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The sun was shining and the fish were biting for the annual Burrendong Classic fishing competition in April

Sensational weather combined with a dam level of 80% encouraged a record breaking 1306 entrants in the Annual 2017 Inland Waterways Rejuvenation Association catch and release fishing competition, held on the Easter long weekend at Burrendong Dam.

The fish were biting and luck was on the side of Lachlan Cole of Orange, who won a kayak donated by the NSW Office of Environment and Heritage (OEH).

In the months since the fishing competition, Lachlan said he has used the kayak around every two or three weeks while it was warm as he loves to get out on the water and wet a line. He also commented that a workmate had borrowed it from him a month ago and has since bought one for his wife to use in the Turon River near their home.

OEH's kayak donation is just one way the organisation is encouraging the local community to get out and enjoy local rivers, with the Wambuul Macquarie River Festival in October 2017 also planned.

Senior Wetlands and Rivers Conservation Officer Tim Hosking said recreational fishers had a big role to play in improving and monitoring the Macquarie River.

"It is great to see the ongoing work of the Inland Waterways Rejuvenation Association volunteers to look after our river health," Mr Hosking said.

"The valuable Inland Waterways Rejuvenation Association efforts to re-snag the river, restore riverbank vegetation and engage recreational fishers all value-add to government programs that also aim to help our native fish and the river they live in.

"The effectiveness of environmental water management that I get involved in, the recently-installed curtain at Burrendong to reduce cold water pollution, or ongoing work by organisations like DPI-Fisheries and Dubbo Regional Council to remove fish movement barriers all substantially benefit from these projects.

"The river is a complex living environment, and we need to use a range of different approaches to make the biggest difference we can.

"By supporting the prizes at the Burrendong Classic we hope to help the Inland Waterways Rejuvenation Association continue to grow their numbers and engagement of recreational fishers in native fish in the catchment. It is our pleasure to offer all the support we can.

"It is our hope that this kind of support can continue into the future," he said.

Birds of a feather flock together in the Macquarie Marshes

The winter–spring period of 2016 saw above average rainfall and river flows in the Macquarie valley, resulting in large-scale flooding and inundation of floodplain areas and the Macquarie Marshes. Floodwaters covered areas of the Macquarie Marshes that are often difficult to reach with managed environmental water flows. The inundation created the perfect conditions for wetland vegetation and nesting opportunities, resulting in a significant waterbird breeding event.

Why are the Macquarie Marshes ecologically important?

The Macquarie Marshes are a large and diverse wetland system on the lower floodplain of the Macquarie River 100 kilometres north-west of Dubbo. The Marshes provide essential habitat for hundreds of species of animals and plants, creating refuges in dry times and breeding habitats in wet times.

The Macquarie Marshes are recognised in the Ramsar convention and in migratory bird agreements with Japan, China and the Republic of Korea.

What was the ecological response to the recent inundation?

Mapping by the NSW Office of Environment and Heritage (OEH) indicates that a total area of 154,000 hectares was inundated across the northern, southern and eastern Macquarie Marshes.

Early natural flows primed the ecosystem and allowed the landscape to respond well to subsequent spring and summer conditions, producing high-quality habitat. This allowed a great number of water birds including ducks, magpie geese and species of waterhens to start breeding. Colonial waterbirds for which the Marshes are famous also began breeding in large numbers.

From October 2016 to January 2017, OEH and University of NSW ground and aerial surveys confirmed at least 21 active waterbird colonies across the Marshes. A total of 15 colonial waterbird species were recorded nesting at these sites. The two largest colonies, with an estimated 30,000 nests, were dominated by straw-necked ibis with smaller numbers of Australian white ibis and glossy ibis.

What was the water management response to the recent inundation?

In the Macquarie valley, recommendations about environmental water management and deliveries are made by the Macquarie–Cudgegong Environmental Flows Reference Group (EFRG). The EFRG is a community–government collaboration comprising various water users, landholders, Aboriginal and environmental groups and NSW Government departments. The Commonwealth Environmental Water Holder and Murray–Darling Basin Authority also have representatives as observers to EFRG meetings.

In the three years before this event, the catchments were very dry and water availability was low.

Therefore the EFRG managed environmental water conservatively, targeting beneficial flows to the river and to core marsh areas.

By winter–spring 2016, with Burrendong Dam reaching capacity and all water user accounts being full, the EFRG revised its previous watering strategy to that of a wetter scenario. Flood Mitigation Zone (FMZ) rules were also enacted (as per the Water Sharing Plan), allowing for water to be used for environmental benefit while minimising downstream impacts. OEH provided advice to WaterNSW regarding the needs of waterbird colonies in the Marshes, so that beneficial flow releases could be considered in the FMZ release strategy.

Macquarie Marshes inundation figure

Keeping watch over a wandering wetland - August 2016

It's big. It's complex. And it's on the move.
But don't be alarmed.
Scientists are keeping a close eye on this wandering giant.

The Macquarie Marshes are a network of wetlands spread over some 200,000 hectares in the state's central west. This mosaic of wetlands is connected by a lattice-work of channels creeping out across the floodplain.

Fed by the Macquarie River, the Marshes are constantly expanding and contracting with the seasons. When water is readily available, the full length and breadth of the Marshes bursts into life. When the season is dry and soil moisture declines, the wetlands contract to a series of refuge sites, with thousands of hectares of River Red Gums fed from shallow groundwater reserves.

But there's more to the story than just seasonal change. Scientists are unravelling a long history of movement that has seen significant changes in the course and structure of the channels on the floodplain that shape these iconic wetlands.

Dr Tim Ralph

Dr Tim Ralph

Environmental scientist Dr Tim Ralph has spent the past 15 years studying the factors that influence change within the floodplain wetland environment.

His research into the hydrology (water in the landscape) and geomorphology (the development of landforms) of the Macquarie Marshes is helping to inform their management.

'The Macquarie Marshes are dynamic, therefore our conservation and management strategies need to be dynamic too,' Dr Ralph said.

'There are so many inter-related factors that affect the condition of the system. The volume, speed and sediment load of water entering the system is one part of the equation. Soil structure is another.

'Vegetation also plays a critical role in determining how and where water is spread through the wetlands.

'The Marshes occur where they do because the Macquarie River naturally develops smaller channels that allow water to spread across the floodplain and into the wetlands.

'Smaller landforms such as natural levees and flood-outs determine where water flows or ponds within the wetlands.

'A small change to the landforms, or the processes that create landforms, can have a large impact on the movement of water in a particular location,' he said.

It's a process that can occur over short and long timeframes.

'In the past 15 years, several channels in the Macquarie Marshes have adjusted their course slightly or become wider and/or deeper, or partly infilled with sediment,' Dr Ralph said.

'When I first visited in 2000-01, the Marshes were in a wet phase with channels flowing and overflowing regularly. Wetland plants and animals were flourishing.

'During the millennium drought, the Marshes dried out significantly and wetlands contracted to core areas around the few channels that received natural flows, environmental allocations or stock and domestic base flows.

'In that time there were productive periods when a relatively small flow entered the Marshes, but overall, the system was devitalised.

'The Marshes have adapted to variability in water supply, so when the drought broke in 2010 they responded strongly,' he said.

Dr Ralph's research has revealed a dynamic history of wetland landform change over the past 100 to 200 years, as well as evidence of wetland evolution occurring over thousands of years.

Aerial photographs, satellite imagery, topographic survey data and parish maps have provided an insight into the recent history of channel and wetland change in the Marshes. Samples of surface sediment and soil, along with sediment cores, have allowed Dr Ralph to study long-term patterns of sediment accumulation, erosion, soil quality and fire. This combination of approaches shows a wetland ecosystem that is constantly on the move.

Comparison of aerial views

Southern Marshes 2008 vs 2010

'The movement of channels on the floodplain has shifted patterns of flooding and areas of aquatic habitat in the southern section of the Marshes quite significantly.

'For example, between the 1880s and 1920s, large areas of wetlands surrounding the Old Macquarie River in the southern Macquarie Marshes Nature Reserve contracted back to Monkeygar Creek and some were abandoned.

'Other wetland areas grew or changed elsewhere on the floodplain. The boundary of the nature reserve was also modified to reflect some of these changes in the early 20th century,' he said.

Earlier this year, Dr Ralph and colleagues Dr Paul Hesse and Dr Yoshi Kobayashi released the findings of their research into the Macquarie Marshes in a paper entitled Wandering wetlands: spatial patterns of historical channel and floodplain change in the Ramsar-listed Macquarie Marshes, Australia.

The document brings together their various information sources and research findings to create a series of maps demonstrating the mobility of the Macquarie Marshes over the past one-hundred-plus years.

This research is an important link in the chain, helping to inform the management of the Macquarie Marshes, in particular the use of environmental water to support this unique wetland system.

'We have seen that small changes in channels and drainage patterns can have significant impacts on flood patterns and wetland ecology,' Dr Ralph said.

'By identifying, assessing and monitoring pressure points and hotspots of change, we can better understand the impacts of controlled flows on the character of the Marshes.

'My research can also help to determine which parts of the Marshes are likely to respond to environmental flows,' he said.

Dead tree branches on a bank by water

The lead of the small flow in the Gwydir between Boolooroo Weir and Yarraman, April 2016

The Office of Environment and Heritage is the lead agency for the management and delivery of environmental water in NSW to sites including the Macquarie Marshes.

Senior Wetlands and Rivers Conservation Officer, Tim Hosking has worked with Dr Ralph since 2008 to integrate his research into management of the wetlands.

'The work of scientists like Tim Ralph and others is critical if we are to get the best environmental benefit from the water we're managing,' Mr Hosking said.

'The relationship between erosion and sedimentation and environmental water is a developing area of information.

'We know that healthy wetland vegetation - something we try to maintain with environmental flows - leads to reduced erosion and also more spread of water into floodplain and wetland areas.

'Reed beds and water couch are also known for their ability to catch sediment, performing a great job of filtering water, but this also means they are prone to the effects of sedimentation.

'As environmental water managers we need to keep a close eye on stream and wetland physical changes so we can get the best environmental outcome for the water asset in our care.

'Environmental water management also relies on good science to inform annual and longer term decision-making.

'In the Macquarie valley, the Macquarie-Cudgegong Environmental Flows Reference Group advises OEH on the best course of action with consideration of the latest available science.

'Management of the land and water is highly specific to the physical, ecological and socio-economic elements of the system.

'As a result, there is no simple recipe for management. Scientific information, water management experience and strong community collaboration are all essential to ensure the long term future of these iconic wetlands,' he said.

Aeral view of marshes

Southern Marshes (Willancorah)

Water filling channels in wetlands

Water re-entering the Macquarie River downstream of the southern reserve

Narran Lake Nature Reserve expanded - February 2016

A breeding site for migratory birds now has added protection thanks to an extension of the Narran Lake Nature Reserve Ramsar site.

The reserve, in northern NSW, has been expanded from 5343 hectares to 8447 hectares.

It's good news for migratory waterbirds birds that use the site to feed and breed.

For more information see the media release: Over 3,100 hectares added to Narran Lake Ramsar

The Narran Lake Nature Reserve has been expanded. Photo D Love OEH.

The Narran Lake Nature Reserve has been expanded. Photo D Love OEH.

Dr Joanne Ocock: environmental scientist

Dr Joanne Ocock is an environmental scientist with the NSW Office of Environment and Heritage. She has worked in locations around the globe and is now focused on wetlands in NSW. This is the story of her career so far . . .

What I do . . .

I do a lot of fieldwork which is mostly walking around counting things - in wetlands and forests, during the day and at night - which is awesome. I then do the data analysis, write reports and scientific papers on what we have found and what it means. I also work in the lab dissecting things and counting very small things. Sometimes we are asked to provide advice on a particular animal or wetland area. I also work in the field of environmental water in NSW.

Who inspired me?

A mentor would probably have been my boss for work I did on Mongolian freshwater fish. Jonathan Baillie was a Fellow and is now head of Conservation Programs at the Zoological Society of London. He was a nice, genuine guy who got great things done and inspired me to want to do the same things.

Where I studied

I studied at Canterbury University, Christchurch New Zealand, and did my PhD at the University of New South Wales, Sydney. My studies have opened the door to being in a position where I enjoy my work, I get to see very special places and amazing animals, and feel like I'm making their life a little bit better and more secure.

Things I've done

I've travelled throughout Australia and around the world. I haven't always been paid for it, but there have been amazing experiences along the way. I've been to Mongolia and become an expert on the conservation of Mongolian fish. I've identified new species of freshwater invertebrate in New Zealand, radio-tracked frogs around marshes, flown around in a small aeroplane and canoed through wetlands to count birds, hung out in Thailand studying frogs and dissected tadpoles to see what they eat.

People I've met

Through my work I've met a lot of people who are passionate about wetlands, animals, and securing a better future for them. I work with a diverse range of people from other scientists and natural resource managers to landholders, school kids and people who are just passionate about supporting local wetlands.

Best bits

The best part of my job would be wading through water at night, listening to lots of different kinds of frogs calling all around me. It's also great when I see people become more interested and engaged in frogs, waterbirds and wetlands. Even better when local landholders start to tell me about the different frogs they see by their correct names rather than just green ones and brown ones.

My work has taken me all over Australia and around the globe. I'm originally from Christchurch, New Zealand. I studied there then worked in London. That's where I got the opportunity to travel to Mongolia. Then it was off to Thailand looking at frogs and back to New Zealand working in the high country. When I moved to Australia, the crucifix frog was the first amphibian I saw - it was the start of many great things to follow.

Dr Joanne Ocock

Dr Joanne Ocock

Crucifix frog front

Crucifix frog

New environmental water video for the Macquarie Marshes

Have a look at some spectacular footage of the Macquarie Marshes.

OEH with MidState productions has developed a new 'Macquarie Marshes Wetlands' video about environmental water management in the Macquarie Valley.

New look for Macquarie Marshes poster

Macquarie Marshes poster

The beauty and wonder of the Macquarie Marshes has been captured in print with a new, full-colour poster available now.

The poster includes information on the cultural, economic and environmental importance of the marshes as well as the threats and challenges being addressed by partner agencies in the management of the iconic site.

Developed by the NSW Office of Environment and Heritage and the Murray Darling Basin Authority, the poster replaces a popular 1996 version that was out-of-print and in need of an update.

NSW OEH Senior Wetland Conservation Officer Tim Hosking said the poster incorporated some of the original artwork along with a variety of photos and graphics.

“The poster was developed with input from many community members and other agencies,” Mr Hosking said.

“Our thanks go to all those people who submitted photographs and helped make the poster as eye-catching and informative as it is.

“As well as the focus on Macquarie Marshes, the poster’s flipside provides a more general look at wetlands and their importance in the Murray-Darling Basin.

“There’s a diagram of the wetland food web as well as a cross-section of a typical wetland and five steps to improve wetland health that anyone can do,” he said.

Schools and individuals are encouraged to obtain a copy online or by calling the NSW OEH Regional Operations office at Dubbo on (02) 6883 5330. Postage is free for individual orders.

Native fish set to benefit from Burrendong Dam's cold water curtain

Native fish will be among the beneficiaries of a new multi-million dollar cold water curtain at Burrendong Dam.

Members of the Environmental Flows Reference Group wearing hi-viz vests wakling inspecting the cold water curtain at Burrendong Dam

Members of the Environmental Flows Reference Group inspect the cold water curtain at Burrendong Dam. Photo Tim Hosking OEH

The flexible curtain has been constructed around the intake tower to allow warmer, oxygen-rich surface water to be released downstream.

And the benefits are expected to flow for the whole river system.

The NSW Office of Environment and Heritage (OEH), with advice from the Macquarie-Cudgegong Environmental Flows Reference Group (EFRG), has already made use of this warmer surface water.

A ‘piggyback flow’ of 5000 megalitres was delivered to the eastern marshes in early September. The flow supplemented recent rainfall as well as stock and domestic flows.

A second flow of 30,000 megalitres was scheduled to reach the Macquarie Marshes in mid-October.

Senior Wetland and Rivers Conservation Officer Tim Hosking said the new curtain and warmer water would enhance the effects of these environmental flows and provide benefits to recreational river users as well.

“Anyone who has gone for a swim downstream of the dam will tell you how cold the water can be in the middle of summer,” Mr Hosking said.

“Until now, water for irrigation, town use and the environment has been released from a fixed intake point towards the bottom of the dam. In spring and summer that water can be quite cold and low in dissolved oxygen compared with conditions that would naturally occur in the river.

“The effect on river plants and animals – native fish in particular – has been significant.

“Research has shown that colder water impedes fish growth and reduces the length of their breeding season.

Burrendong Dam cold water curtain

The Burrendong Dam cold water curtain is now operational. Photo Tim Hosking OEH

“Native fish wait for warmer water to breed which now doesn’t occur until later in spring and summer. By then, the European Carp have already spawned and competition for food is fierce, as carp compete at the very bottom of the food web by destructively eating algae and vegetation.

“Cold water also reduces the productivity of riparian and aquatic vegetation which further contributes to the challenges experienced by native fish” he said.

Mr Hosking said the ecosystem response to the curtain may be muted in the first year or two, but the effects over the next three to five years should be significant.

“The whole ecosystem will benefit - from the macro-invertebrates to the yabbies, shrimp, platypuses, native fish, turtles and waterbirds,” Mr Hosking said.

“With the right conditions, we hope to see improvements for native fish in the river reach between Burrendong and Narromine.

“From a social perspective, river users will notice warmer water when they go for a swim and over time, they’ll start to see more native plants and animals present in the river.”

The OEH is just one of several stakeholders keeping a close eye on the effects of Burrendong Dam’s new cold water curtain; with ongoing research being conducted by a team from the University of Technology Sydney, and additional funding allocated from the Commonwealth for NSW Department of Primary Industries (Fisheries) to undertake a system-wide fish survey.

In the meantime, staff from the OEH are looking forward to seeing the first effects of the season’s environmental flows, enhanced by warmer water via Burrendong Dam’s cold water curtain.

Fast facts

  • The cold water curtain has been constructed at a cost of $3.4 million.
  • The flexible rubber curtain can be moved up and down with the level of the water behind the dam.
  • The initial concept design was funded by NSW Rivers Environmental Restoration Program, a Commonwealth program.
  • Further design and construction costs were shared equally between the NSW Government and State Water customers.
  • The environmental water release is a collaborative effort guided by an Environmental Flow Reference Group (EFRG) :
    • The EFRG meets several times per year to discuss environmental watering strategies, outcomes and planning.
    • The Murray Darling Basin Authority has identified native fish outcomes as an annual priority in the Macquarie River under the Murray Darling Basin Plan.
    • Environmental flows in the Macquarie are managed by NSW OEH with key assistance from the Commonwealth Environmental Water Office (CEWO), State Water Corporation and the EFRG.

 

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Page last updated: 10 August 2017