- Daily Telegraph (21 March 2001):
“Rivers run black”
- West Australian (27 March 2001):
“ Estuaries are ailing: study”
- The Australian (4 April 2001):
“ Irrigators to pay more for damage”
- Courier Mail (5 June 2001):
“ Fertiliser and mud ‘burying the Reef’”
- Sydney Morning Herald (21 Feb 2002):
“ Rivers added to NSW’s endangered list”
These headlines are a few recent examples of Australian river and estuarine systems that are in severe trouble due to human activity. Let's look at the first one…
In April 2001, acid plumes with a pH level as low as ‘3’ were detected in the Richmond and Macleay Rivers in northern New South Wales. Although recent acid flows and effects were not as great as in the 1994 floods, frequent low-level acidic discharges will continue to kill benthic organisms and affect estuarine ecosystems.
Cost (loss) to the Fishing Industry in NSW
The annual loss of fish catch in New South Wales as a result of disturbed acid sulfate soils is estimated to be $1 million and a similar figure is estimated for the oyster industry (Department of Natural Resources 1999). Coastal acid sulfate soils disturbance by humans has been linked to major fish kills and outbreaks of red spot disease in fish, and to the increased incidence of acid-tolerant, disease-carrying mosquitoes.
Agricultural activities upstream can have big impacts downstream
Many estuaries in Australia are fed by agricultural catchments. The water runoff from rain events carries the nutrients and other agricultural compounds into the waterways. The products of acid leachate from soils have been implicated in the increasingly severe Lyngbya algal blooms experienced in Moreton Bay (Queensland), however, high phosphorus loads exacerbated by agricultural fertilisers also trigger the blooms.
The effects of eutrophication are evident Australia-wide. For example, in NSW, between 1997 and 1999, two algal blooms potentially harmful to marine organisms, and seven blooms potentially toxic to humans were recorded. These bloom frequencies were similar to those recorded between 1994 and 1996.
This becomes both food safety and consumer confidence issues that can and does affect marine primary producers in very significant ways. Contaminated edible bivalves in the Ballina and Newcastle areas in recent years led to 59 and 23 cases of gastroenteritis, respectively.
Tasmanian Hydro-electric power: Always 'clean and green'?
Since the 1880's, mine water and tailings have been discharged from the Mount Lyell copper mine into the King River. An estimated 100 million cubic metres of solids containing toxic metals has settled on the banks and bed of the King River and within areas of Macquarie Harbour where bottom sediments contain very high concentrations of copper, lead, iron and manganese.
After the closure of the mine and the reduction of tailings going into the river, the levels of copper and acidity have actually increased as the metals are released from the sediments in the river, especially when flushed by water used for power generation.
The increased sudden flushing of this region during peak power demand for the proposed Basslink interconnector will have the potential to exacerbate this problem, further elevating the risks for marine farming in Macquarie Harbour. The sudden use of a few megalitres of water for power generation has the potential to cost the marine farming industry downstream substantial dollars. What is the best common good to be gained by the use of this water? A one-off payment for exported power?
There are many competing interests for water, all with different needs and requirements, all placing a different value on the resource.
So how can you place a realistic $ value on water?
On a global scale, the water sector has been subject to a range of significant micro-economic reforms. Water utilities are being increasingly driven by commercial objectives within a framework of environmental and economic regulation.
"Value", in any sense of the word, has meaning in relation to scarcity. Uniqueness, rarity, replaceability, usefulness, abundance are all related to value. And water is a scarce resource.
The economy of a region is based on a framework of producers/consumers of goods and services, and this must include the requirements of the natural environment.
A 'fugitive' resource
Unlike many resources, (e.g., labour or materials such as building materials), the use of water for one purpose does not necessarily preclude its use for another. It is a resource that moves constantly from one region to another, even evaporating when stored in dams, hence the 'fugitive' label. To make a realistic estimate when valuing the quantity and quality of water at any given point in time and location, one needs to know whether the proposed use is competitive, complementary or independent of another use.
To deplete natural resources in the pursuit of economic growth is very much like living off the capital rather than profit gained by exploiting that capital (while leaving it intact). Sustainable development is defined as the maximum economic development that can be achieved without using up the capital.
A local perspective
To bring this whole issue into a local perspective and to illustrate clearly that it is not always bad news, we can use the Little Swanport estuary on the East Coast of Tasmania as a good example. This estuary is fast becoming a Tasmanian exemplar that could give some good lessons to other managers...
Past policy makers have been known to operate under the premise that if one drop of water makes it to the ocean, then that is one drop too much! But the management philosophy is changing from maximum exploitation to sustainable holistic use… Policy makers have now in their infinite wisdom recognised that the environment is a legitimate user of water resources…
Little Swanport Estuary
This estuary is supplied by a significant catchment area including some of the Tasmanian agricultural sector. It empties into Great Oyster Bay on the east coast and is now being exploited in a more environmentally sustainable way. There is a growing consciousness of the fragility of the system and the difference that seasonal variations can bring to it.
For over 4500 years (probably a lot longer), humans have harvested seafood from the waters of the Little Swanport estuary.
Middens
Middens in the Little Swanport Estuary are extremely important archeological sites, with carbon dating indicating a history back to 2500BC. The vast majority of shells still evident in the remaining middens are those of large, mature oysters.
This is a clear indication that the Aboriginals consciously practiced sustainable harvest methods, leaving the immature stock in the water to grow to maturity and breed. An obvious respect for sustainable harvesting techniques that lasted millennia.
Lime works
The lime works in the same area were established on a commercial level in 1896/1897, sourcing the shells from middens covering some 80 acres up to 8 feet deep in the banks and sand dunes of the estuary.
Wild oysters industry
During the 1800's wild oysters were harvested in large numbers. Early records show that 5,235,000 (436,250 dozen) native oysters were harvested and brought to market from Little Swanport in one of the best harvest years. By the early 1880's, the fishery (Tasmania wide) had become unsustainable and declined.
The Report of the Royal Commission (1882) suggested that this decline was due to overfishing, mussel encroachment, disease and inclement weather. Indications were that the clearing of the land for settlement and agriculture also led to increased silt loads in the rivers and bays which is said to have killed many beds.
This is a demonstrated lack of respect for sustainable harvesting practices from a supposedly more developed regime. The new settlers were quite obviously living off the capital rather than the income, managing to substantially damage the fragile ecosystem in less than a century.
A realistic evaluation of ecosystems:
"The services of ecological systems and the natural capital stocks that produce them are critical to the functioning of the Earth's life-support system. They contribute to human welfare, both directly and indirectly, and therefore represent part of the total economic value of the planet." (Robert Costanza et. al., 1997)
Costanza tells us “…We have estimated the current economic value of 17 ecosystem services for 16 biomes, based upon published studies and a few original calculations.
By applying Costanza's calculations to Little Swanport, the various biomes are valued.
These are the values per hectare per annum of the ecosystem services (1994 $US).
• Open ocean $252
• Estuaries $22,832
• Seagrass/algae beds $19,004
• Continental shelf $1,610
• Temperate forests $302
• Grass/rangelands $232
• Tidal marshes/mangroves $9,990
• Swamps and floodplains $19,580
• Lakes and rivers $8,498
• Cropland $92
These figures speak for themselves… The near-shore and estuarine values outclasse the rest by a significant amount. This method looks at the ecosystem as a whole, valuing everything individually and then comparing in a holistic way.
Little Swanport is no exception. There are not only oyster farms in the estuary, but an oyster hatchery that supplies around 74% of the oysters to growers of Pacific Oysters in southern Australia… The value of this industry is 'multi-millions' of dollars... all dependent on the estuary.
$ value from Little Swanport primary production
Oyster production in the Little Swanport estuarine area is worth around $31,500 per hectare per annum. With dollars spent locally and consistent employment for many people, the return to the community is obvious. For a comparative land-based example, poppy production returns around $4,000 per hectare per annum with minimal return to the community and little employment…
However, despite the demonstrated returns to the community, oyster farms and the natural environment are the end users of the water resources available to this estuary.
The water quality is determined by conditions in the catchment area. These conditions can be seriously affected by varying combinations of factors. However, there is a conflict between agricultural and aquacultural interests for water allocation and the subsequent quality of the water once it has been used (if it actually makes its way back into the estuary).
Vast percentages of agricultural irrigation are wasted due to evaporation. Excess runoff brings with it the fertilisers, pesticides, herbicides etc that are used in the region. It also brings bacteria such as E Coli from both agricultural and wild animal excreta, something that can cause major problems for water quality… And that always equates into problems for shellfish quality downstream when levels become excessive.
Dams
At present there is a proposal for three upstream dams to be constructed in the Little Swanport catchment area. These will hold 1280 megalitres. For a comparative perspective, the nearby townships of Orford, Triabunna, Swansea, Coles Bay and Bicheno use a total of 911 megalitres annually…
These proposed dams will create <1 job but actually threaten >18 jobs if water flows through the high value oyster farms are reduced. This puts at risk an ecosystem that supports a $25.5 million industry.
Dams (especially those 'in-stream') can create some very real threats to the estuarine ecosystem. Low flow rates can seriously impact on the breeding cycles of various aquatic animals vital for the food chain in the marine environment, thereby affecting wild catch fisheries.
With reduced fresh water flows, marine water will encroach much higher into the estuarine waterways than previously, displacing other species and disrupting the balance of the ecosystem. Dams have significant evaporation (and sometimes seepage) problems. This is a waste of around 30%. The total take is much more than the storage as the dams are continually needing to be topped up. A 1 megalitre dam actually uses 1.3 megalitres.
Evaporation removes water but leaves the solids and dissolved minerals. Over time there is a buildup of salinity in the remaining water and the dam can become increasingly salty to a point where it is unfit for agricultural use. Organic matter and salinity can combine to lower the pH level to a point where it can’t sustain freshwater life. Disposal of this water can create problems. Irresponsible disposal into the estuarine environment can have a devastating effect on the ecosystem.
Dams in the Little Swanport catchment area
- Water Management authorities state that there are 18 dams in the catchment area, with another 11 proposed.
- Examination of 1:25,000 maps (current to 1992) show 1158 dams in the catchment area.
- A recent helicopter survey within 7 km radius of Little Swanport estuary found another 56 dams constructed since the maps were published...
Part of the decision-making process for water allocation has to take into account dam numbers, types and volume. How can the value of the water be accurately assessed and allocations made when there is absolutely no way of knowing how much water is being illegally retained and drained off upstream? There are NO management controls or licence conditions over the use of fresh water once it has been taken.
There is a way forward…
Factors being brought into play for this region include:
- Integrated Catchment Management
- Provision for the environment
- Established principles of management
To achieve this, members of the Little Swanport community formed the ‘Little Swanport Catchment Committee'. This committee formulated a management plan based on environmental AND economic values, looking to manage the area for the best common good.
Little Swanport catchment management
This plan is a significant example of a proactive community approach to the management and water allocation issues. It is a dynamic plan, ready for adaptation and adjustment. The committee composition is representative of all of the relevant stakeholder groups within the region. Significant issues have been identified and prioritised. Proposed Protected Environmental Values (PEVs) and principles have been defined for development. Further refining and implementation of this plan will have significant benefits, one being that it will provide a template for other regions to base a management plan upon.
Conclusion:
The issues involved with water resource usage are many and varied, especially considering the fact that it is a resource that can be used a number of times before exiting the estuarine system. Add to that the complexities involved in satisfying the requirements of all competing users while trying to determine the best common good from the water usage in the region. Then factor in the environmental, socio-economic and aesthetic values and there is a complex equation that will have different values for each catchment area.
The critical issue immediately apparent is water quantity and the allocation of the resource on a fair and equitable basis. That is fair enough to begin with, but the critical issues for the end user are not only quantity, but also quality. The end user may be the environment. It may be (as in Little Swanport) that the end user is an oyster-grower using what is left over for the environment after all other users have had the first use of the water.
When considering a multi-million dollar business such described, the best common good for the area must especially factor water quality into the equation, particularly once the water nears the end of its course from the land to the sea. The philosophy must be holistic.
To consider this scarce resource in any other way is unwise management. It is intergenerationally irresponsible and is most certainly out of step with the true definition of sustainable resource exploitation.