Managing people, water, food and fish in the Murray–Darling Basin, south-eastern Australia

Authors


Abstract

The Murray–Darling Basin (MDB) covers 1.1 million km2, involves six legislative jurisdictions, a myriad of different agencies and illustrates the many complexities of managing fishes, people and water. Its rivers provide water for agriculture, are highly regulated and generally in poor health. Water allocation reform is underway to improve ecological condition but provision of water for environmental outcomes competes with agricultural requirements. Murray–Darling Basin rivers and fishes are important culturally and contribute substantially to tourism and recreational fishing. The MDB has a low number of fish species, now estimated to be at 10% of their pre-European abundance, and all subject to a range of threats, many related to water use and associated infrastructure. The MDB Native Fish Strategy takes a coordinated, long-term, whole-of-fish-community approach to address priority threats and rehabilitate populations. This strategy provides a holistic approach with many actions that complement the potential benefits of water reform.

Introduction

As a consequence of a range of anthropogenic impacts, freshwater lakes and rivers are among the most threatened habitats in the world (Malmqvist & Rundle 2002). This has resulted in freshwater fishes having a high number of documented extinctions with about 37% of species considered threatened (IUCN 2012). The use and management of water for irrigated agriculture and the production of food often conflicts with conservation requirements, including the management of freshwater fishes. Balancing the benefits from the use of water for irrigation against the environmental cost is a central challenge to resource planning in aquatic ecosystems (Lester et al. 2011). As the world's driest inhabited continent, Australia magnifies many key issues relating to water usage and management. Often described as a ‘land of droughts and flooding rains’, it exhibits great variations in rainfall with Australian rivers having very low run-off [<4% of rainfall on average for the Murray–Darling Basin (MDB); ABS (2012)] and highly variable flows compared with the rest of the world (Puckridge et al. 1998; Arthington & Pusey 2003). This climatic and hydrological variability has stimulated high investment in water storage and irrigation infrastructure, particularly in south-eastern Australia (Fig. 1) and provision of water for environmental outcomes competes with demands for agriculture.

Figure 1.

Map of the Murray–Darling Basin (grey shaded area) showing major impoundments (triangles) and key population centres in south-eastern Australia. Small circles > 25 000 population; large circles > 1 million population. Darker line is the Murray River.

This paper provides a case study for the complex, multijurisdictional management of people, water, food (agriculture) and the management of fishes in a large river system, the MDB in south-eastern Australia. It outlines the complexities of managing fish among competing needs and highlights a Native Fish Strategy (NFS) that takes a coordinated, long-term, whole-of-fish-community approach to address priority threats to rehabilitate fish populations. This strategy provides a positive and holistic approach applicable to other large river basins and should fit within the realm of water reforms occurring in the MDB.

The Murray–Darling Basin

The MDB covers 1.1 million km2 or 14% of Australia's land area and contains its three longest rivers: the Darling (2740 km) (see Breckwoldt et al. 2004); the Murray (2530 km) (see Mackay & Eastburn 1990); and Murrumbidgee (1690 km) (see Crabb 1997). It encompasses four States (South Australia, Victoria, New South Wales and Queensland) and a Territory (Australian Capital Territory; see Canberra, Figure 1) (collectively termed the States) and together with the national government, is subject to six legislative jurisdictions and their governmental departments and agencies that often have varied and disparate responsibilities. This provides considerable challenges to effective natural resource management. The MDB is an area of national significance for social, cultural, economic and environmental reasons and it contains nationally significant environmental assets that are reliant on water to maintain ecosystem health (ABS 2012). Water use and management are coordinated across jurisdictions through the Murray–Darling Basin Authority (MDBA, previously Murray–Darling Basin Commission), with most of the MDBA funding coming from collaborative contributions from the Federal and State governments. Natural resource management (including most rivers and fish populations) is the prime responsibility of State governments. The national government may supplement State funds for some actions, particularly for issues/problems of national importance (e.g. nationally threatened species).

People of the Murray–Darling Basin

Australia has a population of only about 24 million, which is largely concentrated in urban centres, particularly the capital cities, mostly along the east coast (Fig. 1). Just over 2 million people live in the MDB with 10% employed in agriculture (compared with 3% Australia-wide), although the number of farmers is decreasing (a 10% reduction from 1996 to 2006) and the average farmer age is increasing (by 4 years over 1996–2006) (ABS 2012).

Many of the native fishes of the MDB are highly valued by the community, especially icon species such as Murray cod, Maccullochella peelii (Mitchell) (Rowland 2005; Koehn & Todd 2012). Native fish have important ecological, social, cultural and economic values and provide a key link between people and their river systems. Although <4% of the population is recognised as indigenous (ABS 2012), Aboriginal people have important cultural connections to MDB fishes (Rowland 2005; Ginns 2012). Recreational angling is an important pastime in Australia with a participation rate of almost 20% nation-wide and higher in rural areas (Henry & Lyle 2003). Angling provides significant contributions to regional tourism and many farmers and rural agriculture workers are also keen fishers; there are genuine linkages between industry, employment, recreation, industry water usage and the environmental health of rivers.

Agriculture and food in the MDB

Australia is one of the world's major agricultural producers and exporters of grain, beef, dairy, cotton, wool, wine and other horticulture, with the MDB contributing 39% of Australian production. Agriculture occupies 84% of MDB land area with products to a value of approximately $AUS 15 billion per annum (2005–2006) (ABS 2012). Water use, land area and value of individual agricultural products are given in Table 1. The concentration of agricultural development in the MDB has resulted in significant ecological pressure on aquatic systems, with high levels of flow regulation, water abstraction and floodplain and riparian modification (Murray-Darling Basin Commission 2004).

Table 1. Percentage of area irrigated, agricultural water use and value of production for major agricultural products in the MDB
Product% of irrigated area in MDB% water agricultural consumptionGVIAP $M% GVIAP
  1. GVIAP, Gross value of irrigated agricultural production; NA, Not available; MDB, Murray–Darling Basin.

Pasture4317NANA
Non-rice cereals2010NA2
Cotton152079717
Rice6166
Grapes6NA72216
Fruit and nuts5589820
Vegetables2212
DairyNA1793820

Water in the Murray–Darling Basin

The MDB accounts for 66% of Australia's total agricultural water consumption (2007–2008; Murray-Darling Basin Authority 2010). Within the MDB there has been a large investment in storage dams and water infrastructure for irrigation and agriculture, which consumes 83% of water in the MDB. Most dams are located in eastern MDB capturing run-off from the western edge of the Great Dividing Range (Fig. 1), the largest being Dartmouth Dam with a capacity of 3900 GL (Crabb 1997). This high level of water infrastructure, operations and water consumption has caused significant changes to flow regimes, especially in the Murray River (Fig. 1) with reduced natural flooding and major changes to flow seasonality (Close 1990).

There is much concern over the health of rivers in the MDB with 19 of 23 river valleys rated in poor to extremely poor ecological condition (Davies et al. 2010). There are many concerns of overallocation of water (Lester et al. 2011) with flows at the mouth of the Murray River now being zero for 40% of time, compared with 1% of the time under natural flow conditions (CSIRO 2008). Concerns regarding overallocation and environmental damage were recently highlighted during the millennium drought (1997–2010) (Murphy & Timbal 2008), which covered the whole MDB (ABS 2012) and greatly impacted both irrigated agricultural production and environmental assets (Kingsford et al. 2011). Such climatic extremes are expected to occur more frequently under climate change predictions (CSIRO 2008).

In response to the degraded nature of rivers, a National Water Initiative (NWI) was launched in 2004 with the States and national Government officially recognising the need to improve the coordination of water management, efficiency of water use and the health of Australia's river and groundwater systems. The NWI instigated a range of reforms to the water industry, including improved water planning, water trading and water accounting. New national legislation (Water Act 2007; http://www.environment.gov.au/water/australia/water-act/index.html) was introduced to regulate water usage in the MDB. This legislation dictated the development of a Basin Plan to address overallocation and overuse of existing water resources and find a balance that optimised economic, social and environmental outcomes (Murray-Darling Basin Authority 2010).

The proposed Murray–Darling Basin Plan has proven to be one of the most controversial reforms of natural resource management in Australia's history, generating high levels of political debate and public protest from regional irrigators. It aimed to reduce the consumptive use of water by up to 4000 GL yr−1 (Murray-Darling Basin Authority 2010). Following public consultation and debates (still ongoing), this reduction objective has been lowered to 2750 GL yr−1 over a 7-year transition period; to be achieved through infrastructure improvement schemes and water licence buybacks, with an estimated cost of $AUS 3.1 billion (Murray-Darling Basin Authority 2011). Whilst environmental improvements have been the driver of these water reforms, most debate has revolved around socio-economic consequences relating to agriculture. There has, however, been minimal inclusion of fish contributing to biodiversity, conservation or economic benefits or major involvement of recreational fishers.

Managing fishes in the Murray–Darling Basin

As a result of a generally arid climate and historical isolation, Australia has relatively few freshwater fish species with high levels of endemism (approx 260; Allen et al. 2002; Pusey et al. 2004). The MDB has only 44 naturally occurring species over half of which are of conservation concern (Lintermans 2007; Koehn & Lintermans 2012) and impacted by a range of threats; many relating to the presence and operation of water infrastructure (Murray-Darling Basin Commission 2004; Table 2). Native fish management has traditionally been undertaken on an individual State basis dominated by single issues/species/locations. State and national conservation listing processes differ, and there are often separate plans for recreational fisheries. In addition, there is often a disconnect between the management of fish and management of their habitats, especially the management of water (see Koehn & Lintermans 2012).

Table 2. Key threats to fish relating to the use of water and water infrastructure in the MDB (modified from Murray-Darling Basin Commission 2004; Koehn & Lintermans 2012)
ThreatReferences
  1. MDB, Murray–Darling Basin.

Flow regulationLoss of flow, flow variation and seasonality, loss of low to medium floods, permanent flooding, extended periods of no and low flowsClose (1990); Kingsford et al. (2011); Arthington & Pusey (2003); King et al. (2010)
Habitat degradationRemoval of in-stream woody habitats, sedimentation; conversion of lotic to lentic habitatsKoehn (2001); Koehn et al. (2004a)
Lowered water qualityPoor water quality, including blackwater events cause fish kills; cold water pollution due to low-level releases from deep damsKoehn (2005); Todd et al. (2005); Sherman et al. (2007); King et al. (2012)
Barriers to fish movementsImpediments to fish passage and loss of population connectivity resulting dams, weirs, levees, culverts, etc.Barrett & Mallen-Cooper (2006)
Encouragement of alien speciesStocking of lakes, conversion of lotic to lentic habitats that favour alien speciesKoehn (2001)
Loss of fish into irrigation channelsFish diverted into poor habitats of irrigation channelsKoehn et al. (2004b); King & O'Connor (2007)
Damage to fish over weirsBoth adult and juvenile fishes can suffer damage and mortality when passing weirsO'Connor et al. (2006); Baumgartner et al. (2006)
Loss of fish into irrigations pumpsJuvenile and smaller fishes can suffer damage and mortality when passing weirsBaumgartner et al. (2009)

Native fish populations within the MDB have suffered substantial declines and are estimated to be at about 10% of their pre-European settlement (mid-late 19th century for the MDB) levels and without any intervention it has been suggested that they would be likely to fall to 5% over the next 40–50 years (Murray-Darling Basin Commission 2004). The dire state of freshwater fish populations in the MDB resulted in the development of a Native Fish Strategy (NFS) to attempt to remedy the situation (Murray-Darling Basin Commission 2004). The NFS has been described and evaluated in detail by Koehn and Lintermans (2012) and is an ecosystem-based approach that uses research and on-ground management to improve the status of native fish in the MDB using best available knowledge. This strategy has fish as its focus, rather than being an added component to other strategies (e.g. wetlands, salinity) and takes a whole-of-fish-community approach. The NFS is a commitment between all jurisdictions to rehabilitate native fish populations through addressing existing threats, with an emphasis on rehabilitation rather than maintaining the status quo, which would inevitably result in continuing declines and loss of species (Murray-Darling Basin Commission 2004). Its overall goal is to rehabilitate native fish communities in the MDB back to 60% or better of their estimated pre-European settlement levels after 50 years of implementation (Murray-Darling Basin Commission 2004; Koehn & Lintermans 2012).

The NFS fits within existing water and natural resource management structures and enhances existing programmes. Governance is based around representation from the individual jurisdictions through an NFS Advisory Panel (policy and science representatives from each State) and national agencies (Koehn & Lintermans 2012). It has a strong commitment to engage both the community and jurisdictional agencies, with formation of a Community Stakeholder Taskforce and a team of NFS coordinators in each jurisdiction, who link research and projects to management and engagement through a formal communication strategy (Koehn & Lintermans 2012). The NFS has also established Demonstration Reaches; partnership projects with the community and relevant agencies, where a series of restorative actions are applied and rigorously evaluated to illustrate the value of integrated action on multiple threats in a river reach (Barrett 2004).

The need for new scientific knowledge and its synthesis was recognised as a key component and the NFS has supported a significant research portfolio of more than 65 projects (Janet Pritchard Murray–Darling Basin Authority personal communication). This portfolio was developed following identification of key research needs and rehabilitation priorities with direct policy implications or management actions such as: habitat rehabilitation; alien fish management; fish movements; damage or mortalities due to irrigation infrastructure; and environmental flows (see Koehn & Lintermans 2012).

One such key project is the Sea to Hume fish passage programme that includes the construction of 15 fishways to provide fish passage along 2225 km of the Murray River between the Murray mouth and the Hume Dam at Albury (Barrett & Mallen-Cooper 2006) (Fig. 1). Not only has this programme contributed to the knowledge of fish movements and the appropriate design, testing, construction and monitoring of fishways (Barrett & Mallen-Cooper 2006; Barrett 2008), but associated research has also addressed other in-stream barrier-related issues such as the loss of larvae into irrigation channels (Koehn et al. 2004b; King & O'Connor 2007) and damage when passing over weirs (Baumgartner et al. 2006) or by extraction using irrigation pumps (Baumgartner et al. 2009).

Discussion

Rehabilitation of freshwater habitats and their fishes is a rapidly growing area of management (Cowx & Welcomme 1998; Bernhardt et al. 2005; Roni et al. 2005), but success can often be hampered by the overallocation of the water resource. Nowhere is this more so than in the MDB. The seriousness of the situation has been highlighted by lessons from the millennium drought and reinforced by predictions of reduced run-off and flows due to climate change. Overallocation within the MDB has now been recognised and the proposed water reforms to improve river health have resulted in a highly charged political debate. Despite native fish populations being an indicator of the overall health of the rivers (Harris 1995), they have largely been ignored in this debate. Because of their recognition by the community, however, the status of native fish populations in the Murray–Darling Basin is likely to be a key criterion by which the public will judge the success of the proposed Basin Plan.

The community clearly recognises the need to rehabilitate native freshwater fish in the MDB and these fishes provide key links between people and their waterways. This could be recognised as a way to illustrate benefits of the Basin Plan and the improved environmental water allocation and management. Healthy fish populations increase community connection to the river, especially for indigenous and rural communities. The public recognition of icon species such as Murray cod could be exploited to help engender community ownership of water reforms through shared ecological objectives relating to improved fish populations and angling opportunities (Koehn & Todd 2012).

Provision of improved environmental flows is one key component of river rehabilitation that should result from water reforms. Justification for the allocation of environmental water (see King et al. 2009, 2010) will come under increasing scrutiny and this highlights the continued need for appropriate supporting science. Environmental watering, however, also needs to be supported by communities; both local (usually rural) and those more distant. While the population of the MDB is about two million people, an additional 10 million people live in capital cities and nearby population centres that also have an interest in the Basin and its fishes. During the millennium drought both of these communities were confronted by the dramatic impacts of such low flow conditions, and recognised the need for increased flows to the rivers. An ongoing challenge is to maintain this support and recognition in non-drought times and there is an opportunity to connect people to the suite of other actions that can be delivered to support river health and native fishes. On their own, improved environmental flows will not be enough to alleviate all impacts on native fishes and there is a need for complementary remedial actions to address other threats. The NFS suggested that about 42% of the rehabilitation goals for native fishes could be achieved by adequate environmental water allocations and the recognition that interventions to address other key threats are also needed (Murray-Darling Basin Commission 2004). The NFS provides many actions that provide ecological benefits independent of any new environmental water allocations, but which support the ecological objectives of both the Water Act and the Basin Plan to improve the ecological health of the MDB.

One of the challenges for restoration is the issue of shifting baselines when recovery targets or the quantum of work needed is set too low (Humphries & Winemiller 2009). The potential $AUS 3.1 billion suggested to fund water buybacks dwarfs the < $AUS 5 million yr−1 spent on the NFS and the question must be asked – how much expenditure is needed to really achieve any of the stated objectives?

While economic data for agricultural production are relatively easy to obtain (see Table 1), this is not so for other industries within the MDB and there is a need to include the full economic benefits of all industries when considering basin economics. Healthy rivers are essential for other industries such as tourism and recreational angling. For example, in 2009–2010, the contribution of tourism to Australia's gross domestic product was estimated to be 2.6%, with tourism employing just over half a million people. In the same year, international visitors consumed almost $AUS 23 billion worth of goods and services produced by the Australian economy (ABS 2012). An initial assessment of the economic contribution of recreational angling to the MDB suggested likely estimates of: $AUS 1.35 billion p.a. direct expenditure; $AUS 357 million added expenditure; a $AUS 403 million contribution to GDP; and a contribution of 10 950 jobs (Ernst & Young 2011). Such figures indicate the need to engage recreational fishers as a key stakeholder in the MDB and its water, as there are significant social and economic advantages to the recreational angling and tourism industries through having healthy rivers and healthy fish populations.

Although the NFS is well supported throughout the MDB and has been considered to have caused a substantial shift in the management of native fish in Australia (Koehn & Lintermans 2012), it has largely been ignored among the heated, political, water-reform debate. The long-term nature of the NFS (50 years) and its whole-of-basin, multidisciplinary and community focussed basis is a major strength and complements the actions needed to achieve the environmental outcomes of the Basin Plan. There is a need to fit this programme to rehabilitated fish populations within the package of water reforms to help maximise its benefits to this major ecological asset.

Acknowledgments

The author wishes to thank all those who support fish in the Murray–Darling Basin, especially the MDBC/A Native Fish Team, NFS coordinators, Simon Nicol and Mark Lintermans; and to Ian Cowx and Nancy Leonard for the initiative of holding the international Great Rivers symposium at the 2012 World Fisheries Congress and producing this publication. Comments on this manuscript were kindly provided by Fern Hames, Janet Pritchard and anonymous reviewers. At the time of publication there is considerable public outcry as the NFS will now cease at the end of June 2013 due to a review of program funding following State jurisdictional budget cuts.

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