Tuesday, May 31, 2016

Canadian Influences on Shared Waters

LAKE ST. CLAIR:  Sometimes we forget that our neighbors across the border share with us similar concerns about water quality in Lake St. Clair.

Norman DeBono of the London (Ontario) Free Press wrote earlier this spring that heavy rains caused sewage overflows at London, polluting the Thames River, which flows into Lake St. Clair. City records show 59,473 cubic meters of raw sewage and 91,171 cubic meters of partially treated sewage were discharged to the river in the first quarter of the year.

Inadequately treated sewage contains phosphorus, which feeds algal blooms in Lake St. Clair and farther downstream in Lake Erie.

Another cause for concern is suspended sediment in the Thames River, much of it erosion from Ontario farms. A sediment plume clouding Lake St. Clair, beginning at the mouth of the river, can be seen often in satellite photos.

LAKE ERIE:  As you might expect, Canada monitors water quality in the Great Lakes. Some Canadian researchers look for toxins in Great Lakes fish. Results of recent tests in Lake Erie warrant our attention.

“Since the 1970s there has been a dramatic reduction in contaminants in Great Lakes. Harmful pollutants have been phased out or banned resulting in over 90% reduction levels for some contaminants. As the ecosystem recovers, contaminant levels continue to decline at most locations, with some exceptions. For example, a slight upward trend in contaminant levels in some Lake Erie fish is occurring.”

No comments:

Post a Comment