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Thesis
THE ARTIFICIAL REEF EFFECT OF WORLD WAR II ERA SHIPWRECKS IN THE NORTHERN GULF OF MEXICO
University of West Florida
Master of Science (MS), University of West Florida
2007
Abstract
Deepsea fishes and their associated habitats have not been well studied in the northern Gulf of Mexico (Gulf). Furthermore, little is know about whether fishes in the deep Gulf utilize shipwrecks as artificial reef habitat. The objective of this study was to examine the utilization of shipwrecks as habitat by fishes across a depth gradient in the northern Gulf. I examined community structure, diet, trophic structure using stable isotope values (13C, 15N, and 34S), and age of fishes associated with six World War II era shipwrecks ranging in depth from 87 to 1,964 m. Statistical analysis of community structure estimates revealed significant differences existed among wreck sites (ANOSIM: p 0.001) and among sample locations within sites (ANOSIM: p 0.001). At the three shallowest sites, reef- or structure-associated fishes were predominant over wreck sites. Fish communities over deep wrecks were similar to those away from wrecks and consisted mostly of halosaurs (Family: Halosauridae), cusk eels (Order: Ophidiiformes), grenadiers (Family: Macrouridae), and eel (Family: Anguilliformes) species, listed in order from highest to lowest relative abundance. Diet of fishes was determined by analysis of gut contents (n = 107) and trophic position was further clarified by analysis of muscle stable isotope values (n = 79). Results revealed a range of trophic levels and sources of production as benthic, pelagic, or chemosynthetic. At the two shallowest sites, 13C and 15N values among fishes indicated a range in feeding from planktivores to piscivores, and 34S values indicated a range in benthic versus pelagic prey. Stable isotope values among fishes at the third shallowest site indicated little difference in trophic levels and a pelagic source of production. At the three deepest sites, 13C and 15N values indicated feeding at middle trophic levels, and 34S values indicated a pelagic source of production. A total of 97 otolith sections (84 adults and 13 juveniles) were examined. On the two shallowest wreck sites, fish tended to be larger at age and younger overall than fishes on deeper wreck sites. Results from this study provide insight into the ecological function of shipwrecks as large artificial reefs along a depth gradient. The artificial reef affect of shallow wreck sites was apparent, but for shipwrecks below 1,500 m, no artificial reef effect was observed for fishes.
Details
- Title
- THE ARTIFICIAL REEF EFFECT OF WORLD WAR II ERA SHIPWRECKS IN THE NORTHERN GULF OF MEXICO
- Resource Type
- Thesis
- Publisher
- University of West Florida
- Format
- text
- Identifiers
- 99380090833606600
- Academic Unit
- Biology
- Language
- English
- Awarding Institution
- University of West Florida; Master of Science (MS)
- Theses and Dissertations
- Master of Science (MS), University of West Florida