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PhD Dissertation Defense: Matthew D. Kenworthy
January 11, 2019 @ 10:30 am - 11:30 am
The PhD Dissertation Defense of Matthew D. Kenworthy will be presented by the University of North Carolina at Chapel Hill Department of Marine Sciences and Institute of Marine Sciences (IMS). The main location of this event will be in room 222 of UNC’s Institute of Marine Sciences in Morehead City, NC. The defense will be streamed live to conference room 3204 on the 3rd floor of Murray Hall on UNC main-campus in Chapel Hill, NC and online via Zoom (Meeting ID: 252 726 6841). This event will be held on Friday, January 11th at 10:30 am.
Title: The movement ecology of large, mobile fishes in North Carolina estuaries.
Abstract: Coastal and estuarine ecosystems have been recognized as essential juvenile habitats for many commercially and recreationally important fishes. As such, linkages between availability of healthy coastal habitats and fish production have been an important drivers of marine ecosystem conservation and restoration efforts. Yet, identifying what exactly constitutes critical habitat for juvenile fishes remains challenging. North Carolina marine ecosystems are typically comprised of heterogeneous mosaics of distinct habitats (seascape) such as seagrass meadows, oyster reefs, saltmarshes, and mudflats. Key to identifying the value and function of these habitats within estuarine seascapes in supporting fishery production is quantifying spatiotemporal use of target habitats by fishes. However, this is complicated by the fact that fish move around over multiple spatial and temporal scales. Therefore, I explored the movement ecology and habitat selectivity of recreationally important fishes in multiple North Carolina estuaries. Specifically, I addressed three major questions: 1) Does the movement behavior of a large predatory fish (red drum) enhance landscape-level connectivity among estuarine saltmarsh complexes? 2) Does a large predatory fish (red drum) express fine-scale habitat selectivity within a saltmarsh complex that can be used to infer critical habitats in estuarine seascapes? and 3) Does the size, nature of emergent structure, and landscape context of man-made oyster reefs influence habitat use by red drum, black drum, and southern flounder in the New River Estuary (NRE)? Examination of dispersal, activity space, and residency by red drum identified limited movement between marsh complexes thus implying that minimal linkages among these spatially separated habitat complexes are occurring on a sub-annual scale. Fine scale analysis of red drum habitat utilization identified greater than expected selection for structured habitats along saltmarsh edges. Finally, man-made cultch reefs monitored in the NRE were visited by our focal species in similar modes and frequencies as unstructured habitats following the destructive harvest of oysters. At the larger and more structurally complex artificial reefs in the NRE we observed a greater volume of detections of black drum; however, no distinguishable relationships were observed for red drum and southern flounder. This research both expands on and corroborates previous studies analyzing the movement ecology of these three fish species. Continued exploration and analysis of spatial ecology for these recreationally important fish species will better inform stakeholders about the value of various estuarine habitats and guide managers in prioritizing conservation plans to maximize ecosystem function and production.