What They Did
* Bachelor of Science
completed 2002, University of Guelph
* Master of Science
completed 2004, University of Guelph
Richard D. Moccia
Toxicity of Clostridium
botulinum type E neurotoxin to great lakes
fish: implications to avian botulism.
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.
Yule Adam M;
LePage Veronique; Austin John W; Barker Ian K; Moccia
low-level exposure of the round goby (Neogobius
melanostomas) to Clostridium botulinum type E neurotoxin.
Adam M; Barker Ian K; Austin John W; Moccia Richard D
of Clostridium botulinum type E neurotoxin to Great Lakes
fish: implications for avian botulism.
Adam M; Austin John W; Barker Ian K; Cadieux Brigitte;
Moccia Richard D
of Clostridium botulinum neurotoxin type E in tissues from
selected freshwater fish species: implications to public