6.0 Aquatic Macroinvertebrate Distribution and Abundance in Long Point Bay

6.1 Introduction

In comparison to the Great Lakes proper, little is known about the invertebrate communities inhabiting coastal wetlands. Also, with the exception of the Inner Bay monitoring work done by Wilcox and Knapton (1994), there has been very little research done on the invertebrates of Long Point Bay and its associated wetlands. This is unfortunate, as the lack of detailed long-term monitoring prevents a comparison of changes in invertebrate distribution over space and time. Consequently, we can only make predictions as to the effect that introduced zebra and quagga mussels have had on the native invertebrate community of the Inner and Outer Bay.

Invertebrates facilitate aquatic plant breakdown and decomposition, and they provide an essential nutrient link between primary producers and higher trophic levels (Murkin and Batt 1987). Certain species of non-breeding waterfowl have been reported to consume large quantities of macroinvertebrates (Murkin and Batt 1987), and it has been reported that use of ponds by dabbling ducks in the spring is positively correlated with invertebrate abundance (Joyner 1980). Invertebrates are also consumed by several other species of wetland dependent birds such as Red-winged Blackbirds (Agelaius phoenicus), Pied-billed Grebes (Podilymbus podiceps) and Sedge Wrens (Cistothorus platensis)(Weller 1981). Invertebrates are also a critical dietary component of most fish species, particularly of juveniles (Scott and Crossman 1973; Morrison et al. 1997), and are also consumed by amphibians, reptiles, and mammals (Murkin and Batt 1987).