I. Morphology of Lakes
A. Bathymetric
maps
contour lines = isobaths (iso-equal; bathy-depth)
surveying and sonar
B. Morphometry
1. Maximum depth = zm
2. Maximum length = l
3. Maximum width = b
at right angles to the maximum length line
4. Area
A0 - surface area
Az - area of contour at depth z
5. Volume
V = volume of the whole lake
Vz = volume below depth z
6. Mean depth 
7. Relative depth
ratio of maximum depth (z) to the mean diameter of the lake at the
surface,
expressed as a percentage
8. Shoreline development.
L = length of shore line
9. Hypsographic curve
area at each depth – m2 or %
can use to calculate the volume
10. Depth-Volume curve
volume at each depth – m3 or %
sediment water interactions
II. Lake and Stream Zonation -- See page 132 of Wetzel
A. Lakes
1. Epilittoral -
2. Supralittoral
-
3. Littoral -
extends
from the seasonal high water level down to where the vegetation doesn't
grow due to a lack of light
eulittoral
upper littoral
middle littoral
lower littoral
4. Littoral-Profundal
- no higher plants
(can be algae)
5. Profundal -
sediment
free of vegetation; low light
6. Pelagic - open
water
a. trophogenic (euphotic) - enough light for production >
respiration
b. tropholytic - darker – respiration > production
B. Streams
1. Eucrenon - the
origin of the stream
2. Hypocrenon
3. Rithron - stony
stream zone
4. Potamon - lower
energy part of the stream - river
5. Riparian zone
5. Drainage classification
stream orders
C. Biological groups associated with zones (lakes only)
1. Pelagic
a. Seston - all particulate matter in the open water
(1) bioseston -- the living component
(2) tripton -- non living seston = detritus
b. Nekton -
can swim against currents
c. Plankton - movement influenced by turbulence
(1) euplankton - spend whole
life cycle in open water
(a) bacterioplankton
(b) phytoplankton
(c) zooplankton
(2) meroplankton - periodically enter the plankton, but can't
spend
their whole life cycle there
(3) pseudoplankton - organisms that don't really live in
pelagic,
but are swept there accidentally
2. Benthos
- organisms that live on the sediment water interface
a. Phytobenthos - 'macrophytes' higher plants; algae
b. Zoobenthos
3. Other
a. Pleuston - at the air-water interface
b. Neuston - microscopic pleuston
c. Periphyton - plants (and bacteria) that live on the
substrates
(1) epiphytic
(2) epipelic
(3) epilithic
(4) epipsammic
d. Psammon - interstitial fauna -- they live between sediment
grains
BONUS
QUESTION OF THE WEEK (Due at beginning of
class
Name a lake formation type that often has very irregularly shaped basins. Would you predict that lakes of this type tend to be eutrophic or oligotrophic? (Say which and describe why in one or two sentences)