Media backgrounder: The Beneficial Cattail: An input into a regional bioeconomy

The International Institute for Sustainable Development is demonstrating how innovative ecosystem management transforms a difficult environmental problem into an array of environmental, social and economic benefits. IISD is showing how the cattail (Typha spp.), a common wetland plant, can be a valuable input into a modern bioeconomy. Harvesting and processing cattails produces low-cost bioenergy, fights eutrophication (nutrient loading) by capturing phosphorus, recycles this phosphorus into fertilizer, produces carbon credits and improves wetland habitat.

IISD's current research on cattail harvesting was chosen as a Sustainia100 solution at the United Nations Conference on Sustainable Development (Rio+20). The project was also awarded a 2011 Manitoba Excellence in Sustainability Award in partnership with the University of Manitoba and Ducks Unlimited Canada. The project is based on harvesting cattails and is an important proof of concept of IISD's Lake Winnipeg Bioeconomy Project.

What are cattails?

Cattails are a common wetland plant, with roughly 10 species occurring worldwide. Many species produce a tremendous amount of biomass in a single growing season, compared with many other biomass sources that require multiple seasons before they can be harvested.

What is a bioeconomy?

A bioeconomy is an economy in which the basic building blocks for industry and the raw materials for energy are derived from plant- and crop-based (renewable) sources. A regional bioeconomy is developing in Manitoba, Canada. IISD and its partners are demonstrating bioeconomy concepts by harvesting cattails in urban and rural areas including natural wetlands, engineered treatment wetlands, storm water retention ponds, ditches, urban greenbelts, and marginal agricultural land. The initial research was conducted in partnership with Ducks Unlimited Canada and the University of Manitoba at Netley-Libau Marsh, a large coastal wetland at the mouth of Lake Winnipeg, the 10th largest freshwater lake in the world, and the most eutrophic large lake in the world.

What are the benefits?

1. Nutrient removal: Harvesting the nutrient-laden cattails permanently removes phosphorus from the marsh, which benefits downstream waterways by decreasing nutrient loading.
2. Bioenergy production: The harvested cattails can be turned into compressed fuel products (e.g., pellets and cubes) used for bioenergy production.
3. Carbon credits: Cattail biomass can be burned in place of coal and other fossil fuels, resulting in fewer greenhouse gas emissions, and generating profitable carbon credits.
4. Phosphorus recovery: The ash from the burned cattails contains phosphorus, which can be recycled into fertilizer. Phosphorus is a scarce and strategic natural resource, critical to global food security.
5. Habitat improvement: Removing the dense accumulation of dead plants opens the marsh to sunlight, spurring new plant growth and renewing wildlife habitat.

How does cattail harvesting support sustainable development?

Three of the biggest sustainable development challenges in the world are the need for sustainable energy, clean water and food security—all of which are demonstrated by cattail harvesting.

Economic benefits: Cattail biomass produces low-carbon energy at a cost of CAD$0.025 to CAD$0.050 per kilowatt hour, comparable to or cheaper than other biomass sources. In Manitoba, coal costs roughly CAD$70 per tonne; cattail costs between CAD$50 and CAD$85 per tonne, depending on how it is processed. Cattail also offers a viable carbon offset product, while removing phosphorus at a lower cost than traditional wastewater treatment.

Social benefits: Marginal agricultural land typically produces little income for farmers; cattail harvesting offers new revenue streams from marginal lands that boost farm income and increase rural resilience, avoiding the ethical "food versus fuel" question that arises when biomass crops are grown on prime agricultural land.