Archives for April 2016

Soil is a living organism

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There are many ways to improve productivity and yield on farm, however there is a growing movement of producers who look at their soil condition as the place to begin.

Central Queensland Soil Health Systems (CQSHS) is a not for profit group of farmers seeking new and improved ways of growing crops and pasture whilst reducing costs over the long term.

It is widely recognised that soil biology needs soil carbon levels of 3% or more to become fully active. The calcium/magnesium ratio also needs to be correct so that soil PH will be at the desirable level. The group have also found compaction is a widespread issue for good water and air infiltration, vital for healthy soil.

Believing farmer-driven research and trials can address multiple issues at any one time through multiple science disciplines, the aim of CQSHS is to have all landholders involved, regardless of land use. Home gardeners, graziers and growers of crops were certainly given an education at the 3rd Soil Health Symposium April 26/27.

Leading experts and scientists like Dr Greg Bender, Dr Neil Wilson and David Hardwick introduced the concept that soils, like us, need to be treated holistically – addressing the importance of organic matter, mineral levels, pH and microbiology to support optimal growth in plants.

Forum with speaker Dr Neil Wilson, microbial ecologist, University of Sydney
Forum with speaker Dr Neil Wilson, microbial ecologist, University of Sydney

Farmers and garden enthusiasts alike, may have found the scientific information intense, but came away understanding the complexity of soil management.

Fortunately David Hardwick was there to help them understand what they’d learned in the forum by ‘role playing’ in the field, and demonstrations of the latest technology and machinery made accurate lime application easy.

Spraying lime using the latest application technology.
Spraying lime using the latest application technology.

Local farmer Allan McLean has been on the land all of his life, working his property with cattle and cane for 67 years and was keen to share his experience with everyone.

Adaptations made on his property include reduced tillage, stool splitting and the use of legumes to improve pasture (signal grass) to name a few. Cattle have been an integral part of land management in rough terrain where fire can be an issue.

A founding member of CQSHS Allan feels collaboration is the way forward “Collectively we can come up with better strategies to improve practices, soil health is very important to remaining a viable farming enterprise. I’ve seen the benefits in soils becoming easier to till, hence less costs to work the soil and water retention from rain and irrigation greatly improved resulting in less runoff.”

Reef Catchments has been proud to support the event since it’s inception, thanks to funding from the Australian Government’s National Landcare Programme.

Regional Landcare Facilitator Jacob Betros understands optimum soil condition is essential to all forms of agriculture, and ensuring healthy soils can deliver greater production to producers in an environmentally conscious manner.

His job is to support groups and individuals to promote sustainable farm and land management practices.

“Not only do we work with sugarcane, but the programme also focuses on grazing, horticulture, and forestry. New scientific information regarding soil health is being generated faster than ever, and it’s important for local land managers, to adapt this information and implement new methods, to remain viable, and ensure sustainable production for future generations.”

According to Jacob, the most exciting change to date has been the improvement to soil compaction through remediation on Simon Mattsson’s cane farm.

“Intercropping with sunflowers has really given the soil a new lease on life. I was recently at his property and have seen how well the cane as done in the year following the sunflower harvest.” Jacob said. “Increased production means increasing economic viability. This ensures the Central QLD Coast region benefits environmentally and continues to offer stability to the community with employment, tourism, and agricultural industries.

More information about Central Queensland Soil Health Systems and National Landcare Programme

Baby barramundi ascending

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Following fishway monitoring in the Mackay-Whitsunday region, sampling on Boundary Creek in the Rocky Dam Creek Catchment in Koumala revealed juvenile barramundi as small as 43 mm were successfully ascending the fishway.

Catchment Solutions aquatic ecologist, Matt Moore, remains excited about the construction of purpose built fishways in the Mackay-Whitsunday area.

“Most fishways built in the past have not presented conditions favourable for weaker swimming juveniles – they only ever recorded larger 150mm +Barra – so scientists thought this was the minimum size – but really it was poor fishway design, and poor knowledge of fish biology/migration. Every fishway we build we gain new knowledge on migration.”

65 mm juvenile barramundi (top) and crescent perch (bottom) (1)

The numbers, and particularly the small size of the barra are significant, some of the smallest juvenile barra recorded migrating through fishways in Australia.

“This is an indication that our newly designed fishways are successful at passing fish- as in the past fishway designs, like Marian weir, Fitzroy river, were based on northern hemisphere designs- specifically for Atlantic salmon, which can jump, our fish can’t. So the velocity and drops between pools must be smaller, which is what we have done.” Mr Moore said.

The concrete-cone fishway consists of 75 mm drops between pools – whereby the fish use their ‘burst speed’ to swim through this small ‘drop’ before reaching the pool, resting, and going again, until they reach the wetland habitat upstream.

At their peak, 2 barramundi an hour were migrating through the concrete-cone fishway. The fishway was successful at passing other important fish species attempting to reach their nursery habitat, including giant herring, silverbiddy’s, mullet, crescent perch and banded scats.

Importantly, all these fish species are diadromous (migratory), migrating between the sea where they breed and freshwater habitats such as wetlands and rivers. These habitats have abundant food resources and good in-stream cover (habitat) which enables them to feed, grow quickly and evade large predators before migrating back downstream to breed. In just 2 days 4056 fish successfully migrated through the fishway.

Choosing locally sold and sustainable fish like Barramundi means not only are you buying fresh, but you’ll support your local seafood industry – providing a much needed boost.

“More Barra and mullet migrating upstream through fishways reaching their nursery wetland habitats, means more fish for anglers to catch. If they don’t reach wetlands they get eaten by the abundant predators that live in the estuary. This is why correctly designed fishways are so important, now and into the future.” Mr Moore said.

*Fishway: Many important commercial and recreational fish species require unimpeded access between freshwater and estuarine habitats to complete their life cycle or maintain sustainable populations. Fishways (also often known as fish ladders or fish passes) are structures placed on or around anthropogenic barriers such as dams or weirs to give fish the opportunity to migrate. Fishways are designed, constructed and maintained to facilitate aquatic connectivity between upstream waterways, wetlands and estuarine ecosystems and provide fish passage though barriers that could otherwise prevent, delay or obstruct fish migration.

Native fish can’t jump

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Reef Catchments and local landholders are working to improve the health of the O’Connell River through removing barriers and improving in-stream habitat.

To many, paradise is living and fishing in and around the Mackay Whitsunday region with many visitors coming to the region each year for the opportunity to catch a Barra or Jungle Perch. The region is blessed with many beautiful streams and river to explore with the potential to catch a fish in the process. However, over a century of development has impacted on the ability of diadromous fish species migrating up through the river systems.

Diadromous fish move between the fresh and saltwater environments for some aspect of their lifecycle. The movement of Diadromous fish along our waterways is considered crucial to their life cycle and breeding patterns. In Mackay-Whitsunday there are 48 freshwater fish species and half of those are ‘diadromous’, Queensland’s two most important and iconic in-shore commercial net species, barramundi and sea mullet (Williams, 2002) require unimpeded access between freshwater and estuarine habitats to maintain sustainable populations (Mallen-Cooper, 2000)

Native fish species also require the right in-stream conditions to maintain populations including habitat complexity and deep pools for sustaining populations during the dry season.

With funding through the Australian Governments Reef Programme Reef Catchments has been working with Landholders to improve aquatic health and connectivity to implement activities along the regions rivers and waterways. Works being undertaken include revegetation along riparian zones, which will provide shade to cool the river, bank stabilisation and the removal of fish barriers and construction of fish ladders. Undertaking these activates is essential to sustain fish populations and ensure that fish are able to deal with any future pressures.

Fish movements within the river system

Native fish, such as Barramundi, swim up the creeks as small juveniles and then use that safe habitat to find plentiful food away from predators. They may stay there more than a year before they grow big enough to swim back downstream and, as bigger fish, prosper in the major estuaries opening into the sea and spawn. If those juveniles are blocked from migrating upstream, they must instead take their chances among the bigger predators downstream and are much less likely to grow to adulthood.

Taking this into consideration Reef Catchments has been constructing fish ladders on some of the rivers barriers to allow greater migration up and down stream. One fish ladder constructed was at Forbes Rd crossing.

Forbes Road Concrete Causeway Fish Barrier

A concrete causeway on Forbes Rd across the O’Connell River in Bloomsbury was preventing the migration of fish species and impacting local fish populations. The causeway barrier consisted of a series of pipe culverts which ‘dropped’ into the river below. The velocity of water flowing through these culverts was too fast for fish to swim through and the drop on the downstream side of the pipes into the river was too high – as native fish, unlike their northern hemisphere cousins; Atlantic Salmon, can’t jump.

So in November 2013, Reef Catchments funded Catchment Solutions to construct a partial width rock ramp fishway so that the fish can ascend through the fishway, negotiating the causeway barrier into important upstream habitats. Fish are then attracted to the fishway as flows pass through it. The fishway consists of a series of pools interspersed by rock ridges. The rock ridges consist of large 1.5 m boulders, with small gaps in-between. The drops between the pools are 75 mm. Fish use their ‘burst speed’ to negotiate each rock ridge in the fishway, before resting in the pool.

One metre long barramundi sampled (electro-fishing) while undertaking fish community monitoring in the lower freshwater reaches of the O'Connell River.
One metre long barramundi sampled (electro-fishing) while undertaking fish community monitoring in the lower freshwater reaches of the O’Connell River.

Aquatic habitat improvement on the O’Connell River

Reef Catchments has been working with local landholders to implement a range of activities along the O’Connell River to improve aquatic health and reduce the loss of productive agricultural land. Works being undertaken include revegetation, reprofiling and rock toe reventment to reduce eroding banks and imbedding large woody debris within stream to increase habitat complexity.

The activities being undertaken along the O’Connell River will provide significant benefit to native fish species opening up the rivers and providing habitat and good water quality to ensure healthy and sustainable populations for the years ahead.