Kimberley James

Responses of freshwater biota to rising salinity levels and implications for saline water management: a review

All of the plants and animals that make up freshwater aquatic communities are affected by salinity. Many taxa possess morphological, physiological and life-history characteristics that provide some capacity for tolerance, acclimatisation or avoidance. These characteristics impart a level of resilience to freshwater communities. To maintain biodiversity in aquatic systems it is important to manage the rate, timing, pattern, frequency and duration of increases in salinity in terms of lethal and sublethal effects, sensitive life stages, the capacity of freshwater biota to acclimatise to salinity and long-term impacts on community structure. We have limited understanding of the impacts of saline water management on species interactions, food-web structures and how elevated salinity levels affect the integrity of communities. Little is known about the effect of salinity on complex ecosystem processes involving microbes and microalgae, or the salinity thresholds that prevent semi-aquatic and terrestrial species from using aquatic resources. Compounding effects of salinity and other stressors are also poorly understood. Our current understanding needs to be reinterpreted in a form that is accessible and useful for water managers. Because of their complexity, many of the remaining knowledge gaps can only be addressed through a multidisciplinary approach carried out in an adaptive management framework, utilising decision-making and ecological risk assessment tools.

Using building adaptation to deliver sustainability in Australia

Purpose – This paper seeks to establish the rationale for existing office building adaptation within Melbourne, Australia, as the city strives to become carbon neutral by 2020. The problems faced by policy makers to determine which buildings have the optimum adaptation potential are to be identified and discussed.Design/methodology/approach – This research adopts the approach of creating a database of all the buildings in the Melbourne CBD including details of physical, social, economic and technological attributes. This approach will determine whether relationships exist between attributes and the frequency of building adaptation or whether triggers to adaptation can be determined.Findings – This research provided evidence that a much faster rate of office building adaptation is necessary to meet the targets already set for carbon neutrality. The findings demonstrate that a retrospective comprehensive examination of previous adaptation in the CBD is a unique and original approach to determining the build...

Effect of salinity on four freshwater macrophytes

The sublethal effects of salinity on four freshwater macrophyte species commonly found in floodplain wetlands in north-eastern Victoria (Myriophyllurn crispaturn, Eleocharis acuta, Potarnogeton tricarinatus and Triglochin procera) are reported. These species taken from the same freshwater wetland showed a wide range of salt sensitivities; P. tricarinatus was the most sensitive followed by M. crispatum and then E. acuta and T. procera. A progressive depression of growth rate and plant size was observed for each species when grown at salinities greater then 1000 mg L-1. The onset of these changes in growth pattern occurred earlier at the higher salinities. Both sexual and asexual reproduction were blocked in M. crispatum at salinities greater than 1000 mg L-1, even though 52% of plants survived after 72 days growth in water of salinity 7000 mg L-1.

Impact of secondary salinisation on freshwater ecosystems: effect of experimentally increased salinity on an intermittent floodplain wetland

Intermittent wetlands are particularly at risk from secondary salinisation because salts are concentrated during drawdown. We conducted a field experiment to examine the effect of adding salt at two different concentrations (to achieve nominal conductivities of 1000 μS cm–1 (low salt) and 3000 μS cm–1 (high salt)) on water quality, freshwater plants and epiphytic diatoms in an intermittent wetland during a 3.3-month drawdown. Conductivity increased to 3000 and 8500 μS cm–1 in low-salt and high-salt treatments respectively. Salt was apparently lost to the sediments, causing protons to be released from the sediments and reducing water column pH from 6.9 to 5.5 in the low-salt treatment and to 4.0 in the high-salt treatments. Forty days after adding the salt, biomass, %cover and flower production in Potamogeton cheesmanii were significantly reduced, whereas Amphibromus fluitans was not significantly affected. The salt effect on Triglochin procera was intermediate between the other two macrophytes. Significant reductions in the density, species richness and diversity of epiphytic diatoms occurred in the high-salt, but not in the low-salt, treatments. Our work shows that increases in salinity, and thus conductivity (up to 8500 μS cm–1), in low-alkalinity intermittent wetlands can change water quality, with significant adverse effects on some macrophyte and diatom communities.

The value of oral history in natural resource management : the Balcombe Estuary Reserve, Mount Martha, Victoria

Abstract This study investigates the benefits of using oral history as a tool for the sustainable management of estuaries. Twenty-two semi-structured interviews were conducted to generate oral history records for the Balcombe Estuary Reserve, a small estuary in a periurban zone on the Mornington Peninsula, Victoria. These interviews establish a more complete picture of changes in land use and ecological change to the estuary since European settlement of the area, and document community values. The interviews were followed with a survey to further explore management issues in the area. Use of oral history was found to be an effective approach to assist holistic estuarine management, especially when complemented by other sources of information.

Examining the perception of tenants in sustainable office buildings

Purpose – The purpose of this paper is to address two major challenges faced by sustainable building owners: first, address the gap between an occupant’s expectations of sustainable building outcomes and what the building actually provides and second, overcome the lack of user knowledge about sustainability design and operation for a particular with regards to performance. Design/methodology/approach – This study used a focus group approach to investigate the gap between: user expectations and sustainable building performance. The study surveyed occupants of sustainable office buildings in Melbourne, Australia. Findings – There is no significant relationship between users’ expectations and users’ experience of sustainable building performance and users’ knowledge about sustainability and the building they were worked in. Research limitations/implications – The research was limited to sustainable office buildings. New office buildings seeking to incorporate sustainability which need to focus on the needs o...