Aide, Argonne National Laboratory (1975)
Research Technologist, Northwestern University Medical School (1975-76)
Teaching & Research Assistant, University of California, Berkeley (1977-82)
Post-doctoral Research Biochemist, University of California, Berkeley (1983)
Lecturer & Visiting Assistant Professor
      Dept. of Wildlife & Fisheries Sciences,  Texas A&M University (1983-87)
Assistant Professor (1987) to Professor of Biology (2001 - ),
      Memorial University of Newfoundland
Visiting Scientist, Kewalo Marine Laboratory, University of Hawai'i (1994-96)
Member, Council on the Status of Endangered Wildlife in Canada (COSEWIC) (2001 - )