Title

Smallmouth Bass Population Demographics in Missouri Ozark Streams and an Evaluation of a Statewide 305-mm Minimum Length Limit

Abstract

The Ozark streams of Missouri provide anglers with unique Smallmouth Bass Micropterus dolomieu fishing opportunities. To ensure the sustainability and potential of these fisheries, we sampled five streams in the Ozark highland ecoregion of southern Missouri via recreational angling methods. From our samples, we developed estimates of recruitment, growth, and mortality, and assessed current regulations for Smallmouth Bass. To accomplish these objectives, we aged otoliths from 75 legal (305-mm) fish on each stream. Back-calculated length-at-age estimates were formed for sublegal lengths, and were paired with electrofishing length distributions on each stream using an age-length key. These data were used to develop estimates of dynamic rate functions and models of yield, spawning potential, and number of memorable fish for each study population. We found that recruitment was stable on each stream, but growth and mortality varied among streams. We also found that models of yield, spawning potential, and number of memorable fish varied greatly among streams. Our results showed that the current 305-mm statewide minimum length limit is applicable for some of our study streams, but yield, spawning potential, and trophy potential could increase with more restrictive length limits on some of our study streams. More spatially explicit length limits can help these Smallmouth Bass populations reach their growth potential. This information can help inform stream management in Missouri and across the Ozark region of the Midwest.

Department(s)

Biology

Document Type

Article

DOI

https://doi.org/10.1002/nafm.10350

Rights Information

© Ivyspring International Publisher. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/). See http://ivyspring.com/terms for full terms and conditions.

Publication Date

12-1-2019

Journal Title

North American Journal of Fisheries Management

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