesting limits are difficult to establish and that by developing a market for a native species, pressure from both legal and illegal harvesting may increase. This has not always occurred, however. For example, as the Committee noted in Chapter 4, harvest quotas for kangaroos in South Australia are often not filled and harvests continue to be determined by population size. Kelp harvesting on King Island remains essentially steady, although there is a ready market should production increase.⁸⁷

If commercial use rather than culling for pest control is the primary object of the wildlife harvest, management of the target species may change.⁸⁸ Efforts may be made to expand and improve the quality of the population and to ensure a more reliable yield.⁸⁹ Possible interventions identified by the Committee include:

a) increase supply of a limiting factor at a critical time (for example water);

b) modify habitats to favour the target species;

c) remove competing species or predators;

d) protect the target population at critical times (for example nesting); and

e) captive breeding and release.

Many plant species have adaptations that make them resistant to attack by native parasites and diseases and so less in need of chemical protection than most exotic species. However, such benefits are not inevitable. Though local species may be resistant to local pests, parasites and diseases, those that can attack them are likely to have evolved with them. If their conditions of growth are changed, the native plant may become more vulnerable to attack.⁹⁰ Soil compaction and altered drainage associated with harvesting, as well as vehicle contamination, can increase the risk of disease.

The Committee understands that the true extent to which harvesting affects the long-term viability of a natural system can only be determined through research and by stringent monitoring. The eight-year research program that is the basis of kangaroo quotas illustrates the effort required to provide a sound basis for substantial native-species harvest.⁹¹

Environmental Impacts of Cultivation and Farming

Many of the impacts of harvesting on wild populations can be avoided through the domestication of native species, where this is practicable.⁹²

The farming of fish and other native animals in preference to wild-harvest has also received support from industry, although this is more equivocal.⁹³ Not all species are suited to farm production (for example, as noted in Chapters 4 and 6, kangaroos have inappropriate behaviour and brown snakes do not breed readily in captivity). Several submissions also raised issues of animal welfare in relation to farming of native animals.⁹⁴

Loss of nutrients from the crop applies, as in any farming system.

Genetic change and loss of diversity is the norm under conventional farming systems. These systems require uniformity in the plants and animals used. It was explained to the Committee that producers need genetically reliable cultivars that minimise demands on cultivation or animal husbandry, are easy to harvest and satisfy market demands.

Genetic pollution, as described above, is a risk peculiar to farm or cultivation systems that use native plants and animals.⁹⁵ Only native species are able to introduce modified genetic material into wild populations of native species. The Committee was informed that currently the DNRE has no practical program available to it to monitor the effects of gene flow between cultivated crops and wild populations.⁹⁶

In addition, disruption of the composition and social structure of the wild animal populations can occur if populations of farm-bred native animals are released or escape to the wild.⁹⁷

Environmental Impacts of Ecotourism and Recreation

The impacts of recreation on native species, apart from hunting and fishing, do not derive from direct removal of individuals from populations. Hunting and fishing incur the risks associated with removal of selected individuals. In this respect they involve similar risks to those attending wild-harvest, albeit generally at a lower level.

The rise of tourism to the forefront of world economic activity has only occurred in the last 20 years and the last five years have seen considerable expansion and change in the tourist industry in Victoria.⁹⁸ Because the industry is changing rapidly, it is difficult to assess its ecological sustainability.⁹⁹

Though tourist activities do not directly consume plants or animals, the Committee found that they are not without impacts. Extensive evidence of visitor pressure can be found. Examples are soil erosion, stream-bank damage, introduction of weeds and diseases, trampling, water pollution and litter.¹⁰⁰ Pressures to ensure that tourists see favoured species may lead to habitat modification or introduction of excessive numbers of favoured species with resultant population imbalance, genetic pollution and overgrazing of native vegetation.¹⁰¹

Too much human presence or feeding of animals can lead to changes in animal behaviour, such as relocation, nest desertion and dependence on feeding by humans.¹⁰² For example, it has been found that female dolphins with young "are unable to rest on peak days [in Port Phillip Bay] when there may be more than 60 approaches to their territory an hour by commercial tours plus the attention of ferries, power skis, dive and recreational vessels". ¹⁰³

The Dolphin Research Institute, in its submission, explained that minimising impacts on animals must be based on a sound understanding of their ecology. This includes avoiding actions to change the animal's behaviour. In the opinion of the Institute:

Wildlife-based tourism should only be allowed if appropriate interpretation programs form part of the experience, conveying sound values and knowledge to patrons. The use of wild populations for tourism with the inherent risks can only be justified if there is a long-term conservation outcome linked to quality education programs.¹⁰⁴

To be sustainable these impacts cannot exceed either the self-sustaining capacity of the ecosystem or management inputs to ensure that the natural resource base is maintained. Tourism Training Victoria explained to the Committee that one of the major deficiencies in present knowledge relates to the `carrying capacity' of natural areas and species; that is the number of visitors that a given ecosystem can sustain and the management required to ensure sustainability.¹⁰⁵

All relevant tourism strategies support the principle of ecologically sustainable development, but translation of these strategies into practice is often not evident. This, according to Preece et al., is due to a lack of understanding of processes and leadership on environmental matters. Consequently they recommend that:

Governments review the deficiencies in the understanding of environmental matters in the tourism industry and take appropriate steps to rectify these deficiencies. ¹⁰⁶

Whether native plants and animals are the main focus of the activity, or it is concerned with a broader landscape, maintenance of the total ecosystem is necessary if the use is to be sustainable. Where animals are viewed in a small segment of their habitat (for example the little penguins on the beach at Phillip Island) sustainability of the activity depends on the maintenance of their whole habitat, even though this is not directly enjoyed by tourists.¹⁰⁷

Benefits from tourist activities may not necessarily lead to allocation of sufficient resources to maintain the whole ecosystems on which they depend. However, it is common for those utilising and enjoying a native species to be involved with only a small part of its habitat. They may be ignorant of the wider needs of the habitat and their impacts on it, or unable to contribute to its maintenance, or it may not be in their interest, as individuals, to do so.