Case Study: Weed Harvesters Offer a Solution to Aquatic Plant Problems in the Bay

BACKGROUND INFORMATION

4945-acre bay within Green Bay, extending across the Door County Peninsula
Bay is artificially linked to Lake Michigan with a shipping canal
Substantial activity from commercial and recreational watercraft
Home to 4 marinas and 2 yacht clubs with 750 boat slips & about 80 moorings
Port is home to a major ship building and repair facility and a Coast Guard Station

Arial view of Sturgeon Bay

PROJECT CHALLENGE

Aquatic plants, both native and invasive species, are abundant in the Bay
Curly-leaf pondweed and Eurasian watermilfoil found to be quite widespread
Naturally occurring floating plant material captured around boats and slips
Abundance of floating vegetation quickly fills harvester requiring two unloading sites
Runoff from lawn fertilizers contributes to aquatic plant growth

THE SOLUTION

The 50-foot long, 13-foot-wide Aquarius Systems TH-34 Trash Skimmer vessel features twin catamaran hulls and a water jet propulsion system. The Trash Hunter® operates for 10 months out of the year removing floating debris and litter for the 10-mile stretch of the Passaic River.

Wings on the front of the boat direct debris onto conveyor belts that move the conveyor into an onboard storage hold. When the boat reaches capacity, the conveyor belts discharge the debris onto an Offloading Conveyor and into a dumpster before it is disposed of at a landfill.

Aquarius Systems lake weed harvester in Wisconsin.

Aquatic Weed Harvester transfering weeds to a shore conveyor.

In 2022, the fleet of equipment removed 1,621 loads of aquatic vegetation. The nutrient rich vegetation was taken to local homes and farms to be used as fertilizer. The phosphorus contained in the harvested vegetation has the potential to produce 607 tons of algae.