The Lake Huron Centre For Coastal Conservation
Advocating Wise Stewardship of Lake Huron's Coastal Ecosystems
Other Pollutants
PCBs
The Maitland Valley Conservation Authority commissioned a sediment and biological monitoring study on the Nine Mile and Maitland Rivers to see if there was a need for concern over metal, pesticide/herbicide and PCB bioavailability. Preliminary results of the 2000 study period suggested that mean PCB concentrations in minnows collected at Goderich and Port Albert were above the Great Lakes Water Quality Agreement’s aquatic life protection guideline of 0.1 mg/kg.
Follow-up monitoring in 2001 indicated that PCB concentrations were below the GLWQA guideline. However, other minnow species were used in the evaluation and the conclusions are based on the assumption that there were no species specific differences in PCB bioaccumulation.
Tritium
The Grey-Bruce Health Unit began a sampling program in 1996 to monitor nearshore waters updrift and downdrift of the Bruce Nuclear Power Development (BNPD). The BNPD consists of two nuclear power stations containing a total of eight nuclear reactors. This monitoring was in response to growing public concern about tritium being released into the lake from the nuclear facilities at the BNPD (Paton and Wardell, 1997).
Samples have been collected by Ontario Power Generation at each of the cooling water outfalls as a requirement by the Ministry of Labour. Until the Health Unit study, no tritium sampling had ever been taken of nearshore waters north or south of the plant. The Health Unit sampled nearshore waters between Kincardine and Southampton to determine tritium levels in drinking and recreational waters and to ensure that those levels were safe for the public. The results of the study indicated that there was no current health risk to the public. Bruce Power continues to monitor the lakeshore stations between Southampton and Kincardine and submits the results to the Health Unit.
Algae
Concerns of nutrient enrichment and algal growth in the Great Lakes have been high for the past three decades. Between 1978 and 1981, the Ministry of Environment undertook a baseline investigation of Cladophora growth in the nearshore waters of Lake Huron to gain a better understanding of the sensitivity of Lake Huron to Cladophora in the presence of phosphorous inputs.
The investigation focused on Goderich, south of the Maitland River mouth, and the Bruce Nuclear Power Development (BNPD) area, including Inverhuron. Another study area included the nearshore waters of southern Georgian Bay (Nottawasaga Bay). Much of the area was characterized by the presence of good substrate for the growth of the potentially nuisance aquatic algae, Cladophora. It was roughly estimated that over 70% of the nearshore area (within the 10 meter contour) of Lake Huron, from Sarnia to Tobermory, provides suitable substrate for Cladophora growth (MOE, 1982).
On one occasion in 1978, sloughed Cladophora fouled approximately 10 kilometers of Lake Huron shoreline in the vicinity of Goderich. During this time, average total phosphorous concentrations at 9 stations along the southeastern shores of Lake Huron were averaging 0.022 mg/L, slightly higher than the PWQO of 0.02 mg/L (MOE, 1982).
More recently, the Town of Goderich has been faced with removing truck loads of algae from its beaches (see Figure 3). In 2001 and 2002 in particular, the Town would routinely remove 4 to 6 gravel truck loads of algae 2 to 3 days a week for the entire summer period (June to September). Prior to 2001, algae on the beach had been a modest problem with removal of light amounts once per month or once every two weeks (P. Spain, 2003).
The algae was particularly problematic for the Town because of the foul odour it produced. Lab analysis of the algae was undertaken in 2001 and 2002 (late June each year) and found it to contain Rhizoclonium spp., a filamentous algae of the Cladophoraceae family (GAP, 2002).
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The Lake Huron Centre for Coastal Conservation P.O. Box 178, Blyth, Ontario, Canada N0M 1H0 Phone: (519) 523-4478 Email: coastalcentre@lakehuron.on.ca |
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