BUI v Bird or Animal Deformities or Reproduction Problems
Status: Requires Further Assessment
What was the original problem? Gross visible deformities, such as crossed bills, were seen in colonial water-bird colonies in Hamilton Harbour. These were considered to be the result of historical industrial and municipal inputs to the Harbour and airborne contaminants falling within the watershed. Snapping turtles showed reproduction anomalies and high levels of polychlorinated biphenyls (PCBs).
When wildlife survey data confirm the presence of deformities (e.g. cross-bill syndrome) or other reproductive problems (e.g. egg-shell thinning) in sentinel wildlife species.
Delisting Guideline: When the incidence rates of deformities (e.g. cross-bill syndrome) or reproductive problems (e.g. egg-shell thinning) in sentinel wildlife species do not exceed background levels in inland control population.
What Has Been Done?
The Province of Ontario program for Municipal and Industrial Abatement (MISA)
is likely the principal factor in the
reduction of ongoing contaminants directly to Hamilton Harbour. Similar measures to prevent or diminish air borne
contaminants getting into the watershed have been ongoing at an international level.
How Are Things Today?
- There has been a 30 year decline in contaminant levels measured in herring gull eggs from Hamilton Harbour (see Figure). While concentrations of certain contaminants found in sentinel species are higher in Hamilton Harbour than some other Area Of Concerns, contaminant-induced effects do not appear to be limiting factors at the population level for colonial waterbirds in Hamilton Harbour. Nevertheless, hatching success of snapping turtles was the second lowest measured in 14 sites across the lower Great Lakes. While there are no recent reports of gross deformities of colonial waterbirds in the Harbour, standardized surveys for deformities have not been conducted in over 20 years, possibly influencing the likelihood of detecting deformities.
What Still Needs To Happen?
- There is a need to develop and confirm reference sites for comparison to Hamilton Harbour, preferably within Lake Ontario
- Ongoing studies by Environment Canada to measure contaminants and assess endpoints of reproduction and deformities in sentinel species need to continue
- Remedial Actions for Randle Reef and the ArcelorMittal Boat Slip need to be completed
- PCB source track-down needs to continue in the Windermere Arm of the Harbour
When Will The Status Change?
This will be determined when further assessment of this BUI is carried out.
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Photo Credit: Dave Heidebrecht