Date of Award

Spring 5-1-2025

Document Type

Thesis

Degree Name

Master of Science in Coastal Marine and Wetland Studies

Department

Coastal and Marine Systems Science

College

College of Science

First Advisor

Derek Crane

Second Advisor

John J. Hutchens

Third Advisor

Erin J. Burge

Additional Advisors

Brena Jones

Abstract

Fish movement studies have traditionally focused on species that support commercial and recreational fisheries, but recently more focus has been given to non-game, stream fishes because of their recognized importance in maintaining biodiversity within these ecosystems. Stream fish movement is described as being “restricted” and following a leptokurtic distribution via diffusive spread related to environmental and biological factors. Many studies of stream fish movement ecology in North America have occurred in high-gradient streams with coarse substrate in mountains or in streams of the interior plains. Sandhills streams of the southeastern USA are characterized as warm-water, low gradient, and dominated by sand with unique fish assemblages. Therefore, results from previous studies may not apply to Sandhills fishes. My objectives were to use the sandhills chub (Semotilus lumbee), a species of conservation concern that is endemic to the Carolina Sandhills, to test hypotheses related to diffusive spread, the restricted movement paradigm, and environmental and biological drivers of movement in these understudied headwater streams. From October 2022 to October 2024, sandhills chub movements were measured using capture-recapture methods in 1,400 m reaches of two North Carolina, USA, streams. I described net movement, total absolute movement, seasonal movement, and spawning movement by calculating kurtosis, skewness, median distance moved and used a χ2-test to examine directional movement bias. I tested for diffusive spread using linear regressions between distance moved and time at large and determined what factors were related to movement using generalized linear mixed models. The median distance moved was 0 m and 87% of fish moved ≤ 200 m. The limited movement of sandhills chub suggested that they do not follow patterns of diffusive spread. Seasonal and overall movement distributions were leptokurtic, and movement was not related to the environmental or biological factors I investigated. Movement distributions during the spawning season followed a similar pattern and were highly leptokurtic, with a median distance moved of 0 m. Additionally, there was no evidence of directional movement bias during the spawn. I hypothesized that sandhills chub have limited movements because of several reasons. They co-evolved with beavers, which naturally fragmented headwater streams in this region, possibly restricting movement. Homogeneous habitat conditions and ample cover could also explain why sandhills chub movements are limited, along with the effects of potentially high levels of intra- and interspecific interactions in low-productivity streams. This study provides insight into movement ecology of a Sandhills stream species. Given that restricted movements are pervasive in headwater stream leucisids, across a variety of stream types, future research should focus on experiments to elucidate mechanisms of this pattern. A mechanistic understanding of movement patterns will inform conservation and restoration measures in these increasingly anthropogenically fragmented and degraded habitats.

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