The main source of drainage into the Inner Bay is from Big Creek (Photo 1). This creek drains a watershed of 730 km2 and has a mean annual total discharge of approximately 250 x 106m3 (or 6.5 m3/sec) (Leach, 1981; Environment Canada, 1992). A majority (68%) of the annual suspended sediment load is transported between February and May during peak discharge events i.e. runoff from storm events and snow melt.
The potential export and release of sediment bound phosphorus into Lake Erie from Big Creek can be significant (Stone et al., 1991). Berst and McCrimmon (1966) concluded that nutrient and sediment loading from Big Creek had contributed to eutrophication of the Inner Bay and that this enrichment is continuing (Leach, 1981).
Leach (1981) conducted a detailed survey of water quality in the Inner Bay in 1978-79 in order to compare the results to data collected in 1962 by Berst and McCrimmon (1966). Several of the conclusions of Leach (1981) include:
o Mean concentrations of nitrate in 1979 were high in spring, declined sharply in May to low levels in summer and increased in the fall;
o Chloride loadings from Lake Erie north shore watersheds are probably related to application of salt and road de-icing materials (from Ongley, 1976);
o Total alkalinity in the Inner Bay also followed a seasonal pattern with minimum levels coinciding with summer macrophyte production; o From 1962 to 1979 mean total alkalinity increased by one third, nitrates were not observed in 1962 but were present up to 117 ug/L in 1979;
o Dissolved oxygen does not appear to be a problem due to lack of thermal stratification and macrophyte photosynthesis.
The Inner Bay was described by Leach (1981) as eutrophic. Apparent changes in the Inner Bay from 1962 to 1979 included increases in nitrate and nitrite nitrogen and total alkalinity (Leach, 1981), indicating greater photosynthesis by macrophytes and continuation of a gradual enrichment process in the Inner Bay. The future eutrophic status of Inner Bay is largely dependent on nutrient loading.
The Nanticoke Environmental Committee's research indicated that the thermal regime of the Bay has not been altered (Haymes and Dunstall, 1989). Water temperature increases are restricted to the immediate discharge areas such as the Nanticoke Thermal Generating Station (TGS). In fall the temperature increases 1 - 2°C above ambient temperatures beyond the immediate discharge area and extending to Peacock Point. During the summer, temperature increase extends even beyond Peacock Point; however the TGS has little effect on lake temperature more generally (Haymes and Dunstall, 1989). Several fish species, such as Smallmouth Bass, Rock Bass, White Bass, Black Crappie, Carp, Rainbow Smelt, Yellow Perch, and Walleye, (for scientific names see Chapter 6 on Fisheries of Long Point) spawn in or near the TGS discharge channel. Also, several species including Yellow Perch, Rock Bass, Smallmouth Bass, White Bass, White Sucker, Black Crappie, Alewife and Gizzard Shad have been caught in larger numbers near the TGS discharge channel than at other locations. This could be attributed to currents, higher temperature, protection from nearshore wave action or increased food availability.
A study of water quality in Big Creek and the Inner Bay is being conducted by Environment Canada, based on water and sediment samples collected during 1991-92. Water and sediment samples were collected from stations every two weeks from April to October (Figure 2).
Spatial and temporal variation in the data will be assessed, along with water and sediment guideline exceedences (personal communication, John Merriman, Canada Center for Inland Waters, Burlington). Theses relating to water quality in the north shore tributaries and in the Inner Bay, have been completed by Radovic (1995) and Downey (1994) and consist of substantial summaries of studies and information to date. These two theses demonstrate, among other things, that inconsistency in the dates and nature of the measurements limits attempts to understand trends in water quality. Considerable detail on water quality in Big Creek is also available in Stone et al., (1991).
Zebra mussels (Dreissena polymorpha) -small, prolific bivalves - were probably released into Lake St. Clair in ship ballast water in 1986 (Van Moorsel, 1992). Since then, Quagga mussels (D. bugensis), another prolific bivalve, has also been introduced to the Great Lakes. Together these two species have spread throughout the Great Lakes and some inland lakes and waterways. In parts of Lake Erie, beds of mussels have approached densities of 900,000/m, higher than those recorded anywhere else in the world (Ministry of Natural Resources Bulletin 1992).
It is unknown what the long term impact of Zebra and Quagga mussels will be on the water quality of Lake Erie and on the Inner Bay. Their effects in the Inner Bay presently appear to have resulted in increased clarity as well as increased vegetation growth due to their high filtering capacity.
Figure 3 is an attempt to characterize and describe the key issues and areas of concern for water quality in the Long Point Bay. The mapped issues represent a summary of the various point and non-point sources of pollution and related human activities highlighted in this chapter. Areas of concern indicate those sites where problems seem to need management attention.
Craig, B. 1993. Fisheries of Lake Erie and the Long Point Area: Past and Present Long Point Environmental Folio Publication Series. (Nelson, J.G. and Lawrence, P.L. eds). Technical Paper 4, Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.
Downey, A.M. 1994. Long Point Bay Water Quality Assessment: Adequacy for Consumption, Industrial Uses and Aquatic Life BES Thesis. Department of Geography, University of Waterloo, Waterloo, Ontario.
Downey, A.M., Radovich, S. and Lawrence, P.L. 1994. Water Quality of Long Point Bay: Issues and Areas of Concern for Planning and Management Long Point Environmental Folio Series. (Nelson, J.G. and Lawrence, P.L. eds). Technical Report 7. Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.
Environment Canada. 1992. Historical Streamflow Summary-Ontario Inland Waters Directorate, Water Resources Branch, Water Survey of Canada, Ottawa, Ontario.
Haymes, G.T. and Dunstall, T.G. 1989. The Influence of Industrialization on the Aquatic Environment of Long Point Bay, Lake Erie, in the Vicinity of Nanticoke, 1968 to 1983 Ontario Hydro Research Division, Toronto, Ontario.
Lawrence, P.L. and Beazley, K. 1994. Land Cover Change in the Long Point Area 1955 - 1990 from Aerial Photography Long Point Environment Folio Publication Series (Nelson, J.G. and Lawrence, P.L. eds). Technical Note 2, Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.
Leach, J.H. 1981. "Comparative Limnology of Inner Long Point Bay, Lake Erie, and Adjacent Waters of the Outer Bay" Journal of Great Lakes Research 7(2): 123-129.
Mudroch, A. 1981. A Study of Selected Great Lakes Coastal Marshes Environment Canada. Scientific Series No. 122, National Water Research Institute, Burlington, Ontario.
Merriman, J. 1994. Canada Centre for Inland Waters. Personal Communication.
Ongley, E.D. 1976. "Sediment Yields and Nutrient Loadings from Canadian Watersheds tributary to Lake Erie: an Overview" Journal of Fisheries Research Board of Canada 33: 471-484.
Pauls, K. and Knapton, R. 1993. Submerged Macrophytes of Long Point's Inner Bay: Their Distribution and Value for Waterfowl Long Point Environmental Folio Publication Series. (Nelson, J.G. and Lawrence, P.L. eds). Technical Paper 1. Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.
Radovic, S. 1995. Long Point Bay Tributary Water Quality Assessment: Adequacy for Consumption, Industrial Uses and Aquatic Life BES Thesis. Department of Geography, University of Waterloo, Waterloo, Ontario.
Serafin, R. 1989. Research and Monitoring for Environmental Protection: Twenty Years of Research and Monitoring at the Nanticoke Industrial Complex on the North Shore of Lake Erie. Unpublished Reports, University of Waterloo, Waterloo, Ontario.
Stenson, R. 1993. The Long Point Area: An Abiotic Perspective Long Point Environmental Folio Series (Nelson, J.G. and Lawrence, P.L. eds). Technical Paper 2. Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.
Stone. M. 1994. Personal Communication. University of Waterloo.
Stone, M., English, M.C., and Mulamootil, G. 1991. "Sediment and Nutrient Transport Dynamics in Two Tributaries of Lake Erie: A Numerical Model" Hydrological Processes 5: 371-382.
Stone, M. and English, M.C. 1993. "Geochemical Composition, Phosphorus Speciation and Mass Transport of Fine-grained Sediment in two Lake Erie Tributaries" Hydrobiologia 253: 17-29.
Whillans T., Francis, G.R., Grima, A.P., Regier, H.A., and Berkes, F. 1987. "Stemming a Dirty Tide: Long Point Bay, Lake Erie" International Journal of Environmental Studies 22: 41-52.
Van Moorsel, G. 1992. "Control Cost Likely $6 Billion Over 10 years" London Free Press February 21. London, Ontario.
Wilcox, S. 1993. The Historical Economies of the Long Point Area Long Point Environmental Folio Publication Series. (Nelson, J.G. and Lawrence, P.L. eds). Working Paper 1, Heritage Resource Centre, University of Waterloo: Waterloo, Ontario.
Wilcox, K. and Knapton, R. 1994. An Ecosystem Approach to Management of an Internationally Significant Waterfowl Staging Area: Long Point's Inner Bay Long Point Environmental Folio Publication Series. (Nelson, J.G. and Lawrence, P.L. eds). Technical Paper 5. Heritage Resource Centre, University of Waterloo, Waterloo, Ontario.