Change and Great Lakes Shipping and Boating
and low cost waterborne cargo transportation have shaped the economic
growth of the region for centuries. This shipping delivers iron
ore/taconite, coal, grain, limestone, salt, and petroleum products
to the Midwest. The Great Lakes-St. Lawrence water transportation
system supports more than 30,000 jobs in the US and Canada. Business
revenue and personal income resulting from the movement of cargo
in the system tops $3 billion/year. Recent findings from the Great
Lakes Regional Assessment suggest that increased water temperatures
and evaporation could contribute to a lake level decline of approximately
1.5 to 3 feet on various Great Lakes within the next 30 years. What
does that mean for the stakeholders who rely on using the Great
Lakes for commercial and recreational purposes?
With below normal
precipitation and above-normal temperatures in 1998-99, lake levels
have continued to drop as much as 6 inches. Lower lake levels mean
ships cannot carry as much. Commercial carriers are very dependent
on water depth in channel-ways and harbors.
There are more
than 4 million recreational boats are owned within the Great Lakes
states. Michigan ranks as the top state for boat owners in the US.
Serving these boat owners is a large network of marinas (over 1800
in Minnesota, Wisconsin and Michigan alone). Low water also makes
it more difficult for recreational boaters. There is greater chance
of damage when entering or leaving the water. There is greater risk
of running aground in harbors, marinas, or while underway in lakes
or rivers because of propeller, keel, or hull strikes on lake bottom,
boulders or shoals. Boating
and Shipping Assessment report (PDF) available here.
to the Great Lakes Carrier´s Association, a 1,000 foot-long
vessel (of the type that is used for intra-lake transportation),
loses 270 tons of capacity for each inch of draft loss. Draft
is the distance between the water line and the bottom of the
vessel. Ocean-going vessels (sized for passageway through
the St. Lawrence Seaway), which are approximately 740 feet
long, lose 100 tons of capacity for each inch of draft lost.