Modelling the effects of dam removal on migratory walleye (Sander vitreus) early life-history stages

Abstract

Many dams in the USA have outlived their intended purpose and an increasing number are being considered for removal. Yet, quantitative studies of the potential physical, biological and ecological responses are needed to assess dam removal decisions. In this paper, the responses of migratory walleye (Sander vitreus) to increased spawning habitat availability as a result of dam removal was studied by comparing scenarios with and without a high-head dam in the Sandusky River (Ohio), a major tributary to Lake Erie. A conceptual, ecological model was proposed to define the relationship between hydrodynamics and walleye spawning, egg hatching, larval drift and survival. A mathematical, ecological model of the early life-history stages was then developed and coupled with time series of depth and velocity predictions over the spawning grounds from a 1-D hydrodynamic model. Model simulations were run for 1984-1993 for both the with-and without-dam scenarios to assess the potential benefit of dam removal. The simulation results demonstrated that velocity, depth and water temperature are major factors influencing adult walleye spawning success. Without the dam, 10 times the amount of spawning habitat would be available for walleye to spawn. This increase in spawning habitat area resulted in up to five times the total egg deposition and seven times the larval output to the nursing grounds, based on the assumption that 5% of the walleye population of Lake Erie migrated up the Sandusky River to spawn. We concluded that the spawning habitat in the current condition (with the dam) is limiting and additional spawning habitat upstream could significantly increase the number of larval walleye drifting to Lake Erie. The model sensitivity analysis showed that the number of walleye migrating up the river in spring is the dominant factor for larval recruitment to the lake.

Portfolio theory as a management tool to guide conservation and restoration of multi‐stock fish populations

“…Unfortunately, the levels of production necessary to achieve Option 3 are orders of magnitude greater than current production from these production areas. This option may perhaps be an unrealistic target without major investment in mitigating spawning habitat degradation and solving river-to-lake connectivity issues that currently plague Lake Erie's riverine stocks (Mion et al 1998, Cheng et al 2006, Bennion and Manny 2011. If the current and continued cultural demands on these systems preclude sufficient habitat (and hence, stock) rehabilitation in western Lake Erie's spawning tributaries, then management options 4 and 5 may offer the next best targets for optimal production dynamics, as both seem attainable.…”

“…Our analysis identified that the quickest path to balancing the larval production portfolio likely starts with improving production from the Sandusky River. Fortunately, managers are in the final stages of a process leading to the removal of the Ballville Dam (USFWS 2014), which should increase access to spawning habitats (Jones et al 2003) and improve larval production (Cheng et al 2006). Removal of this barrier on the most depressed spawning stock could generate immediate dividends to the Lake Erie walleye population.…”

“…In addition, both river systems have barriers to fish movement. Initially built in the 1840s at rkm 55, the Providence and Grand Rapids dams restrict upstream access on the Maumee River (Zheng et al 2009), whereas the Ballville Dam, built in 1911 at rkm 29, restricts access to upstream spawning grounds on the Sandusky River (Cheng et al 2006). In the Detroit River, dredging and re-deposition of riverbed material, to support shipping channel construction and maintenance, has resulted in spawning and nearshore nursery habitats losses, as well as changes in flow dynamics Manny 2011, Hondorp et al 2014).…”

Multicriteria Decision Analysis of Stream Restoration: Potential and Examples

“…Walleye are native species and top predators in the Lake Erie ecosystem, and are highly valued both ecologically and for sport and commercial fisheries (Locke et al 2005). Historical fisheries data and research (Mion et al 1998;Evans et al 2002;Jones et al 2003;Cheng et al 2006;Gillenwater et al 2006) indicate that, there exists a significant amount of upstream walleye spawning habitat that would be made accessible by removing the dam. But, its removal may also provide access to spawning and nursery habitat for sea lamprey (Petromyzon marinus), an invasive species that negatively impacts the Lake Erie fish community.…”

A One‐Dimensional Hydrodynamic and Water Quality Model for a Water Transfer Project with Multihydraulic Structures

“…The typical representatives include WASP [6], QUAL2E [7], Environmental Fluid Dynamics Code (EFDC) [8], Computational Fluid Dynamics (CFD) [9], and DHI MIKE (Danish Hydraulic Institute) [10]. These models were widely applied to rivers, lakes, estuaries, and water transfer projects with large amount of hydraulic structures (gates, culverts, dams, and bridges) [10][11][12][13]. Although water flow was difficult to be determined when it gets through hydraulic structures, hydraulic regulation was crucial for water resources management and water quality control [14].…”