A macrophyte modelling approach for identifying water quality delisting targets in Cootes Paradise

Session: Poster session

Rex Tang, Fisheries and Oceans Canada, [email protected]
Susan Doka, GLLFAS, Fisheries & Oceans Canada, [email protected]

Abstract

Cootes Paradise (CP) is an urban wetland as part of the Hamilton Harbour Area of Concern (AOC). Historical sources of nutrient inputs degraded the system’s water quality and caused cumulative stress on fish habitat. Submerged aquatic vegetation (SAV) provides critical fish habitat and its recovery is crucial to AOC’s delisting efforts. We developed predictive models to recommend water clarity (Secchi depth) targets that can achieve minimum 230 hectare of SAV presence in CP. The Royal Botanical Gardens has been monitoring macrophyte growth since 1996, sampling was conducted from June to August using designated 50m transects and 1m² quadrats. Utilizing this database, we explored various modeling approaches for SAV presence and cover.  Random forest models were determined to be the most accurate approach. The final model consists of Secchi depth, west wind fetch, water level, and had high accuracy (Accuracy = 0.88, Kappa = 0.77) for predicting the presence of SAV. The model was then applied spatially using a digital elevation model to predict areas of CP where SAV was likely to occur under different water level and water clarity scenarios. The implications of the modeling results on SAV presence and establishment of a water clarity target will be discussed.

1. Keyword
water quality

2. Keyword
Hamilton Harbour

3. Keyword
vegetation