Cattail biomass and nutrient survey of Netley-Libau Marsh

The study finds that Netley-Libau Marsh is currently degraded and not functioning as a healthy coastal wetland, with total phosphorus levels in the water significantly exceeding Manitoba Water Quality Guidelines. However, the marsh's cattail communities store substantial amounts of nutrients—estimated at 525 tonnes of phosphorus and 1,965 tonnes of nitrogen—and the report argues that restoring 25% of lost plant communities could further increase these storage capacities by 130 and 500 tonnes, respectively.

• Netley-Libau Marsh has suffered significant ecological degradation over several decades due to dredging, drainage, and water management, leading to a decline in wildlife habitat and a loss of plant communities. Between 1979 and 2001, open water areas increased from 8,880 hectares (35%) to 13,125 hectares (51%), while vegetation cover declined by nearly 32%.
• Water quality samples from August 2009 show that total phosphorus (TP) concentrations in the marsh range from 0.39 to 3.53 mg/L (with one site reaching 9.56 mg/L), which is significantly higher than the Manitoba Water Quality Guideline limit of 0.025 mg/L.
• The cattail (Typha spp.) community in the marsh is estimated to store 525 tonnes of total phosphorus and 1,965 tonnes of total nitrogen. Additionally, the soil layer is estimated to contain 230 tonnes of phosphorus and 305 tonnes of nitrogen.
• Restoring 25% of the lost plant communities and organic litter layers in Netley-Libau Marsh could increase the storage potential for phosphorus by 130 tonnes and nitrogen by 500 tonnes.
• The average dry biomass yield for cattails in the marsh is estimated at 18,870 kg (18.9 tonnes) per hectare, with an average plant density of 43 plants per square metre and an average height between 260 and 290 centimetres.
• Nutrient distribution within the cattail community shows that the greatest proportion of nitrogen is found in above-ground plant material, whereas the largest phosphorus reserves are located in the below-ground roots and the soil layer.
• The Red River is the primary source of nutrient stress for Lake Winnipeg, contributing nearly 60% of the phosphorus entering the lake, with 14% originating from agriculture and 11% from wastewater effluent in Manitoba.
• Harvesting nutrient-rich aboveground cattail biomass can permanently remove stored phosphorus from the aquatic system, providing a feedstock for bioenergy and biomaterials while reducing nutrient loading to the watershed.

APA

Grosshans, R. E., Venema, H. D., & Oborne, B. (2012). Cattail biomass and nutrient survey of Netley-Libau Marsh. International Institute for Sustainable Development. https://www.iisd.org/system/files/publications/advancing-netley-libau-marsh-restoration-efforts.pdf

Chicago

Grosshans, Richard E., Henry David Venema, and Bryan Oborne. Cattail biomass and nutrient survey of Netley-Libau Marsh. International Institute for Sustainable Development, 2012. https://www.iisd.org/system/files/publications/advancing-netley-libau-marsh-restoration-efforts.pdf.

Wikipedia

{{cite report |last1=Grosshans |first1=Richard E. |last2=Venema |first2=Henry David |last3=Oborne |first3=Bryan |title=Cattail biomass and nutrient survey of Netley-Libau Marsh |publisher=International Institute for Sustainable Development |date=April 2012 |url=https://www.iisd.org/system/files/publications/advancing-netley-libau-marsh-restoration-efforts.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{grosshans2012cattail, author = {Grosshans, Richard E. and Venema, Henry David and Oborne, Bryan}, title = {{Cattail biomass and nutrient survey of Netley-Libau Marsh}}, institution = {International Institute for Sustainable Development}, year = {2012}, month = apr, url = {https://www.iisd.org/system/files/publications/advancing-netley-libau-marsh-restoration-efforts.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }