Darwin Harbour, NT, Australia.
MAP 1.
In relation to the practices of recreation and leisure pursuits in Darwin Harbour many issues have come to the fore. Resulting from urbanisation of the greater Darwin and Palmerston metropolitan areas, these cities pose threats to the traditionalmarine and coastal environments due to urban spread. The general consequences of a growing population, their approach to the use and management of marine resources have been identified to the demise of Darwin Harbour's aquatic fauna, flora and biotic ecosystems. During the course of the twentieth century, public awareness of environmental issues has been relatively minimal. The general community has demonstrated an attitude consistent with the belief that natural resources were inexhaustible. However, within the last twenty years or so a concentrated effort to change the community's perspective of environmental concern has developed.
Darwin Harbour is the largest tidal estuary in Australia. As such it is the home for many species and habitats for a wide range and variety of biota. Both animal and plant biodiversity extend from the smallest of life support organisms to the largest of the predatory fauna, that of the salt-water crocodile. However, this reptile is almost controlled in Darwin Harbour at present. This has resulted from the policies of the Department of Parks and Wildlife to free our study area from these predatory reptiles. Government agencies and private enterprise subsequently developed an interest in the harbour as an untapped source of potential development for economies which exploit recreational pursuits for both locals and tourists alike. Darwin Harbour is ideal. Consequently, this waterway offers the recreational pleasure seeker many activities for leisure and relaxation. Presently, the range of these activities cover the expectations of the regions residents and the more popular of these activities are shown in Table 1. This table is adapted from the results of a study by Brown and Reynolds (1997) and also gives an insight into the importance of these activities to the general Darwin public.
One of the major contentious issues concerning the Darwin Harbour at the present is that of the removal of mangroves for economic development. This issue has contention because many aquamarine fauna rely on these forests as nurseries and as a permanent residences and/or seasonal habitats (Hutchings and Recher, 1983). This study by Hutchings et al investigated the relationships between the mangrove hosts and the fauna, which inhabit the mangal wetlands. In a study of wetlands of northern Australia, New Guinea, Irian Jaya and other Southeast Asian countries, Collette (1983) has also concluded that:
It is now accepted by our society that marine invertibrates and vertibrates do breed in the mangrove forests. As a consequence of these breeding cycles certain sports and recreational activities have evolved which exploit the large populations of free-range fish in the Darwin Harbour. Other recreational pursuits have evolved which rely on the clarity and clean water qualities, which the Darwin Harbour presently provides. Questions which are raised here is how do the present mangal forests support recreational practices and what are the perceptions of the recreation seeking public to the preservation of the mangrove habitats and wetlands.
1.1 Aims of the Report.
1.1.1 What are the Recreational Activities in Darwin Harbour?
Ever since the Darwin Harbour region was settled by Europeans in the nineteenth century it has enjoyed a continued, if somewhat sporadic, economic progression. The social, economic and cultural standards of the predominantly European society, have been affected by a decidedly 'tyranny of distance' phenomenon. However, although Darwin closer to Asian countries than to the nations capital, Canberra, the present social conditions prevailing do not differ to any degree to that in the rest of Australia. Recreational and leisure pursuits within marine environments in all Australian states are relatively similar. Whilst one of the most popular sporting activities and one which has widespread acclaim is that of amateur fishing. In all of the states/territories legislation has been enacted to regulate this pastime activity as there are covering commercial fishing operations. The Northern Territory is no different. The ############# has been enacted here to manage and to maximise the fishstocks in territory waters and to encourage fishing tourism and to regulate the amateur fisher person's catch.
However, amateur fishing is not the only cherry in the pie. Sailing on water is another popular sport on the Darwin marine environment. This city, being situated on a an approximately 500 sq klm harbour, one of the largest protected waterways in the country. SCUBA diving, water/jet skiing, swimming and boating, also hold important places on the recreational activity list for Darwin Harbour because of the marine nature of the region and the water characteristics of the activities. Nevertheless, other activities exist on the foreshores and the harbour littoral which do not necessarily rely on an acqa-marine environment to exist. These are important to her harbour economy because they bring people here for the aesthetic qualities and values of the surrounds. Picnics, walking/jogging/cycling, outdoor entertainment/festivals and just plain sightseeing are items which relax many people and bring them to the harbour environs and surrounds. These are some of the activities which are reliant on the clean, healthy existence of mangrove forests on the intertidal plains, creeks and rivers of the Darwin Harbour wetlands.
1.1.2 To Determine Areas of Mangroves which are of Significance for the Recreational Use of Darwin Harbour:
It is undisputed that Port Darwin is a natural harbour. Although, with the increase in this area's population just how natural should the associated waterways remain. Urbanisation is responsible for the clearing of many mangal areas on Darwin Harbour foreshores. Mangrove forests are found in many parts of the globe and only on shorelines which are sheltered from the prevailing winds. They very often grow between the low-water tide level and the high-water spring tide mean within the rivers, creeks, estuaries, tidal wetlands and on offshore islands. The mangroves of Darwin harbour are no exception to this general tendency. Traditionally, mangroves have been considered as wastelands. They are full of insects, mud and are generally referred to as rather unsavoury places. Only occasionally did people venture into mangrove forests. This was only limited to fisher people looking for fishing bait. Some third world countries even used mangrove timber for firewood. However, generally the Darwin experience has seen the urbanisation processes having priority over preservation of the mangals. An increasing population demands more recreational faculties and infrastructure. They also demand the construction of accommodation and housing on a scale
proportionate to the population increase These innovations are more often than not being constructed on reclaimed lands requiring the removal of mangroves. Artificial constructs such as marinas, fishing boat ramps and shelters, water front housing estates and high-rise harbour view apartments are now displacing the original, natural harbour foreshore areas.
1.1.3 To Determine Relationships between the Mangals and Regional Fauna:
Mangals are nurseries for marine and aquatic lifeforms. From the smallest organisms in the food chain to large predatory fish, many sea-creatures have life cycles which begin within mangrove shallows. Mangrove vegetation also acts as a food source for a wide variety of avifauna which includes flying-foxes. Snakes and other land mammals such as possums also use mangroves as habitats at some stage in their life cycle. Additionally a wide variety of crustaceans, molluscs, insects and other micro-organisms which inhabit mangrove regions and act as a food source for larger organisms These animals and micro-fauna rely on the ecosystems' life support mechanisms for reproduction and longevity. These natural ecosystems within the Darwin Harbour littoral are maintained presently as a dominance of the mangrove forests with a relative scattering of human population around the north and north-east corner of the harbour. Palmerston and Darwin are the twin major cities with a population of approximately 100,000. The diversity of the mangal fauna is overwhelming because of the many organisms which support and in turn are supported by the wetlands. Darwin Harbour mangroves are halophytes, that is they live in saline conditions. Consequently, the fauna which is supported by the mangals are reliant on the overall conditions of the harbour, the surrounding seas and oceans and the general environmental conditions at any particular time period. As the foreshores here are relatively untouched by human occupancy and enterprise, harbour and mangrove food chain can support a healthier, greater and wider population of mangal life including avifauna, aquafauna and terrafauna.
1.2 The Physical Definition of Darwin Harbour: For the purpose of this report the area for consideration has been determined as the area of sea to the south-east of a direct line between Lee Point in the north of Darwin to Charles Point to the south of Darwin. This area includes the tidal seas and tidal wetlands of the Darwin Harbour region but does not the greater Darwin Harbour Catchment area (See map 1).
1.3 Determining the Study Environment: There are three fundamental factors which are important to Darwin Harbour. They are (a) the Water; (b) the traditional human environments and (c) the definition of the study area.
1.3.1 The Water: The presence of good, quality and flowing water is imperative to any wetland watercourse. The presence of non-polluted reliable, water in Darwin Harbour is essential for human well being. Therefore water is a crucial constituent in the build-up of the Darwin Harbour's construct.
1.3.2 The Traditional Environments: Occupying this space is the organic and the inorganic substances inherent in this area. These are the living biota residing in the various habitats and the non-living objects such as the geological strata and structure of the area.
1.3.3 The Importance of Darwin Harbour:
Russell J. Stevens
