Urban Waters

Gateway to Improved Long-term Spawning (GILS)

A team of local fisheries and habitat experts have installed four HUB's (Habitat Underwater Basket) to introduce quality habitat for fish along the shipping channel of the Milwaukee River Estuary. Theriverbanks of interest are along the shipping channel and are lined with vertical steel sheet walls, retaining walls, concrete, and steel bulkheads to provide structural stability and eliminate erosion from passing barges. It is impossible for fish to survive in these areas of the river due to dredging and lack of vegetation to support them.

HUB’s are rubber containers attached within the corrugations of steel bulkheads and contain a variety of wetland plants that young fish use for food and shelter. Unique designs have been engineered to reflect wall conditions, water quality, freeze/thaw patterns, ice and wave action, tolerant vegetation, and target species needs.

A pilot project known as the "Habitat in Hard Places” program lasted only one year because of high plant mortality. This, however, was due primarily to late-season deployment. Prior to installation, the HUB’s tested well; both in the field and lab then re-sprouted after the winter freeze. Following Installation, the WI DNR along with local non-profits will monitor plant and aquatic life, and data collected will be used to prove the success of our pilot project before we expand.

Our long-term goal is to increase fish population and improve spawning patterns along the shipping channel of the Milwaukee River Estuary. Short term project objectives include:


• Identifying potential installation sites
• Selecting plant species
• Determining alternative plant rearing facilities & techniques
• Finalizing locations and bolstering project interest.
• Determining alternatives for attachment mechanisms, flotation containers, soil and plants; choose best method
• Fabricating attachment device
• Establishing plant nursery and begin incorporating plant-rearing techniques
• Determining the best statistical methods to evaluate fish use of the structures
• Determining winter die off rate in HUB’s, spring re-sprout rate of plants and use by fish species.
• Monitoring of HUB’s for plant vitality, basket maintenance, and fish use
• Developing recreational and aesthetic surveys
• Placing fish & assemblage data in the MMSD/USGS historical database


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Project Partners