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The Conversation

10 October 2013


Australia is already feeling the effects of climate change, with record-breaking temperatures not just over summer, but over the past 12 months as well. Research suggests that such events are many times more likely thanks to climate change.

The IPDD fifth assessment report on climate science found evidence for climate change is unequivocal. The impacts of increasing frequency and intensity of extreme weather events on people and our environment are real and undeniable. But what’s happening to our animals and plants? Our research in Queensland is starting to give us some clues. Read more

 

 

 

The Conversation

23 July 2013


Rising temperatures are linked to a decrease in carbon dioxide (CO2) absorption by tropical forests, according to a 50-year study published today.

Greenhouse gases, such as CO2, contribute to global warming, sea level rises and extreme weather events, previous studies have shown. Read more

 

 

 

Dr. Helen Murphy (CSIRO)

Containment is a frequently advocated strategic objective for countering plant invasions. The goal of containment is to prevent establishment and reproduction of a species beyond a predefined area, whereas eradication aims to remove all individuals of a species.  Containment is often perceived as a valid fallback option when eradication has failed or is deemed impossible with the available resources.  However, many infestations are likely to be no more amenable to containment than eradication, because the ecological drivers that determine containment success are the same as those that limit successful eradication, e.g. seed-bank persistence, dispersal mechanisms and capacity, and detectability. 

CSIRO Tropical Ecosystems Hub researchers in collaboration with QPWS (Project 7.2 Invasive species risks and responses) have been using modelling approaches to understand where, why and when land managers might shift their management focus from eradication to containment.  We have undertaken a net present value analysis of the costs of eradication and containment and derived rules to guide land managers in determining (1) the circumstances under which a containment strategy is likely to be more effective or efficient than an eradication strategy, (2) the effect of a ‘breach’ (i.e. establishment or reproduction outside predefined management areas) on each type of management strategy, and (3) the situations in which containment would form a valid fall-back strategy for a breach in an eradication program. 

While containment has one major advantage over eradication, in that a smaller area can be managed, this must be balanced against its disadvantage; that it must continue indefinitely. Our modelling results show how different invasions will be more effectively managed by either eradication or containment based on the soil seed longevity, the discount rate, and most importantly, the size of the infestation relative to the width of the buffer zone which is defined by dispersal capacity.  Thus, invasive species with long soil seed bank lifetimes in economic systems with high discount rates will tend to be better managed with containment than eradication. Crucially, there is a threshold invasion size below which it will be better to eradicate than contain, and above which the opposite is true.

Our research also clearly shows that the two management strategies incur very different additional costs if they experience an unexpected breach. This suggests that a consideration of the likely types of breach in a given system may provide further support for either eradication or containment, but also that automatically accepting containment as a default fall-back for a breached eradication program is not valid.

Figure 1. Zones of eradication and containment. When the invasion diameter is small relative to the distance over which seeds are dispersed, eradication is likely to be cheaper than eradication over the long term. When seeds are long-lived in the soil or the discount rate is high, containment is likely to be cheaper than eradication.

 

Figure 2. A simple model of weed management and possible breaches of containment. The radius of the occupied zone, r, is comparable to the size of the invasion. The width of the buffer zone, d, should be related to dispersal processes of the invader (Fletcher et al. 2013).

For more information, contact Dr. Helen Murphy (helen.murphy@csiro.au)

 

 

The Torres Strait is a region dominated by marine environments that provide resources for local communities and have important social and cultural values. The condition of marine water quality can influence marine foods, human health, marine ecosystems and ecological processes in the region.

Previously, no detailed water quality hazard analysis was done for the region, however, potential issues were identified, including regional pollution linked to mining, port developments and land clearing, primarily in Papua New Guinea; more localised pollution from sewage and stormwater discharge; and pollution directly and indirectly associated with shipping, including marine infrastructure.

A Tropical Ecosystems Hub project lead by the TropWater team at James Cook University described all existing and potential sources of pollution and associated risks to the Torres Strait marine environment and public health. The information was documented to facilitate uptake of findings to key research users, and to design a basic monitoring program that measures the success of pollution management in the Torres Strait.

The project team developed a hydrodynamic model to better understand the dispersal of different water borne pollutants and the associated risks as many of the pollutants are large scale and mostly derived from outside the Torres Strait region. The model revealed variable flushing, including highly energetic small-scale flow dynamics near shoals, reefs, islands and passages, while water tends to stagnate in other areas where pollutants, including metals, may accumulate.

The project found that, whilst there are a number of local pollutant sources that may pose a risk to marine ecosystems and foods in the Torres Strait, the largest threats come from beyond the region and are compounded by the potential risks associated with the transit of large ships.

Information on the current status and future potential of pollutant sources in the region is now available in a spatial database.

Jon Brodie & Jane Waterhouse, TropWater, JCU

 

English.news.cn

15 October 2013


CANBERRA, Oct. 15 (Xinhua) -- Australian scientists found that an innovative new approach to sugar cane plantation weed management trialed in select Great Barrier Reef (GBR) catchments have shown a dramatic 90 percent reduction in runoff of highly soluble herbicides into waterways, a latest research statement of CSIRO, Australian national science body, showed on Tuesday.

The results of the study have been published in the international journal Science of the Total Environment. It is supported by the Australian federal government through Reef Rescue Research and Development funding from Caring for Our Country Initiative. The Reef Rescue program is a five-year, 200-million-AU dollars (almost 189.3 million US dollars) investment by the Australian government. Read more

The Morning Bulletin

15 October 2013


A NEW national opinion poll conducted by Essential Research show four in every five Australians want dredging and dumping banned in the Great Barrier Reef, according to the Australian Marine Conservation Society.

Great Barrier Reef campaign director Felicity Wishart said dredging and dumping should not be taking place in the World Heritage-listed reef. Read more

 

 

Mother Nature Network

03 October 2012


The Australian government admits the Great Barrier Reef has been neglected for decades after a study showed it has lost more than half its coral cover in the past 27 years.
Environment Minister Tony Burke said research released Tuesday by scientists from the Australian Institute of Marine Science and the University of Wollongong should be setting off alarm bells across the country. Read more
 
 
 
 

Channel NewsAsia

10 July 2013


Australia admitted Wednesday conditions at the Great Barrier Reef are "poor" as it battles UNESCO threats to downgrade its heritage status over concerns about pollution and development.

Environment Minister Mark Butler released a report card showing that the reef's health had slumped since 2009 due to cyclones and floods, despite progress on reducing agricultural runoff. Read more

 

 

 

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