Transcript Lake Ontario - New York Sea Grant

Lake Ontario
Grants No. 0528674 (NSF) and NA06OAR4170017 (NOAA)
Created by: Helen Domske, NY Sea Grant
Lake Ontario
Lake Ontario is ranked as the 12th largest
lake in the world. Lake Ontario’s surface
area of 7,340 square miles (18,960 sq km)
makes it the smallest of the Great Lakes.
Credit: GL Fisheries Commission
Bathymetry of Lake Ontario
NOAA GLERL
Lake Ontario Facts
The eastern outlet basin of the lake is much shallower and smaller
than the main basin. However, with many embayments and
peninsulas, the eastern outlet basin accounts for more than 50% of
the lake's shoreline.
The lake's drainage area is dominated by forests (49%) and
agriculture (39%). A total of 7% of the basin is urbanized.
Average Depth
283 feet
86 meters
Land Drainage Area
24,720 sq. mi.
64,030 sq. km.
Maximum Depth
802 feet
244 meters
Shoreline Length
712 mi.
1,146 km.
Volume
393 cu. mi.
1,640 cu. km.
Population
US (2000); Can (2001)
9,751,655
Water Area
7,340 sq. mi.
18,960 sq. km.
Retention Time
6 years
Credit: GL Fisheries Commission
Lake Ontario Facts
Lake Ontario's current nutrient levels are
characteristic of an oligotrophic (low productivity)
system.
A total of 86% of inflows comes from the upper
Great Lakes and Lake Erie through the Niagara
River.
Water quality is affected by upstream sources and
inputs from local industry, urban development,
agriculture, and landfills.
Credit: GL Fisheries Commission

About 93% of
the water in
Lake Ontario
flows out to the
St. Lawrence
River; the
remaining 7%
leaves through
evaporation.
Source: USEPA
From: A LaMP-based Biodiversity Conservation Strategy for Lake Ontario
Native Migratory Fishes
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Lake-tributary fishes: Lake sturgeon, Atlantic salmon, suckers,
redhorse, walleye, brook trout
Lake-ocean fishes: American eel
Wetland spawners: Northern pike, muskellunge, and yellow perch
From: A LaMP-based Biodiversity Conservation Strategy for Lake Ontario
Photos: H. Domske
The Welland Canal connects Lake Erie and Lake Ontario
From: http://www.wellandcanal.com
Welland Canal Facts
1st
2nd
(1829) (1845)
Number Of Locks
Width Of Locks
Length Of Locks
Depth Of Canal
40
6.7m
33.5m
2.4m
27
8.1m
45.7m
2.7m
3rd
(1887)
4th
(1932)
26
13.7m
82.3m
4.3m
8
24.4m
261.8m
8.2m
The building of the canal was a labor intensive venture. Construction crews\
made up of European immigrants had very few tools to work with other than
picks and shovels. The men on these crews were paid about a half a dollar
for a day's work. The operation of the canal also required a great deal of
physical labor as horses and oxen were used to tow the ships (schooners)
from one lock to another on paths that still exist today as streets by the
name of towpath. The total cost of the canal was 8 million dollars and the
man responsible for initiating the project was a young entrepreneur by the
name of William Hamilton Merritt. He would later become known as the
founding father of the Welland Canal.
From: http://www.wellandcanal.com
Lock doors closing…
Lake water levels are influenced by dams and locks in the
St. Lawrence River.
Ecosystem Restructuring: The Culprits –
Zebra & Quagga Mussels
Total non-Dreissena Benthos & Dreissena Biomass in
east basin Lake Ontario (Station 81)
*
800
Q
8
700
7
600
*
Q
6
500
5
400
4
3
*
Q
non-Dreissena
Dreissena
Q
*
2
1
Dreissena wet Biomass g /m2 +shells
Wet Biomass g/m2 +shells
9
300
*
Q
200
**
Q
100
**
Q Q
0
** *
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
*
.
Year
Fisheries and Oceans Canada
Pêches et Océans Canada
Photos: DFO
Credit: SOLEC 2011
In Lake Ontario the dominant attached alga is
Cladophora. In the 1960s and 1970s this alga caused
serious problems in the near shore zone. It had
explosive growth, which detached and fouled local
beaches at the peak of the summer recreational
season. Research at that time showed that Lake
Ontario was receiving an excess of phosphorus, which
normally limits Cladophora growth in the shallow, wellilluminated near shore zone.
Credit: Ontario Water Works Research Consortium
Cladophora
Credit: Ontario Water Works Research Consortium
Nearshore Zone Food Web and
Fisheries Highlights
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Although zebra mussels once dominated the nearshore
zone, they are now found primarily in water less than 10
feet deep. Quagga mussels now dominate the lake bottom
from the water's edge to depths beyond 400 feet.
At the base of the food web, the abundance of green algae
(phytoplankton) is lower than what would be expected for
the current level of phosphorus (plant nutrient) in the water
due to the effects of zebra and quagga mussels.
Spring abundance of diatoms, a microscopic
algae that is an important food source for
zooplankton and opossum shrimp (Mysis),
has declined in the Eastern Basin since the
establishment of zebra and quagga mussels.
Mysis shrimp
Source: NYS Department of Environmental Conservation
Early Commercial Pressures
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Commercial fishing
practices are also
partially to blame for the
demise of Atlantic
salmon in Lake Ontario.
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Spawning salmon were
captured or hindered by
pound nets and weirs.
Native Lake Ontario Fishes: 100 Years Ago
Whitefish
Lake Herring
Lake Trout
Atlantic Salmon
The Historic Fish Community in Lake Ontario
Atlantic salmon
Emerald shiner
Lake whitefish
Lake trout
Blue
pike
Lake herring
Bloater
Walleye
Burbot
Yellow perch
White bass
Lake sturgeon
American eel
Deep-water sculpin
Bowfin
Bullheads/Catfish
Slimy sculpin
Credit: Dave McNeill, NYSG
The Present Lake Ontario Fish Community
Alewife
Sea lamprey
Rainbow smelt
Blueback herring
Round goby
Common carp
White perch
Chinook
salmon
Brown trout
Atlantic salmon*
Lake trout*
Rainbow trout
Credit: Dave MacNeill, NYSG
Enter the “Evil Alewife”: a Paradox
It looks benign, but it has been a serious nuisance species and a benefit!?
Credit: Dave MacNeill, NYSG
Mass die-offs
Important Time Periods for Lake Ontario Fisheries:
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Early-late 1800s: Welland Canal system, lamprey enter,
watershed changes: deforestation, damming, siltation,
unregulated salmon fishing, alewives introduced, salmon
collapse and extirpated.
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1920s and 1930s: Sea lamprey predation, highly-prized fish
populations collapse, increased harvest on alternative fish
species, introduction of smelt and double-crested cormorant,
smelt and alewife dominate offshore, alewife die-offs,
human population growth, industry, nutrient inputs.
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1950s and 1960s: Population collapses of many native
species, severe decline of lake trout/burbot, St. Lawrence
Seaway opens, TFM used for sea lamprey control, massive
alewife die-offs, contaminant loadings, hydroelectric power
use, successful stocking, concern for nutrient loading,
double-crested cormorants decline.
Credit: Dave MacNeill, NYSG
Important Time Periods for Lake Ontario Fisheries:
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1970s and 1980s: Beginning/expansion of stocking
efforts, sportfishery worth millions of dollars,
alewives and smelt under some control, invasive
species introductions by ballast water, nutrient/toxic
abatement, signs of successful lake rehabilitation.
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1990s and early 2000s: Stocking rates/sportfisheries
peak & decline, more ballast invasions with negative
impacts on fish/ecosystems, double-crtested
cormorant populations explode, alewife/smelt decline,
signs of successful lake trout reproduction, fisheries
sustainability?
Credit: Dave MacNeill, NYSG
Results of Human Impacts
on Lake Ontario Fish Communities:
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A shift from dominant species that are large and longlived (i.e. lake trout, Atlantic salmon, lake sturgeon) to
smaller, short-lived fish species.
A shift in populations with relatively stable
populations (numbers and age) to unstable populations
that fluctuate considerably (numbers/ages).
A shift from populations with diverse habitat
preferences and diverse physical characteristics to
populations that thrive only in narrow range of habitats.
A shift in abundance of highly-prized, commercial fish
species for human food, to species to fish species that are
of little or no commercial value.
Credit: Dave MacNeill, NYSG
The Niagara River is the connecting channel between Lake Erie and
Lake Ontario and a major source of hydroelectrical generation.
Wetlands are important
habitats on Lake Ontario
and serve as spawning
areas for a number of fish
species.
Tourism plays an important role in the economy around Lake Ontario.
The Seaway Trail National Scenic Byway brings tourists to the area.
Double-Crested Cormorants
New York State used
"oiling" of cormorant eggs
to prevent their hatching.
DEC also destroys nests
and "hazes" nesting areas
in spring and fall to try to
prevent the birds from
feeding on fish.
Double crested cormorants can have negative impacts on islands and
other habitats where they nest. Their excretions and nesting activities
destroy ground vegetation and trees around nest, eliminating habitat for
other birds and animals. There are reported cases where cormorants
have displaced other colonial nesting species such as great blue herons,
common terns and black-crowned night herons from their nesting sites.
Double-Crested Cormorants
One of 6 cormorant species native to North America, 35
worldwide, only species typically found inland.
First nested in Eastern Lake Ontario in 1945.
Populations grew, by 1970 was 125 pairs in all the Great
Lakes and at one point reached 750,000.
Connie Adams, NYSDEC
Cormorant Prey Species
Connie Adams, NYSDEC
Bald Eagle
•
Indicator Species
• Nesting Habitat
Restoration Efforts
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•
43 prime nesting sites
identified in Ontario and
New York
Eight nesting platforms
constructed
Photo: OMNR