Leatherback turtles (Dermochelys coriacea) in Newfoundland and Labrador: distribution, diet, threats and the use of education in recovery efforts

Brock, Hope Maria Elizabeth (2006) Leatherback turtles (Dermochelys coriacea) in Newfoundland and Labrador: distribution, diet, threats and the use of education in recovery efforts. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (3MB)

Abstract

Leatherback turtles (Dermochelys coriacea) are critically endangered (IUCN) throughout their range which extends into waters off Newfoundland and Labrador (NL). Geo-referenced sightings, strandings and entrapments were used to map distribution in relation to bathymetry, and remotely-sensed sea surface temperature and chlorophyll density data. Coastal waters (< 50 m in depth) characterized by the warm seasonal layer and increased medusan abundance provide critical leatherback habitat. Caloric content of two jellyfish species (Aurelia aurita and Cyanea capillata) were determined using bomb calorimetry and used to extrapolate energy requirements of leatherbacks while foraging in northern waters. Daily food energy requirements (43-155% of body mass) confirm the need for high density jellyfish aggregations during their foraging season. While foraging off NL leatherbacks are at risk for entrapment in all types of fishing gear, with the number of entrapments greatest in August and September, and along the south coast. Necropsy results indicate ingestion of plastic debris is a definite threat, while injuries associated with stranding events suggest vessel collisions should also be considered a potential threat. Species at risk education initiatives were also considered. An objective of this study was to examine the current curricula in NL with regards to species at risk, and to evaluate an educational programme aimed at teaching school-aged children about the biology of, and threats to, leatherback turtles.

Actions (login required)

View Item