Item – Theses Canada

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OCLC number
948510061
Link(s) to full text
LAC copy
LAC copy
Author
Ross, David,
Title
Trace metal content in Panamanian marine turtles, its potential to differentiate populations, and implications for human consumption
Degree
M. Sc. -- McGill University, 2015
Publisher
[Montreal] : McGill University Libraries, [2015]
Description
1 online resource
Notes
Thesis supervisor: Catherine Potvin (Internal/Supervisor).
Thesis supervisor: Hector Guzman (Internal/Cosupervisor2).
Includes bibliographical references.
Abstract
"Anthropogenic input of chemical pollutants into the marine environment has led to substantial increases in the concentrations of naturally occurring trace metals, often with detrimental effects on the health of exposed marine animals and humans. Although they are a common food source in many tropical countries, quantitative toxicological assessments of marine turtles are generally limited in number of species investigated, number of data per species, and geographical distribution of samples. Chapter 1 presents a comprehensive review of sea turtle toxicology, and sea turtle eggs in particular given their widespread human consumption. From 70 collated studies reporting As, Cd, Hg, and/or Pb concentrations in edible sea turtle tissues, Loggerheads (Caretta caretta) and Green turtles (Chelonia mydas) were most frequently reported, with over half the data from liver, kidney, or muscle tissues. Eggs made up less than 10% of the data. Globally, no species was distinct for any metal; Cd and Hg showed tissue-specificity to kidney and liver, respectively; and Cd was significantly highest in the Pacific Ocean. Using a standard adult body weight (62.0 kg) and serving size (75 g), Cd was the most toxic metal. On average, eating d"5 g week-1 would induce Cd poisoning from either Green or Loggerhead kidney and liver, and Hg poisoning from only Loggerhead liver. Chapter 2 presents measurements of 12 trace metals in Green turtle and Olive Ridley (Lepidochelys olivacea) eggs from Pacific Panama. Qualitatively, the metal profiles measured were similar to previous reports, with 8 of 12 falling in their previously reported ranges. In my samples, interspecific differences were found on a per-site basis, and geographic differences for each species, but the interaction of these patterns prevented overall significant differentiation. Cd was, again, the most toxic metal; however, consumption of these eggs at the reported average rates is unlikely to induce metal poisoning in adult consumers. However, males and females aged 16-30 and children up to ~3.4 yrs (~16.5 kg), consuming eggs at their maximum reported rates of 15 eggs day-1, 30 eggs day-1, and 5 eggs day-1, respectively, may be putting themselves at risk of developing symptoms of long-term heavy-metal poisoning. The research presented here supports previous findings that Cd is highest in Green turtles, but that other toxic metals (Hg and Pb) are typically higher in more carnivorous species; we also show that, given the data available, patterns frequently observed in local comparisons are not always globally robust. Furthermore, we show that Cd is on average the most toxic metal in marine turtles concerning human health, but that additional analyses are needed to fully understand the health-risks of global sea turtle consumption."--
Other link(s)
digitool.Library.McGill.CA
digitool.library.mcgill.ca
escholarship.mcgill.ca
escholarship.mcgill.ca
Subject
Biology