Fish Assemblage Response to Environmental Gradients and Altered Dendritic Connectivity in the Red River Basin, Central Louisiana

Louisianas small streams provide critical habitat for diverse ecologically and economically important fish species. However, the relationship between these fish assemblages and habitat variables remains poorly understood. The role of anthropogenic alteration of dendritic stream connectivity is of specific interest and has been shown to significantly influence stream ecology. This study explored the interaction among watershed characteristics, stream connectivity, stream physico-chemistry, and fish assemblages in little-studied Red River basin of central Louisiana as well as how reservoir littoral zones compared to streams, both in terms of fish assemblage and habitat.
Fish and habitat were sampled in 21 headwater streams, half of which flowed directly into a reservoir, and in four reservoir littoral zone sites. Multivariate analyses indicated that level of dendritic connectivity did not explain a significant amount variation in stream fish assemblages. Fish assemblage composition and its relationship to common environmental gradients were similar in in all streams regardless of connectivity. Additionally, the assemblage and habitat of the reservoir littoral zone was comparable to that found in streams indicating that reservoirs were not serving as deleterious barriers to stream fish assemblages. However, individual species modeling revealed greater abundance of three species in streams with unaltered connectivity. These results do not parallel trends observed in other examinations of altered dendritic connectivity, however, they are concurrent with studies of coastal plain fishes response to other disturbances. Understanding the magnitude and structure of response to disturbance is critical for preserving aquatic ecosystems and focusing conservation efforts. Even systems such as the Red River Basin, which evidence strong resilience to human disturbance, warrant closer inspection before heedless system alteration continues.

Identiferoai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-11042015-125939
Date15 December 2015
CreatorsReuter, Catherine Nell
ContributorsRutherford, Marcus, Kaller, Michael, Kelso, William
PublisherLSU
Source SetsLouisiana State University
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lsu.edu/docs/available/etd-11042015-125939/
Rightsunrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.

Page generated in 0.0016 seconds