About The Project This project holds the R code in support of a manuscript:
Title: Efficacy of exclusion periods for mitigating harm to freshwater fishes moving into a Great Lakes coastal wetland
Authors: Jonathan D. Midwood, Paul A. Bzonek, Morgan Piczak, Tys Theÿsmeÿer, Douglas C. Braun, Tyler D. Tunney, Sean M. Naman, Colin Lake, and Jacob W. Brownscombe
Publication: J.D. Midwood, P.A. Bzonek, M. Piczak, T. Theÿsmeÿer, D.C. Braun, T.D. Tunney, S.M. Naman, C. Lake, and J.W. Brownscombe. Efficacy of exclusion periods for mitigating harm to freshwater fishes moving into a Great Lakes coastal wetlan Modelling complex spatial–temporal drivers of habitat suitability for an imperilled stream fish. In Submission to CJFAS.
Abstract: Understanding the timing of fish migrations and other life history processes can facilitate improved species protection by limiting harmful perturbations from human activities during critical periods. Exclusion periods (i.e., periods when harmful human activities are not permitted near or in-water; alternately timing windows or restricted activity periods) are among the most commonly applied measures used to mitigate harm to fish or fish habitat in aquatic ecosystems, but few studies have explored their efficacy. We used a 25 year dataset collected at an actively managed fish passage barrier in western Lake Ontario to assess the efficacy of coolwater (15 March – 31 May) and warmwater (01 May – 15 July) exclusion periods. Results indicate that the species evaluated are well protected when the coolwater and warmwater exclusion periods are both applied (i.e., no species with >30% of the spawning run unprotected). Individually, however, the exclusion periods are less effective (6/16 species with >30% unprotected). Some early spawning cold- and coolwater fishes (e.g., Rainbow Trout [Oncorhynchus mykiss] and Northern Pike [Esox lucius]), moved in prior to the start of the coolwater exclusion period and would be most at risk if works persisted into its first few weeks. There was considerable interannual variation in peak arrival timing for the 16 species assessed. The development of models that forecast arrival timing based on within-year conditions (e.g., seasonal water temperatures) is recommended as they could inform risk-based within-year decision making on whether works can continue into the exclusion period. Overall, results support the continued application of exclusion periods as an effective measure for mitigating harm to fish and fish habitat.
Usage: The data and R code used to prepare the Cootes Paradise Fishway dataset, summarize and derive plots and tables presented in the manuscrsipt, and implement relevant models are provides. Copy or clone the files and you should be able to reproduce the analysis and figures seen within the manuscript.
Contact: [email protected]