Irrigation Canals as an Aid to Fisheries Development in the West

Eco Management Restoration

Boys²

2012

Summary The impact of water diversion on fish populations is a global issue. Many countries have invested substantial funding into research and implementation strategies to ensure fish are protected at diversions that take water out of rivers for agriculture and other human uses. The most common management action is the installation of fish screens, and a wide range of designs are presently available that suit a large range of diversions. The Murray–Darling Basin is the largest catchment in Australia and has been substantially developed over the past 100 years to store and divert water for that protect fish from escaping into the irrigation systems. Recent studies have determined that water diversions have substantial impacts on native fish populations, but there are presently no coordinated efforts for mitigation strategies. The purpose of this review is to highlight aspects of successful screening programmes worldwide and identify those that could be directly applied to the Murray–Darling Basin. The development of similar programmes in the United States, New Zealand and the United Kingdom has identified that sufficient information and technology exists to inform the development of fish screening programmes. There is no need to commence implementation from first principles, and substantial progress can be achieved by applying successful aspects of other programmes. By identifying existing designs, defining ecological targets, developing generalised guidelines appropriate for local conditions and engaging the community, a co‐ordinated and successful fish screening programme could be directly applied to the Murray–Darling Basin. This would have substantial benefits for the long‐term sustainability of native fish without compromising water supply requirements.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reducing the perversion of diversion: Applying world‐standard fish screening practices to the Murray–Darling Basin

Eco Management Restoration

Boys²

2012

“…A unique fish passage issue is entrainment or diversion into irrigation infrastructure (King & O'Connor 2007). Work in North America has demonstrated that many migrating salmonids are removed from waterways when water is abstracted irrigation and potable (Post et al 2006;Prince 1923). The significance of this issue is profound with a high percentage of salmonid recruitment being affected in the Columbia River Basin (McMichael et al 2004).…”

Section: Interactions With Irrigation Infrastructurementioning

confidence: 99%

Fish passage in the Murray‐Darling Basin, Australia: Not just an upstream battle

Eco Management Restoration

Zampatti²,

Jones³

et al. 2014

Summary Construction of instream barriers, preventing fish from accessing spawning, nursery and feeding habitat, is a major issue impacting fisheries sustainability throughout the world. Since European settlement, development in the Murray-Darling Basin for irrigation and potable water supplies has led to the construction of over 10,000 barriers to fish movement. The Native Fish Strategy listed fish passage as a major driving action and was proactive in progressing cost-effective solutions to help inform large-scale rehabilitation programmes. The strategy identified a list of high-priority barriers for mitigation works based on feedback from jurisdictional agencies. Research initiatives were then implemented, with measurable outcomes, to help address key knowledge gaps. Research demonstrated that a project to restore passage to the Murray River main channel was meeting all ecological and engineering objectives. Follow-on work identified low-cost mechanisms to improve the effectiveness of existing fishways without compromising ecological functionality. The Native Fish Strategy was also explicit in addressing fish passage issues at irrigation infrastructure and wetland regulators. Work to minimise these impacts included quantifying the scale of irrigation-associated infrastructure and also optimising screen designs to be retrofitted to pump systems to prevent fish entrainment. Options to enhance lateral movement were also identified. The objective of this study is to summarise the fish passage issues progressed by the Native Fish Strategy to develop basin-wide solutions to enhance fish passage over the long term.

“…First, fish could be directly removed from river systems. It is generally assumed that, once an individual has entered an irrigation system, it is effectively lost from the main river population (Prince 1923) unless appropriate return mechanisms are provided (Dougherty, Hall & Wallingford 1995). Therefore, if many individuals are consistently lost to irrigation diversions on an annual basis, the size and age structure of main‐channel fish populations may be skewed towards larger and older fish with stronger swimming abilities.…”

Section: Introductionmentioning

confidence: 99%

Effects of irrigation pumps on riverine fish

Fisheries Management Eco

Reynoldson²,

Cameron³

et al. 2009

The total number and condition of fish extracted via high and low flow irrigation pumps was assessed over a 2-year period in the Namoi River, Australia. A combination of boat electric fishing and fyke netting was used for 10 weeks during the peak irrigation period to determine species and size classes susceptible to entrainment during water abstraction. Over 2300 fish passed through the pump outlets over the study period, with many individuals (7.5% of total) both killed and injured. The maximum number of fish entrained in a single day was 232. Mortality was significantly higher from the high volume pump site, but only large (>200 mm long) or small (<50 mm long) fish were killed. Medium-sized fish (50-200 mm long) largely survived the abstraction process; although 70 were injured (3% of total), only one was killed (0.07%). The Electric fishing surveys showed that only four species were present in storage dams, suggesting that survival through the pump systems may be size and species specific. Fish that survived the water abstraction process had no opportunities to return to the main river system and were effectively classified as lost from the main river population. The development of suitable mitigation measures, including operational changes and screening, are suggested as mechanisms to prevent extraction and minimise any adverse impacts arising from irrigation development.