Evaluating Effects of Exploitation on Annual Apparent Mortality Rates of Paddlefish Using Mark–Recapture Data

Document Type

Article

Publication Version

Version of Record

Publication Date

2-2015

Departmental Paper Identifier

NRM-170

Keywords

NRM-170

Abstract

Knowledge of the effects of exploitation on population dynamics is critical to effective conservation and management of fish populations. To improve our understanding of the effects of sport fishery exploitation on populations of Paddlefish Polyodon spathula, we tested eight additive and compensatory harvest mortality hypotheses for the Paddlefish population in Lake Francis Case (LFC), South Dakota, with 33 years of tag recovery data using dead recovery models in Program MARK. We evaluated additive and compensatory harvest mortality hypotheses by modeling the effects of sport fishery closures on annual apparent survival and tag recovery rates. Our most-supported hypotheses indicated that exploitation prior to the functional closure of the sport fishery (i.e., when exploitation became negligible) was an additive source of mortality. Annual apparent mortality estimates (i.e., 1 ¡ annual apparent survival) of our most-supported model decreased from 0.237 (SE D 0.036) to 0.110 (SE D 0.063) following the functional closure of the sport fishery and coincided with a decrease in recovery rate from 0.095 (SE D 0.015) to 0.010 (SE D 0.004). These results suggest that relatively unregulated sport fishery exploitation can substantially increase mortality rates of Paddlefish populations. The effects of exploitation on mortality likely differ between populations and temporally within populations due to differences in density-dependent mortality rates.

Publication Title

Transactions of the American Fisheries Society

Volume

144

Issue

2

First Page

337

Last Page

344

Pages

8

Format

application/pdf

Language

en

DOI of Published Version

10.1080/00028487.2014.991445

Publisher

Taylor & Francis

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted within the U.S.

Comments

This work was published in Transactions of the American Fisheries Society 144:337-344

This document is currently not available here.

Share

COinS