Anoxic water upwelling potentially limits fish habitat in Hamilton Harbour: 3D hydrodynamic modeling

Session: 04. - Restoring Hamilton Harbour: Tilting at Windmills or a Possible Dream?

Bryan Flood, University of Toronto, [email protected]
Mathew Wells, University of Toronto Scarborough, [email protected]

Abstract

Ubiquitous internal waves observed in Hamilton Harbour (Lawrence et al. 2004) have the ability to structure, both temporally and spatially, the water column and associated water quality parameters. Despite improvements in water quality, hypolimnetic hypoxia remains a common occurrence in the Hamilton Harbour AOC (Hiriart-Baer, Milne, and Charlton 2009), with consequences for available fish habitat. Internal seiches due to wind forcing result in upwelling of low-DO hypolimnetic waters, altering the amount and location of viable habitat for fishes over timescales of days. These periodic upwellings lead to swash zones within which water quality characteristics such as temperature and dissolved oxygen can vary rapidly and for relatively prolonged periods (order of tens of hours to days). With the development of a 3D hydrodynamic model of Hamilton Harbour, we will provide insight into the development, frequency, and spatial and temporal extent of these events over timescales of a couple seiche periods (Fundamental internal seiche period ~ 11 h). Results from this study will provide insight into duration and extent of upwelling events, and estimates of swash-zone extent, allowing us to aid and direct aquatic habitat restoration efforts.

1. Keyword
hydrodynamic model

2. Keyword
Hamilton Harbour

3. Keyword
habitats

4. Additional Keyword
Internal Seiche

5. Additional Keyword
Hypoxia