Methylmercury (MeHg) is one of the most threatening contaminants affecting fisheries worldwide. Patterns of bioavailability and bioaccumulation of this metal remain poorly understood, especially within estuaries. We examined biotic and abiotic factors which influence mercury (Hg) bioaccumulation within a largely unstudied estuarine predator, longnose gar (Lepisosteus osseus ), while describing its life history and dietary patterns. Chapter I introduces the state of knowledge of Hg bioaccumulation within estuaries and longnose gar biology. Chapter II outlines age, growth, and reproduction of this long-lived and highly fecund fish within two coastal rivers. Longnose gar display determinate fecundity and are batch spawners with group-synchronous oocyte development spanning most of the year. Chapter III describes the dietary components and ontogenetic shift of this species from small benthic fishes to large pelagic fishes. Chapter IV concludes that longnose gar are not representative of other fishes in MeHg bioaccumulation, though they are excellent indicators of MeHg exposure for estuarine fishes. This is the second study to explore reproductive offloading of Hg in a spawning fish and found predictable Hg levels within oocytes. Chapter V summarizes that these studies provide valuable insight into the ecological role of longnose gar and their patterns of Hg uptake.
|Advisor:||Shervette, Virginia R.|
|Commitee:||McDonough, Christopher J., Owens, David W., Reed, Lou Ann|
|School:||College of Charleston|
|School Location:||United States -- South Carolina|
|Source:||MAI 53/06M(E), Masters Abstracts International|
|Subjects:||Ecology, Toxicology, Surgery, Biological oceanography, Zoology, Aquatic sciences|
|Keywords:||Bioaccumulation, Estuary, Life history, Longnose gar, Mercury, Trophic ecology|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be