Fishing profits in Wheatbelt

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Jenne BrammerThe West Australian
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Barramundi in the Wheatbelt?

That's what one enterprising Mid West couple are farming in an effort to combat salinity and make a profit as a bonus.

David and Jane Coaker have set up the venture on their Morawa grain-based property by establishing a sophisticated saltwater barramundi farming facility.

After several years of trial and error, and considerable investment, their aquaculture operation has been up and running since early 2014.

Their extensive system uses a combination of pumped saline and bore water, which fills a series of tanks that are used to grow fish.

An important element is the monitoring equipment which ensures correct temperature, oxygen levels, pH, and pump flows are maintained across all tanks.

Mr Coaker said the process started when fingerlings weighing 5g-10g, generally purchased in cohorts of 12,000, were grown to 100g in nursery tanks housed in a large shed.

Upon reaching 100g, the fish are moved into one of two 160,000 litre tanks based in a greenhouse, and grown to between 600g and 1.2kg.

These tanks were constructed from old truck tyres, plywood and a tank liner, and can farm up to eight tonnes of fish when fully stocked.

Mr Coaker said once fish reached about 600g, they started being live transported to Perth using specialist containers each holding about 250kg, and equipped with oxygen tanks and diffusers.

"We sell about half a tonne at a time until we run out of fish, leaving the remaining fish in the tanks to continue growing," he said.

Mr Coaker said he aimed to put through about three or four cohorts of 12,000 fingerlings annually.

It takes about nine months for the fish to reach the maximum weight of 1.2kg, though most are sold beforehand.

The system requires about a third of the water to be replenished daily and the saline, nutrient-filled water that is removed is then used to irrigate a 2ha plot of NyPa grass, which metabolises salt and can be used as stock feed.

In terms of markets for the live fish, Mr Coaker's key customers are Asian restaurants based in Perth, with which he deals through specialist distributors.

"The Perth live market is a good market but it is very small," he said.

"We are still in the process now of trying to work out new markets for different species, in order to take it to the next level."

Mr Coaker said there was a market for fish sold fresh on ice, but the price was less attractive.

"This market is much larger and there is a lot of work to be done here in order to maximise returns," he said.

"Sales will range from supplying locally throughout the Mid West through to the big processors and retailers in Perth."

Although the aquaculture operation had evolved into a large scale project, Mr Coaker said that was not the initial intention.

"It all began when we started draining our salt-affected land," he said.

"In doing that, we built open deep drains to lower the water table, and then pump the water back into the evaporation basins.

"We thought we could use these saline ponds to grow fish, but these fouled up with too much waste.

"We tried a few different things, but that these were unsuccessful."

Determined not to be beaten, Mr Coaker said he then sought the expertise of Gavin Partridge and Bruce Ginbey of the Australian Centre for Applied Aquaculture Research, part of Challenger Institute of Technology in Fremantle.

Dr Partridge has a PhD in inland saline aquaculture and Mr Ginbey is an aquaculture systems specialist.

Together, they helped the Coakers design the prototype for their current aquaculture system.

The system used by the Coakers is called a recirculating aquaculture system and is believed to be the biggest of its type operating in WA.

Even though, after several hiccups, the system is now running smoothly, Mr Coaker said there was still much work to be done.

"We still have to refine our filtration system as we still have a few problems there," he said.

"We are also going to try a few other species that have been identified as being pretty good and we need to look at expanding our market base."

Because of the intensive feed requirements - the fish require feeding at least three times daily using formulised pellets - the Coakers have employed a full-time staff member.

Mr Coaker said the barramundi operation had helped towards reclaiming a 450ha block where the drainage system was contained.

Before the drain being installed, only about 321ha of this was arable, but this year a further 100ha or so had been planted with canola, Mr Coaker said.

"Most of the arable area is now back under cultivation, although still under duress," he said.

"Some of it will have to be planted to saltbush due to the severity of the salinity."

To further aid the Coakers' fight against salinity, this year 28,000 trees and shrubs were planted along the drainage lines by Ian Pulbrook, of Greenoil Tree Nursery, in Yandanooka.

Mr Pulbrook collects all the seed locally, ensuring all species planted are suited to the area.

Mr Coaker said the establishment process had been challenging and financial and time investment requirements had put pressure on the business.

But he expected going forward, the operation would be less time-intensive, and it would break even next year.

"The biggest challenge has been educating ourselves and putting a system together that works," he said.

"We did everything two or three times over before we could get it to work.

"But on the positive side, we have demonstrated we can grow a very good product.

"We have established the salt water fish will grow well here.

"That's been heartening."

With much of the hard work complete in establishing the system, Mr Coaker hopes to strike the right balance between his new aquaculture venture and his 9300ha cropping program, which this year includes wheat, canola, barley and lupins.

He has been under added pressure this year because of a particularly dry start to the growing season in the area.

The Coakers sold out of sheep earlier this year because they no longer fitted their rotation system, and because they had established the aquaculture as an alternative enterprise, Mr Coaker said.

"One of the driving factors in following the barramundi operation all the way through is knowing we would have a business on the farm that does not rely on the rain," he said.

"And it's good to know we are not letting the saline land sit there being unproductive."

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