Kathryn H Taffs

Palaeolimnology in eastern and southern Australian estuaries

John Tibby et al. — Sun, 05 Feb 2012 20:10:46 PST

Forestry at Southern Cross University: fifteen years in review

Diana Lloyd et al. — Sun, 05 Feb 2012 20:10:44 PST

After 15 years, it is timely to review the 4-year bachelor degree in forestry offered by Southern Cross University (SCU), now the only remaining such 4-year degree in Australia. The SCU program is characterised by innovative teaching, a strong fieldwork component, emphasis on research, and strong links with local interest groups (both environmental and industrial). The progressive introduction of two-site delivery and on-line lectures has maintained the viability of the course despite modest student demand.

The Burrum River estuary: identifying reference sites for Australian sub-tropical esturine systems using paleolimnological methods

Brendan Logan et al. — Sun, 05 Feb 2012 20:10:43 PST

There is a pressing need to obtain historical information on estuaries so that levels of natural variability and ecosystem thresholds can be identified. Once these factors are known, estuaries that exhibit high conservation value and minimal impact from anthropogenic activity can be acknowledged and protected. In order to understand and quantify the level of change that may have occurred due to human impact, near pristine estuaries that have the potential to act as reference sites need to be identified. However, this is often difficult due to a lack of documented knowledge of estuary variability. This paper retrospectively assesses environmental conditions in the Burrum River, a sub-tropical east Australian estuary on the coast of Queensland, using diatom and stable isotope analyses. These techniques were combined with AMS ¹⁴C dating methods to determine if this system has undergone any natural or anthropogenically induced change. Diatom assemblages have shown very little variation over the past 5,000 years, indicating minimal changes to water quality. Upper and lower limits for δ¹³C and δ¹⁵N stable isotope results also infer that the sources of carbon and nitrogen to the Burrum River estuary have remained constant over this time period. Carbon inputs have been dominated by marine autotrophic production, whilst nitrogen inputs are indicative of terrestrial sources. Hence, the Burrum River has not been altered by anthropogenic activities and is a suitable reference site for benchmarking impacted sub-tropical estuaries. This paper demonstrates that paleolimnological techniques can be applied successfully to identify estuaries that are suitable as reference sites.

Applying paleolimnological techniques in estuaries: a cautionary case study from Moreton Bay, Australia

Brendan Logan et al. — Tue, 28 Sep 2010 17:43:05 PDT

Paleoecological techniques provide useful tools to identify restoration targets and natural variability for management programs. In the past decade development of these techniques has enabled the application of paleoecology within estuarine environments. However, despite these advances, caution needs to be exercised when employing paleoecological techniques in some estuary types. This study used a novel combination of chronological, diatom, geochemical and isotopic data to develop an understanding of the environmental changes that have occurred as a result of human activities within Moreton Bay, an open estuarine environment in sub-tropical east Australia. Results indicated mixed success of these techniques with 210Pb results indicating only background levels, 14C results indicating sediment deposition from mixed sources, no diatom preservation and inconsistent results between geochemical and isotope proxies. Sufficient evidence did exist to identify that the Moreton Bay sediments have been derived from different sources over the past 10 000 years, most likely as a result of rainfall changes to the adjacent catchment areas. However, isotope records were not able to identify the most likely sources of these sediments. Problems with diatom preservation were most probably due to the marine salinity and high temperatures associated with a sub-tropical open embayment estuary. It is recommended that these results are reflected upon for development of future estuarine paleolimnological studies. Past results have indicated successful application of paleoecological techniques in riverine estuaries. Hence, it is recommended that future studies attempting to identify environmental history of estuaries incorporate river influenced locations rather than marine dominated sites. This should ensure better diatom preservation and more definitive geochemical signals

Differentiating records of recent climate change from anthropogenic impact in the coastal margin: an example form eastern Australia

Kathryn H. Taffs — Wed, 15 Sep 2010 16:55:14 PDT

Historical nutrients status in the Richmond River in the absence of monitoring data

Brendan Logan et al. — Tue, 24 Aug 2010 16:10:47 PDT

A monitoring program for the recovery of Salty Lagoon, Evans Head, NSW

Kathryn H. Taffs — Tue, 24 Aug 2010 16:10:47 PDT

Implementation of a monitoring program for the recovery of Salty Lagoon, Evans Head, NSW

Kathryn H. Taffs — Tue, 24 Aug 2010 16:10:46 PDT

Assessing changes in nutrient status in the Richmond River estuary, Australia, using paleolimnological methods

Brendan Logan et al. — Tue, 24 Aug 2010 16:10:45 PDT

Eutrophication from nutrient over-enrichment is a serious problem for the coastal zone and the estuarine environment globally. Australian estuaries are generally oligotrophic, but assessing whether they are becoming more eutrophic over time is inhibited by a lack of long-term monitoring data. The Richmond River, Australia, provided an ideal example of an estuary under anthropogenic pressure where the use of paleoecological techniques may potentially be used to reconstruct changes in nutrient status over time. Five cores were extracted from depositional areas in the Richmond River, and subjected to paleo-magnetic profiling and loss-on-ignition testing to ensure the core of greatest integrity was selected for further analytical work. Results from diatom and stable isotope analyses combined with 210Pb and AMS 14C dating show a strong indication that the total phosphorus levels in the Richmond River have fluctuated since 1940. Evidence also suggests that these fluctuations are most likely a function of climate. This study has successfully applied paleolimnological techniques to the estuarine environment to produce information that can be used by environmental managers to aid decision making in relation to nutrient control for the Richmond River. Further work using paleolimnological techniques should be aimed at the extraction of a core containing diatoms that pre-date European settlement and include analyses of specific lipids and fatty acid biomarkers.

Forensics report

Jeffrey F. Parr et al. — Tue, 24 Aug 2010 16:10:45 PDT

Palaeoecology: a tool to improve the management of Australian estuaries

Krystyna M. Saunders et al. — Sun, 29 Nov 2009 16:26:47 PST

Addressing environmental problems in estuaries is a worldwide problem. Establishing benchmarks and targets for management is critical, whether the aim is conservation, restoration or ‘sustainable wise use’. Palaeoecological techniques have rapidly improved during the past decade, particularly with advances in methods that allow high resolution quantitative assessments of environmental change, allowing pre-impact conditions, the rate, extent and direction of change, and range of natural variability to be determined. Australian estuarine ecosystems are qualitatively different to the often more well-studied estuaries in North America and Europe, which means site-specific studies of Australian estuaries are needed to inform management. While a potentially useful and valuable tool, palaeoecological techniques have not yet been widely adopted and practically implemented as part of estuarine management strategies and policy frameworks in Australia.

We discuss the role palaeoecological techniques have to play in estuarine management and current problems limiting their adoption and implementation. We aim to encourage communication and dialogue between scientists and environmental managers about the potential for widespread practical adoption and implementation of palaeoecological techniques into Australian estuarine science, management and policy frameworks.

Mapping the environment: reflections on a self-guided geography teaching book and its interrelationships with internal and external delivery of a University course

William E. Boyd et al. — Wed, 30 Sep 2009 21:43:34 PDT

Sampling of land types by protected areas: three measures of effectiveness applied to western New South Wales

R L. Pressey et al. — Sun, 19 Apr 2009 22:45:29 PDT

At the end of 1997, the Western Division of New South Wales had 22 reserves with a total extent of 9458 km2 or 2.9% of the region. We used five measures to follow the effectiveness of the reserve system as it developed between 1960 and 1997. Two of the measures — number and total extent of reserves — are basic statistics in any review of protected areas. The other three measures concern how well the reserve system sampled the region's land types (e.g. ecosystems, vegetation types), defined here as land systems mapped at 1:250,000. The first of these measures was representativeness — the number of land systems sampled to a threshold level. The second was efficiency — the proportion of the reserve system contributing to, but not in excess of, conservation targets set for each land system. The third measure of sampling effectiveness was vulnerability bias — the extent to which reserves have been dedicated in parts of the region with most risk of vegetation loss. The representativeness of the reserve system at the end of 1997 was very low. Results for efficiency showed that a substantial part of the reserve system was not contributing to conservation targets. This partly reflected extensions of reserves to improve their design, highlighting the trade-off between design and efficiency. Values for vulnerability bias were close to those expected if reservation had been indifferent to risk of vegetation loss from clearing or cropping. Higher values would be expected if reservation had been intended to secure good examples of the more vulnerable land systems before clearing or cropping compromised conservation targets. Fluctuations in efficiency and vulnerability bias since 1960 can be related to the establishment and extension of individual reserves. We finish the paper by placing our measures of effectiveness in the context of a more comprehensive list needed to deal with issues such as environmental gradients and species' requirements for long-term persistence.

The role of surface water drainage in environmental change: a case example of the Upper South East of South Australia; an historical review

Kathryn H. Taffs — Sun, 19 Apr 2009 22:45:26 PDT

The role of surface water drainage in environmental change in Australia is rarely appreciated. Drains can modify surface water hydrology, not only altering flow regimes but also rapidly dispersing contaminants and altering the natural hydrological balance of associated flora and fauna. Yet drainage continues to be considered a viable management strategy rather than as a cause of land degradation. The impact of surface water drainage in an inherently saline area of South Australia, the Upper South East, is investigated. Surface water drains were constructed by developers in an attempt to increase the area of land available and viable for agricultural land use. Drainage strategies altered the natural direction, magnitude and frequency of surface water flow. The Upper South East has experienced periods of both increased surface water and flooding, and surface water deficit, in the past one hundred years. The region now receives less surface water than under pre-European conditions, but local runoff is channelled into and through the wetlands more rapidly than before European settlement. Future management strategies are likely to continue this trend, to the detriment of remnant natural wetlands.

A diatom-based Holocene record of human impact from a coastal environment: Tuckean Swamp, eastern Australia

Kathryn H. Taffs et al. — Sun, 19 Apr 2009 22:45:25 PDT

Diatom-based paleolimnological studies are being increasingly used to track anthropogenic change in estuaries. Little is known, however, about the direction and nature of longterm environmental changes in Australian estuaries. In this study, shifts in diatom assemblages preserved in a ²¹⁰Pb and C¹⁴ AMS dated sediment core from Tuckean Swamp were analysed to determine environmental changes that had taken place as a result of changing land-use practices. Prior to European impact, the diatom assemblage remained relatively stable and was dominated by Actinocyclus normanii and Diploneis smithii. An increasing dominance of Cyclotella meneghiniana correlates well with changed land use activities in the catchment area and indicates an increase of freshwater influence in the swamp’s environment. A major shift in species composition began ~1970, Eunotia flexuosa becoming dominant. The assemblage shifts recorded at this site appear to be consistent with environmental changes triggered by human activities such as vegetation clearance, drainage and the construction of a barrage. This study demonstrates the use of paleolimnoology in an estuarine environment to provide pre-impact data necessary for management of the aquatic environment.

A microwave digestion technique for the extraction of fossil diatoms from coastal lake and swamp sediments

Jeffrey F. Parr et al. — Sun, 19 Apr 2009 22:45:24 PDT

This study provides an introduction to a microwave digestion technique for the extraction of fossil diatoms from sediments. The microwave technique is compared with the standard diatom extraction technique of Battarbee (Diatom analysis. In: Berglund B.E. (ed.), Handbook of Holocene Palaeoecology and Palaeohydrology. John Wiley and Sons) that uses a combination of dilute hydrochloric acid and hydrogen peroxide and the advantages and disadvantages of their use are discussed. The results suggest that the microwave technique is fast, inexpensive and most importantly produces replicable fossil diatom assemblage data. Small samples sizes are used (0.3 g) for the microwave method thus lower quantities of chemicals are required (6 ml), which significantly decreases the cost of sample processing. Our results show that the microwave digestion technique is a viable alternative that will produce similar results within a shorter period of time.

Mapping the environment: a professional development manual

William E. Boyd et al. — Sun, 19 Apr 2009 22:45:23 PDT

This book provides a basis for developing skills in the most fundamental techniques used, and an overview of the more advanced methods and equipment available for studying, recording, interpreting and communicating information about the environment. Includes 140 useful exercises that encourage practical application of theories.

The distribution and abundance of marine debris on isolated beaches of northern New South Wales, Australia

Kathryn H. Taffs et al. — Sun, 19 Apr 2009 22:45:22 PDT

Beach debris items were collected and categorized during surveys of five isolated beaches on the northern New South Wales coastline in September 2003. The selected beaches covered more than 21 km of contiguous coastline. Litter density and distribution per 500 m segment was calculated. The highest density of litter was found on the most isolated beaches with little public access but no protection by headlands from the ocean swells. The results indicate that management of beach debris needs to focus on reducing the litter entering the marine environment.

Diatoms as indicators of wetland salinity in the Upper South East of South Australia

Kathryn H. Taffs — Sun, 19 Apr 2009 22:45:21 PDT

Wetland degradation in the Upper South East of South Australia is an urgent management concern. Scant recent environmental data is available for the region and long-term monitoring data is lacking. Usually a palaeoecological analysis is able to reveal environmental change in the medium- to long-term past. However, the region is not conducive to palaeoecological investigation due to a fluctuating upper groundwater aquifer and alkaline soils which have destroyed most microfossils. It was found that the diatom assemblage was preserved in the wetlands of the region for the period of European settlement. Analysis of the diatom assemblage enabled production of an inferred salinity curve. In combination with a small amount of historical information that was available, the salinity trend for the wetlands, for the period of European agricultural activities, was identified. It was found that, while groundwater salinity has been increasing, the wetland areas have experienced a freshening of surface water. This is due to an increase of throughflow of surface water, a result of constructed drainage systems flushing salts from the wetlands. Despite the freshening of wetlands they continue to degrade due to the changed hydrology, an impact of the drainage structures.

Scheduling priority conservation action in production landscapes: priority areas in western New South Wales defined by irreplaceability and vulnerability to vegetation loss

R L. Pressey et al. — Sun, 19 Apr 2009 22:45:19 PDT

Scheduling conservation action is necessary when the available resources for conservation are insufficient to adequately protect all of the natural features (e.g. species, vegetation types, ecosystems) in a region, at least in the short-term. We propose an approach to scheduling conservation action in production landscapes. It is based on two characteristics of potential conservation areas. The first is vulnerability — the likelihood or imminence of destruction or alteration of native vegetation. The second is irreplaceability — the likelihood that an area will be needed to contribute to a set of conservation targets nominated for the region's features. We argue that highest priority for conservation action should go to those areas with both high vulnerability (urgent protection needed to avoid destruction) and high irreplaceability (few or no alternatives if destroyed). To establish the context and rationale for our approach, we review some previous methods for scheduling nature conservation. We then apply our approach to the Western Division of New South Wales, a region of about 325,000 km2, by deriving information on the vulnerability of 248 land systems to two threatening processes (clearing and cropping) and measuring the irreplaceability of potential conservation areas. Our results are maps of areas where conservation action is most urgently needed if regional conservation targets are not to be compromised.