Limitations to the feasibility of using hypolimnetic releases to create refuges for riverine species in response to stream warming

Given predicted increases associated with human-induced climate change, stream temperatures are likely to approach upper tolerance limits of aquatic biota within the coming decades. Little information is available regarding thermal tolerance limits of lotic fauna or mechanisms allowing fauna to persist following high temperature events (e.g. use of thermal refuges). Cold-water refuges can facilitate survival of fish in the Northern Hemisphere, but little evidence of similar refuges exists elsewhere.Planned releases of hypolimnetic, or a mixture of top and bottom, waters from reservoirs have recently been touted as a novel method to potentially ameliorate extreme temperature events. However, the feasibility of this technique has not been fully discussed in the published literature. Therefore, we present a literature review, an analysis of thermal data for some large dams in southern Australia in relation to known thermal tolerances of native fauna, and an assessment of current management practices regarding the technique. We show that hypolimnetic releases have variable impacts on water temperatures downstream of a dam, depending on size, off-take infrastructure and management practices but, even where there is an effect, knowledge gaps are too numerous for this technique to be currently feasible. Furthermore, hypolimnetic releases generally evoke negative connotations among natural resource managers, due to the occurrence of cold-water shock in some species. If knowledge gaps and limitations can be addressed, it is possible that the technique may be considered in future, so we present potential tools for future assessment, capacities and limitations and discuss potential scenarios where environmental managers might consider this technique.

Response of feral cats to a track-based baiting programme using Eradicat baits

Summary The feral Cat (Felis catus) is a significant threat to Australian fauna, and reducing their impacts is considered an essential action for threatened species conservation. Poison baiting is increasingly being used for the broad scale control of feral cats. In this study, we measured the population response of feral cats to a track-based baiting programme using Eradicat baits in the semi-arid northern wheatbelt region of Western Australia. Over two years, 1500 baits were laid once annually and the response of feral cats was measured using remote cameras in a before–after, control–impact design. There was a significant reduction in feral cat activity in the second year, but not the first. During bait uptake trials, corvids removed the most number of baits, followed by cats and varanids. The lack of a response to baiting in the first year may be due to existing low cat numbers in the baited area and/or the timing of the baiting. We provide a list of key recommendations to help inform future cat baiting programmes and research.

Effects of phytophthora cinnamomi on heathland flora and fauna of the Eastern Otway Ranges

The plant pathogen, Phytophthora dnnamomi, is a cause of dieback disease observed in sclerophyll vegetation in Australia, The effects of P. dnnamomi on flora and fauna were studied at two locations in heathland vegetation near the coastal town of Anglesea, Victoria. The pathogen was isolated from soils beneath diseased heathland plants. The extent of diseased vegetation was assessed by the presence and absence of highly sensitive indicator species, Xanthorrhoea australis and hopogon ceratophyllus. The characteristics of heathland vegetation exhibiting dieback disease associated with the presence of P. dnnamomi were investigated. Plant species richness was similar between diseased and non-diseased areas however diseased areas were characterised by significant declines in the cover and frequency of susceptible species, increases in resistant species and increases in percent cover of open ground. Compared to non-diseased areas, diseased areas exhibited fewer shrub species and decreased shrub cover. The percentage cover and number of species of sedges, lilies and grasses were higher in diseased areas. Structural differences were significant between 0-0.6 m with decreased cover of vegetation in diseased areas. Differences in structure between diseased and non-diseased areas were not as great as expected due to increases in the cover of resistant species. A number of regenerating X australis were observed in post-disease areas. Cluster analysis of floristic data could clearly separate diseased and non-diseased trap stations. The population dynamics and habitat use of eight small mammal species present were compared in diseased and non-diseased areas using trapping and radio-tracking techniques. The number of small mammal species captured in post-disease areas was significantly lower than non-diseased areas. Mean captures of Antechinus stuartii and Rattus fiisdpes were significantly lower in diseased areas on Grid B. Mean captures of Rattus lutreolus were significantly lower in diseased areas on both study grids. Significant differences were not observed in every season over the two year study period. Radio tracking revealed more observations of Sminthopsis leucopus in non-diseased vegetation than in diseased. Cercartetus nanus was frequently observed to utilise the disease susceptible X. australis for nesting. At one location, the recovery of vegetation and small mammal communities in non-diseased and diseased vegetation after fuel reduction burning was monitored for three years post-fire. Return of plant species after fire in both disease classes were similar, reaching 75% of pre-fire richness after three years. Vegetation cover was slower to return after fire in diseased areas. Of the seven small mammal species captured pre-fire, five were regularly captured in the three years after fire. General linear model analysis revealed a significant influence of disease on capture rates for total small mammals before fire and a significant influence of fire on capture rates for total small mammals after fire. After three years, the influence of fire on capture rates was reduced no significant difference was detected between disease classes. Measurements of microclimate indicate that diseased, burnt heathland was likely to experience greater extremes of temperature and wind speed. Seeding of diseased heathland with X. australis resulted in the establishment of seedlings of this sensitive species. The reported distributions of the mamma] species in Victoria were analysed to determine which species were associated with the reported distribution of dieback disease. Twenty-two species have more than 20% of their known distribution in diseased areas. Five of these species, Pseudomys novaehollandiae, Pseudomys fumeust Pseudomys shortridgei, Potorous longipes and Petrogale pencillata are rare or endangered in Victoria. Four of the twenty-two species, Sminthopsis leucopus, Isoodon obesulus, Cercartetus nanus and Rottus lutreolus am observed in Victorian heathlands. Phytophthora cinnamomi changes both the structure and floristics of heathland vegetation in the eastern Qtway Ranges. Small mammals respond to these changes through decreased utilisation of diseased heathland. The pathogen threatens the diversity of species present and future research efforts should be directed towards limiting its spread and rehabilitating diseased areas.

Valuation and reporting of native fauna in monetary terms: compatibility between a market-Based system and natural resources?

A change in community values and priorities has introduced ethical,
environmental and social issues into the way in which business conducts
its activities. There are an increasing number of managed investment funds focusing on socially responsible investment (SRI) by concentrating on firms that operate according to predetermined criteria for environmental, social and ethical issues. For investors in these funds environmental stewardship issues are integrated with concern over financial resources and performance. In this paper the accounting and reporting by business activities concerned with conservation of wildlife are examined. The world of accounting has functioned for many years with relatively few accounting standards devoted to specialised industry needs. In 1998 the Australian Accounting Standards Board and in 2001 the International Accounting Standards Board issued standards devoted to agriculture. Both standards deal with the reporting of managed biological assets and require application of essentially the same approaches despite the Australian standard requiring net market value while the International standard requires fair value. In this paper we analyse how one conservation firm Earth Sanctuaries Ltd. (ESL) has applied AASB 1037 and then we explore the implications for conservation firms operating in geographical locations outside Australia. It is suggested that AASB 1037 and indeed lAS 41 may not provide value appropriate information for investor decisions relating to accounting profits for such firms. Our examination shows that it is appropriate to reconsider accounting guidelines provided by these standards in order to link the information relating to economic and environmental performance. Transparency may be improved by a move closer to Elkington 's (1997) triple bottom line reporting. We therefore contend that the issues arising from the use ofAASB 1037 and lAS 41 need to be widely considered by all standard setters, particularly given the increasing attention to SRI.

Land use, water quality and ecological responses in Lake Colac – trends from Australia

Purpose - Recently, Colac Otway Shire in Australia released its management plan for Lake Colac, claiming over-enrichment of the lake with nutrients and degraded water quality. This paper aims to investigate these claims by establishing a correlation between key water and ecological indicators and land uses.

Design/methodology/approach - Examines the correlation between impairment and stressors in Lake Colac. This was achieved by identifying the likely sources of pollutants into Lake Colac; identifying any existing monitoring program; and characterizing the water and sediment inputs. The likely impacts of increased nutrients and sediment levels on indigenous flora and fauna were also examined. The use of meiofauna (very small benthic metazoan animals) was investigated as an indicator of degraded sites. Plankton diversity as a measure of water health was also assessed.

Findings - Water quality in Lake Colac was found to vary both temporally and spatially, and exhibited low attainment against acceptable trigger values/objectives. At current levels the lake can be classified as poorly degraded. Likely sources of pollution were identified to be related to land uses in the catchments. The biota of the lake, investigated at four study sites, yielded a sparse, benthic macrofaunal assemblage that was dominated by oligochaetes. In contrast, an abundant and taxonomically diverse meiofaunal assemblage was noted. Future meiofaunal analyses are likely to resolve suitable biotic indicator species of free-living nematodes in response to land use and waterway threats specified in the study. Originality value - This work will provide a better understanding of integrated environmental systems to enable development of best management practices, thus transforming the way the land and water are used in the future. Following the present work, other key water and ecological indicators (increased dispersion and dominance of biological species) at five additional sites were studied. Alternative management options for the effluent generated at Colac Sewage Treatment Plant and possible ecological effects of each option were also evaluated. More recently, a sediment characterization study was also carried out at sensitive sites representative of locations where build up of sediments and algae outbreaks are reported. This will enable classification of sediment and evaluation of dredging options.

An evaluation of the role and impacts of alien finfish in Asian inland aquaculture

Asia dominates global aquaculture production accounting for over 80% of the total and the mainstay in Asian aquaculture is finfish. Over the years, Asia has experienced a number of inter-continental and intra-continental transfers/introductions/translocation of finfish species, between nations and watersheds, beyond their natural range of distribution, primarily for aquaculture development. In this article all such species are referred to as alien species. An attempt is made to evaluate the importance of the production of alien species in selected Asian nations, using statistics of the Food and Agriculture Organization. Also, negative effects, if any, based on literature surveys, of alien species in relation to displacement of indigenous species, and on biodiversity and/or genetic diversity together with associated pathogen transfers are evaluated. The major alien species, based on their significance to Asian inland aquaculture considered, are the tilapias, catfish, Chinese and Indian major carps and common carp. It is estimated that currently alien species account for nearly 12% of the cultured finfish production (2.6 million tonnes) in Asia, valued at US$ 2.59 billion, and the contribution exceeds 40% when Asian countries excluding China are taken into consideration. Inland finfish aquaculture in some Asian nations, such as Indonesia and the Philippines, is predominated by alien species, and in some others, e.g. Bangladesh and India, the contribution from alien species has been increasing steadily. It is suggested that overall alien finfish species have done little ecological harm to native flora and fauna. However, in the wake of increasing anthropogenic development taking place in watersheds the resulting environments are often made unconducive to indigenous species but not to some alien species, thereby potentially and indirectly making the latter invasive.

Changes in vegetation sand floristics under a powerline easement and implications for vegetation management

Utility corridors such as powerlines are widespread linear easements of highly modified vegetation which often fragment natural areas of conservation significance. Vegetation management along these easements is aimed at modifying vegetation structure by the removal of all tall shrubs and trees, which may have adverse impacts on flora and fauna diversity. Victoria's Bunyip State Park is bisected by a high voltage powerline easement which is managed by a four year slashing cycle. Repeated slashing has altered plant species composition and structure of the drier slope and ridge vegetation compared to unslashed adjacent Open Forest vegetation, but Wet Heath within the management zone has remained largely unmodified. At a broad level, plant species diversity in the easement is increased, and higher vegetation density has created small mammal habitat. The powerline easement did not appear to facilitate weed invasion. Vegetation management by repeated slashing has altered the vegetation, but does not appear to have had adverse conservation impacts on local plant and small mammal diversity.

A Wuchiapingian (Late Permian) brachiopod fauna from an exotic block in the Indus–Tsangpo suture zone, southern Tibet, and its palaeobiogeographical and tectonic implications

A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.

Carboniferous brachiopods from the "Levipustula Fauna" in central-western Argentina : biostratigraphic, palaeoclimatic, and palaeobiogeographic implications

The “Levipustula fauna” is a relatively diverse fossil assemblage composed of brachiopods, bivalves, bryozoans, gastropods and crinoids that appears in glaciomarine sequences related to the Carboniferous glacial event that affected the central-western Argentinean basins. Brachiopods that characterize this fauna have been studied in some of the classical localities of the Argentine Precordillera in San Juan province.

In the Hoyada Verde Formation, the “Levipustula fauna” is usually located immediately above the glacial diamictite horizons and appears to be associated with the mudstones facies of the postglacial transgression. From a palaeoecological study, three brachiopod subfaunas are distinguished in this formation: the lower “Neospirifer” (“Trigonotretidae” gen. nov.) subfauna, above which the more diversified Kitakamithyris subfauna occurs, and the upper Levipustula subfauna, with the dominant species being attributed to Levipustula levis Maxwell. The Hoyada Verde fauna, as well those identified in the La Capilla Formation (Cerro El Morado locality), have been proposed as the typical “Levipustula fauna”. However, in the Leoncito Formation, the “Levipustula fauna” occurs in sandstones horizons located below the glacial diamictite beds. This fauna is poorly diversified and the brachiopods are characterized by “Neospirifer” (“Trigonotretidae” gen. nov.)-Septosyringothyris assemblage and Levipustula is not abundant. This fauna has been considered a colder “pre-interglacial fauna”.

The significant taxonomic, palaeoecologic and taphonomic variations of the “Levipustula fauna”, as well as its position in the glacial sequences, suggest an important palaeoenvironmental control related to Carboniferous glacial dynamics. From the palaeobiogeographic viewpoint, this fauna shows the highest affinity with the Eastern Australian basins from where it was previously described.

Flowering ecology of honey-producing flora in South-East Australia

This report examines the flowering ecology (flowering patterns and the production of floral resources, i.e. nectar and pollen) of important Australian melliferous (honey-producing) flora. Aspects of flowering ecology that can have a negative impact on invertebrates, including honeybees, were also investigated. The research was based on information sourced by highly experienced, commercial beekeepers and, so, provides a valuable written record of long-term observations relating to flowering ecology which otherwise may be lost following the death of beekeepers. Results of this study are of far-reaching importance, not only to the beekeeping industry, but to land managers, the general public and the future of Australian flora and fauna.

An understanding of flowering ecology is vital for many reasons, including implementing appropriate management practices which ensure the sustainability and growth of natural resources and industries like the beekeeping industry. Despite the importance of such studies, very little research has considered flowering ecology in Australian flora. Furthermore, research often was based on short-term data; long-term data are widely acknowledged as being necessary in such research in order to determine ‘real’ flowering patterns. Thus, studies of flowering ecology which use long-term data are vital.

Victorian index of estuary condition : recommended themes and measures

Deakin University was engaged by the Department of Sustainability and Environment to develop an Index of Estuary Condition (IEC) for evaluating the environmental condition of Victorian estuaries. The Index will ultimately complement the existing Index of Stream Condition (ISC) by providing a consistent statewide assessment of the environmental condition of estuaries. This will better enable:

• Estuarine condition to be reported at regional, state and national levels.

• Prioritisation of resource allocation.

• Strategic evaluation of management interventions in estuaries.

Workshops involving participants with expertise in a variety of disciplines were convened to integrate learnings from assessment programs currently being developed interstate and overseas. This report synthesises and builds on the output from those workshops which:

• Identified key components (themes) of estuaries that contribute to estuarine condition.

• Contributed to development of a broad conceptual model for Victorian estuaries

• Identified possible measures of each theme

In keeping with the sub-indices of the ISC, six themes were identified for use in the IEC: Physical form, Hydrology, Water quality, Sediment, Flora and Fauna. Several measures within each theme are recommended to assess estuary condition.

Implementation of particular measures in the IEC partly depends on the investment required to both collect and interpret the required data. With regard to data collection, each measure was assessed according to whether there is an established sampling procedure, how frequently data need to be collected and the level of expertise required for collection and processing. For interpreting the data, measures were scored on whether baseline condition is established and whether descriptions and scores are developed which reflect the extent of deviation from that condition. These scores were used to indicate which measures are feasible to implement immediately and which require further investigation.

A trial of the recommended IEC measures in a selection of estuaries is recommended as it would provide an opportunity to test the measures and their suitability for application statewide. It is suggested that the trial is conducted in estuaries subject to various levels of threats within each of the four estuary classes described by Barton et al. (2008)

Studies on Australian hydroids : the genus Eudendrium and the fauna of the seagrass Amphibolis

An important Athecate genus, Eudendrium, and a group of species of the Thecata, the latter ecologically related by life on a common substrate, are reviewed. Eudendrium, hitherto poorly known in Australia, comprises 17 species, including 10 undescribed species with 71% Australian, and high provincial endemicity. Eudendrium may be a shelf genus avoiding turbulent oceanic waters. Species of Eudendrium are predominantly epizoic and some gregariously settling colonies may live for five years. Identification of sterile material is refined by using the cnidome in a key to classification. The species and population dynamics of hydroid epiphytes of the endemic southern Australian marine angiosperm Amphibolis were investigated with revision of historically vexatious taxa. In contrast with the northern hemisphere, no Athecata are associated with southern Australian seagrasses. Seventeen species from eight thecate families are associated with the two species of Amphibolis, including one undescribed species, H&lecium amphibolum, and one new record for Australia, Aglaophenia postdentata. The Lineolariidae is revised and a new genus, Millardaria, erected for a species from seagrass in Madagascar. The high endemicity (58%) and host-specificity of hydroids to Amphibolis is an evolutionary consequence of isolation of the seagrass dating from break-up of the Tethyan Sea. Hydroids occur throughout the year in the Amphibolis leaf canopy with a mean annual epiphytism of 44% on A. antarctica in the eastern continent and 86% in the western continent; epiphytism is 52% on A. griffithii in the western continent. Half of the eight important species are dominant epiphytes across the southern continent but the species and order of abundance varies regionally. Most are pioneer colonists with short, repetetive life-cycles lasting from weeks to a few months. Three species epiphytise the seagrass stems but only one is a leaf-canopy dominant. The canopy community comprises small, fast-growing species or dwarfed variants of species larger in other habitats: these ecomorphically constant forms are associated only with seagrass. Strategies for survival in the harsh Amphibolis environment include adnate colonies and gonothecae adnate or recumbent to the substrate, marked strengthening of the hydrorhiza, various hydrodynamic adaptations of the hydrotheca, early maturation and production of numerous small ova.

Aspects of the interaction between Xanthorrhoea australis and Phytophthora cinnamomi in south-western Victoria, Australia

Diseases in natural ecosystems are often assumed to be less severe than those observed in domestic cropping systems due to the extensive biodiversity exhibited in wild vegetation communities. In Australia, it is this natural biodiversity that is now under threat from Phytophthora cinnamomi. The soilborne Oomycete causes severe decline of native vegetation communities in south-western Victoria, Australia, disrupting the ecological balance of native forest and heathland communities. While the effect of disease caused by P. cinnamomi on native vegetation communities in Victoria has been extensively investigated, little work has focused on the Anglesea healthlands in south-western Victoria. Nothing is known about the population structure of P. cinnamomi at Anglesea. This project was divided into two main components to investigate fundamental issues affecting the management of P. cinnamomi in the Anglesea heathlands. The first component examined the phenotypic characteristics of P. cinnamomi isolates sampled from the population at Anglesea, and compared these with isolates from other regions in Victoria, and also from Western Australia. The second component of the project investigated the effect of the fungicide phosphonate on the host response following infection by P. cinnamomi. Following soil sampling in the Anglesea heathlands, a collection of P, cinnamomi isolates was established. Morphological and physiological traits of each isolate were examined. All isolates were found to be of the A2 mating type. Variation was demonstrated among isolates in the following characteristics: radial growth rate on various nutrient media, sporangial production, and sporangial dimensions. Oogonial dimensions did not differ significantly between isolates. Morphological and physiological variation was rarely dependant on isolate origin. To examine the genetic diversity among isolates and to determine whether phenotypic variation observed was genetically based, Random Amplified Polymorphic DNA (RAPD) analyses were conducted. No significant variation was observed among isolates based on an analysis of molecular variance (AMQVA). The results are discussed in relation to population biology, and the effect of genetic variation on population structure and population dynamics. X australis, an arborescent monocotyledon indigenous to Australia, is highly susceptible to infection by P. cinnamomi. It forms an important component of the heathland vegetation community, providing habitat for native flora and fauna, A cell suspension culture system was developed to investigate the effect of the fungicide phosphonate on the host-pathogen interaction between X. australis and P. cinnamomi. This allowed the interaction between the host and the pathogen to be examined at a cellular level. Subsequently, histological studies using X. australis seedlings were undertaken to support the cellular study. Observations in the cell culture system correlated well with those in the plant. The anatomical structure of X australis roots was examined to assist in the interpretation of results of histopathological studies. The infection of single cells and roots of X. australis, and the effect of phosphonate on the interaction are described. Phosphonate application prior to inoculation with P. cinnamomi reduced the infection of cells in culture and of cells in planta. In particular, phosphonate was found to stimulate the production of phenolic material in roots of X australis seedlings and in cells in suspension cultures. In phosphonate-treated roots of X australis seedlings, the deposition of electron dense material, possibly lignin or cellulose, was observed following infection with P. cinnamomi. It is proposed that this is a significant consequence of the stimulation of plant defence pathways by the fungicide. Results of the study are discussed in terms of the implications of the findings on management of the Anglesea heathlands in Victoria, taking into account variation in pathogen morphology, pathogenicity and genotype. The mode of action of phosphonate in the plant is discussed in relation to plant physiology and biochemistry.

Water quality, bacterial flora and production in shrimp farms in Sri Lanka

This study investigated the possibilities of improvement in the brackish water shrimp culture industry in Sri Lanka. Feeding rates could be further reduced without negative effect on shrimp growth while improving effluent water quality. Improvements of feed quality and pond management practices were also suggested.