4.0 Limnology of Long Point Bay

4.1 Introduction

Table 4.1 Means of environmental characteristics in Big Creek, the Inner Bay and the Outer Bay, April to November 1979.

Long Point Bay and its associated wetlands provide internationally important staging habitat for waterfowl and many other migratory aquatic birds, while the Bay is considered to have the most important fish spawning and nursery habitat in Lake Erie (Whillans 1985). However, while wetlands are resilient ecosystems in many respects, they can be ecologically sensitive, particularly with regard to water quality (following Downey et al. 1994, the term water quality as used in this report includes the biological, chemical and physical characteristics of water with respect to its suitability for environmental and human purposes). This is somewhat problematic because human activities such as agriculture, urbanization, industrialization and recreation continue to increase throughout the Long Point vicinity, and each of these can adversely affect water quality. As increased human activities put stress on the ecological functioning of wetlands, these waterbodies become less suitable for several species of flora and fauna, and this in turn, adversely influences economically important activities such as hunting, fishing, and ecotourism. It is encouraging that, despite intensive agricultural development throughout the Big Creek catchment, and urban and industrial expansion along its shores, Long Point Bay has the highest water quality in nearshore Lake Erie (Heathcote 1981). It is also encouraging that water quality has been identified as one of the key areas of concern by local citizens (Weller 1989).

Due to the interrelated and integrated nature of the individual components of the Long Point system, it is conceptually useful to consider the limnology of the system on a land-stream-bay-lake continuum (Francis et al. 1985). Consequently, this chapter deals with five primary areas associated with Long Point: (1) Big Creek and its associated drainage basin, (2) marshes associated with Big Creek and the Inner Bay, (3) the Inner Bay (that portion of the Bay situated west of the sandspit that extends between Turkey Point and Pottahawk Point), (4) the Outer Bay (includes the area extending from Turkey Point, northeast to Peacock Point, south to the tip of the Long Point spit and west along the shoreline to Pottohawk Point), and (4) Lake Erie (Figure 1.1). Each segment of the system has, to a certain degree, ecological influence and dependence on other component parts of the system, with the extent being dependent on the location in the continuum, and the parameter in question (see Table 4.1 for a comparison of several Big Creek, Inner bay and Outer Bay aquatic parameters). For instance, pesticide use in the catchment influences the nutrient and pesticide loadings of the Bay and Lake, while lake level fluctuations and seiches influence the hydrology of tributaries and marshes. As researchers have generally selected and studied the limnology of only an individual component or subset of the system's component parts, available limnological information for the five areas is unbalanced and disjointed in its coverage over space and time. However, this chapter attempts to provide a clear and concise overview of the limnology of the entire system as it is presently known. Being in the centre of the continuum, Long Point Bay and associated marshes are strongly influenced by watershed runoff through Big Creek, as well as by hydrological conditions on Lake Erie. Therefore, a discussion of both watershed and Lake Erie limnological and physiographic characteristics is warranted.

Source: Leach 1981