Environmental Engineering Reference
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oligotrophic lakes had few phytoplankton and were common in areas dominated by rocks, whereas
eutrophic lakes contained abundant phytoplankton and occurred in fertile, nutrient-rich, lowland
areas (Wetzel 2001). Hypereutrophy is the stage before senescing to a dystrophic stage and illing
completely with sediment.
Naumann recognized that the “quantitative production of phytoplankton” on which his clas-
siication was based could be inluenced by other factors, resulting in the classiications listed in
Table 16.1 (Naumann 1929, cited in Carlson and Simpson 1996).
16.2.4 G
eneraL
c
HaracterIStIcS
and
t
ropHIc
S
tatuS
The differences in the trophic status of lakes are somewhat analogous to the differences between
a “creek” and a “crick” described in Chapter 2. As characterized by Patrick McManus (1981),
creeks “tend to be pristine,” they “sparkle in the sunlight. Deer and poets sip from creeks, and
images of eagles wheel upon the surface of their mirrored depths.” Cricks, on the other hand,
“shufle through cow pastures, slog through beaver dams, gurgle through culverts, and ooze
through barnyards.”
Henry David Thoreau in
Walden
(1854, irst published as
Walden; or, Life in the Woods
) stated
that there is “nothing so fair, so pure, and at the same time so large, as a lake, perchance, lies on
the surface of the earth.” In the chapter on ponds, he described Walden Lake as “remarkable for its
depth and purity as to merit a particular description. It is a clear and deep green well, half a mile
long and a mile and three quarters in circumference, and contains about sixty-one and a half acres;
a perennial spring in the midst of pine and oak woods, without any visible inlet or outlet except by
the clouds and evaporation. The surrounding hills rise abruptly from the water to the height of forty
to eighty feet, though on the southeast and east they attain to about one hundred and one hundred
and ifty feet, respectively, within a quarter and a third of a mile. They are exclusively woodland.”
… “The hills which form its shores are so steep, and the woods on them were then so high, that,
as you looked down from the west end, it had the appearance of an amphitheatre for some land of
sylvan spectacle.” Further, “the water is so transparent that the bottom can easily be discerned at the
depth of twenty-ive or thirty feet. Paddling over it, you may see, many feet beneath the surface, the
schools of perch and shiners, perhaps only an inch long, yet the former easily distinguished by their
transverse bars, and you think that they must be ascetic ish that ind subsistence there.”
Thoreau described the nearby “Flint's, or Sandy Pond, in Lincoln, our greatest lake and inland
sea, lies about a mile east of Walden. It is much larger, being said to contain one hundred and ninety-
seven acres, and is more fertile in ish; but it is comparatively shallow, and not remarkably pure.”
TABLE 16.1
Trophic Lake Types Suggested by Naumann
Lake Type
Characteristics
Oligotrophy
Lakes with low production associated with low nitrogen and phosphorus
Eutrophy
Lake type with high production, associated with high nitrogen and phosphorus
Acidotrophy
Lake type with low production, with pH values less than 5.5
Alkalitrophy
Lake type with low production, associated with high calcium concentrations
Argillotrophy
Lake type with low production, associated with high clay turbidity
Siderotrophy
Lake type with low production, associated with high iron content
Dystrophy
Lake type with low production, associated with high humic color
Source:
Carlson, R.E. and Simpson, J.,
A Coordinator's Guide to Volunteer Lake Monitoring Methods
,
North American Lake Management Society, Madison, WI, 1996.
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