Lake Banook and Lake Micmac Weed Harvesting Project

Nuisance aquatic weed growth in Lake Banook and Lake Micmac was reported to the municipality in summer 2009 and again the following year. Specimens collected during those years indicated the weeds of interest were non-invasive native species, primarily of the pondweed family.

In 2013, the municipality contracted Stantec Consulting Ltd. to assess the causes and possible solutions to the ongoing nuisance aquatic weed growth in the lakes. Their report indicated both short-term and long-term solutions would be required to address the problem. Short-term solutions proposed for the municipality’s consideration included herbicide application, sediment dredging and removal, and mechanical weed harvesting.

In February 2015, Regional Council directed staff to seek approval from the province to manage weeds in Lake Banook and Lake Micmac, to implement short-term weed management through contracted mechanical harvesting services, and to prepare recommendations for long-term options for weed control on the lakes.

A successful pilot harvesting project was conducted in the lakes in August and September 2015, resulting in the removal of an estimated 82,500 pounds of weeds over eight days.

In 2016, Stantec Consulting Ltd. and Natural Ocean Products Inc. were selected to conduct weed monitoring and weed harvesting services, respectively, on Lake Banook and Lake Micmac for 2016, 2017, and 2018.

The harvesting plan aims to minimize the impact of aquatic weeds on recreational and competitive boating in the lakes, to reduce year-over-year growth in standing plant matter, and to mitigate risks from loose weed cuttings, impacts on adjacent property owners, and the potential for inadvertent fish mortality.

Weed monitoring services will help target locations for focused harvesting and will document the extent and effectiveness of the harvesting activities. These services will permit staff to show the harvesting locations, the amount of weeds harvested and relative change in weed canopy year over year, and to conduct detailed project assessment.

Why is the municipality harvesting weeds in Lake Banook and Lake Micmac?

Lake Banook and Lake Micmac are regional recreational assets for the municipality that serve the recreational and competitive paddling communities. Aquatic weeds at or near lake surface pose safety hazards to boaters and limit the opportunity for fair competitions on the Lake Banook race course.  In February 2015, Regional Council directed staff to proceed with mechanical weed harvesting. August 2015 marked the first year for weed harvesting and a three-year contract has been secured for 2016-2018.

2018 weed-harvesting schedule

This year, weed harvesting will begin on July 17 and will likely conclude by mid August.

What happens to the weeds after they are cut?

The mechanical harvester automatically collects the weeds in a bag immediately after they are cut, and the bag is tied off by operators when it is full. Full bags are towed by the harvester until the end of the day, then they are deposited into a container. Harvested weeds are transported to a designated compost facility for final disposal.

What weeds are the focus of harvesting operations? Are they invasive?

Three pondweeds form the focus of the municipality’s harvesting efforts: Potamogeton perfoliatus, Potamogeton foliosus, and Elodea canadensis.  Although native to Nova Scotia, their growth in recent years has become so abundant, and their distribution so broad, that they now pose both a nuisance and a potential hazard to boaters in some locations.

Project cost

Further to an investment of $97,000 in a successful 2015 pilot project, the municipality has secured both monitoring and weed harvesting services for 2016-2018. Following an RFP process, three-year contracts were awarded to Stantec Consulting Limited for monitoring services (totalling $183,900) and Natural Ocean Products for harvesting services (totalling $390,000).