What an Agricultural Community Can Do to Reduce HABs when Phosphorus Application is Already Low

Session: 41b. - Great Lakes Harmful Algal Blooms Research from Watershed Influence to Ecosystem Effects

Sue Miller, North Bay-Mattawa Conservation Authority, [email protected]
Sue Buckle, North Bay-Mattawa Conservation Authority, [email protected]
Joel Harrison, North Bay-Mattawa Conservation Authority, [email protected]

Abstract

The Wasi River watershed (~300 km²) is one of the few areas within the North Bay-Mattawa Conservation Authority’s area of jurisdiction that supports agriculture. Wasi Lake (6.8 km²⁾ and Callander Bay, an isolated, 12 km² embayment of Lake Nipissing, both experience algal blooms, which many blame on agricultural practices. This has pitted stakeholders against each other and stymied constructive mitigation efforts since the 1980s. Farmers feel land application of nutrients is already limited; soil tillage is minimal. Research supports the farmers’ contention but also identifies watercourses through farmlands as problem areas. Years of draining wetlands to increase arable land and straightening water courses has intensified peak flows and erosive forces downstream and reduced the physical and biological capacities of streams to attenuate nutrients. This talk discusses current efforts to engage agricultural land owners in looking at their own lands to consider what changes individuals could make to aid efforts to moderate stream response to storms and spring freshet. For example, setting aside areas for small wetlands is expected to be an important starting point. It is hoped that dialogue will improve understanding by all parties and spawn a variety of strategies that will prove beneficial. 

1. Keyword
outreach

2. Keyword
hydrodynamics

3. Keyword
harmful algal blooms