BioHaven Floating Islands were developed by Bruce Kania, founder of Floating Island International, and his team in Shepherd, Montana. Bruce describes the science behind the technology as follows:
Floating Islands are made of layers of plastic matrix bonded together with marine foam. The foam provides buoyancy as well as adhesion. The plastic is 100% recycled polyester, PET, sourced from drink bottles, though other forms of plastic could be used. The foam is polyurethane. The standard reserve buoyancy is adjustable, from a typical island which is 5.5 lbs per square foot up to 61.5 lbs per cubic foot of island. (Reserve buoyancy is the amount of weight a floating island can support without sinking).
The surface area of a single square foot of island, 8 inches thick, is 198 sq ft. This is provided by the fine fibers which make up the non-woven matrix. Expanded, a 250 sq ft island is the equivalent of 1 acre of actual surface area. Think wetlands and how valuable an acre of wetland is when it’s actual land area! Our islands provide the equivalent without taking up valuable land, and they work in deep or shallow water.
The surface area is important because microbes in the water need a surface to proliferate on. Think of a bottle you throw into the water – it doesn’t take long before it’s covered in green slime! This is biofilm and biofilm is made up of microbes, single cell organisms that need nitrogen and phosphorus to thrive. These nutrients, which arrive in the water column via fertilizers, are harmful to water as they allow algae to grow; but if we give microbes somewhere to live, they’ll use the nutrients for their own growth before algae get to them. Thus the microbes keep the water clear of algae, and in so doing prevent algae depleting the water of oxygen.
Research studies prove that BioHavens do what we say they will do. A two-year study conducted by a third party scientist (and funded jointly by the state of Montana and Bruce Kania) affirmed that, under optimal test conditions, BioHavens remove 20 times more nitrate than the best previously published study (BoR, 2005), 10 times more phosphate, and 11 times more ammonia than the amount which is considered a benchmark for best performance.
Microbes are the very base of the food chain. If microbes are allowed to thrive, the rest of the food chain can flourish. Microbes produce zooplankton (slime) which fish and other creatures feed on. This is a source of carbon, and this carbon is effectively sequestered by the creatures that feed off a BioHaven.
BioHavens are a very significant tool for carbon sequestration in other ways, given that they represent new land mass for trees and plants to grow which would otherwise not exist. During the process of photosynthesis they use up CO2 from the atmosphere. They trap carbon solids in their roots and in time drop them into the anaerobic sediment, where they can no longer release CO2. CO2 is one of the harmful greenhouse gases that contribute to global warming.
As well as removing nutrients from the water column, BioHavens can remove heavy metals, in either dissolved form of in the form of fine particulates (studies by NIWA in NZ corroborate this).
Applications for the water-cleansing features of BioHavens include wastewater lagoons, farm ponds, stormwater ponds, acid mine drainage ponds, golf courses, rivers and any waterway susceptible to algal blooms caused by fertilizer run-off.