Development and implementation of habitat availability models to determine lake sturgeon restoration strategies in northern Lake Michigan tributaries

Dan J Daugherty, Purdue University

Abstract

Lake sturgeon Acipenser fulvescens have experienced declines in abundance, reductions in distribution, and losses or fragmentation of lotic spawning, staging, and nursery habitats since the early 1800s. Research aimed at understanding the status and population characteristics of remnant lake sturgeon stocks has facilitated interest in the restoration this species throughout the Great Lakes region. However, little information exists on the availability, quality, and distribution of life-stage specific habitats in tributaries throughout the basin. The purpose of this study was to develop a standardized method to evaluate lake sturgeon habitats in Lake Michigan tributaries and to develop a habitat-based decision-tool model to aid determination of the most appropriate restoration strategies for each system. Geo-referenced habitat information (i.e., substrate composition, water depth, and channel gradient) was modeled using an inverse-distance weighted interpolation technique and applied to a lake sturgeon habitat suitability index model to produce spatially explicit models of life-stage specific habitat characteristics in ten northern Lake Michigan tributaries. In systems currently supporting lake sturgeon, high quality spawning and staging habitat comprised 1 to 6 and 17 to 47%, respectively, of the available habitat in each system. However, lake sturgeon access to a majority of these habitats (range, 30 to 100% of the available habitat) is currently impeded by dams. High quality juvenile (i.e., age-0) habitat was ubiquitous in these systems and comprised 69 to 100% of the available habitat. Application of these data to the decision-tool model indicated that provision of fish passage or the creation of supplemental spawning habitat should be considered to restore lake sturgeon populations in these systems. In tributaries where lake sturgeon have been extirpated, high quality spawning and staging habitat comprised 0 to 23 and 0 to 9%, respectively, of the available habitat, whereas high quality juvenile habitat comprised 39 to 99%. Application of these data to the decision-tool model suggested that restoration efforts should focus on the creation of spawning and staging habitat prior to the development of stocking programs to re-establish lake sturgeon populations in these systems.

Degree

Ph.D.

Advisors

Sutton, Purdue University.

Subject Area

Aquaculture|Fish production

Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server
.

Share

COinS