The Washington herald., 1922-04-20
DESCRIBES FEATUREs
OF CHEsAPEAKE BAY.

/ tonlGht at O'CLOCK.
DESCRIBES FEATURES
OF CHEsAPEAkE BAr.
The important physical charac-
ters Of Chesapeake Bay were de-
scribed by Prof. r. p. Cowles Of
the Johns Hopkins University and
special investigator OF the Bureau
Of Fisheries at the last meeting OF
the Biological Society. The com
parative shsilowness OF the bay.
the deep holes along the east shore
and the mud. sand. gravel. clay.
fuller's earth. peat and oyster
shells forming the bottom In vari-
Gus regions were mentioned.
The large amount OF fresh
water from many rivers meets the
great mass Of salt water from the
ocean" he said. He pointed out
Z that the mixing Of these waters is
not complete. that the saline water
is found at the bottom and that
the water, near the eastern shore
seem to have q greater amount OF
salt than those along the western
shore, at least in the lower half OF
tht bay.
As a result Of the survey IL has
been found that usually the tenn
perature OF the water Increases
with the depth during December
and January. that IL decreases with
the depth during April. June and
I July. and that in March and Sep
/ tember there is little or no differ
ence between the temperature Of
the surface and the bottom. The
water OF the bay in general H.
alkaline in reaction: that. however.
/ in a few regions Il is slightly acid.
indicating pollution"
Mention was made Of the results
| obtained with the current meter
which records the velocity and d.
rection OF the current at any depth.
Observations every one and a half
hours with this instrument yielded
the interesting information con-
cerning tidal currents. that AZ
times in any one locality the water
at the bottom may be moving up
the bay and at the surface toward
the mouth: that at other times the
surface water may be almost stag
| nsnt while that at the bottom IL
may be moving with considerable
velocity either up or down the
bay.
/ Any or all these physical data
may have an important bearing on
the distribution and the activities
of tho animals and plants in CheSa-
peake Bav.
After describing the various in
struments and meahods used on
the many cruises which the survey
has taken within the last few
years. Prof. Cowles summarized
the practical bearing of the work
as follows:
First. an effort has been made
to determine the normal biological
and physical conditions throughout
4 the year SO that when great NOR
tslity OF fishes. oysters. clans.
crabs. etc. occurs there will be
normal data at hand from which
to determine the abnormal condi-
tions that bring about the trouble
second. TO learn all that Is possible
concerning the movements OF lay
ers Of water OF different density
different temperature and different
plsnkton content fish food value,
in the hope that the information
may throw light on the migration
OF fishes and crabs into and in
Chesapeake Bay At certain times Of
the year; third. to studv especially
the fauna Of deep koies which oc-
cur In many places: fourth. 90
study the so-cslled barren bot
toms at the mouths Of rivers
and. fifth, to gather as much in
F., formation as possible which will
bear on the conservation of the
fisheries resources OF Chesapeake
Bay"
After thirty years OF slow. persist
ent advance since is first appearance
in this country near the Mexican
border. the boil weevil has now
reached the limit OF cotton cultiva-
tion. except in western Texas. south
1 western Oklahoma. northeastern
| North Carolina and Virginia