According to pleadings filed by the United States of America in USA v SFWMD,
Case No. 88-1886-CIV-HOEVELER (S.D. Fla. filed Oct., 1988)
Eutrophication is "a
process characterized by an abundant accumulation of nutrients that support a dense growth
of plant and animal life, the decay of which depletes the waters of oxygen. In the
Everglades, eutrophication is an unnatural process which is triggered by excessive
nutrient pollution." [note 1].
An oligotrophic ecosystem, fostering an unique array of wildlife in diverse habitats
developed and maintained under naturally low nutrient conditions, pristine Everglades
marsh is "characterized by low biological growth rates (productivity) [and high
levels of dissolved oxygen]. In the aquatic portions of the natural Everglades ecosystem,
this means that the growth of plant and animal life is limited by extremely low
concentrations of phosphorus and/or nitrogen." [note
2].
Scientists found that even small increases in nutrients disrupted microbial processes
important in the cycling of nutrients in the marsh. The destabilization of the naturally
oligotrophic Everglades ecosystem by the "influence of artificial nutrient
sources" [note 3] leads to alterations of the algal mat,
and is later manifested at the macrophyte, or large plant, level in the form of invading
fronts of cattail monocultures. By the time nutrient impacts reach this level, the damage
to the ecosystem's biological communities is irreparable.
Because of "the limited ability of the system to rid itself of phosphorus,"
Dr. Ronald Jones, a federal expert witness and Professor at Florida International
University, estimated that the effects of elevated phosphorus levels in Everglades peat
soils may remain for hundreds of years. [note
4] Once
saturated, Everglades peat soils are unable to absorb more nutrients from the SFWMD
inflows carrying them south from farms in the EAA. This unabsorbed phosphorus is
"transported downstream and taken up by unsaturated peat. Thus, as excess phosphorus
continues to be added to the marsh, the zone in which the peat soil accumulates and
becomes saturated with excess phosphorus expands." [note
5].
It was estimated that by the late 1980's, over 6,000 acres of Loxahatchee
N.W.R. sawgrass communities had been taken over by cattails. [note
6]
The marsh was "becoming a less diverse nutrient-dependent system as algae, plants and
other organisms [were] replaced by pollution-tolerant species." [note 7].
