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West End of Lake Ontario (ON022)

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West End of Lake Ontario (ON022)

Hamilton, Ontario

Latitude 43.315°N
Longitude 79.520°W
Altitude 75m
Area 549.54km²

Site Description

This site is defined generally as the part of Lake Ontario west of a line stretching from Port Credit on the north shore to the mouth of the Niagara River on the south shore, and bounded on the west by Burlington Bar. The shoreline is one of low relief (<10m), with unconsolidated cliffs of clay-silt sediments. The coast is straight, with beaches across the mouths of small rivers ('Southeast Coast' subdivision), sedimentary rock outcrops ('Burlington Bar System' subdivision), and a wide sand barrier, up to 2 m, high across Hamilton Harbour. There is widespread artificial protection of the shoreline. Erosion rates are low as shoreline is relatively sheltered and prevailing winds are westerly. Shore-zone ice can persist up to 4 months; ice forms at west end of the lake by late December, and breaks appear in late February. Water currents are sensitive to wind direction, but appear to be predominantly counter-clockwise around Lake Ontario. Water temperatures reach 24 degrees C in late summer. Maximum lake depth at the west end of the lake is 100 m; lake contours indicate a gradual slope from the shoreline to this depth.

Beginning in 2015, an IBA-wide volunteer waterbird census is being held every other Saturday. More details, including a Map are available here.

Birds

The west end of Lake Ontario is not a discrete area, but is defined by the impressive congregations of waterfowl which have gathered there annually since about 1990, primarily in late winter and early spring. Flocks of mainly diving ducks number in thousands, sometimes tens of thousands, with the more abundant species being Greater Scaup, White-winged Scoter, and Long-tailed Ducks (these three species all occur in numbers greater than 1% of their estimated North American population). Amongst these huge flocks, several other species of diving duck occur in impressive numbers for an inland location - including Common Goldeneye, King Eider, Red-breasted Merganser, and Surf Scoter.

Where the flocks gather within this area appears to be weather dependent; that is, strong winds cause the flocks to shift locations, presumably in response to demands for shelter and feeding opportunities. The concentrations of waterfowl are most likely in response to the invasion and colonization of the shallow waters by dreissenid mussels, Zebra Mussel Dreissena polymorpha and Quagga Mussel D. bugensis. It is likely that most foraging for mussels by scaups, goldeneyes and scoters occurs on shelves less than 20 m deep around the perimeter of the lake; however, Long-tailed Ducks can forage in depths up to 100 m.

Conservation Issues

Pollution is the primary concern due to the amount of industrial development and agriculture around the western end of Lake Ontario. In particular, the biomagnification of toxics and pesticides through dreissenid mussels as food for the diving ducks is a concern. Shoreline development also has the potential for impacting birds, as does irresponsible disturbance of flocks by watercraft.

IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status
Long-tailed Duck
Number Year Season
10,9812017Spring
8,063 - 13,4602017Winter
10,871 - 20,0002016Winter
17,000 - 20,0002016Fall
9,300 - 11,9712016Spring
16,900 - 56,8512015Winter
8,650 - 29,3912015Fall
10,350 - 15,0002014Fall
33,0802014Winter
10,000 - 13,0072013Winter
10,0002013Fall
10,000 - 15,0002012Fall
10,8002012Winter
21,0002011Winter
10,0002011Fall
10,0002010Winter
16,000 - 37,6002010Fall
8,883 - 10,0002009Winter
20,0002009Fall
10,000 - 200,0002008Fall
8,000 - 68,9202007Winter
100,000 - 105,4302007Fall
8,000 - 103,0002006Fall
15,800 - 24,3002005Winter
8,000 - 8,5002004Fall
30,0002003Fall
8,500 - 40,0002003Winter
20,0002002Fall
10,0002002Spring
10,000 - 50,0002001Winter
50,0002001Fall
10,000 - 25,0002000Fall
10,000 - 40,0002000Spring
52,0002000Winter
26,000 - 28,5001999Fall
10,0001999Winter
20,0001998Fall
10,000 - 25,0001998Spring
10,000 - 30,0001997Spring
25,000 - 30,0001994Fall
10,0001993Spring
Greater Scaup
Number Year Season
6,038 - 7,1272017Winter
5,000 - 5,2002015Winter
7,0002014Winter
5,9882013Winter
14,4442012Winter
14,6302011Winter
6,5002010Winter
12,4602007Winter
4,7002006Winter
7,1942005Winter
5,0002004Fall
20,0002002Fall
4,500 - 25,0002001Fall
10,0002001Winter
6,000 - 10,0002000Fall
5,000 - 7,0002000Winter
4,7701999Fall
15,0001999Winter
8,0001998Fall
7,500 - 30,0001997Winter
5,000 - 10,0001996Fall
5,000 - 10,0001996Winter
10,0001995Fall
10,0001995Spring
5,000 - 10,0001995Winter
8,0001994Fall
5,000 - 10,8001994Winter
5,3131993Fall
6,7501993Spring
5,0001993Winter
100,0001992Winter
Common Goldeneye
Number Year Season
5,0672013Winter
4,3572012Winter
7,4442011Winter
3,9692010Winter
9,7562003Winter
12,0001998Winter
30,0001997Winter
8,7001994Winter
5,0001993Spring
5,0001992Fall
Red-breasted Merganser
Number Year Season
2,1032017Spring
3,5002015Fall
2,0002014Fall
3,0002013Fall
3,1962013Winter
5,000 - 6,0002012Fall
1,7782012Winter
6,4192011Winter
2,600 - 3,5922010Winter
5,0002010Fall
4,000 - 6,0002009Fall
3,000 - 4,0002008Fall
3,0002007Fall
5,0002004Fall
2,0001990Fall
Rusty Blackbird
Number Year Season
502017Spring
252015Spring
25 - 562013Fall
25 - 452012Fall
352012Spring
322011Fall
29 - 2002011Spring
502007Spring
301996Fall
601995Fall
Little Gull
Number Year Season
7 - 172017Fall
5 - 92017Summer
2 - 52017Spring
22015Fall
22015Spring
32014Fall
2 - 72014Spring
32010Spring
22009Spring
2 - 32006Spring
22005Spring
22004Spring
2 - 32003Spring
22002Fall
Red-necked Grebe
Number Year Season
2,3782017Spring
1,0602016Spring
4002012Fall
360 - 1,2502012Spring
4002011Fall
5252010Spring
450 - 9042008Spring
350 - 8502005Spring
1,500 - 2,0002004Spring
4001998Fall
420 - 1,2941996Spring
White-winged Scoter
Number Year Season
7,5002014Fall
18,2352014Winter
5,5002013Fall
5,2122013Winter
8,0002012Fall
2,5432012Winter
4,3642011Winter
9,5002010Spring
1,3492010Winter
5,0002009Fall
5,4102008Winter
15,0002005Winter
10,0002003Winter
10,0001998Winter
5,0001997Spring
10,0001996Spring
5,0001996Winter
11,1001995Fall
6,000 - 11,1001995Spring
7,0001995Winter
10,0001994Spring
5,000 - 10,0001994Winter
5,000 - 10,0001993Spring
10,0001993Winter
5,000 - 15,0001992Spring
Red-throated Loon
Number Year Season
327 - 4901995Fall
Tundra Swan
Number Year Season
2,0462016Spring
Chimney Swift
Number Year Season
25 - 452017Spring
252016Spring
25 - 602015Fall
25 - 402015Spring
252012Summer
35 - 382011Fall
1002010Fall
302010Spring
242007Summer
35 - 1202006Fall
2302005Fall
Acadian Flycatcher
Number Year Season
12016Fall
12015Spring
12014Spring
12013Spring
12009Spring
22005Spring
12000Spring
Prothonotary Warbler
Number Year Season
1 - 22011Spring
12008Spring
12007Summer
12007Spring
12005Spring
22001Spring
11996Spring
11995Spring
11993Spring
Barn Owl
Number Year Season
12009Fall
Kirtland's Warbler
Number Year Season
12012Spring
Loggerhead Shrike
Number Year Season
11992Spring
Yellow-breasted Chat
Number Year Season
12013Fall
12012Fall
12011Spring
12010Spring
12009Spring
12007Spring
12006Spring
12005Summer
12004Spring
12000Spring
11999Spring
11998Spring
11997Spring
11995Spring
11992Spring
Waterbirds
Number Year Season
30,0001995Fall