A partial fisheries survey of Esau Lake, Presque Isle County. (Fisheries research report: 888)

-5 -Biological Characteristics
Vegetation
Time did not permit a complete biological inventory. That the
biological productivity of a lake is dependent to a very large extent
upon plant growth is quite generally accepted. Very little vegetation
was observed in Esau Lake and this consisted almost entirely of bulrushes
(Scirpus sp.). A very small amount of muskgrass (Chara sp.) was also seen.
The sparsity of vegetation in this lake is probably caused by several
factors. Among these factors are wind and wave action, which prevent
aquatic plants from becoming rooted, and the marl bottom which is not
well suited to plant growth.
Fish Foods
Both direct and indirect observations indicate that fish foods are
not abundant. No collections were made. Some bottom food organisms were
found in the gravel along shore (immature aquatic insects, snails, and
crayfish). No observations relative to the abundance of plankton (microscopic free-swimming or free-floating plants and animals, e.g. water bloom
and water fleas) were made, but judging from the clarity of the water,
plant or phyto-plankton was not abundant at this time of year. This
plankton is an important source of food for small fish. Forage fish make
a third type of fish food. Two rather large schools of minnows were seen
in the vicinity of the dock at the Boys Camp.
Fish Present, Growth, and Natural Propagation
Game fish known to be present are rock bass, perch, and smallmouth
bass. Each of these species was seen. Smallmouth bass are not abundant
but are reported to reach good size in the lake. Rock bass and perch are

fairly numerous and give every appearance of being dwarfed. About 10 rock
bass and 5 perch were captured with hook and line. None were of legal size.