Shelley Burgin

BioBanking: an environmental scientist’s view of the role of biodiversity banking offsets in conservation

Offsets, first formalised in the United States of America in the 1970s for wetland mitigation, are now widely used globally with the aim to mitigate loss of biodiversity due to development. Embracing biodiversity offsets is one method of governments to meet their commitments under the Millennium Development Goals and the Convention on Biological Diversity. Resource extraction companies see them as a method of gaining access to land, while the community may perceive them as a way of enhancing environmental outcomes. In New South Wales, Australia, BioBanking legislation was introduced in late 2006 with the aim of ‘no net loss’ of biodiversity associated with development, particularly expanding urban and coastal development. The strengths of the legislation are that it aims to enhance threatened species conservation, and raise the profile of conservation of threatened species and habitats. Weaknesses include (1) the narrowness of the definition of biodiversity; (2) the concepts are based on a flawed logic and immature, imprecise and complex science which results in difficulties in determining biodiversity values; (3) likely problems with management and compliance; and (4) an overall lack of resources for implementation and long-term monitoring. It is concluded that the legislation is a concerted effort to deal with biodiversity loss, however, stakeholders have concerns with the process, and it is unworkable with the complexity of such ecosystems (compared for example to carbon credit trading), and underdeveloped disciplines such as restoration biology and ecology. Despite these criticisms, there is a need for all stakeholders to work to improve the outcomes.

Urban wildlife : more than meets the eye

EVER since European settlement of Australia, there have been countless species of fauna which have dramatically declined in distribution and abundance. In the past 200 years, at least 21 species of birds and 19 species of mammals have become extinct (Burgman and Lindenmayer 1998). This pattern of extinction is evident throughout the mainland and islands of Australia, although the local extinction of fauna in urban areas is often overlooked. How and Dell (2000) present alarming data on the plight of urban fauna in Perth, where over half of the native mammal species have become locally extinct.

'Tough love and tears' : learning doctoral writing in the sciences

Contemporary changes to the doctorate mean student researchers are likely to be expected to write differently, write more and more often, and yet, despite a growing interest in doctoral education, we still know relatively little about the teaching and learning practices of students and supervisors vis-a-vis doctoral writing. This paper draws from a research study into the writing experiences of higher degree students and their supervisors in one science, health and technology-based university Faculty. The study used surveys, interviews and focus groups to collect information from students and supervisors about their experiences of doctoral writing and their perceptions about its development. By attending to the writing-related pedagogical practices of supervisors, this article explores how doctoral writing can be the stage for the playing out of tensions over changing roles and identities aggravated by contemporary pressures on doctoral education.

Recreational impacts on the fauna of Australian coastal marine ecosystems

This paper reviews recent research into the ecological impacts of recreation and tourism on coastal marine fauna in Australia. Despite the high and growing importance of water-based recreation to the Australian economy, and the known fragility of many Australian ecosystems, there has been relatively limited research into the effects of marine tourism and recreation, infrastructure and activities, on aquatic resources. In this paper we have reviewed the ecological impacts on fauna that are caused by outdoor recreation (including tourism) in Australian coastal marine ecosystems. We predict that the single most potentially severe impact of recreation may be the introduction and/or dispersal of non-indigenous species of marine organisms by recreational vessels. Such introductions, together with other impacts due to human activities have the potential to increasingly degrade recreation destinations. In response, governments have introduced a wide range of legislative tools (e.g., impact assessment, protected area reservation) to manage the recreational industry. It would appear, however, that these instruments are not always appropriately applied.

Hotspots of biodiversity or homogeneous landscapes? : farm dams as biodiversity reserves in Australia

In many countries the ubiquitous farm dam or pond is an integral component of agricultural landscapes. In Australia there are in excess of half a million farm ponds, used largely for irrigation or for watering stock. In contrast to Europe, these wetlands are being decommissioned in response to the introduction of government policy that regulates water usage from these dams. They are also being in-filled with expanding urbanisation without consideration of their benefits as reservoirs of biodiversity. We compared the diversity of macroinvertebrates in farm dams with nearby stream habitats on a cool temperate tableland in central New South Wales. There was greater diversity in-stream than in the dams; however, dam sites showed a larger mean diversity and total diversity per site than in-stream. Species recorded in-stream were more frequently represented by single individuals while species were recorded more consistently in dams. We also observed that macroinvertebrate assemblages were more similar to those in the same dam in different seasons than to adjacent dams in the same season. Some species recorded had not previously been recorded from farm dams. In contrast to the general consensus that Australian farm dams are homogeneous environments with a range of common widespread species, we showed that they provide a variety of sustainable reservoirs of biodiversity within the landscape. They also have the potential to provide ‘stepping stones’ between undisturbed and modified habitats, in part countering the fragmentation that occurs as a result of agricultural practices.

Impact of urban development on aquatic macroinvertebrates in south eastern Australia: degradation of in-stream habitats and comparison with non-urban streams

Internationally, waterways within urban areas are subject to broad-scale environmental impairment from urban land uses. In this study, we used in-stream macroinvertebrates as surrogates to measure the aquatic health of urban streams in the established suburbs of northern Sydney, in temperate south eastern Australia. We compared these with samples collected from streams flowing in adjacent naturally vegetated catchments. Macroinvertebrates were collected over a 30-month period from riffle, edge and pool rock habitats and were identified to the family level. Macroinvertebrate assemblages were assessed against the influence of imperviousness and other catchment and water quality variables. The study revealed that urban streams were significantly impaired compared with those that flowed through naturally vegetated non-urban catchments. Urban streams had consistently lower family richness, and sensitive guilds were rare or missing. We found that variation in community assemblages among the in-stream habitats (pool edges, riffles and pool rocks) were more pronounced within streams in naturally vegetated catchments than in urban waterways.

Effects of non-consumptive wildlife-oriented tourism on marine species and prospects for their sustainable management

Marine non-consumptive wildlife-oriented tourism, whereby tourists observe and/or interact closely with animals, without purposely having a detrimental effect on them, has been growing globally in recent decades. Human-mediated feeding (provisioning) is widely used by tour operators to attract target species, facilitate viewing and interaction with tourists. Although potential effects of such provisioning on terrestrial fauna have been given moderate scientific research attention, equivalent research in the marine environment is limited. Effects of provisioning marine wildlife may include direct habituation, behavioural change, and/or dietary impacts among individuals and species. There may also be disruption to the species associated assemblage. It was found that the literature on the effects of non-consumptive wildlife tourism is fragmented and results from different areas and taxa are frequently contradictory. Most studies appeared to be of a few years duration, at most. This reflects the relative immaturity of the industry - many enterprises studied typically commenced within the 1990 s. Studies (other than fish) tended to focus on a focal species with few addressing the wider implications for the associated assemblage. Supplementary feeding may also have impacts on the health and wellbeing of provisioned animals. It is concluded that such nature tourism is often not benign - focal species and their assemblage are often disrupted. We conclude that funding to better understand the impacts and thus address them is imperative. To supplement funding for the research and monitoring required, an additional charge could incorporated into the fee charged to those engaging in marine wildlife tourism.

Patterns of bird predation on reptiles in small woodland remnant edges in peri-urban north-western Sydney, Australia

The predator–prey relationship plays an integral role in community structure. In the presence of habitat fragmentation, the dynamic interaction among co-existing species may be disrupted. In this paper we investigated the interaction between small skinks resident in open woodland remnants and the predatory birds that cross-forage between the remnants and the surrounding peri-urban matrix. Skinks were found in significantly fewer numbers in the edge of remnants compared to their core. In contrast, predatory birds were in largest numbers at the edge compared to the core of remnants. We found that there was a strong negative correlation between skink numbers and predatory birds (individually and combined) consistent with higher predation pressure in the edge compared to the core of remnants. Strike rates on decoys that mimicked skinks were also higher in the edge compared to core habitats, consistent with higher predation rates in this edge habitat.

Effects of organic and heavy metal pollution on chironomids within a pristine upland catchment

Several studies, particularly in the Northern Hemisphere, have demonstrated that chironomids are responsive to pollution (e.g., heavy metals, organic). In Australia, there is limited evidence that chironomid species have differential sensitivities to water pollution, with several studies reporting high tolerance of heavy metal pollution. We investigated the impact of both zinc-rich mine waste and organic effluent on chironomids within an effectively pristine background using the Chironomid Pupal Exuviae Technique (CPET). Chironomid species assemblages were strongly influenced by both mine drainage and organic pollution. Community composition differed between unpolluted streams and locations downstream of the pollution sources, and between the two different sources of pollution. Thirty seven of the most abundant species exhibited strong responses to water pollution varying from greatly increased abundance to complete absence. Ten species had higher abundance at one of the polluted sites compared to unpolluted sites; six in the presence of zinc pollution and five in the presence of organic pollution. One species responded positively to both pollution types. Our results indicate that contrary to the mixed reports of Australian chironomids for being insensitive to pollution, we found that they displayed a strong pollution response to both organic and heavy metal contamination.

Carnivory and nitrogen supply affect the growth of thebladderwort Utricularia uliginosa

A glasshouse experiment was designed to determine whether the terrestrial bladderwort species Utricularia uliginosa Vahl. gained any growth advantage from carnivory at different levels of nitrogen enrichment of the substrate. Three organism treatments were used: a control, a protist-only treatment (Euglena spp.) and a protist + meiofauna treatment (Euglena spp. plus nematodes, copepods, ostracods, cladocerans and Acarina). The organism treatments were factorially combined with three nitrogen levels (N0, N1, N2). Populations of Euglena were successfully established in the substrate of pots in the protist, and meiofauna + protist treatments, and were found in the traps of plants growing in these treatments. Populations of the meiofauna from the inoculating cultures were successfully established in the meiofauna + protist treatment, and were trapped by plants in these treatments. A background contamination of the control and protist-only treatments by Acarina occurred over the course of the experiment; however, numbers of Acarina in these treatments were at least an order of magnitude lower than numbers of meiofauna in the meiofauna + protist treatment. Non-acarinid meiofauna were restricted solely to the meiofauna + protist treatment. Organism treatment interacted significantly with the nitrogen level of the substrate to affect growth of Utricularia. Plants trapping Euglena (+ Acarina) had significantly less dry weight than control plants at the N0 base level of nitrogen; this negative effect of trapping Euglena on plant growth disappeared at the two higher nitrogen levels. The dry weight of plants trapping the full range of meiofauna at the N0 level was comparable with control plants. Plants trapping the full range of meiofauna + Euglena at the N1 level had significantly more dry weight than plants trapping Euglena only, and the highest dry weight of any treatment; the benefit of trapping the full range of meiofauna + Euglena was non-significant at the N2 level. Dry weight of plants was not significantly affected by nitrogen in any organism treatment. These results suggest that carnivory was overcoming a nitrogen deficiency induced by Euglena at the N0 level, but was overcoming deficiencies of other nutrients at the N1 level.