WARNING SIGNS Surface algae, excessive weed growth, odour and cloudy water generally indicate something is wrong — and it’s often poor nutrient management
When Max Menard took an aquaculture course from Alberta Agriculture 13 years ago, the plan was to raise trout. But increasingly, Menard’s business is about water quality.
“Having trout is a good barometer for how healthy the water is,” said Menard. “If the trout aren’t living in there and aren’t surviving, there are definitely improvements that can be made.”
Menard and his father Dan own Smoky Trout Farm outside Red Deer and raise about 120,000 pounds of rainbow trout each year for farmers, ranchers and acreage owners; fish and game associations; golf courses; and the Alberta Conservation Association. The Menards also sell weed-eating grass carp. The fish are grown indoors. Trout eggs are hatched in late September and mid-November, so everything is ready to sell by mid or late June.
“It gets too hot to stock trout indoors in July and August — the temperature differential between the ponds and our facility is too high,” said Menard.
Their foray into water-quality consulting began about five years ago when customers approached them about problems they were having with water quality.
“We started selling aeration systems and now it has blossomed into all kinds of things like bird deterrents and feeders for feeding fish,” said Menard.
Many people don’t know the signs of poor water quality, and only contact the Menards when dead fish appear in their dugout. Surface algae, excessive weed growth, odour, and cloudy water generally indicate something is wrong — and it’s often poor nutrient management.
“It’s usually caused by nitrogen or phosphorus run-off from livestock or fertilized crop land,” said Menard. “In those situations, the oxygen levels are not sufficient to break down those nutrients.”
Low oxygen levels favour anaerobic bacteria, which produce hydrogen sulphide gas that creates taste and odour issues, weeds, and algae, including toxic species. Duck weed can coat an entire pond and cut off oxygen transfer on the surface, which can be an issue as 90 per cent of oxygen transfer in a pond occurs on the surface. Oxygen levels also fall as temperature rises, which results in ‘summer kill.’ Aerating ponds helps circulate oxygen and maintain water quality. Not all ponds need to be aerated, but the Menards recommend adding aeration systems when dugouts are constructed.
Dead grass and plant material, as well as soil, release nutrients that can turn into sludge — some older dugouts can have as much as two feet of it on the bottom.
“We have products where the bacteria will actually consume that muck, because it’s a source of organic carbon,” said Menard.
Smoky Trout Farm (www.smokytroutfarm.com) also sells beneficial bacteria, which Menard calls “a chemical-free way of managing nutrients.”
“What it does is it shifts the nutrients from the plant kingdom into the animal kingdom,” he said. “Instead of algae and weeds eating the nitrogen, it’s the bacteria, which are then consumed by other microorganisms and aquatic insects and then the fish are at the top of the food chain.”