What They Did Back Then

* Bachelor of Science completed 2002, University of Guelph

* Master of Science completed 2004, University of Guelph

Advisor: Professor Richard D. Moccia

Toxicity of Clostridium botulinum type E neurotoxin to great lakes fish: implications to avian botulism.

Adam's thesis work revolved around testing the sensitivity of fresh water fish species to Clostridium botulinum neurotoxin.  In the late 1990's and early 2000's, large-scale mortalities of fish-eating birds were observed on the Great Lakes, and more specifically on Lake Erie. Type E botulism was established as the primary cause of death. The mechanism of type E botulism exposure in fish-eating birds was unclear. Given that these birds are thought to eat live fish exclusively, it seemed likely that their prey played a key role in the process, but the role of fish as potential transport vectors of botulinum neurotoxin type E (BoNT/E) to birds had not been adequately investigated. Adam's research indicated that fish show variable sensitivities to BoNT/E and show unique clinical signs (loss of balance, erratic swimming) that could result in the impaired fish being selectively fed upon by live fish eating birds.  Also, free toxin was available in dead fish and could be transferred to the live fish eating birds, but did not represent a human health risk if consumed. 



A Fish Botulism Exposure Model was developed to compare the sensitivity of rainbow trout, round goby, walleye and yellow perch to botulinum neurotoxin type E ( BoNT/E) at four treatments; 0, 800, 1,500 and 4,000 Mouse Lethal Doses. Comparisons revealed that significant variability exists in clinical signs and mortality patterns between the four species. Each species expressed unique clinical signs consisting of changes in both behaviour and skin pigmentation prior to death. Yellow perch lived significantly longer ( p< 0.05) than the three other species at all treatments. Post mortem analysis of experimental fish demonstrated that BoNT/E was present in both the filet musculature and non-fillet samples of some species. Results of this study suggest that live fish can represent a significant vector for transfer of BoNT/E to birds that eat live fish, but human health risks associated with the consumption of these species during botulism epizootics are minimal.

 Where They Are Now


Following completion of his Masters Degree, Adam worked at the University of Guelph doing research for a year and then obtained a one year term position as an Environmental Officer working with Environment Canada. This employment had Adam working with the Pulp and Paper and Metal Mining Industries, and their environmental responsibilities with in the Environmental Effects Monitoring Program of the Fisheries Act.  Following this term position he moved to Public Works and Government Services Canada (PWGSC), as an Environmental Officer and now A/Senior Environmental Officer.  Adams currently works in the Environmental Services division as a Project Manager for site assessments, environmental assessment, remediation, sediment, and risk assessment work.  He works with a wide range of other government departments and private sector consults.  Adam is also currently participating in the PWGSC Leadership Development Program, a competitive internal program to help develop leadership and management skills and abilities with in the department.


Other Publications:

Yule Adam M; LePage Veronique; Austin John W; Barker Ian K; Moccia Richard D

Repeated low-level exposure of the round goby (Neogobius melanostomas) to Clostridium botulinum type E neurotoxin.


Yule Adam M; Barker Ian K; Austin John W; Moccia Richard D

Toxicity of Clostridium botulinum type E neurotoxin to Great Lakes fish: implications for avian botulism.


Yule Adam M; Austin John W; Barker Ian K; Cadieux Brigitte; Moccia Richard D

Persistence of Clostridium botulinum neurotoxin type E in tissues from selected freshwater fish species: implications to public health.



















Intubation of rainbow trout.


Round goby.