The Need

Many freshwater bodies of the world suffer from the disastrous, interrelated combination of nearby wetland habitat loss, nitrogen loading, and toxic algal blooms. This problem is seen throughout the United States in nutrient heavy storm water ponds, drinking water reservoirs, and the Great Lakes. Historically, functional wetlands and floodplains create robust aquatic ecosystems that are resilient to mitigate toxic algal blooms and subsequent eutrophication. However, these critical ecosystems have largely been replaced by human development, resulting in numerous water bodies that experience the growth of toxic algae during summer months. This impacts critical habitat, drinking water resources, and recreation and tourism. The problem will amplify as rising global temperatures create better conditions for toxic algae and increased pressure on freshwater resources. Yet, solutions have to develop a large-scale habitat are sparse, and the wetland and floodplain restoration projects invariably require the purchase of valuable private land and coordination between multiple landowners.

The Technology

Researchers at The Ohio State University, led by Jacob Boswell, have developed a perforated conical vessel made of buoyant concrete for the use of floating aquatic plant species. The concrete mixture allows water to permeate the vessel while remaining afloat and the vessel supports a soil volume sufficient to grow water-loving plants like willow and cypress along with a large range of other edge and emergent wetland species.

Commercial Applications

• Environmental restoration
• Toxic algae bloom reversal and prevention
• Fish and amphibian habitat growth

Benefits/Advantages

• The advantage of this design is that, because of the soil volume it can hold, it is able to support a larger variety of plant species including water-loving trees like willow and cypress.
• The durability of the concrete makes the vessel appropriate for use over long periods in deep-water situations. Unlike existing floating islands made of recycled plastic, the materials used in the vessels fabrication are chemically inert and naturally occurring.