A study of the ecological impact of beach nourishment with dredged materials on the intertidal zone / by Francis J. Reilly, Jr.
| Author/creator | Reilly, Francis J. author. |
| Other author | Bellis, Vincent J., 1938- degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 1978. |
| Description | viii, 108 leaves : illustrations, maps, charts ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | During the winter and spring of 1977-78 approximately 1600 meters of high energy sandy ocean beach at Fort Macon State Park was nourished with spoils dredged from the State Port Harbor at Morehead City. This report is the result of a twenty-month study of the nourished beach and a comparable non-nourished beach. Shannon-Weaver species diversity indices ranged from 0.00 to 0.64 on both beaches during the six months prior to nourishment. Generally Shannon-Weaver values were higher on the nourishment beach prior to nourishment due to the higher number of species present. High species number is attributed to the close proximity of the nourishment beach to the Beaufort Inlet. After nourishment began the non-nourished beach maintained the same diversity and density patterns that both beaches had displayed prior to nourishment although there was seasonal variation. The species diversity on the nourished beach became undefined at the onset of nourishment because the density of all species dropped to zero. This situation remained at the nourished beach until the cessation of nourishment activities. During the nourishment activities, the Fort Macon beach was sub-divided into two segments (the area which had already been nourished and the area not yet nourished) . While all organisms in the nourished area disappeared, no Increased population densities were noted from the adjacent non-nourished area. Near the end of nourishment activities this non-nourished area showed both a drastic reduction in diversity and a change in species composition, thus indicating a certain edge effect of nourishment. A special transect designed to monitor rate of recovery after nourishment indicated that a speedy recovery was largely dependent upon recruitment from pelagic larval stocks. It also seemed to indicate that high turbidities associated with nourishment can prevent this recruitment. Lastly it showed that those species unable to recolonize through pelagic larval recruitment returned to the area much more slowly. Comparing before nourishment data with after nourishment data at Fort Macon there is little evident change in the densities of the most dominant secondary producer the mole crab, Emerita talpolda, however when comparing size class data before and after, and with the comparison beach the effects of nourishment are obvious. While a complex age/size class array was evident prior to nourishment at Fort Macon, and after nourishment at the comparison beach, only young of the year age classes were observed for any intertidal species present at Fort Macon. This lack of older and larger individuals and consequently biomass was reflected in lower densities of important migrating consumers at the study site. Although the populations of these consumers were probably not affected, they were noticeably absent from the nourished area during and after nourishment, and probably had moved to adjacent areas. The beach showed signs of recovery. Only Em̌rita talpoida returned in near normal density, all other numerically important species had also returned but in significantly lower density. |
| Local note | Joyner-"Presented to the faculty of the Department of Biology ... in partial fulfillment of the requirements for the degree Master of Science in Biology." |
| General note | Presented to the Faculty of the Department of Biology |
| General note | Advisor: Vincent J. Bellis |
| Dissertation note | M.S. East Carolina University 1978 |
| Bibliography note | Includes bibliographical references (leaves 86-93). |
| Genre/form | dissertations. |
| 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 |