Ichthyofaunal community structure at a coal combustion by-product reef and natural oyster reef in Galveston Bay, Texas /
This thesis presents the results of a study from February 1993 to March 1994 on the differences in fish community structure at a coal combustion by-product (CCB) artificial reef and a natural oyster reef in Galveston Bay, Texas. It is based on a fisheries-independent sampling effort using experiment...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Summary: | This thesis presents the results of a study from February 1993 to March 1994 on the differences in fish community structure at a coal combustion by-product (CCB) artificial reef and a natural oyster reef in Galveston Bay, Texas. It is based on a fisheries-independent sampling effort using experimental gill nets, and a fisheriesdependent creel survey. Although few statistically significant differences in community structure were found among experimental sites, conspicuous disparities did exist among some parameters. It is likely that high variability associated with a small sample size (12 months) was cause for the acceptance of the Null Hypothesis (H.). Earliest comparisons conducted in February 1993, approximately 7 months after CCB reef deployment, revealed higher nekton yields at both level bottom control and natural reef sites than at the CCB reef site. Occupation of the reefs interstitial spaces by organisms such as mud crabs (Family Xanthidae), gobies (Family Gobiidae) and other cryptic species probably lagged behind fouling community development and, as such, limited attractiveness of the CCB reef substrate to larger predators. Consequently, the reefs infancy coupled with the dominance of a demersal foraging strategy employed by estuarine-dependent species helped contribute to catch statistics which imply the artificial reef was less attractive than a level bottom site and far less attractive than a natural reef. This trend in catch statistics continued throughout the study; however, a persistent measure of community growth was observed over the duration of the study. CCB reef site catches contributed only 13.5% of the total catch per unit effort (CPUE) during the first sampling effort in February 1993. By November, CCB reef site catches contributed 28% of the total catch (107% increase in relative production), and actually surpassed natural reef site catches. CCB reef site fish community structure was greatly influenced by both density-dependent and density-independent processes. Analysis of catch data indicated that these processes are not mutually exclusive, and influence community structure at different time-scales. Within seasons (Winter-Spring and Summer-Fall), the supply of a preferred food source was the most important factor influencing the reef s community structure. |
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| Item Description: | Vita. "Major subject: Wildlife and Fisheries Sciences". |
| Physical Description: | xii, 113 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references: pages 79-83. |