TRENDS

The rate at which wetlands have disappeared over the past two centuries is alarming. This rate, fortunately, has slowed in recent decades. It has not, however, been abated. In the 1970's, the USF&WS estimated that there were approximately 187,570,200 acres of wetlands remaining in the United States. In the 1980's it is estimated there were only 185,259,900 acres.

Over that ten year span, 2,310,300 acres (approximately 1.2 percent) of the nation's remaining wetlands were lost. This calculates to a continued yearly wetland loss of 0.12 percent (Dahl and Johnson 1991).

Of the three wetland systems that occur in Illinois, Palustrine wetlands have been the most negatively affected at the national level. Between the 1970's and 1980's these wetlands disappeared at an average rate of 0.25 percent every year. Lacustrine systems, on the other hand, actually increased in abundance by an average of 0.04 percent every year. Riverine systems showed no significant change in overall abundance during this time (Dahl and Johnson 1991).

No exact, current wetland loss rates in the 1990s for Illinois have been determined by state or federal resource agencies. At the time this publication was completed, however the USF&WS and the USDA/NRCS were both engaged in studies to determine wetland loss rates from the 1980's to the 1990's and the causes for these losses. It is estimated that Illinois continues to lose wetlands at rates very similar to those last known to be occurring nationally (Illinois Department of Natural Resources 1994).

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