Long Point Environmental Folio, Chapter 9 J.G. Nelson and K.L. Wilcox, Editors, 1996

Waterfowl and Long Point's Inner Bay*

Kerrie Wilcox and Richard Knapton

*This chapter is largely derived from Wilcox, K., and Knapton, R. 1994. "An Ecosystem Approach to Management of Long Point's Inner Bay: An Internationally Significant Staging Area for Waterfowl" Long Point Environmental Folio Series. Technical Paper #5. Heritage Resources Centre, University of Waterloo, Waterloo, Ontario.

Context

Ducks, geese, and swans, collectively known as waterfowl, require a range of essential areas during their annual cycle. Staging areas, used by waterfowl during long distant travel, act as stepping stones and refueling stops on flights to and from wintering and breeding grounds. Not only are the food resources in staging areas essential for migration, but also for egg production during the breeding season, and for survival on wintering grounds (e.g. Stroud et al., 1990; Ankney and MacInnes, 1978). Each stop over area is an essential link in a chain of sites. Conservation of such sites is crucial for waterfowl survival.
Long Point, Ontario, is an important staging area for North American waterfowl. Each year the marshes of Long Point are visited by hundreds of thousands of waterfowl during spring and fall migration. In fact, Long Point has been reported to have the greatest waterfowl use of any area on the Great Lakes during migration (Dennis and Chandler, 1974; Dennis et al. 1984).
Long Point is recognized internationally as a significant staging area for waterfowl with its designation as a wetland of international significance or a "Ramsar site". Irresponsible development, boating, fishing, and other activities in the Inner Bay are, however, potential threats to this critical staging area. To understand the effects of development and to minimize and mitigate impacts, it is essential to know where waterfowl are resting and feeding during their stay at Long Point, what foods and other resources they are using, and how these are changing over time.
Located on the north shore of Lake Erie, Long Point is the largest sand spit or peninsula on the Great Lakes and one of the most extensive wild areas left in southwestern Ontario (Reznicek and Catling, 1988). Long Point's Inner Bay is defined as the area enclosed by the Long Point peninsula, the north shore of Lake Erie and an imaginary line between Turkey Point and Pottohawk Point (Whillans, 1985, Figure 1). The Inner Bay is approximately 78km2 in surface area and has one major tributary - Big Creek. Big Creek has a 730km2 watershed that drains the agriculture fields of Norfolk, Oxford and Brant Counties. The Creek accounts for 77% of the water from tributaries entering the Inner Bay (Whillans, 1985), and is the major source of nutrients and suspended materials entering the Bay. Other significant tributaries are Dedrick Creek and Forestville Creek (Figure 1). Eroded materials from exposed sand bluffs, located along the north shore east of the Inner Bay, may be responsible for much of the natural turbidity and siltation in the Inner Bay (Hamley and MacLean, 1979).

Water Depth

The morphology of the Inner Bay has varied considerably in historic times (Whillans, 1977). On the basis of records since 1790, Whillans reported minimum and maximum depths in the Inner Bay of 1.66 m and 12.33 m respectively. Changes in shoreline form and bathymetry are shown in Figure 2.

Figure 9.2 Chronological Bathymetry of Long Point's Inner Bay (adapted from Whillans, 1977)

While the shape of the Bay in the past is generally similar to its shape today, its depth and the details of its shoreline shape have altered considerably. The earliest (1795) bathymetric map, for example, shows the Inner Bay to have a maximum depth of 2m. The 1815 map shows record high water depths. At this time the boat channel, leading into the Inner Bay from Lake Erie apparently reached a depth of over 12m -8m deeper than the present depth of the channel (Pauls and Knapton, 1993). The 1835 bathymetric map shows a second entrance to Lake Erie near the present location of Big Creek. By 1865, the entrance to Lake Erie, at Big Creek, had narrowed and was completely gone by 1925 (Figure 3).

Figure 9.3 1991 Bathymetric Map of Long Point's Inner Bay (adapted from Wilcox, and Knapton, 1993)

Sediments of Long Point's Inner Bay

Shoreline and nearby sediments consist of a clay plain along the Big Creek marshes and the Inner Bay's North Shore. Low hills or till moraines thread through the sand plain to the north of the Inner Bay. Smith (1979) found that the bottom of the Inner Bay was primarily mud from the western shoreline to about 2km offshore. Sandy sediments occur along the south shore adjacent to Long Point and in a large triangular area extending into the Inner Bay south of Turkey Point. Sediments in the central area are sandy loam. Figure 4 shows general sediment types in the Inner Bay as identified by Smith (1979).

Figure 9.4 Substrate Types in Long Point's Inner Bay (adapted from Wilcox and Knapton, 1993)

Vegetation of Long Point's Inner Bay

Submerged vegetation surveys of the Inner Bay completed in 1976, 1991 and 1992, indicated that the dominant plant species were Chara vulgaris (musk grass), Myriophyllum spicatum (Eurasian milfoil), Najas spp. (naiad), and Vallisneria americana (wild celery) (Pauls and Knapton, 1993). Together these four species comprised over 90% of the total plant composition of the Inner Bay in 1991 and 1992. Other common plants found in all three years include: Potamogeton richardsonii (Richardson's pondweed), Ceratophyllum demersum (coontail), P. pectinatus (sago pondweed) and Elodea canadensis (water weed). Figure 5 illustrates the common submerged plants in Long Point's Inner Bay.

Figure 9.5 Common Submerged Plants in Long Point's Inner Bay (Illustrations from Hotchkiss, 1972)

The Open Water area of the Inner bay is dominated by C. vulgaris (Figure 6). This portion of the Inner Bay has predominantly sandy-loam sediments and an average depth currently of 2m. In depths of over 4m in the Open Water area of the bay, M. spicatum is dominant. In the Turkey Point area and the Thoroughfare Point area, C. vulgaris is the most abundant plant (Figure 6). A small portion, of the shoreline in the Thoroughfare Point area is however, dominated by V. americana. These areas both have sandy substrate and range in depth from 1 to 2m.

Figure 9.6 Dominant Submerged Plants in Long Point's Inner Bay (adapted from Wilcox and Knapton, 1994)

The North Shore area has a diverse community of submerged macrophytes. M. spicatum, C. vulgaris, V. americana and Najas spp. are all abundant in this area (Figure 6), which has a mud bottom and ranges in depth from 1 to 2 meters. The Big Creek area also has a diverse community of submerged macrophytes. V. americana is the most abundant plant in this area, followed by Najas spp., M. spicatum , and C. vulgaris. Big Creek area has muddy substrate and a depth of approximately 1m. The Crown Marsh area is comprised mostly by Najas sp. and C. vulgaris. It has sandy substrate and a depth of 1m.

Invertebrate Distributions in Long Point's Inner Bay

Ten different genera of invertebrates were recorded in the 1992 survey. Species of Diptera (Chironomid larva), and Amphipoda (fresh water shrimp) comprised the majority (88.8%) of the non-mollusc invertebrate populations. Other species of some importance included species of Isopoda (scuds), Acarina (water mites), Oligocheata (worms), Hirudinea (blood suckers), and Trichoptera (caddisfly larva).
The largest concentrations of invertebrates, an average of 2074 per m2, were found in the Turkey Point area and the lowest invertebrate concentrations, averaging 717 per m2, were in the North Shore area (Figure 7). The distribution of invertebrates in the Crown Marsh area, Big Creek area and the Thoroughfare Point area was between 50 and 1000 per m2, with 250-1000 per m2 generally being found in the Open Water area of the Inner Bay.
A study of duckling productivity in southern Ontario undertaken by Godin and Joyner, (1981) found that invertebrate densities lower than 3600 per m2 were sub optimal for duckling production i.e., these areas had lower numbers of broods per hectare compared with areas having greater than 3600 invertebrates per m2. The Inner Bay appears unable to support optimal duckling production except in one area, at the edge of Turkey Point area (Figure 7).

Figure 9.7 Invertebrate Distribution and Abundance in Long Point's Inner Bay (adapted from Wilcox and Knapton, 1993)

Foods Consumed by Waterfowl

In a study of the stomach contents of 409 ducks of 9 different species, Pauls and Knapton (1993) found that plant material made up over 90% of the dry weight of food consumed by staging waterfowl. Invertebrates made up less than 10%. Of the 90% plant material, corn comprised 38% of the weight followed by oats at 17%. While waterfowl may obtain the required calories for migration by grazing on grain and corn, they miss some of the essential nutrients that can only be obtained from naturally occurring foods in migration areas (Fredrickson and Taylor, 1982).
C. vulgaris, Najas spp. and V. americana comprised the largest portion of the submerged macrophytes consumed by waterfowl and thus may be an important factor in attracting waterfowl to the area (Pauls and Knapton, 1993). Zizania palustris (wild rice), Sparganium eurycarpum (burr reed) and Scirpus acutus (bulrush) comprised the highest portion of emergent plants consumed by waterfowl and Nymphaea odorata was the only floating leafed plant of significance for waterfowl feeding.
Of the insects and insect larvae consumed by waterfowl, Trichoptera made up the highest proportion, followed by Coleoptera and Hemiptera. Dreissena polymorpha (Zebra mussels) comprised a high proportion of the invertebrates by weight. However, they were consumed almost solely by Scaup (Aythya affinis/Aythya marila).

Waterfowl Use of Long Point and the Inner Bay

Historically waterfowl have used Long Point as a stopover area during their spring and fall migration. Past descriptions of the area indicate that Long Point was heavily used by waterfowl. This use of Long Point was not however, monitored systematically until 1968 when the Canadian Wildlife Service began aerial censuses of waterfowl on the Great Lakes.
Figures 8 and 9 show the distribution of waterfowl in spring and fall of 1992 calculated from aerial survey data of the Long Point Waterfowl and Wetlands Research Fund. The Long Point Bird Observatory has prepared a checklist which gives the status of each waterfowl species throughout the year (Table 1). Figures 8 and 9 only indicate waterfowl recorded in the Inner Bay. Rafts of waterfowl recorded in Long Point Bay, in emergent marshes, and along the north and south shores of the Long Point sand spit are not shown.

Figure 9.8 Estimated Waterfowl Days in the Inner Bay Areas, Fall, 1992 (Wilcox and Knapton, 1993)

Figure 9.9 Estimated Waterfowl Days in the Inner Bay Areas, Spring, 1992 (Wilcox and Knapton, 1993)

Table 9.1 Checklist of Waterfowl at Long Point (adapted from Fazio et al. 1985)

Waterfowl use is described using "waterfowl days". Waterfowl days are calculated by taking the average of the numbers of waterfowl observed on two aerial survey dates and multiplying this by the number of days between survey dates. Spring or fall totals are obtained by summing the results for the entire period. During spring migration, highest waterfowl days were observed in the Open Water area (353 401) followed by Big Creek area (133 476 ). The other areas all had less than 65 000 waterfowl days. During fall migration, highest waterfowl days were also recorded in the Open Water Area. Turkey Point area had the second highest use with over 48 457 waterfowl days. All other areas each had less than 20 000 waterfowl days.

Waterfowl Hunting

Actual numbers of duck hunters using the Inner Bay and its coastal marshes are not well documented historically. However, observations were made about the popularity of the sport at Long Point as early as 1850 (Barrett, 1977). Locations of some hunt clubs are shown in Figure 10.

Figure 9.10 Location of Waterfowl Hunt Clubs and Hunting Areas in the Long Point Biosphere.

Hunting activities during the fall have been described as one of the two main activities that disturb waterfowl, the other being motor boating (Korschgen et al, 1985). Jahn and Hunt (1964) suggested that even the best habitats will be lightly, if at all, used by migrant ducks if human disturbance is excessive. Disturbance of migrating ducks can have dramatic effects on the birds' energy balance and may affect their survival during migration, upon arrival at wintering and summering areas, and also influence breeding success (Frederickson and Drobney, 1979).
Recreational hunting and associated boating activities during migrations of waterfowl at Long Point may reduce its effectiveness as a staging area. Research is needed to learn more about the extent of the disturbances at Long Point and the subsequent energy costs for waterfowl. In the interim, efforts are needed to educate people about the potential effects of boating and to begin to plan and manage to minimize these effects.

Marina, Cottage and Recreational Developments

Cottage and marina developments along the shoreline of the Inner Bay may have significant effects on the Inner Bay as a staging area for waterfowl (Figure 11).

Figure 9.11 Location of Cottage Communities and Marinas around Long Point's Inner Bay

These developments and associated recreation activities are known to affect waterfowl food resources and increase disturbance. In other areas on the Great Lakes, for example Rondeau Bay, cottaging and settlement led to greater sewage inputs, increasing macrophytic biomass at first, then killing of submerged macrophyte beds because of shading by planktonic blooms (Crowder and Bristow,1985)
At Rondeau Bay, the loss of submerged macrophytes resulted in a drastic decline in numbers of migratory waterfowl (Dennis et al., 1984).
Fragmentation of marshes for development and the removal of vegetation to create and maintain boat channels can contribute to sedimentation and subsequently affect food resources. Boating and other recreational activities associated with cottages and marinas may increase disturbance of waterfowl and reduce the effectiveness of the area for staging. While insight can be gained into the impacts of development on staging waterfowl by studies in other areas, more research is needed to determine their impacts at Long Point.

Planning for Staging Waterfowl in Long Point's Inner Bay

Many factors can influence the distribution and abundance of staging waterfowl in an area including availability and accessibility of food resources and disturbance. Based on an understanding of what foods waterfowl are eating and where these food resources are located at Long Point, it is possible to identify areas of the Inner Bay that may be relatively more important to waterfowl. Information on disturbances associated with cottages and marinas and other activities can help to locate areas where stresses may be acting on waterfowl.
Important Areas for Waterfowl
The North Shore and Big Creek areas appear to be relatively more important as feeding areas for staging waterfowl at Long Point than other areas of the Inner Bay. These two areas have a high diversity of plant foods and also have a large number of plant foods preferred by waterfowl. The Open Water area may be relatively more important as a refuge or resting area. The largest numbers and the highest diversity of waterfowl in the Inner Bay are found in this area during both spring and fall migration (Figure 12).

Figure 9.12 Important Areas and Stressed Areas for Waterfowl in Long Point's Inner Bay (Wilcox and Knapton, 1993)

Areas Stressed for Waterfowl
Ironically, the areas that are most important to waterfowl also appear to have the most stresses acting upon them. Both the North Shore and Big Creek areas have concentrations of marinas and cottages along their shorelines. Activities associated with cottages and marinas including use of lawn fertilizers, removal of submerged plants in boat channels, and roadway salts, have been known to have adverse impacts on waterfowl food resources in other areas and thus may stress waterfowl using the Inner Bay (Druin, 1989).
In the Open Water area, boat traffic may stress resting waterfowl. Disturbance diverts their attention from feeding, and thus interferes with their accumulation of fat reserves (Owen and Reinecke, 1979). Waterfowl will not use an area if disturbance is excessive (Jahn and Hunt, 1964).

Summary

Long Point's Inner Bay and coastal wetlands are of critical importance to waterfowl on an international scale (Photo 1).

Photo 9.1 Long Point's Inner Bay (Photographed by K. Beazley)

Every spring and fall hundreds of thousands of waterfowl stop over at Long Point to rest and feed while travelling between wintering areas along the east coast of the United States and the Gulf of Mexico and summer nesting areas in the prairies and in the Arctic.
Intensive water based recreation facilities and activities, boat traffic, and cottage and other development along the shore line of the Inner Bay could threaten the future value of the Inner Bay for waterfowl (Photo 2).

Photo 9.2 Boat Slips on Long Point's Inner Bay (Photographed by P. Lawrence)

A conservation strategy should be developed that attempts to balance the future of waterfowl habitat with human economic, recreational and other activities and needs. Indeed many human recreational and economic activities are dependent on waterfowl and other species and the habitats they need for survival in the long term.
Recreational and economic activities are therefore substantially dependent on the conservation of waterfowl and their habitat for their long term survival or sustainability. It is therefore important that as many individuals and interests as possible support research and conservation efforts, especially in the North Shore and Big Creek areas.

Glossary

Bathymetry	Pertaining to the depth of a body of water and its measurement (Bathymetric)
Macroinvertebrates	large aquatic insects or insect larvae (eg cadisfly larvae
Macrophytes	large aquatic plants (eg wild celery) as opposed to phytoplankton or other small algae
Substrate	the surface to which an organism is attached or upon which it moves

Appendix 9
List of Scientific Names of Waterfowl Species Reported in Text

Common Name Scientific Name
Tundra Swan Cygnus columbianus

Mute Swan Cygnus olor

Snow Goose Chen caerulescens

Canada Goose Branta candensis

Wood Duck Aix sponsa

Green-winged Teal Anas crecca

American Black Duck Anas rubripes

Mallard Anas platyhynchos

Northern Pintail Anas acuta
Blue-winged Teal Anas discors

Northern Shoveler Anas clypeata

Gadwall Anas strepera

Eurasian Wigeon Anas penelope

American Wigeon Anas americana

Canvasback Anas valisineria

Redhead Athya americana

Rind-necked Duck Aythya collaris

Greater Scaup Aythya marila

Lesser Scaup Aythya affinis
Oldsquaw Clangula hyemalis

Black Scoter Melanitta nigra
Surf Scoter Melanitta perspicillata

White-winged Scoter Melamitta deglandi

Common Goldeneye Buceohala clangula

Barrow's Goldeneye Bucephala islandica

Bufflehead Bucephala albeola

Hooded Merganser Lophodytes cucullatus

Common Merganser Mergus merganser

Red-breasted Merganser Mergus serrator

Ruddy Duck Oxyura jamaicenis

Common Name	Scientific Name
Tundra Swan	Cygnus columbianus
Mute Swan	Cygnus olor
Snow Goose	Chen caerulescens
Canada Goose	Branta candensis
Wood Duck	Aix sponsa
Green-winged Teal	Anas crecca
American Black Duck	Anas rubripes
Mallard	Anas platyhynchos
Northern Pintail	Anas acuta
Blue-winged Teal	Anas discors
Northern Shoveler	Anas clypeata
Gadwall	Anas strepera
Eurasian Wigeon	Anas penelope
American Wigeon	Anas americana
Canvasback	Anas valisineria
Redhead	Athya americana
Rind-necked Duck	Aythya collaris
Greater Scaup	Aythya marila
Lesser Scaup	Aythya affinis
Oldsquaw	Clangula hyemalis
Black Scoter	Melanitta nigra
Surf Scoter	Melanitta perspicillata
White-winged Scoter	Melamitta deglandi
Common Goldeneye	Buceohala clangula
Barrow's Goldeneye	Bucephala islandica
Bufflehead	Bucephala albeola
Hooded Merganser	Lophodytes cucullatus
Common Merganser	Mergus merganser
Red-breasted Merganser	Mergus serrator
Ruddy Duck	Oxyura jamaicenis