Current Research

Working M.Sc. Title: Predicting Salmonid Habitat Potential using the 2D Channel Morphology – Southern Interior of British Columbia

Working Abstract/Summary:

Historically, assessments of stream habitat in North America have principally taken what is typically known as either a “limiting factors” or “form-based” approach (Kondolf 2011, Booth et al. 2016). The basis of this approach is that the amount of habitat available can be measured as the portion of the channel that fits the physical conditions preferred by the fish species present (e.g. velocity, depth, gravel size, etc..) and that these conditions limit the biological productivity of a stream (Slaney & Zaldokas 1997, Booth et al. 2016).

In each case, the physical conditions are characterized by surveying the topography of channel at multiple cross-sections; sampling the average flow speed and sediment present on the bed. This data is then used to power either a 1D or occasionally 2D software models that characterize general flow conditions at each cross section given a volume of flow. The flow conditions outputted from the models are then compared against an established set of habitat criteria for the species of interest, estimating the habitat quantity as the portion of the channel at the cross sections that match the habitat criteria.

However, this approach is not without critical limitations, including 1) high cost; 2) accessibility limiting spatial scope; 3) inability to account for habitat complexity and watershed scale processes (Rumps et al. 2017, Kondolf 2011, Booth et al. 2016, Wheaton et al. 2017).  These issues are then compounded, in regions like the BC Interior, where: 1) existing infrastructure, 2) high density of the forest cover and 3) rugged topography limits access. Therefore, comprehensive assessments of stream habitat following traditional methods are rarely feasible for large swaths of Western Canada.

To overcome these limitations, it has been proposed that current assessment procedures incorporate a geomorphological & hydrological “process-based approach” (Kondolf 2011 & Booth et al. 2016), focusing on addressing reach and watershed scale stream processes than rather than just the 1D or 2D physical conditions at one site. Expanding on Moir & Pastnerack (2008), Kondolf (2011), Booth et al. (2016) I have hypothesized that though that in-stream processes & conditions that relate to the quantity and quality of habitat, can be identified and characterized from the top-down 2D profile of the form & structure stream channel’s, as classified by Wheaton et al (2015).

Therefore, I am proposing the following study: a habitat assessment of Duteau Creek in Southern British Columbia, a critical spawning site for Interior Fraser Coho salmon, federally listed as an endangered population, utilizing both a traditional “limiting factors approach” (cross-sectional surveys) and a “process-based approach”. The “process-based” portion will be conducted with geospatial analysis of the geomorphic units comprising the stream channel, utilizing remotely sensed imagery to identify, characterize and map the habitat for native salmonids available. Working out of nearby University of British Columbia Okanagan campus, a multitude of traditional cross-sectional surveys are planned, in order to provide a baseline for assessing the effectiveness of an integrated approach across a range of conditions.

Should the integrated approach prove to be sufficient in comparison to the “limiting factors approach” in evaluating habitat for Pacific salmon it has the potential to 1) Greatly reduce the cost of surveying stream habitats in the Western Cordillera; 2)  Allow for accurate assessments of habitat in watersheds that are currently too large or difficult to access ; 3) Identify issues that may be limiting fisheries productivity that might not have been visible or at least quantifiable before ( e.g. measures of habitat complexity); 4) Reducing the invasive nature of surveying, both from the perspective of accessing private property and disturbances to the stream, a concern in watersheds with sensitive species, as is the case with Duteau Creek.

Advisory Committee: 

  • Dr. Bernard Bauer (Supervisor)
  • Dr. Dwayne Tannant
  • Dr. Leigh Burge
Past Research

Honour’s Thesis: An Assessment of Sockeye Salmon Habitat Potential in Lower Vernon Creek, British Columbia

Abstract:

Anadromous salmon were extirpated from most of the Okanagan Basin over 50 years ago due to aggressive river channelization projects and subsequent installation of flow-control structures that precluded fish passage. As part of the Okanagan River Restoration Initiative (ORRI), however, there are efforts underway to reintroduce salmon into Okanagan Lake and its tributaries.  Lower Vernon Creek, despite having experienced large scale habitat degradation and flow modification, would likely serve as a prime spawning stream and also facilitate further fish passage into Kalamalka Lake.

The principal objective of the research was to provide an up-to-date assessment of the habitat value of Lower Vernon Creek in the context of the inevitable reintroduction of Sockeye into the upper parts of the Okanagan Basin. A study was designed with four distinct components: (1) repeat stream walks to provide a qualitative-expert assessment of reach viability; (2) substrate sampling and analysis to assess spawning gravel capacity for redd building; (3) water quality monitoring to identify possible constraints on habitat preferences by fish; and (4) hydraulic modeling to simulate the range of conditions likely encountered through a typical hydrological year. The results indicate that only two of five sub-reaches in the section between Kalamalka Lake and Okanagan Lake are suitable for salmon. Bed siltation and bottom armoring were major issues in the other reaches. The hydraulic modeling for high, average and low flow conditions suggests that less than half of the study sites would have hydraulic conditions required by spawning Sockeye (assessed using the Froude number, flow depth, and flow velocity), during hydrological conditions encountered in a typical year. However, the study results also suggest that the stream may be more productive than has previously been assessed, and it may only require modest restoration efforts to greatly enhance the overall capacity of the stream to support anadromous salmon.

Supervisor: Dr. Bernard Bauer