Ecological Concerns

From Great Lakes Wiki

Ecology

Dams

Most of the rivers that empty into the Great Lakes are riddled with dams. Most dams were built and re-built in the 20th century and have reached, or soon will reach, the end of their useful lives. Dams serve many purposes, particularly dams were built for power production during early settlement and development. Dams have also provided recreational uses, fish and wildlife production, water supply, and occassionally flood control. While the benefits derived from power production were instrumental in establishing community and manufacturing power, that is no longer true. In the last few decades, the ecological problems associated with dams has become much more evident. They alter temperature and flow regimes of the river, trap sediment and organic material, block passage of native fish and other aquatic organisms, and present recreational and navigational hazards.

Many fish populations have declined as a result of the prescense of dams, most notably lake sturgeon and coaster brook trout. When they are unable to reach their spawning ground the population suffers. Fish passage for strong swimming and jumping species such as trout and salmon has been improved by installation of fish ladders around dams however many species of fish are unable to use current fish ladders because they are too steep or provide current that is too swift. Dam removal has become an increasingly common means of providing fish passage and improving stream ecological functions.

The lowermost dam on Great Lakes tributaries provides some benefit at least. The presence of some dams has prevented the spread of almost all invasive species. However, even the lowermost dams are aging and in some cases no longer provide this protection. Learn more from DNR and from the Michigan Rivers Partnership.

Multiple Uses

The waters of the Great Lakes are plagued by interaction between human and non human use- especially in harbors, bays and rivers. Political economists call these situations ‘negative interdependencies’ or ‘externalities’ when the interaction is not beneficial, such as marinas negatively affecting fish stocks. It is inevitable that excessive subjection to any single use will result in an undesirable situation, much the same as the saying too much of anything is never good.

‘Common pools’ or ‘common-property resources’ are another common term applied to the Great Lakes and are when people are vying for the same resource. No matter how much of one resource initially exists in an area, if there are multiple parties responsible for subtracting from it, it will certainly run out.

The balance between these two situations is a constant struggle for Great Lakes Communities. The multiple uses practiced in the Great Lakes create a segmented community of interested parties. There is a never-ending search to find the balance between commercial fisheries, recreation, environmental health and ecology.

Biomagnification

Although the Great Lakes have been restored to a point that almost no areas have toxic levels of contamination, there are still risks involved with the existing pollution. Many of the animals living higher on the food chain are experiencing levels millions of times higher than that of other species, due to biomagnification through the food chain. This process is notably affecting predator fish and birds, such as trout, salmon and eagles.

Biomagnification occurs when a small fish, species A, has a certain level of toxins in its body. It is then eaten by its predator, species B, who needs ten of them a day to stay healthy. A large predator, such as a trout or salmon, must then eat ten of species B a day, but in doing so is consuming toxins equivalent to 100 of species A. The amount of toxins in the food chain increases as you go up.

Areas of Concern and Restoration

An Area of Concern, or AOC, is a location recognized to have been environmentally degraded and in need of remedial action. There are 43 AOCs in the Great Lakes basin. Remedial action for the AOCs began in 1985 when the International Joint Commission recommended that the Canadian and United States governments formulate remedial action plans, or RAPs, for each of the AOCs.

A RAP has 3 stages, to identify the problem and possible solutions, create a plan to execute one of the solutions and finally report on the achievements of the implemented plan.

Mark Sproule-Jones, author of “Restoration of the Great Lakes: Promises, Practices, Performances” says that AOCs are designed to, “recognize, in part, that the traditional institutional designs for environmental cleanup are inadequate” (3). He says the restoration experiments for the area promise four benefits.

• Provide a method for people interacting with the Great Lakes to cooperate and restore the affected areas and create a use for the resources that is sustainable.
• Create a more efficient web of power that will keep control of restoration projects with local stakeholders.
• Facilitate opportunities between the groups involved to reach mutual consensus.
• Gauge the achievement and accountability of public agencies involved in the restoration (4).

Sproule-Jones says, “The promises of RAPs and remediation on the Great Lakes were many and important. The performances were modest; however, the potential remains great” (115). ==Other Possible Topics==
Eutrophication, Oxygen Depletion, Biodiversity, Sustainable Development, Air Pollution, Climate, Hydrology
External Resources

The EPA Great Lakes Concerns of Today
Sproule-Jones, Mark. Restoration of the Great Lakes: Promises, Practices, Performances. Vancouver: UBC Press, 2002.

Ecological Concerns

Invasive Species

Native Species