Residency and habitat utilization of Southern flounder, Paralichthys lethostigma, in a North Carolina coastal watershed / by Michael Ryan Spidel.
| Author/creator | Spidel, Michael Ryan author. |
| Other author | Rulifson, Roger A. (Roger Allen), 1951- degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 2009. |
| Description | ix, 106 leaves : illustrations (some color), color maps ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | In 2008 the commercial harvest of southern flounder ParaUchthys lethostigma had a landed value of 5.6 million dollars, making southern flounder the most profitable commercial finfish fishery in North Carolina. However, southern flounder has recently been listed as over-fished in North Carolina. Soft bottom habitats in coastal rivers and estuaries are critical to young southern flounder and are being threatened by dredging operations, shoreline development, mining operations and bottom disturbing fishing gear. In the North Carolina Southern Flounder Fishery Management Plan (FMP) the North Carolina Division of Marine Fisheries (NCDMF) highlighted the importance of protecting and improving critical fish habitat for southern flounder to increase growth, survival, and reproductive success. However, there has been a limited amount of research devoted to determining and identifying the importance of critical freshwater (0- 0.5 ppt) habitat for the southern flounder fishery in North Carolina. Southern flounder are known to utilize coastal rivers, but the duration of their residency is unknown. Residency and use of freshwater habitats by southern flounder was examined using fatty acid profiles and total mercury levels of muscle tissue, and otolith microchemistry. Southern flounder were collected using fishery independent techniques in 2007 and 2008 from three locations in coastal North Carolina: the Tar and Pamlico Rivers, and Pamlico Sound. Results indicated that 74% of southern flounder collected in the Tar River were resident, pre-spawning fish. Fatty acid profiles of resident southern flounder had low n 3:n-6 ratios ([x-bar] = 2.01, SD = 0.40), elevated total mercury levels ([x-bar] = 0.105, SD = 0.034), and low otolith strontium concentrations confirming residency in a freshwater environment. Age-0 and older sub-adult southern flounder were commonly found utilizing flat, shallow muddy-sand or sandy banks in the curves of the river. Total mercury levels were elevated in southern flounder residing in freshwater, but were substantially below the human consumption advisory guideline of 0.4 mg/kg. Reduced growth and low abundance are several indicators that coastal rivers are not optimal habitat for southern flounder, but should be considered as important, secondary habitat. |
| General note | Presented to the faculty of the Department of Biology. |
| General note | Advisor: Roger A. Rulifson |
| Dissertation note | M.S. East Carolina University 2009 |
| Bibliography note | Includes bibliographical references (leaves 43-50). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | Access Content Online | ✔ Available |