Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1994. / Includes bibliographical references (leaves 154-168). / by Daniel Kelly Treiber. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1998. / Includes bibliographical references (leaves 171-178). / by Junghai Xu. / Ph.D.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1996. / Includes bibliographical references (leaves 119-131). / by Maria G. Athanassiou-papaefthymiou. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1997. / Includes bibliographical references. / by La Creis R. Kidd. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Division of Toxicology, 1995. / Includes bibliographical references (leaves 107-125). / by Esequiel Eduardo Barrera. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1992. / Vita. / Includes bibliographical references (leaves 207-226). / by Susan Bina Malaikal Verghis. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Division of Toxicology, 1994. / Includes bibliographical references (leaves 81-87). / by Joanne S. Kang. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1998. / Includes bibliographical references (leaves 165-190). / by Hilary A. Coller. / Ph.D.

The Atlantic Goliath Grouper, a large, long-lived reef fish in the southeastern United States, was fished to near extinction decades ago. It is now showing signs of recovery in Florida waters due to protection from fishing in state and federal waters that started in 1990. While providing some optimism for their future, recent discovery of high mercury levels in this species is cause for concern. Indeed, I contend that such levels could not only impede their full recovery but present a human health problem if the fishery were re-opened. For my dissertation, I investigated their spawning patterns and trophic ecology, the latter of which included investigations of the organisms in their diet that lead to mercury accumulation in their tissues. Mercury presents a problem because of its neurotoxic effects and its ability to bioaccumulate in some forms. My research demonstrates that mercury levels in Goliath Grouper are not only much higher than the Environmental Protection Agency’s suggested safe levels for human consumption, but that they are likely impacting the overall health and reproductive potential of this iconic species. / A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2019. / February 25, 2019. / diet, Goliath Grouper, health, mercury, spawning patterns, trophic ecology / Includes bibliographical references. / Felicia C. Coleman, Professor Directing Dissertation; Markus Huettel, University Representative; Scott C. Burgess, Committee Member; R. Dean Grubbs, Committee Member; Thomas E. (Tom) Miller, Committee Member; Joseph L. Travis, Committee Member.

Three non-gadoid fish species, trout (Cynoscion regalis), English sole (Paraophyrys vetulus) and Pacific red snapper (Scomber i~onicus) have been tested for the recovery of trimethylamine oxide (TMAO), trimethylamine (TMA), dimethylamine (DMA), and formaldehyde (FA) during postmortem storage at 4°C and -S°C. TMAO, TMA, and DMA content was determined by measuring them as the salt derivative of picric acid. FA was determined by using the 3-Methyl-2-Benzothiazolinone hydrazone test. In muscle tissue of red snapper and English sole, it was clear that initially TMAO decreased during storage at 4°C, while the amounts of TMA, DMA, and FA increased. When these species were stored at -S°C, only a slight decrease . in the amount of TMAO was measured. Less TMA was formed at -S°C than at 4°C. There was no DMA production in these two species at -S°C and the amount of FA that was formed was significantly less (p < 0.05) than that formed when the storage temperature was 4°C. In the muscle tissue of the trout, no TMAO, TMA, nor DMA was recovered at both storage temperatures. There was no significant difference (p < 0.05) between the amounts of FA recovered from the trout stored at both storage temperatures. The amount of FA recovered from all of the species decreased significantly after 7 days at 4°C and 50 days at -5°C. FA values may be used as an indication of freshness in those fish species which do not produce TMA during storage. TMA was not produced in the tissue of the English sole and the red snapper during frozen storage. No TMA was recovered from the tissues of the trout stored at 4°C and -5°C. In order to obtain reliable data, FA values would have to be determined for each species and each storage condition. FA values would only be reliable if measured before incipient spoilage takes place (7 days at 4°C and 50 days at -5°C). When TMA is produced in fish tissue, the measurement of it combined with organoleptic evaluation would be a more useful tool than FA value in evaluating fresh saltwater fish, both gadoid and non-gadoid species, during refrigerated storage.