Invasive Fish Species and their effect on Lake Ontario’s Environment
FRIDAY AUGUST 20TH 2010
“”Eye Of The Storm”: Invasive Fish Species and their effect on Lake Ontario’s Environment.
Hamilton Harbour is a hypereutrophic and highlycontaminated environment due to urban and industrial growth. Studies cite Randel Reef, Windermere Arm, Red Hill Creek are problem areas. Eutrophication of the Lake accelerated with the population increase in the Lake’s drainage basin at the beginning of 1900 until around 1974.
Researchers tend to concentrate on Lake Ontario’s pollution issues as: (1) contamination of water, sediment and biota with a wide variety of contaminants. In the overlying water in Lake Ontario sediments can consume a large amount of oxygen from the lake. This overlying water is a common habitat for different varieties of aquatic life which are highly dependent on the supply of oxygen in order to survive. In a 2,000 study by McMaster University’s Chemistry Department the suspended particles and the fate of Aquatic Systems is addressed.
Invasive Zebra Mussels. In an interesting 1997 – 2,000 study undertaken by the University of Vermont centred on ” Zebra Mussel clusters.” It was the arrival of Zebra Mussels that changed our beautiful Great Lakes to “mire.” Their study focused on : (1) the impact of the zebra mussel colonies on water chemistry in Lake Champlain, and, (2) ecosystem changes. The results of this study showed that : (1) zebra mussels encrustation may decrease the structural integrity of four shipwrecks, especially their iron fastenings; and, (2) zebra mussels may decline where calcium concentrations are low.
Invasive Rusty Crayfish. In a 2,000 study by the Department of Biological Sciences, at the University of Notre Dame sends up “red dangerflags.” as their researches tell us the Rusty Crayfish is invading the Great Lakes, and has previously invaded many inland water bodies in the upper Midwest, and Southern Ontario. They red flag with “invasive” rusty crayfish as Lake Erie ( and Lake Ontario drains from Lake Erie), Lake Michigan and Lake Superior all have rusty crayfish. In their samples, 30 % of the rusty crayfish occurred in river mouths. Researchers cite the lack of studies on the rusty crayfish. Their findings show two major problems: (1) in inland water badies, the rusty crayfish often replace native crayfish; and, (2) rusty crayfish have other ecosystem effects, e.g., (a) reduction of submerged vegetation, and (b) reduction of invertebrates, and possible fish populations.
Walleye. At the beginning of the 2,00 study by the Ontario Ministry of Natural Resources in Peterborough they immediately cite ” it is since the arrival of zebra mussels in North America that dramatic changes in water transparency occurred in the Great Lakes basin.
Their researchers studied Walleye (Stizistedion vitreum) because of its economic value and known sensitivity to light. And, they used to publish information to measure preferred light and temperative conditions for walleye. Plus, this study predicts how changes in water quality will affect the amount of habitat that is suitable for walleye. They used Optimum Secchi Depth Tool (2 4 m). Here , the proportion of lake area and volume was measured that meets light and temperature conditions optimal for walleye. Their results show “Secchi depth changes observed in some Great Lakes can have a dramatic effect on the supply of walleye habitat, and, consequently the production of walleye.
Lake Whitefish and Slimy Sculpin. Lake Whitefish (Coregonus clupenformis) were important commercial fish species throughout Lake Ontario in 1900. By 1970s they were rare along the southeastern shore, and, by mid 1980s numbers began to climb in the northeastern basin. But, in the mid- 1990s their numbers plummeted when dreissenids colonized in 1990s. So, in the 1990s whitefish were caught in deeper waters in southeastern Lake Ontario and they were in poor condition. Although Lake Whitefish lack pharynaeil teeth, their muscular stomachs grind dreissends.
Diporeia was a staple in the diet of nearly all endemic benthic fishes especially Slimy Sculpin which in 2,000 is the most abundant fish in Lake Ontario.In 1993 Diporeia were found in abundance in depths of 55 – 130 m, by 1995 the population was declining. Then, they were only abundant at 130 m.
Slimy Scalpin’s abundance declined sharply between 1991 – 1992 in southeastern Lake Ontario and somewhat further along the south shore from 1996 – 1999 which should have reduced predatation on Diporeia. Lake Whitefish formerly fed on Diporeia but in 1998 their diet was Mysis and fingernail clams. Three results were found in this study: (1) some researchers stated the population was due to competition for diatoms with dressenids; (2) but this studies researchers found composition of the sediment may be a factor, and (3) other chemical/biological process may be involved.
Rainbow Trout. In a 2,000 study by Environment Canada the researchers stated ” Hamilton Harbour is the recipient of contaminants from municipal/industrial surface runoff and atmospheric deposition. In a previous study of blood plasma of immature Rainbow Trout caged in the windermere Arm of Hamilton Harbour they found elevated concentration of the egg yolk protein in these fish and considered it useful to detect estrogenic chemicals.
In a follow-up study they tested the ability of the water from the Windermere Arm in whole fish (21 days static renewal test in a laboratory). the immature Rainbow Trout and Whole Fish tests were done to access the estrogenic potency of serval water samples taken from (1) the mouth of the Windermere Arm to the mouth of the Red Hill Creek, and (2) then along Red Hill Creek to a point above the out-fall of the Hamilton Wentworth water water plant.
Conservation vs Control in Coote’s Paradise Hamilton
FRIDAY JULY 23 2010
In 1974, a request came form RGB for control of Coote’s Paradise. But, the Hamilton Harbor Commission held tightly to the control it claims it had under the 1912 Act Of Parliament by which it was created. In fact, the 1912 Act of Parliament …supercedes the 28 year-old RGB legislation.
Now, the conservation issue in 1974, was the preservation of Coote’s Paradise being in doubt because of a recommendation that would doublethe release of sewage into Coote’sParadise. It was suggested to construct a sewage line along the base of Coote’s Paradise and Burlington Bay to the east-end Woodward plant. Then RGB director, Leslie Laking, had great concerns about the decision. he said “The RGB would have no effluent in Coote’s Paradise from here on in.” And, chairman of the Harbor Board, Ed Tharen, ” pointed an accusing finger at the Dundas sewage treatment plant as the major polluter responsible for that gunk being poured into Coote’s Paradise.”
Stewart Morison, Ducks Unlimited Canada which is an offshoot of the U.S. group, in 1987, expects to spend $43 million in 1988 to build and restore wetland habitat for waterfowl. Morison looked at prospects for involvement in a Coote’s Paradise project proposed by RGB biologist Len Simer. From the high level bridge, Simer described the marshland’s problems and potential underlining three issues that hamper growth of plants needed for good wildlife habitat. Perceptual opportunities for current difficulties hampering wildlife habitat in Coote’s are a justaposition of elements and how they relate to each other, such as :: (1) wind-stirred mud; (2) bottom-feeding carp, and, (3) changing water levels. Carp and other invasive species continue to be an issue, even in 2,010 , Reduction of Carp is due to the Fishway operation. This allows other fish and plants to return to the marshland.
In 1988, Ducks unlimited Canada said “Half of Coote’s Paradise can be restored to the wetlandwildlife preserveit was earlier this century. DUC, provincial manager John Blain told RGB board of directors. The now flooded swamp and surrounding wetlandsat the far west end of Hamilton Harbor are part of RGB property. Blain said “Coote’s Paradise restoration – We believe it’s feasible in terms of both biology and engineering and asked the conservationgroup to investigate.
In 1988, DUC would build more than 3 km (2 miles of earthen dikes to wall off 3 km (250 acres) of open water below the McMaster UniversityCampus. This exciting initiative included: (1) Water depth would be lowered to foster the growth of natural marsh plants needed for good wildlife habitate; (2) There would be NO CARP to uproot young plants; and, (3) There would be less wind-stirred MUD to block sunlight.
Coote’s Paradise had another concern in 1988 because the region set sites on a Perimeter Road (now hwy. 403). The north-side alternative was cheapest to build at $48 million. Planners backed the north-south site because it would offer drivers an attractive view of the waterfront. The Hamilton Harbor Commission would have to approve the scheme. Now the negative side is beastly ugly because it includes three issues:
(1) Noise would affect the western harbour and
proposed waterfront park. ( Now in 2,010 we
have a beautiful waterfont part with little
(2) The harbor’s surface area, volume and fish
habitat would be reduced.
(3)Fill would be needed in Coote’s Paradise. And, thank goodness for former Alderman Mary Kiss, who recommened “to build 403 hwy WITHOUT PUTTING FILL IN COOTE’SPARADISE – one of the most ecologically important areas
Memory is like Jazz. Life jazz, memory has more to do with now than then. Then is just fiction now.
in Two Sides of a Centre
Robert Clark Yates
Would like to thank Robert Yates for his inspirational books and watchful eye on Cootes paradise.
Enjoy the pictures and information today and have a great weekend.