A monitoring buoy is about to be deployed in Lake Hood next week and several rounds of trials of products to mitigate cyanobacteria blooms are planned in the lake this summer.

Group Manager of Infrastructure and Open Spaces Neil McCann said the buoy would gather information about water temperature and the level of dissolved oxygen in the lake.

The buoy will be in the body of the main lake, offshore from the existing lake outlet (near the southern end of the bunded water-ski area).

“We have also sent expressions of interest forms to 15 product suppliers who might like to be involved in the in-lake trials, and the intention is to choose four or five products to test. We’ll be looking at how effective these products are at dealing with cyanobacteria and how cost effective they are if applied across the lake.”

The expressions of interest forms have been sent to a range of suppliers offering product solutions, including those suppling ultrasonic, beneficial bacteria, hydrogen peroxide and copper sulphate products.

Mr McCann said Council was also monitoring weed that was starting to grow as temperatures warmed.

“It is too early in the season for the weed harvester to be effective, however we’re keeping a close eye on this and will instruct our contractor to start harvesting when the time is right.”

Council is also aware the community is talking about algae that has appeared in the lake in recent weeks.

Mr McCann said Council had asked its cyanobacteria expert Professor Susie Wood to take a look.

“While it’s unsightly, it is not a risk to humans and it will likely flush out or disappear with wind.

“We believe it is green filamentous algae and this usually grows attached to the bottom of the lake bed, but after a few warmer days, or as it thickens, it can detach and form floating rafts. These mats tend to indicate nutrient-rich water, so they are possibly responding to the high levels of groundwater entering the lake and this is why we need the hydrodynamic model, as it will assist us with understanding the dynamics of the lake.”

Mr McCann said gathering as much information as possible would help create a base line of lake conditions.

“Then the hydrodynamic model will simulate water circulation patterns, which are key to understanding how nutrients enter the lake and where they settle and accumulate, which then contribute to the algae blooms.”

Council officers continue to meet fortnightly with Professor Wood and her team with the aim of improving water quality in the lake and slowing the growth of algae during summer.

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