VOL. XV, NO. 4. JULY 197O

ON THE COVER-

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Coccoliths

Ihe shape on our cover is the plate of
a group of minuscule golden brown algae,
called coccolithophorids. Magnified about
58,000 times, they can be studied in detail only
with the aid of an electron microscope.

Coccoliths make up the bulk of the "White
Cliffs of Dover" and were found in extremely
thin "chalky" layers in Black Sea sediments,
which were determined to exist almost entirely
of one species: Emiliania huxleyi.

During a bloom of these plants, a liter of
surface water may look milky and contain up
to one million cells of these algae.

Library of Congress Catalogue Card Number: 59-34518

Jan Hahn, Editor

Articles may be reproduced in whole or in part by daily
news media, provided credit is given to: Oceanus, periodi-
cal of the Woods Hole Oceanographic Institution.
Periodicals must request the Editor's permission to reprint.
Illustrations may not be reproduced without permission,
nor may the contents be published in book form.

Noel B. McLean

Chairman, Board of Trustees

Paul M. Fye

President and Director

Columbus O'D. Iselin

H. B. Bigelow Oceanographer

Bostwick H. Ketchum

Associate Director

Arthur E. Maxwell
Director of Research

OCEANUS

Vol. XV, No. 4, July 1970

THE WOODS HOLE OCEANOGRAPHIC INSTITUTION
Woods Hole, Massachusetts

Editorial

JL OR many years we felt a lack in the coverage of Oceanus in that we rarely
seemed to have articles on the geochemistry of the sea. This issue, devoted to the
cruise in the Black Sea made by the R.V. "Atlantis IT in April and May 1969,
covers quite a bit of ground, literally and figuratively. Some of the fare is a bit
heavier going than our readers usually enjoy. Still — this is an important aspect
of modern oceanography which, after all, has become more and more complex.

Not the least important aspect of the Black Sea cruise was the international
cooperation and the opportunity to exchange ideas with Russian oceanographers.
Scientists from many nations took part in the work at sea on various legs of the
cruise. The ship visited two Russian ports and we cannot think of a better way to
"show the flag" than having a modern, extensively equipped research vessel do so.

Russian visitors
examining Black Sea
bottom records
on board the
R.V. 'Atlantis II'

KARADENlZ

e p

HEPHOE MOPE

'Atlantis IF Cruise #49
to the Black Sea

IHE Black Sea is one of the more unusual bodies of water in
the world. Marine life, as we generally know it, can exist only in
the upper 200 meters. Below that depth there is no oxygen present,
so that only certain bacteria which need no oxygen can survive.

Rainfall and run-off from rivers and land drainage exceed
evaporation, causing a surface layer of water of relatively low
salinity and corresponding low density. The accumulation of fresh
water, together with temperature conditions in the upper layers of
the Black Sea, also prevent aeration of the deeper water through
convection currents. The only way in which the deeper water
could be renewed under these circumstances is through inflow of
oxygenated deep water from the outside. However, the Bosporus
Ridge, which rises to some 40 meters from the sea surface, prevents
the entrance of Mediterranean water.

The deep water in the Black Sea is practically stagnant; below
200 meters the oxygen has disappeared, instead large quantities
of hydrogen sulfide (the smell of rotten eggs) are present. This is
caused by the decomposition of rich organic material which has
drifted down from the productive surface layers and, in decompos-
ing, has used up all the free oxygen. From the bottom up, the
toxic water extends upwards for about 1800 meters, while the
stagnant part has about five times the volume of the upper portion
where other forms of marine life are present.

Similar conditions exist in some Norwegian fjords, although
not necessarily on a year round basis. In the open sea, as far as
we know, there is only one stagnant basin, the Cariaco Trench
off the coast of Venezuela. The anearobic conditions in that trench
were discovered in December 1954 by Mr. L. V. Worthington of
our staff. Chemical and geological investigations in the trench
were carried out later from the R.V. 'Atlantis' by Drs. F. A.
Richards and J. M. Zeigler then on our staff.*

*See: The Cariaco Trench," by F. A. Richards, Oceanus, Vol. Ill, No. 3,
Spring 1955.

On 'Atlantis IF Cruise #49

to the

by J. M. HUNT

I

Black Sea

T all started in the fall of 1968 when
we received a grant from the National
Science Foundation (N.S.F.) to return to
the Red Sea following our successful
studies there in 1966. When it became
apparent that the Suez Canal would re-
main closed, we received permission from
N.S.F. to change the area of study to
the Black Sea. Many of our scientists
long had wanted to enter the Black Sea
but there were political as well as sci-
entific problems involved in the logistics
of this kind of a cruise. Fortunately,
in January, 1969, two distinguished Rus-
sian oceanographers visited the Boston-
Woods Hole area to lecture and attend a
meeting of the Intergovernmental Oceano-
graphic Commission of UNESCO. These
were Professor Monin, Head of Oceanog-
raphy at the Academy of Sciences of the
U.S.S.R. and Admiral Rassokho, Chief of
the Hydrographic Office at Leningrad.
Both of these gentlemen were receptive
to our proposed study of the Black Sea
especially when we offered to accommo-
date some Russian oceanographers on the
cruise.

We planned a multi-disciplinary cruise
involving all aspects of oceanography with
personnel from several universities both
in the U.S. and abroad. We included
invitations to scientists of all the border
countries, Turkey, Bulgaria, Rumania, and
the U.S.S.R. Also, the suggestion was
made to the Soviets that the R/V
'Atlantis II' stop at two Russian ports,
preferably Novorossiysk and Sevastopol
in order to exchange visits with Russian
oceanographers and to take some of them
on a short cruise.

As the ship left Naples we had foreign
scientists on board from Kiel, Heidelberg,
Gottingen, G0teborg, Ismir, and Trieste.
As the ship passed through the Bosporus,
we picked up two Turkish scientists, one
from the Hydrographic Office in Istanbul
and the other from the Minerals Research
Institute in Ankara.

During the first three weeks in the Black
Sea, it was obvious that the Russians were
not quite convinced of our character. The
shadowing and photographing of our ship
by airplanes and ships plus monitoring of
all communications was fairly continuous
even though the weather was cold and
stormy with a cloud cover most of the
time. The ships always remained a re-
spectable distance behind us especially
when we were towing gear. At all times,
we. stayed beyond the 200 meter contour
or fifteen miles offshore to avoid any
diplomatic problems.

Despite the cold and stormy weather,
about thirty stations were made including
a cluster off the mouth of the Bosporus.
We were lucky in having most of the
equipment in good working order so
that a large amount of geophysical and
heat flow data were obtained along with
a large number of sediment cores and
water samples. Among the more sophis-
ticated equipment on board was a six-
channel automatic chemical analyzer for
determining most of the important chemi-
cal parameters in the sea water.

Istanbul

The first leg terminated in Istanbul on
April 7 where we were greeted by Com-
mander Ozturgut, Chief of the Hydro-
graphic Office of the Turkish navy and his
Aides. We were berthed at a fine dock
positioned almost in the center of the city.
The next day we invited the press and
government officials and educators to
visit our ship. The Turks were greatly
impressed and we received most favor-
able reports in six of the seven Turkish
newspapers. Also, through the U.S. em-
bassy office we arranged a cocktail party
on board for the benefit of representa-
tives of foreign governments in Istanbul.
We had representatives of the Embas-
sies of Rumania, Bulgaria, U.S.S.R.,
England, and West Germany, plus those
from several other eastern and central
European countries. It was a fine friendly
party and it was particularly interesting
how readily the representatives of the
capitalist and communist countries got
along together.

The next day we got into a motor
launch for a ride up the Bosporus to the
Hydrographic Office of the Turkish Navy.
Commander Ozturgut proved to be a
charming host who had spent some time
in America and had obtained a degree
from the University of Michigan. We were
given a detailed report in English from
several of the Turkish scientists regarding
their work in the Black Sea. It was most
interesting that their research covered only
the southern two-thirds of the sea. They
had orders not to penetrate the area to the
north even though they were well outside
the territorial limits of Russia.

No Life

On April 1 1 we headed north for the
second leg on what later proved to be the
most adventurous part of our cruise. Dur-
ing this leg the sun came out, the sea
became relatively calm, and surface tem-
peratures warmed up from about 5° to
about 9°C. Our Russian shadowers dis-
appeared during this leg except for one
jet and one ship that came out to greet
us when we were stationed off the main
Soviet submarine port of Batumi. Our
track during the second leg covered sta-
tions 1461 through 1487. Most of these
were in the eastern half of the Black
Sea. During most of this cruise few
vessels of any kind were sighted. Ap-
parently, most of the traffic in the Black
Sea is in the western half where the popu-
lation in coastal areas is much higher.
The eastern half had almost no shipping,
and fishing vessels are confined to the
coastal areas which contain most of the
marine life. There is no deep-sea fishing
in the Black Sea since the water contains
poisonous hydrogen sulfide at depths
greater than about 100 meters. The inter-
face between the oxygenated surface
waters and the hydrogen sulfide waters is
actually concave with a depth as low as
75 meters near the center of the Black Sea
and up to 250 meters along the edges.
During most of this second leg we saw
no sign of life in the Black Sea except an
occasional dolphin.

On April 4, as the 'Atlantis IT made
her way along the southeast coast of the
U.S.S.R., word was received that the ship
could enter the Russian ports of Novoros-

On the bridge of the 'Atlantis II', Captain E. R. Hitler and Dr. J. M. Hunt check a chart
showing the ship's track and stations in the Black Sea. Seaman A. Sture is on the wheel.

With the snow capped
Caucasus mountains in
the background, a box
corer is hauled back on
deck. Jhis corer opens
up to reveal a square
core of sediment. It was
designed and built in
Kiel, Germany.

siysk and Yalta, where we could visit with
Russian scientists.

Russian Ports

It was a cloudy, foggy day when we
steamed up the long channel leading into
Novorossiysk. We were the first American
ship to enter the port since World War II
and the first foreign oceanographic vessel
ever to visit. As we passed some of the
freighters lined up along the docks we
exchanged waves and smiles with the
crews who consisted of a mixture of men
and women.

While Captain Hiller was dealing with
the port authorities, I welcomed Dr.
Ovchinnikov, Director of the Gelendzhik
Laboratory and his assistants into my
cabin. Dr. Ovchinnikov said that he
wanted to take all of our scientists by
motor launch to Gelendzhik, a small town
about ten miles southeast from Novoros-
siysk. All of the scientists were anxious
to go, so after completing our negotiations
with the authorities, we all boarded the
motor launch.

We were led to what appeared to be an
old estate, probably of some former
wealthy Russian. The Gelendzhik Labora-
tory is actually a collection of buildings
called the Southern Branch of the Institute
of Oceanography of the Academy of
Science, U.S.S.R. At the main building
the American flag was hanging alongside
the Russian flag to welcome us. Inside,
the rooms reminded me of my first visit to
Soviet laboratories in Moscow in 1962.
There were the usual dark red rugs, heavy
drapes over the windows, and plaster
walls. After several welcoming speeches
and a reply by our people, we all sat down
to long tables heavily laden with food and
drink. The Russians always serve vodka,
cognac, and wine and a few bottles of
warm fruit drinks for teetotalers. Caviar,
cheese, fish, and meat plus the good dark
Russian bread are the main food staples.
After exchanging several toasts and gorg-
ing ourselves on the food, we divided into
groups. The Russians provided scientists
with some knowledge of English to each
group. They were quite generous in show-

The Russian version of a Sealab was under-
going pressure tests while our scientific party

was visiting the Gelendzhik Laboratory near
Novorossiysk.

8

Analyzing seawater for nutrients has been
a tedious and time consuming operation. A
prototype model of a new AutoAnalyzer
provided intricate chemical analyses without

ing us everything they were doing and
letting us take pictures of their equipment
and data sheets. In addition they gave us
a large number of their publications, books
as well as reprints. They apparently were
doing considerable research in the Medi-
terranean and except for biology had not
studied the Black Sea in great detail. The
scientists were enthusiastic and particu-
larly happy at the opportunity to discuss
their work. However, it was quite obvious
to most Of us that the laboratories were
poorly equipped. The state of their ana-
lytical chemistry seemed to be that of
western institutions about twenty years
ago. They were forced to work with
relatively simple instruments rather than
the highly sophisticated equipment that is
so common in the U.S. The pattern fit
that of my previous visits to the U.S.S.R.
in that the major centers of science and
education in Moscow and Leningrad re-
ceive the best equipment with the small
isolated laboratories obtaining practically
nothing. The Gelendzhik scientists seemed
to be somewhat out of touch with recent
western developments and even in poor
cooperation with their own scientists at
other laboratories such as Sevastopol. The
people seemed to be eager enough. It was
more a matter of inadequate funds for
both travel and equipment.

danger of contamination. The rotating
sample table is being shown to visiting
Russian scientists by Dr. K. Grasshof, whose
work during the cruise aided in developing
the production models.

Visit & Visitors

During our stay at Novorossiysk, both
scientists and the crew were given com-
plete freedom to visit the city and sur-
rounding areas although we were asked
not to photograph port stations, railways,
and bridges. The local seamen's club
arranged some tours but generally we
wandered around the city on our own in
small groups taking pictures and buying
things at the local stores. At no time was
there evidence that we were being followed.

We left Novorossiysk early on April 29
with three Russian scientists including Dr.
Ovchinnikov. During the next few days
we made several stations in the Black Sea
at which the Russians were able to observe
all of our operations. Only one of them
could speak English so he generally acted
as interpreter. The scope of our equipment
apparently overwhelmed them because
they seemed to make notes about every-
thing.

As we approached Yalta on May 1,
most of the city was enveloped in fog but
we could make out a large number of
banners proclaiming the May Day cele-
brations. In Yalta we were advised by the
Russians that it would not be possible to
visit the oceanographic laboratories in
Sevastopol because they were closed for

the festivities which would last several
days. Several scientists from the Sevasto-
pol laboratories, however, planned to visit
us on May 2nd. We were not surprised
about the Sevastopol visit because this city
has been closed to foreigners for years.
The following morning about fifteen sci-
entists visited our ship from the Institute
of Biology of the Southern Seas including
the Director, Dr. G. G. Polikarpov.
Another ten scientists headed by Dr.
Metalnikov came from the Marine Hydro-
physical Institute of the Academy of
Science of the Ukraine in Sevastopol.

In our first discussions with the Sevas-
topol scientists it became apparent that
they were considerably more competent
scientifically than our friends in Gelend-
zhik. They had a good knowledge of
recent western literature and they showed
great interest in our most sophisticated
instrumentation. We made several good
contacts during these discussions and they
were generous in giving us a large number
of their books and reprints. They have
done considerable work in both the Medi-
terranean and the Black Sea. Sevastopol
is somewhat like Woods Hole in that it
has several marine research organizations
with a long history of distinguished work.
Dr. Polikarpov was genuinely unhappy
that we could not visit his laboratory and
he hoped that this could be arranged in
the future.

Luxury Liners

On May 3 the scientists and crew
had an enjoyable time visiting with Rus-
sians in Yalta both in their homes and
places of business. Yalta is without doubt
one of the freest places I have ever visited
in the Soviet Union possibly due to the
fact that it is a resort city. We were
allowed to photograph anything in the city
and participated in many of the holiday
celebrations. We visited with the crew
and passengers of two large luxury liners
which were berthed next to our ship. Both
of these liners were built in East Germany
and were beautifully furnished including
a large music room and swimming pool.
The ships carry a heavy tourist trade
between Odessa, Yalta, and Istanbul.
There were also several hydrofoils in port
most of which were built in Italian ship
yards. Four of us went for a ride on a

twenty-passenger hydrofoil and soon after
boarding were practically flying through
the water at a speed of about forty-five
knots. The ship handled beautifully except
every so often it would skim over a trough
and hit the following wave so hard that it
would shake the whole ship. We travelled
about ten miles up the coast north of Yalta
taking pictures all the way.

Pleasant Visit

The main square in Yalta had large
portraits of some of the Russian leaders
but most of the people seemed more
interested in having a good time than
listening to the political speeches. The
big dinner/dance hall i n Yalta was
crowded every night with the band playing
western music almost constantly. Most
services are at a premium. Restaurants
for example are so crowded every evening
that you need to know someone in order
to get a table. However, there are many
outdoor eating places and the whole
atmosphere is reminiscent of the New
Jersey seacoast in summer. In fact, the
main walk along the Yalta coast, which is
crowded with Russians from morning to
night, is reminiscent of the Atlantic City
boardwalk.

Although we had soldiers guarding our
ship at Yalta they were much more lenient
than at Novorossiysk. We were supposed
to be on the ship at midnight every night.
Occasionally we didn't make it until early
morning, but the soldier dutifully waited
for us. As in Novorossiysk, it appeared
that the guards were mainly there to pre-
vent Russians from boarding our ship
rather than to prevent us from getting off.

Early on May 4 we departed from Yalta
and made a straight run to Istanbul across
a foggy Black Sea. Several scientists dis-
embarked at Yalta so we put on Mr. &
Mrs. Hauck, the U.S. Vice-Consul sta-
tioned at Istanbul. The cruise to Rhodes
gave them a better understanding of the
operations and problems on an oceano-
graphic vessel. The cruise was com-
pleted in Rhodes on May 7. All in all
it was a most successful event both from
the scientific and the political point of
view. We not only learned a great deal
about the Black Sea but also made friends
with many of the scientists in the countries
surrounding the sea.

10

[cm] 0

20 —I

2900 ± 140
YEARS AGO

FROM METER

TO CENTIMETER

TO MICRON

AND FINALLY TO

ANGSTROM UNITS

by
E. T. DEGENS, S. W. WATSON and C. C. REMSEN, III

60

7140 ± 180
YEARS AGO

•
*

80 —i

'CEAN bottom sediments record the
history of our changing earth. They have
recorded, over a wide span of time, all of
the changes which have occurred in the
geological environment. Morever, the
evolution of organisms can be traced back
in minute detail by carefully investigating
the fossil record preserved in the sedi-
ments. In order to unravel the mysteries
of both the geological and biological past,
mysteries which are often hidden to the
naked eye, scientists are using an impres-
sive arsenal of sophisticated instruments
including mass spectrometers, spectro-
graphs, and x-ray devices. Another power-
ful tool is the electron microscope which
can enlarge materials directly up to
500,000 times without loss of detail in
form and structure.

To illustrate the use of electron micros-
copy to obtain information on the history
of our earth, we have selected the top
one-meter section of a 12 meter sediment
core taken in the central part of the Black
Sea at a water depth of 2,000 meters. On
the basis of radiocarbon dating, the age
of the sediment at the base of that top
meter is almost 10,000 years. Relative to
the age of the earth, which measures in
billions of years, this time interval of
10,000 years does not sound too impres-
sive. On the other hand, 10,000 years
covers quite a bit of the history of man.

100

11

Fine layered structure of a 5 cm section is shown by successive photographic enlargements.
The coin is a U.S. quarter. For our foreign readers, who do not have "two bits" handy, the
diameter of the coin is about 23 mm.

The sediment profile has an extremely
fine layered structure. Many of the details
come to light only if the photograph is
enlarged, as can be seen from the blowup
of a 5 cm section taken from the upper
20 cm of the profile. Light and dark layers
appear to alternate in a systematic fashion
at the rate of approximately 50 per cm
of section. Since the rate of deposition
is on the order of 1 to 2 cm per hundred
years, the observed relationships suggest
an annual or semi-annual deposition cycle.
This core section is not unique. Similar
layers were found at most points of the
Black Sea where cores were taken below
a water depth of 2,000 meters. This would
tend to suggest a history of uniform depo-
sition in the Black Sea over the last
10,000 years.

Coccoliths

The above was clear from an examina-
tion by the naked eye and by photographic
enlargement. The use of an optical micro-
scope, which permits a thousand fold
magnification, provided relatively little
more information. Higher magnifications
were required if the structure of indivi-
dual particles within the sediments were to
be resolved.

When samples from the light colored
layers in the upper 20 cm of the sediment
section were examined in the electron

microscope, it was found that they were
comprised almost entirely of coccoliths,
consisting of a single species Emiliania
huxleyi. These coccoliths are composed
of calcite which is a mineral form of
calcium carbonate (CaCOa) and measure
about 2 to 3 microns in diameter, one is
shown on the cover of this issue. On the
other hand, the black layers of the sedi-
ment appeared to consist entirely of cellu-
lar fragments and organic remains, well
preserved and showing remarkable detail
when examined with the electron micro-
scope.

Chemical Analysis

Prior to the microscopic work, a chemi-
cal analysis of the sediment was made.
Considerable variation in total phosphorus,
organic carbon, organic nitrogen, and cal-
cium carbonate were found within the
sediment section. Organic carbon and
nitrogen increase slowly to a depth of
about 25 cm, at which point they rapidly
increase reaching a maximum value of
about 20 percent for organic carbon and
1.5 percent for nitrogen at 55 cm. These
values then decrease abruptly reaching
minimum values at about 75 cm. Samples
for analysis were removed at intervals of
3 cm, and a 1 cm layer was homogenized
to determine the chemistry. Since the
alternating layers were as thin as one milli-
meter, it must be emphasized that our
chemical analyses only reflect general

12

trends of calcium carbonate (coccoliths)
and organic matter deposition, rather than
a precise value at any given time because
the layers are so thin that it is difficult to
sample a single one without contamina-
tion.

On land, coal and peat deposits are well
known but the presence of such high
amounts of organic material in sediments
of marine origin is unique. Therefore,
emphasis was placed on an electron micro-
scopic examination of those layers extend-
ing from 20 to 70 cm below the surface
of the sea floor. Samples were treated in
various ways. Some were examined di-
rectly while others were stained with a
solution of a heavy metal to add contrast
to the specimen. In certain instances, as in
the case of some of the coccoliths, the high
concentration of metals in the sediments
resulted in a natural staining of the organic
matrix responsible for the deposition of
the shell, thereby revealing the growth
pattern in the form of rings and bands
similar to those observed in trees. Still
other samples were stained with osmic
acid, embedded in an epoxy plastic, and
finally cut into an extremely thin section
with a diamond knife.

Membranes

Numerous structures resembling bio-
logical membranes were clearly visible in
all of these preparations. This was parti-
cularly interesting to us, since membranes
are not normally tound this deep in marine
sediments. Membranes play an important
role in nature; they house the enzymes
needed for energy production within a
cell — thus they may be considered as
the powerhouse, producing energy with-
out which plant and animal cells would
not survive. Therefore, any information
that we might gain on the structure and
formation of membranes in general will be
of significant value.

The most prominent structures found in
the sediments were membranes, usually
in the form of sheets, and casually dis-
tributed throughout the section. Occa-
sionally these sheets of membranes were
aggregated, but since other parts of an
organism were not present, it is impossible
to speculate on the type of lite from
which these membranes originated. Other

A coccolith showing natural staining due to
high concentration of metals in the bottom
sediment.

The chemical analyses of the core section
shown on page 1 1 reflect general trends of
deposition, as explained in the text.

[em]

13

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Tubu/ar membranes of various dimensions

types of membranes seen were of a unique
tubular and branching nature. Since mem-
branes of this type are quite rare in present
day forms of life, we were intrigued by
their abundance in 3,000 to 7,000 year
old sediments. Today, such membranes
are found only in energy producing parts
of the cells (called mitochondria) of higher
organisms and in some bacteria.

Several Explanations

Several explanations for the occurrence
of these membranes in the Black Sea
sediments come to mind. In the first place,
they may be remnants of some unde-
scribed single-celled organisms, which
have been preserved for several thousand
years in the sediments of the Black Sea.
The presence of large amounts of metals
in the pore water of the sediments,* as
well as the lack of dissolved oxygen, may
account for their excellent preservation.

A second possibility is that the tubular
membranes may have been derived from
other kinds of membranes. We do know
that changes in the structure of membranes
occur in cells when there are fluctuations
in the chemical content of body fluids.
During the time period under considera-
tion, such changes also did occur in the
Black Sea environment. During the period
between 3,000 and 7,000 years ago there
was a gradual but fluctuating change in
the Black Sea from fresh water to sea
water. The resulting salinity gradient in
the sediment promoted a natural separa-
tion of organic materials according to their

chemical make-up. This is the same kind
of separation process utilized by the
analytical chemist for the isolation and
identification of individual compounds in
a mixture of organic materials, and is
known as chromatography. This separa-
tion process stimulated structural changes
in the membranes present in the sediment.
Changes in the chemical environment also
resulted in the dissolution or breakdown
of existing organic material. This again
was followed by a natural separation and
concentration of organic fragments and
finally a reaggregation of these compo-
nents into a different structural form took
place.

A third possiblity is that these mem-
branes are of non-biological origin.
Namely, proteins and phospholipids, which
are the principal components of all mem-
branes, were formed on minerals such as
clays and carbonates. These minerals acted
as a kind of copying machine in much the
same way as nucleic acids are used in the
synthesis of biological proteins.

Fragments

In addition to the membranes, frag-
ments composed of structures resembling
certain bacterial cell walls, were found in
some of the sediment layers. Some of
these fragments were spherical sac-like
structures but most appeared tubular.
These structures were 1 to 2 microns wide
and 1 to 15 microns long with sharp
angular ends giving them the appearance
of crystals. At least four distinct arrange-
ments were recognized. Many of these

*See page 30
14

Bacterial cell walls or protein crystals?

fragments are partially intact bacterial
cell walls but the possibility must be con-
sidered that these fragments were formed
as a result of changes in the geological and
biological environment which led to the
breakdown and subsequent rebuilding of
organic molecules. The last idea finds its
strongest support in the wide range of sizes
of the individual organic crystals and their
occurrence in distinct layers within the
sediment section under study. The same
argument holds true also for the mem-
branes which are often concentrated in
layers.

Dormant Bacteria

Some bacteria have been cultured from
these sediments. However, it should be
noted that they existed in the sediments
in a passive or resting stage rather than in
an active stage. This is inferred from the
presence of aerobic bacteria (requiring
oxygen) in an anaerobic habitat (no free
oxygen). These bacteria were derived
from the oxygenated surface waters and
became sedimented like the carbonates
and clay minerals. This observation has
interesting implications since it suggests
that bacteria remain in a state of sus-
pended animation for prolonged periods
of time, perhaps thousands of years.

An interesting idea can be brought for-
ward that sediments, such as those in the
Black Sea, represent a gigantic cell where
processes similar to those in biological

cells are taking place. It is reasonable to
assume that in the early dawn of earth,
processes, sketchily described here, led to
the formation of life. In this sense, such
sediments are both the descendant as well
as the mother of life.*

Little Definitions

METER is equal to 100 centimeters

CENTIMETER is equal to 10 milli-
meters

MICRON is equal to one-thousandth
of a millimeter

ANGSTROM is equal to one ten-
millionth of a millimeter

ANOXIC-ANAEROBIC: refer to con-
ditions when no free oxygen is
present

HYDROCEN-SULFIDE: poisonous gas
-smells of rotten eggs

PORE WATER: water squeezed out of
sediment core

kHz: kiloHerz, formerly kilocycle, one
thousand cycles per second

*Structural Molecular Biology of Phosphates by
J. Matheja and E. T. Degens. Fischer Verlag,
Stuttgart, 1970.

15

In the harbor of Yalta, our R.V. 'Atlantis II' is overshadowed by a Soviet passenger ship.

16

Geophysical Studies In the Black Sea

By D. A. ROSS, E. UCHUPI, C. O. BOWIN and K. E. PRADA

ERTAIN places, because of the magic
of their names, have never ceased to feed
the imagination of men. One of these
places is the Black Sea, which received its
name from the Turks who feared its
stormy waters. Their epithet for the sea
was the word Karadeniz or Black. How-
ever, to the ancients who plied their trade
along its shores, the sea was known as
Pontus Euxinus or Hospitable Sea. The
Black Sea — connected to the Mediterran-
ean by the narrow Bosporus and Helles-
pont, named after Helle, the daughter of
Athamas who drowned there — has served
as the stage for many of the most dramatic
events in human history. From the
steppes that border the northern coast of
the Black Sea came the Achaeans, the
first Greeks who migrated into the pen-
insula that bears their name. To the Black
Sea came Jason and the mighty Argonauts
aboard the 'Argo' in search of the Golden
Fleece. Near the borders of the Black Sea
the city of Troy was destroyed over 1000
years before the birth of Christ. Who can
forget Homer's epic poem describing the
wrath of Achilles, the bravery of Patroclus,
the wisdom of Nestor, and the wilyness
of Odysseus?

Many other events have also played
their acts on the Black Sea stage; Xeno-
phon and ten thousand men marching
northward across the Persian Empire to
reach the shores of the Black Sea; the
foundation of Constantinople and its sack-
ing, first by the Crusaders and later by the
Ottoman Turks; the charge of the Light
Brigade near Sevastopol during the Crim-
ean War; the Gallipoli expedition during
World War I; and the heroic stands of the
Russians during World War II.

Over three thousand years after the
'Argo' sailed into the Black Sea in search
of the Golden Fleece, our vessel en-
tered the Black Sea. The cruise of the
'Atlantis II' may have not been as dra-
matic as the task imposed on Jason, but
much was learned about the natural
history of this nearly landlocked sea.

Russian scientists have long known that
the crustal structure of the Black Sea is
different from typical oceanic or contin-
ental areas. Under the ocean the earth's
crust is about 7-8 km thick, much of
which is basalt. Under the continents the
crust is about 30 km in thickness; of which

17

at least the upper material is granite. The
crust of the Black Sea is over 20 km thick
but apparently does not have seismic ve-
locities associated with granitic material.
Thus it is intermediate between oceanic
and continental crust and may represent
a transition type of crust. Some scientists
have suggested that the Black Sea is in the
process of becoming oceanic; other scien-
tists argue that it is becoming continental.
We hoped during the 'Atlantis IT cruise to
attempt to resolve this problem. In addi-
tion, we also wanted to learn something
about the shallow structure by using a
continuous seismic profiling system
(CSP).*

Gravity Measurements

Gravity measurements were also made
continuously during the expedition. Pre-
liminary analysis of the data shows some
low gravity zones near parts of the coasts
of Turkey and Russia. These zones par-
allel trends of deformed areas occurring
on land and may indicate that crustal
movement is beginning in these areas. If
these movements occur, the Black Sea
eventually may become a large, folded
mountain range. We should know more
about this possibility in a few million
years.

SLUMPED MATERIAL
W

o

1000

2000

0)

"CD

o.

UJ

Q

0

1000

2000

3000

A potpourri of geological structures is shown on a seismic record from the Continental
Slope off the Caucasus mountains. The sediments were folded and faulted with some
large blocks of material that had slumped down from some higher area. The slope also
was cut by numerous submarine canyons.

10 km

A record off the Turkish slope showed gentler folding and several large channels. The
submarine canyons and channels probably are related to rivers on the mainland and
may represent marine extensions of these rivers that were cut when sea level was lower.

*See: Oceanus, Vol. Vll, No. 1, September 1960.
"New Instrument & Methods."

o

0)
vt

18

Profiles from the deeper areas of the Black
Sea— the abyssal plain— generally showed a
much more subdued topography. In these
areas, sedimentary layers (more accurately,
layers which give an acoustical reflection)
can be traced over much of the basin.

Many CSP records showed structures that
suggest possible areas for oil traps. We
showed some of these records to our Russian
colleagues when we visited Novorosiysk and
Yalta.

Sediment samples collected during the
cruise allow us to distinguish the more
recent history of the Black Sea. Appar-
ently conditions found today have re-
mained rather constant for some time.
The deeper parts of the basin have been
structurally quiet, resulting in large, thick
layers of undisturbed sediment that can be

correlated over large areas (see pages 26
& 27) whereas along the continental slope
there has been faulting and folding. Cores
taken from this area generally show indi-
cations of material distributed by turbidity
currents and slumped material.

Up or Down?

The data collected during the cruise has
been almost completely analyzed. In the
near future this information, together with
the knowledge of the geology of the sur-
rounding regions will be used to recon-
struct the geologic history of the Black Sea
and hopefully answer certain questions
such as: Was the Black Sea in the past a
land mass that subsided to its present
depth? Or is the Black Sea an ocean basin
in the process of becoming a continent?

Has the size of the Black Sea fluctuated
with time? What was the effect of the last
ice ages on the sedimentary and hydro-
graphic conditions of the sea? The quest
of the scientists aboard the 'Atlantis IF
may not have been as intriguing or as
dangerous as the quest for the Golden
Fleece, but in the long run, it may be more
fruitful.

The burst of an air gun provides a loud
report which penetrates the sedimentary
layers. The acoustical reflections received
are shown in the other illustrations on this

page. P. Sachs, of our staff, who took this
remarkable photograph underwater was
asked: "Could you hear the bang?" and
replied: "What, what did you say?"

19

Bigger

Biggest

The same sample

of sediment

is shown enlarged

100 fimes, 1000 times

and 10,000 times,

indicating tnat the

white layers

consisted entirely of the

scales of an algae

Emi/iania hux/eyi (Lohmann)

20

S A. KLING

Coccolith Intrusion in the Black Sea

Since the Ice Age

V>«ORES from the deeper parts of the
Black Sea typically consist of very fine-
grained sediment. Many of these sediment
cores, particularly just below the sea bot-
tom, are distinctly layered; white layers
alternate with medium-gray layers. The
individual white layers are usually less
than 1 mm thick and are made up of
minute particles of calcite (the predomi-
nant mineral of limestone). These particles
were examined by light microscope, scan-
ning electron microscope, and transmis-
sion electron microscope to determine the
origin of the layers. Previous reports had
suggested that the layers were composed
of non-biological calcite or of formless
calcite particles produced by bacteria.

The microscopic examination revealed
that the white layers consisted principally
of calcite scales from the skeleton of a
species of tiny one-celled plant named
Emiliania huxleyi (Lohmann). This species,
a member of a group of free-floating
golden-brown algae called Coccolithophy-
ceae, is living today in the Black Sea and
throughout the oceans of the world. Dur-
ing periods of rapid growth and reproduc-
tion, near-surface water can contain up
to a million cells of E. huxleyi per liter; at
this concentration the sea water looks
milky.

The calcite scales produced by E. huxleyi
are small (2-3 micron) radially constructed
button-shaped skeletal parts that are gen-
erally called coccoliths. Each individual
organism produces many identical coc-
coliths, which upon the decomposition of
the organism sink to the sea floor and may
be preserved as a part of the sediment.
In the Black Sea, over a period of the last
several thousand years, E. huxleyi produced
so many coccoliths that at times they were
essentially the only kind of particle that
was deposited on the sea bottom. The
white layers in the Black Sea sediment
contain billions of coccoliths in each cubic
centimeter of material.

by D. BUKRY

Coccoliths, the skeletal remains of micro-
scopic marine algae, are a major compon-
ent of layered sediment in the deeper areas
of the Black Sea.

The alternating medium-gray layers of
sediment contain other material besides
the coccoliths of E. huxleyi. This additional
material has been transported into the
Black Sea by rivers such as the Danube,
Dnieper, and Dniester. Among these
transported particles, which were derived
by erosion from rocks that are at the
surface in areas drained by the rivers,
there are large numbers of old coccoliths.
These eroded and transported coccoliths
belong to species that became extinct from
40 to 70 million years ago, during the
Eocene and Late Cretaceous epochs. Be-
low the zone of white layers (about 3
meters below the sea floor) only old rede-
posited coccoliths occur in the gray
sediment.

Therefore, over the past few thousand
years the sediment deposited in the deep
Black Sea has provided a record of alter-
nating periods when either old transported
coccoliths from land erosion or new cocco-
liths produced in the sea contributed most
of the fine-grained calcite. Although the
most abundant species present, E. huxleyi,
first appeared in the oceans some 240,000
years ago, it was able to invade the Black
Sea only after the last of the great con-
tinental ice sheets had vanished. The sea
level raised by the melting of the ice,
brought the Black Sea by way of the
Bosporus and Dardanelles into communi-
cation with the Aegean and Mediterran-
ean Seas and thence the ocean.

Detailed study of the distribution of
coccolith species in the sediment of land-
locked seas can yield important evidence
about the geological history of such areas,
as coccoliths can be used as tracers for
marine conditions and for erosion of
surrounding land areas.

*Publication authorized by the Director, U.S.
Geological Survey

21

T/'ny plant remains were found of species
which became extinct millions of years ago.
This is Coccolithus bisectus, enlarged 2000
times, from core No. 1 443, found at a depth
of 748 cm in the core.

•f

The locations of the cores examined for coc-
coliths are shown, as well as the major rivers
flowing to the Black Sea, which brought
extinct species of coccoliths from eroded
rock into the sea.

Electronmicrographs by D. Bukry. The scale bar on the lower left of each picture

indicates one micron.

The esthetically pleasing coccolith, shown
on our front cover, appear here only as
tiny dots surrounding a pentagon shaped
Braarudosphaera bigelowi, magnified 2000
times.

The black sediment from the Black Sea,
obtained by a box corer is opened on deck
and examined by Dr. Hunt. The square corer
obtains an undisturbed core and was de-
signed by the Institut fur Meereskunde in Kiel.

• •

22

TRACE METALS

IN THE BLACK SEA

by
P. G. BREWER, D. W. SPENCER, and P. L. SACHS

of the ironies of life is that in order
to measure the few micrograms of many
trace metals found in sea water one must
first catch several kilograms of water.
Thus, in the cold March weather of the
Black Sea, we tugged, heaved, and cursed
at water samplers weighing some 40 kg
(80 Ibs.) each when full.

Our interest in the trace metals, such
as iron, copper, zinc, nickel, cobalt, and
lead, in sea water extends far beyond
merely determining how much is there. We
would like to know how the distribution
of these elements is affected by streams
and rivers, and whether phytoplankton
take up significant quantities of metals
and, when they die, transport the metals
to the deeps as solid particles. Also
whether chemical considerations, such as
the presence of hydrogen sulphide in a
stagnant basin can remove the metals from
seawater by the formation of insoluble
compounds. Apart from these considera-
tions, suspended particles influence the

scattering and absorption of underwater
sound and have an effect on the light
penetration and the color of the sea.

Fine Filters

In order to examine the movement of
these elements through the ocean, we filter
our samples through very fine filter papers
and analyze both the water and the col-
lected particles. When planning our work
for the Black Sea, we had noted previous
observations, and knew that the stagnant
deep water was separated from the oxygen-
rich upper layers by a marked salinity
change. We hoped that minute sinking
particles might accumulate in greater
quantities there. In this transition zone
marked chemical changes must occur, and
we arranged for detailed sampling across
the boundary. To avoid contamination of
the deep water samples by exposure to
atmospheric oxygen, we had to use ultra
clean laboratory conditions with a totally
enclosed pressure filtering system using
nitrogen gas.

23

Dark brown material filtered from the transition zone between the oxygenated surface
water and the anaerobic deep water was found to be due to manganese oxide. Dr.
Brewer (right) shows some filtered samples to Prof. G. G. Polikarpov, Deputy Director in
Science, Institute of Biology of the South Seas, Yalta, whose valuable work is well known
to the oceanographic community.

24

Trace Metals —

At each station our colleagues first
lowered an electrode which measured the
oxygen content of the water continuously.
From this information we arranged our
samples at various depths. One striking
observation made early in the cruise
showed that samples from the transition
zone contained a large quantity of dark
brown particulate material, obvious to the
naked eye as it collected on the membrane
filter. Samples a few meters above and
below this zone seemed very low in sus-
pended matter, much as we had hoped.
The material seemed coarse grained and
was probably formed from oxidation of
material dissolved in the deep water.

We showed samples of this material to
Russian scientists at Gelendzhik and to a
visiting party from Sevastopol, but it
seemed completely new to them. One
explanation for this may be that the thin
layer is difficult to sample.

Once back in Woods Hole, we began
to work on our samples. More than
130 water samples were analyzed by the
fairly new technique of atomic absorption
spectroscopy. The metals were chemically
concentrated and then sprayed into the
flame of the spectrometer. Discharge
lamps which have a cathode made of the
element of interest such as nickel, cobalt
or lead are shone through the flame.
Atoms of the sample formed in the flame
absorb some of the light and the change in
intensity of the beam is measured. A more
powerful technique was available for the
samples of suspended matter. These were
pressed into pellets, about the size of an
aspirin, in a stainless steel press and then
placed in a nuclear reactor. Under the
influence of neutron bombardment, radio-
active isotopes are formed and the radio-
activity of the samples is measured. From
this we can determine the elements pres-
ent. Previously, this involved a great deal
of labor, but modern detectors and elec-
tronics are such that we can determine up
to 14 elements at the same time in one
sample.

Manganese

The dark brown material that puzzled us
was found to be due to manganese, which
has accumulated in the deep waters of the
Black Sea to a level five hundred times
greater than that found in the normal

ocean. The manganese separates as an
oxide (much as iron becomes rusty on
exposure to air) forming the coarse ma-
terial that was filtered out. Our discovery
can now be seen to have wide significance.
Oceanographers have speculated for years
that uptake on the surfaces of iron and
manganese oxides scavenges many metals,
thus, controJling the level of trace metals in
the oceans; thereby in one theory provid-
ing an explanation for the marked loss of
these metals from the ocean over geologi-
cal time, and accounting for the enrich-
ment of such elements as cobalt, nickel,
and zinc in the manganese nodules which
are spread throughout the ocean basins of
the world. Chemists, too, have often used
coprecipitation (or scavenging) with man-
ganese oxides in the laboratory to strip
metals from solution. A naturally occur-
ring precipitate in mid water such as the
one we found gives us a unique chance to
test this theory.

Undissolved Metals

Data obtained for the other metals is
just as interesting. We know that anoxic
basins become stagnant because there is
little or no flushing of the deep water, thus
they tend to act as a trap for elements
such as manganese or iron. However, the
presence of hydrogen sulphide leads to a
chemical reaction in which many highly
insoluble metallic sulfides are formed. For
instance, chemistry text books tell us that
for every atom of zinc in a sulfide solution
there are 400,000,000,000,000,000,000,-
000 solid particles of zinc sulfide. In other
words it is highly unfavorable for the zinc
to remain dissolved. Thus we would expect
to find no dissolved zinc in the deep waters
of the Black Sea. Of course these vanish-
ingly small numbers do not apply in any
real sense to the conditions in the sea,
textbooks are not adequate to describe the
ocean, and may only be used as a starting
point. Our analyses show that small but
significant quantities of many metals are
present in the deep waters of the Black
Sea, and the problem is to explain just
how and what and to characterize the
equilibrium found in nature. Copper, zinc,
cobalt, and molybdenum are all markedly
depleted in the deeps and many months
of work will be needed before we can give
an account of this complex environment.

25

1450

1445

1462

1451

26

Three major events in the geological history
of the Black Sea can be traced across the
sea in the cores shown here. The numbers
alongside two cores indicate the events in

years before the present (BP) as determined
by carbon 14 measurements. The insert shows
the locations where the cores were collected.

Recent Sediments

of

the Black Sea

26

1474

1479

0
10
20
30
-40
50
60

70

80

90

-IOO

[cm]

by D. A. ROSS, E. T. DEGENS,
J. MaclLVANE, and R.M. HEDBERG

O

NE of the more unique aspects of the
Black Sea is that a shallow sill, about
50 meters deep, separates it from the
Mediterranean Sea. Thus, a small drop
in sea level could isolate the Black Sea
from the Mediterranean and the Atlantic
Ocean. We know that sea level did drop,
perhaps as much as 1 20 meters, in the last
20,000 years. In many areas of the world
this lowering caused the shoreline to
move seaward and exposed large parts of
the continental shelf. Places like the Red
Sea, which is also separated from the open
ocean by a shallow sill, started to dry up
and eventually became highly saline ba-
sins. The Black Sea, because many large
rivers like the Danube empty into it, had
a different response. Instead of drying up,
it became a fresh water lake; in fact, it
may have been one of the largest fresh
water lakes in recent times, covering an
area of over 410,000 square km. The
combined area of the five Great Lakes in
the U.S. is about 245,000 square km.

The Black Sea then gives a scientist the
opportunity to study a rapidly (geologi-
cally speaking) but well-documented
changing environment. Geologists have
studied these sea-level changes by examin-
ing cores of marine sediments, but in many
instances they are frustrated because
bottom-living organisms churn and mix
the sedimentary layers, often confusing or
obliterating the record. But in the Black
Sea this problem is absent since the bot-
tom waters have no oxygen. In such an
environment, life for benthic organisms
(except some bacteria) is impossible, and
thus the sedimentary record is undisturbed.

27

A further advantage offered by the Black
Sea is its relatively high sedimentation
rate of about 10 cm per 1000 years, which
can be compared with the average sedi-
mentation rate of about 1 cm per 1000
years for open-ocean environments. There-
fore, events that occurred within the last
10,000 years will be expressed within the
top 10 cm of normal deep-sea sediments,
whereas in the Black Sea the record will
be spread over a 100 cm interval. This
expanded record is, in most instances,
easier to interpret.

Our aim in studying the Black Sea sedi-
ments was to get representative coverage,
and in some localities try for very long
cores. We were successful in the first
objective, less so in the second.

Core 1474

After the collection of our samples at
sea, and the subsequent return of the
'Atlantis IF to Woods Hole with the
material, we started our studies. We had
collected over 600 feet of cores and
quickly realized that a detailed analysis
of all this material would take years. To
bring this to a more reasonable period of
time, we selected one core — 1474—- as a
reference and studied it in detail and sub-
sequently related all the other cores to it.
Core 1474 was selected because it was
collected in an area that we suspected to
have a relatively low sedimentation rate,

and thus would extend as far as possible
back in the geologic past.

Three Units

The core shows three distinct units. The
uppermost unit contains as much as 70
percent calcium carbonate and extends to
about 30 cm below the surface. This is
composed of finely divided layers, which
previously were thought to be of inorganic
origin. Electron photomicrographs of these
layers showed that the layers were com-
posed of the skeletons of a microscopic
planktonic organism called Coccolitho-
phorids.* This thin, finely-laminated se-
quence can be seen in most of the cores
that we collected and individual layers can
be correlated, in some instances, across
the entire basin, a distance of almost
1000 km.

The layers clearly indicate some sort
of periodic sedimentation. Russian scien-
tists have counted the individual layers
and find about 100 of these to a centi-
meter. If each layer is due to a yearly
event, the deposition of this carbonate
sequence should have taken about 3000
years. A carbon 14 age determination
from the base of this sequence indicates
that it is 2900 ± 140 years old. This age
supports the hypothesis that these layers
are due to a yearly event, perhaps a yearly
plankton bloom.

*See: Page 21

The ship's hack and the core
stations made on 'Atlantis II'
cruise 49 in April and May
1969. Core 1474 was studied
in detail.

RIMAMA

BULGARIA

28

The second sedimentological unit is an
organic-rich sequence about 40 cm thick
that underlies the Coccolithophorid zone.
The presence of large amounts of organic
material in marine sediments is surprising.
These sediments were examined using an
electron microscope and numerous struc-
tures resembling biological membranes
were observed* which are not usually
found so deep in marine deposits. They
may be remains of some previously un-
known microscopic organism that inhabi-
ted the Black Sea many thousands of years
ago.

The third unit is an alternating sequence
of light and dark sediment that contains
relatively lesser amounts of organic and
carbonate material. None of our cores
penetrated below this unit.

Fresh Water

Obviously the differences between the
three sequences relate to changes in the
environment. To understand this, a short
description of the recent geologic history
of the Black Sea is necessary. During the
interval from about 12-20,000 years ago,
the Black Sea was isolated from the Medi-
terranean due to the glacial lowering of
sea level. In the later part of this interval,
melting of the ice was intense, and fresh
water ran into the Black Sea, making it
a fresh water lake. Sea level continued
rising during this period until connection
with the Mediterranean was re-established
somewhere between 7 to 12,000 years ago.
At that time, salt water from the Mediter-
ranean started entering the Black Sea and
the salinity slowly started to increase. It
probably was not until about 3000 years
ago, when the carbonate material was
beginning to be deposited, that the salinity
conditions reached those we find in the
Black Sea today. Thus, the third, or low-
est sequence, was deposited during fresh
water conditions when periodic flooding
carried large amounts of material washed
from the land into the basin. The organic-
rich sequence, the second unit, was de-
posited as the flooding started to decrease,
and the Black Sea was going through a
transition from fresh water to its present
salinity. The uppermost unit started being
deposited when the Black Sea had reached
its present salinity conditions. These
changes in the environment were in most

*See: Page 13

50 60 70 Calcium carbonate [%]

1.0 1.2 1.4 organic Nitrogen [%]

20 24 28 organic Carbon [%]

i i i

200

Three distinct events, related to the rise and
fall of sea level, with changes from fresher
to saltier water, are indicated by the carbon-
ate unit on top of core 1474 K, followed by
the dark organic unit from 30 to 70 cm down,
and the alternating light and dark layers
below.

instances rather gradual, however, some
rapid events are suggested by the fine white
layers present in the organic-rich unit.
These thin layers are usually composed of
Coccoliths, suggesting that conditions fav-
orable for their growth prevailed at least
for a short time, prior to their period of
intense growth about 3000 years ago.

So far only the more general implica-
tions have been established, concerning the
relation of climatic and sea level changes.
It is clear that periodic events of shorter
duration, perhaps as short as yearly cycles,
have influenced deposition over the last
several thousand years. The ability to
correlate changes in the depositional en-
vironment of the Black Sea with this
precision presents possibilities for detailed
interpretations which are rare in marine
geology.

29

Fossil Water

by F. T. MANHEIM

M,

.OST of the cores of sediment taken
from the upper layers of the ocean bottom
are clayey in appearance and contain some
water. When squeezed out, such waters
can tell some useful tales to oceanogra-
phers. The fluids may retain some of the
original composition of waters buried in
the history of the sea and tell us how the
chemical composition of ocean water may
have differed in earlier times. The waters
— called pore waters — provide a sensitive
record of reactions between the sediment
and the water and may show the migration
of fluids. For instance, in pore water
studies made in drill cores off Florida, the
author found movements of fresh water
from the land by subterranean aquifers as
far as 120 kilometers from shore.

Pore waters also have long been known
as sources of nutrients. Recently, Dr.
P. Mangelsdorf and his associates at this
Institution reported that only 10 percent
excess of potassium in the sediment waters
could supply several times as much potas-
sium to the ocean as all the streams and
rivers in the world. Drainage from the
land had been considered as the principal
supplier of potassium which is one of the
major elements in the salt content of the
ocean. The excess potassium in the sedi-
ments may occur due to the breakdown
of mineral particles, such as volcanic ash.

Oil Clues

Hydrocarbons found in pore water may
provide oil-finding clues to petroleum
searchers and — on the negative side — may
be the medium by which poisonous pollu-
tants which were deposited in the sedi-
ments are released to the overlying waters.

Present Black Sea salinity normally
ranges from 17-18%0 (parts per thou-
sand) near the surface to between 22
and 23 %0 in the deepest waters. How-
ever, we know from the work of Rus-
sian scientists that the salinity of the
Black Sea was highly variable during the
Pleistocene Epoch, and was probably
unstable back to Cretaceous time (80 mil-
lion years ago). The relatively narrowness
of the channel (and earlier channels) con-
necting the Black Sea with the salty world
oceans is responsible for the variations hi
salinity. With rise and fall of the sea
surface in response to ice accumulations
on land, the channels have changed drasti-
cally in volume and at times have dried
up entirely. The ages of known fluctua-
tions in Black Sea levels probably require
revision and the estimated heights and
depths of the sea levels shown in the
profile are only approximate, but our
illustration gives a qualitative idea of the
relationships between the ages, water
levels, and salinities.

During the latest (Wisconsin or "New
Euxinic") ice age maximum the Black Sea
was entirely cut off. It probably received
less water from rainfall than it lost through
evaporation, but excess stream runoff,
especially that from melting glaciers led
to substantial freshening of the Black Sea.
Soviet scientists continue to dispute
whether the Black Sea was a completely
fresh lake, or retained brackish bottom
waters. Evidence from changing flora and
fauna in the sediments of the earlier Black
Sea proves that the rises and falls in sea
level must have caused drastic changes in
the salt content of the waters. Although
oxygenated waters now extend only 100-
200 meters below the sea surface, fossils
in cores suggests that oxygenated waters
existed deeper during earlier stages. We
do not know how much deeper, or indeed
whether the whole Black Sea became
oxygenated at intervals.

30

After World War II, S. W. Brujewicz
and his colleagues at the Institute of
Oceanology, U.S.S.R. Academy of Scien-
ces, made use of the then newly-developed
Kullenberg piston corer to obtain sediment
cores as long as 1 3 meters from the Black
Sea. The water pressed from the sediment
cores showed startling confirmation of the
hypotheses concerning fresher waters in
earlier Black Sea stages. Most of the data
showed consistently lower salinities in the
pressed out water (pore water) with depth
in the cores. The salinities dropped as
low as ll°/oo, far lower than any values
found today in the Black Sea. Yet even
these values were probably higher than
the original salt content of the pore water,
since salt must have continually diffused
downward from the more concentrated
solutions above, and smoothed out more
abrupt variations in original salinity.

Pressed Water

Using squeezing apparatus on board
ship we set out to confirm the data of the
Soviet workers, to extend them if possible,
learn of possible patterns of fluid migration
or consolidation in the sediments, and
study interactions between the fluids and
the enclosing sediments. The sediments
were pressed in a stainless steel squeezer
similar to those used by the Soviet geo-
chemists (sediments are sealed in by
rubber gaskets and clean pore water is
forced out through ordinary laboratory

filter paper). A new, rapid, and tempera-
ture-compensated hand refractometer per-
mitted immediate determination of salinity
on only a drop of fluid, with an accuracy
of about 0.2°/oo in less than one minute.
Other samples were fused in polyethylene
pipe or in glass ampules with the help of
a propane torch and were saved for later
detailed analysis in the laboratory. Still
other samples were analyzed immediately
for alkalinity or given to the chemists on
board (headed by K. Grasshoff). The
latter group added the samples to the
"AutoAnalyzer program," and analyzed
simultaneously for phosphate, nitrate, am-
monia, nitrite, and silicate.

The work done on board soon con-
firmed the Russian findings of decrease
in salinity with depth. In fact, new record
low salinities of 6°/°° were obtained in
station 1442P, east of Sevastopol off the
Crimean coast. However, near the Bos-
porus a reversal or increase in salinity with
depth in the sediment core was obtained.

The data also revealed the activity of
microbes in oxydizing organic matter by
using dissolved sulfate from the pore water
as their source of oxygen, even though the
water itself contains no oxygen.* At the
same time nutrient salts such as ammonia
and phosphate are released by this activity.

*See: "Nitrosocystis oceanus," by S. W. Watson
and C. C. Remsen. Oceanus, Vol. XIII,
No. 4, Oct. 1967.

POSTGLACIAL

OLD BLACK SEA

75-25

The changes in sea/eve/ dur-
ing alternating cold and
warm periods in the last
600,000 years. The dates of
the periods have been revised,
but the diagram shows a
reasonable picture of sea
level and salinity conditions.

RECENT

600 500 400 300 200 100

TIME (THOUSAND YEARS BEFORE PRESENT)

31

The relative consistency of the salinities
in the pressed out core water over surpris-
ingly large areas encouraged me to plot
all available data, Soviet and ours, to see
whether one could map salinities at given
depths in the sediments from the sea
bottom.

The conclusions from the map of inter-
stitial chlorinity** at depth of 2 meter in
the sediment are:

Pore fluids become less salty with
depth over nearly the entire Black Sea,
probably because of the influence of
fresher waters incorporated in the sedi-
ments during the glacial periods. The only
exception to this occurs on approaching
the Bosporus, where salinities decrease less
and less with depth, and finally begin to
increase with depth. This remains to be
explained. Several areas near major pres-
ent and past river systems become fresher

**Chlorinity is related to salinity by a factor
of about 1.6.

than average with depth; both here and
in the vicinity of the Bosporus we cannot
exclude the possibility that waters are now
moving or have moved toward the Black
Sea via underground pathways. The very
sharp decrease in salt content with depth
at station 1442 suggests that there may be
submarine discharge of fresh water from
extensions of land aquifers now, or that
there may have been such discharge in the
recent past. It is significant that we en-
countered no reversals in salinity within a
core sequence. This may suggest that we
have not penetrated any "warming" inter-
glacial period earlier than the present with
its presumably higher salinities. We can
also conclude that the Black Sea formerly
had bottom water salinity at least as low
as 10°/oo (compared with more than
20% o today).

Analysis of deuterium and oxygen iso-
topes now being done on the pressed out
waters by W. Deuser of this Institution
should tell us more about where the an-
cient Black Sea waters came from.

The "fossil" chlorinity of the Black Sea sedi-
ments at a depth of two meters below the
seabottom, as found by squeezing water

from the sediments. The contours are in parts
per thousand (°/oo). The arrows indicate
possible underground fresh water sources.

46°

44°

42° -

4O°

ISTANBUL;.

SEA OF
MARMARA

32

The fossil record of a short-lived plankton bloom— consisting
of odd shaped particles of aragonite (a variety of calcium
carbonate) was found in the sediments. Particle size
10-40 microns.

is

Stable -Isotope Geochemistry

by W. G. DEUSER

OTABLE-ISOTOPE geochemistry, the
science of variations in the natural abun-
dances of stable isotopes, (species of an
element which differ by weight) is barely
more than a quarter century old. In those
few years it has contributed immensely
to our understanding of many processes
in general geology, biology, and oceanog-
raphy. As an example, it has given us a
rather precise idea of past climates over
large parts of the earth as well as of the
salinities of inland seas in the remote past.
The basic principle of isotope geochem-
istry is the fact that many substances,
whether organic or inorganic, may contain
two or more stable isotopes of a particular
element in slightly varying proportions.
These proportions provide clues to the
source and history of the sample whether
mineral, vegetable, or animal. Especially
useful elements in this regard are carbon
and oxygen. In the case of carbon, for

example, the ratio of the heavy isotope to
the light isotope varies in nature by about
10 percent. On a mass spectrometer it is
easy to measure differences which are about
one thousandth of that range. This then
gives us a means of sub-dividing natural
carbon-containing substances into many
groups based on their isotope ratios. Theo-
retical as well as experimental data accu-
mulated over the years help us to
reconstruct the conditions under which the
substances were formed.

Uniformity

While in the Black Sea, we collected a
variety of samples including marine life,
water, and sediment. After our return to
Woods Hole we analyzed their stable-
isotope content to find out more about the
past history and present constitution of
that unique body of water.

33

Analyses of plankton samples collected
from the upper 100 meters of the water at
stations spread over most of the Black Sea
showed somewhat surprisingly that the
carbon in the plankton is quite uniform
throughout that sea. Earlier investigations
had shown that the carbon-isotope ratio
of the plankton is determined by the
photosynthetic process in the small algae
and that the ratio is very sensitive to the
rate of photosynthesis and to the chemical
and physical conditions of the environ-
ment. The isotopic uniformity of the
plankton, therefore, is a sensitive indicator
for the rapid mixing and homogenization
of the near-surface waters in the Black
Sea. That, of course, stands in stark con-
trast to the near absence of vertical mixing
which is responsible for the stagnant con-
ditions at depth.

Tremendous Bloom

We made one of our plankton tows
in a mass of water in which a tremen-
dous plankton bloom was taking place.
This is a sudden population explosion
of algal cells when the conditions in
the water are just right to stimulate rapid
cell division. Our tow through this bloom

yielded several thousand times as much
plankton as is normally obtained. In the
parcel of water supporting the bloom,
there was almost as much carbon bound
in the cells as there was in the water in a
form available for plant growth. This
beginning scarcity of available carbon was
reflected in the isotopic composition of the
cells and represented the first documented
instance of a beginning carbon shortage in
the marine environment. Most commonly
the other essential life-supporting ingre-
dients are depleted long before the supply
of carbon is affected.

Biological Use

Isotopic analyses of the carbon dis-
solved in the water itself led to some other
unusual discoveries. Quite in contrast to
the open ocean we found that the heavy
isotope of carbon became more and more
scarce with greater depth all over the
Black Sea basin. This tells us that a greater
and greater portion of the dissolved car-
bon has at one time gone through the
process of photosynthesis, that is to say
that in one form or another it was used
biologically. We call this type of carbon
"biogenic" (Greek for arising from life).
The reason for the increasing amounts of

These pentagon-shaped plates were found
among the coccoliths in Black Sea sediments.
They are Braarudosphaera bigelowi. In a

different view it is shown that many of
the box/ilce algae were deposited without
breaking up.

34

biogenic carbon at depth lies in the stag-
nancy of the deep waters. Many of the
organisms which live in the thin layer of
oxygenated water at the top will after
death fall to the bottom where further
decomposition of their remains is pro-
moted only by the bacteria which do not
depend on oxygen. Although this process
is slower and less complete than oxidation
which takes place in the open ocean, the
products of bacterial decay keep accumu-
lating in the deep waters of the Black Sea
and are not carried away in any efficient
manner. We can estimate that the deep
water contains the decomposition products
of organisms which rained down from the
top over the past 2000 years.

The isotope measurements on the water
also allowed us to calculate the extent to
which the hydrogen sulfide in the Black
Sea originated from the sulfate in the water
and how much was derived from decaying
organisms. We determined that between
3 and 5 percent of the hydrogen sulfide
comes from the organisms and that the
influx of dead organisms to the bottom
may have been steadily increasing over
the past 2000 years. Such an intensifying
rain of organic debris implies either a
growing productivity of the Black Sea
during that time or a progressive thinning
of the aerated top waters resulting in the
death of increasing numbers of organisms.

Many Cycles

Isotopic analyses of some of the ma-
terials in the sediment give us more direct
information on the conditions at the time
of deposition of the successive layers of
sediment. So far we have looked at the
carbon isotopes of the organic matter and
at both carbon and oxygen isotopes in
the fine white carbonate layers found in
the upper meter of the sediment. The
organic matter and the carbonates reflect
the climatic conditions at the time of their
formation. The ratios of the carbon and
oxygen isotopes in these substances are

especially sensitive to temperature and
salinity variation. By analyzing these
layers, covering the last 7000 years, we
detected about a dozen cycles varying in
duration from a century to nearly 1000
years.

Fossil Bloom

In the course of the work on the sedi-
ments, the isotopic analyses also led to
the discovery of a pronounced but short-
lived occurrence. Although our investiga-
tions are not yet complete, we believe that
we have found the fossil record of a
plankton bloom which probably lasted for
only part of one season. While analyzing
the isotopic content of a number of car-
bonate layers, all of which were thought
to be composed primarily of coccoliths,
we came across one sample which gave
different results from all the others. Earlier
work we had done on a variety of lime-
forming marine algae suggested that this
carbonate could not be coccoliths but was
formed by another type of algae. The
carbonate is not calcite as are the estheti-
cally pleasing coccoliths. Instead the
electron microscope and the X-ray diffrac-
tometer, an instrument which determines
the crystallographic makeup of a sub-
stance, revealed that the carbonate consists
of odd-shaped particles of aragonite. Thus
far we have not identified the specific type
of algae responsible for this unusual car-
bonate layer. It appears to be the only
such layer deposited during the last 7000
years. The layer is so thin that it probably
was deposited in less than one year. The
isotope analyses indicated that the carbon-
ate originated in warm water quite near
the surface and that it was formed by one
of a group of green algae. We plan to
investigate this phenomenon further and
hope to find out what may have lead to
this unique bloom some 6 or 7000 years
ago. It is an intriguing thought that what-
ever unusual circumstance was responsible
might also have left a record in the sedi-
ments of regions other than the Black Sea.

35

Bottom
Photograph:

by A. C. VINE

The most commonly encountered type of
bottom with a low contrast, mottled appear-
ance. It appears that a few centimeters of
the near surface mud has tended to collect
in somewhat random clumps. Typical clump
separation is 2 cm. It is too soon to specu-

late whether this is a result of gas evolving
from the bottom, from a coagulating type of
sedimentation, or from other causes.

Photograph from Station #1468, depth about
1900 meters.

HEN the 'Atlantis IT radio operator
A. T. Johnston first saw the nondescript
grey mud samples come up from the
depths of the Black Sea, he wondered
how successful our underwater photogra-
phy would be. Alex's remarks were well
taken since he had done much underwater
photography, including some of the early
photographs taken during the search for
the lost submarine Thresher' when he was
working with the Institution's geophysics
group.

How bottom photographs may provide
information has been described in the
excellent book "Deep-Sea Photography."*
The 'Atlantis II' cruise into the Black
Sea gave us a chance to photograph
an interesting marine environment where
little deep bottom photography seems to
have been done.

'"Deep-Sea Photography", Ed. J. B. Hersey,
The Johns Hopkins Oceanographic Studies:
Number 3, The Johns Hopkins Press, 1967.

Among the reasons to take bottom
photographs in the Black Sea area were:
to find evidence of geological activity, to
see if there were any remains of biological
or physical debris, and if anything unusual
might show up in an environment lacking
in oxygen. We also were interested to
find evidence of present or recent water
motion which might show up as bottom
ripples or drag marks. Finally, we would
broaden the geographic base of bottom
photographs in enclosed basins to gain a
better global perspective and to make such
views available to other oceanographers.

We could not find many bottom photo-
graphs previously made in the area. Dr.
R. Hurley of the University of Miami had
shown me some of the few deep photo-
graphs taken from the R.V. Tillsbury' in
the Black Sea during 1965. It seems likely
that Russian oceanographers who have
taken excellent bottom photos in the
Altantic and Pacific Oceans have taken
some photographs, but no published ones
are known to me.

36

from the
Black Sea

»

An example of occasional figurations on the
faoffom is shown in this photo taken at sta-
tion 1452 at a depth of about 2180 meters.
Because organic material is not exposed fo
predators or to oxidation on the way down
and on the bottom, dead marine life or tree
branches might retain a semblance of their

general shape for a long time. Resilient
wooden twigs were found in cores some
4 meters below the sea bottom and provided
an indication of the length of time that
objects may remain unchanged.
We do not know what the objects are in
this photo.

Equipment

The equipment consisted of a frame
holding two downward pointing Edgerton
cameras, one downward pointing elec-
tronic flash and a pinger to indicate the
height of the camera frame above the
bottom. All components of the camera
assembly were self contained, battery
operated, and pre-set.

Each camera contained 50 feet of
35 mm Tri X or Pan X film. The film
transport and the electronic strobe light
were synchronized. Rather than adjusting
both cameras for the same focal distance
and attempting to make stereo pairs, it was
decided to focus one camera for 3 meters
off the bottom and one for 5 meters off
the bottom to make sure that at least one
camera would be in focus. Most of the
films were developed aboard ship so that
the results could be checked and any
necessary changes could be made between
lowerings. Apart from some preventive
maintenance, the cameras performed well.

Although some change in technique might
have been advisable, it was decided to
leave well enough alone.

A typical problem was that, after being
assembled, the cameras were checked by
listening to the motors run through a few
test frames. Since camera lowerings usu-
ally followed coring with the big winch,
this acoustic check occurred during the
confused racket of the core recovery
operations. This caused an occasional
needless disassembly and rechecking of
the cameras. Perhaps it would be a good
idea to bring a stethoscope along!

Maintaining the camera frame from
about 3 to 5 meters off bottom to keep at
least one camera in focus while the ship
was drifting for about one hour, was an
essential and somewhat critical operation.
In principle it was a relatively easy stand-
ard technique. The 12 kHz pinger on the
camera frame sent out uniformly separ-
ated pings. The echosounder on the ship
received and recorded both the outgoing

37

and the bottom reflected signal. If these
two pings arrived with a time separation
of 5l/2 milliseconds or an indicated depth
difference of 4 meters, then the camera
frame was the correct distance above
the bottom. If the arrival time separation
became longer, cable was let out. If
arrival time separation became less, the
cable was hauled in. If the bottom was
irregular and the two arrival time traces
blended together, we hoped that the
camera would merely plow mud and not
catch on the bottom.

Controls

Two factors making bottom focusing
difficult was that the large trawl winch
was not too adaptable to precise control,
and that the clock rate in the pinger was
slightly different than the clock running
our new precision echosounder recorder.
New instruments are apt to acquire acro-
nyms and this one soon was named DCR,
for: "Digital Correlation Recorder." How-
ever, the recorder's versatility in being
able to make certain fine adjustments com-
pensated somewhat for other difficulties.

Seven camera lowerings were made in
the central and eastern portion of the
Black Sea. The locations were determined
when time was available to lower the
cameras and by the desire to photograph

in depths where any peculiarities of an
environment lacking oxygen might be most
conspicuous.

About 50 pictures were taken on each
camera on each of the seven lowerings.
About two thirds of the time during any
one run the camera seemed to be too
close or too far from the bottom. In many
of the remaining pictures it is -difficult to
tell whether the bottom is quite featureless
or whether it was a poor negative. How-
ever, each film strip had at least a few inter-
esting pictures. For rough purposes, it can
be assumed that these photographs were
taken about 4 meters above the bottom
and that the overall picture size represents
about a 2 x 3 meter segment of the bottom.
We plan to print all the negatives with a
special printer which brings out much
detail in bottom photographs, and hope
that with these better prints it will be
possible to give more satisfactory explana-
tions than has been possible so far.

Acknowledgments

As usual there was great cooperation
among the scientific party as well as by
the ship's force. Our primary underwater
photographer Mr. D. M. Owen was not
on board for this cruise but he assembled
the equipment, supplies, and spare parts
so well that both cameras worked on each
of the seven lowerings.

Dinoflagellates from Black Sea sediment

38

PALEONTOLOGIC STUDIES

OTUDIES of fossil organisms in sedi-
ment cores are important to date particular
layers and shed light on the conditions
of the environment when the sediments
were laid down, as well as to further
understanding of the organisms them-
selves. A variety of organisms such as
bivalve molluscs, snails, bryozoa, ben-
thonic foraminifera, sponges, worms, and
ostracoda are found in the shallow water
sediments of the Black Sea, and extensive
stratigraphic descriptions of Black Sea
sediments in the northern coastal zones
are available based on the presence of
bivalve molluscs.

However, a paleontologic attack en-
counters special problems in the deeper
parts of the Black Sea. In his pioneering
studies of samples recovered by the
Chernomorets Expedition of 1890, N. I.
Andrussov noted the virtual absence of
recognizable skeletons of carbonate organ-
isms in sediments below the deep oxygen-
free layers of the Black Sea. Only diatoms
and a few stray foraminifers, ostracodes,
sponge spicules and other minor forms
(probably transported from nearshore
areas) were found here, even though the
sediments contained much extremely fine
carbonate. The carbonate was believed by
John Murray, of the Challenger Expedi-
tion fame, to be inorganically precipitated,
after he examined specimens sent to him
by Andrussov. Subsequent Russian
workers have held several conflicting hy-
potheses concerning the origin of the
carbonates.

Bottom Dwellers

Since bottom dwelling organisms (ex-
cept bacteria) cannot live in the present
deeps of the Black Sea, attention turned
to microplanktonic hardpart - bearing
organisms which on death might settle on
the bottom and be preserved. Radiolaria
and planktonic foraminifera, so useful for
dating studies in cores taken from the
deep oceans, seem to be poorly developed
in the lower salinity water of the Black
Sea. However, silica-bearing diatoms and
spores and pollen appeared to promise
useful data on the sediments. We were
fortunate to have secured the cooperation
of a number of specialists who are cur-
rently studying both types of organisms.

by F. T. MANHEIM

Two new developments occurred in the
study of the earth's geological history. Dr.
D. Wall and Mr. B. Dale of this Institu-
tion discovered during studies of dino-
flagellate distribution in cores from the
Red Sea that these fossilized organisms
could be used to investigate the geological
history of the area. Preliminary examina-
tion of Black Sea cores shows them to be
rich in dinoflagellates. The organisms are
of particular interest because in addition
to the stratigraphic value their presence
or absence in sediment cores indicate
marine versus non-marine conditions of
sedimentation.

Breakthrough

The most exciting faunal breakthrough
occurred in an unanticipated area: cocco-
lithophorids. The plates, or coccoliths, of
these minute (2-20 microns) organisms
make up the bulk of chalks, such as in the
"White Cliffs of Dover" and are wide-
spread in the tropical oceans. However,
although living species had been reported
in shallow water regions of the Black Sea,
they were not reported in detailed micro-
scopic accounts such as those of Andrussov
and Murray, nor noted other than as a
curiosity in subsequent studies. Since the
earlier detailed studies were performed
before the availability of the electron
microscope, (coccoliths can be discerned
by microscope only under the highest
magnification), the cooperation of Dr. D.
Bukry, U.S. Geological Survey at La
Jolla and Drs. S. A. Kling and M. K.
Home of the Cities Service Oil Co., Tulsa,
was obtained to investigate possible cal-
careous organisms in the fine sediments.

Preliminary investigation by scanning
electron microscope of sediments from
several stations in the Black Sea revealed
that the "amorphous carbonates" were
virtually entirely composed of one species
of coccolithophorid, Emiliania huxleyi.

Through the use of the paleontologic
tools, we look forward to a host of new
insights about the organisms themselves,
the age of their enclosing sediment layers,
the temperature, salinity and productivity
of ancient Black Sea waters, the nature
of past land plants and climate in areas
surrounding the Black Sea, and perhaps
some surprises.

39

A Microbiologist's View

by H. W. JANNASCH

lO the marine biologist, the extreme
conditions of the Black Sea pose several
vexing problems that, if solved, promise
a wealth of information. The question,
which of those unique features is a cause
and which is a result of biological activi-
ties, is as fundamental as the chicken-or-
egg question.

The life of the commonly known marine
flora and fauna, phytoplankton, zooplank-
ton, and fishes, is restricted to the upper-
most surface layer separated from the
anoxic deep water by an oxygen/sulfide
interface. But those deep waters, more
than 4/5 of the Black Sea's volume, are
by no means lifeless.

In geological times, the microbial degra-
dation of plant and animal remains has
consumed all of the oxygen in the deep
waters making it uninhabitable for those
animals that need oxygen for breathing.
During the course of evolution, a special-
ized group of microscopic animals has
learned to use materials other than oxygen
for breathing, consequently, the larger part
of the Black Sea became the sole domain
for "anaerobic" bacteria.

The most plentiful of the materials that
can be used for anaerobic respiration in
seawater is sulfate. The left-over product
is the smelly hydrogen sulfide. Sulfide and
oxygen eliminate each other quickly, pro-
ducing the definite interface: oxygen and
aerobic life in the top layer; sulfide and
anaerobic life in the deep waters.

This interface acts like a bottom with
holes: some of the organic material origi-
nally produced by plants in the surface
waters are retained in the upper layer,
others are lost to the abyss. This sinking
of the heavier particulate material consti-
tutes the basis of life, the source of energy,
for the rich population of anaerobic micro-
organisms in the deep anoxic waters.

Active Centers

Taking samples throughout the water
column and culturing the various types of
bacteria in hundreds of tubes, we found
first of all two extensive centers of active
sulfide production: one directly below the
interface and another one just above and
in the surface layer of the sediments.

The ingenuity of microbes in finding
ways to live in adverse environments does
not stop with the respiration of sulfate.
We isolated bacteria from the upper layers
of the anoxic waters which used nitrate
for the same purpose. Furthermore, the
high content of methane gas dissolved in
the deeper Black Sea water indicated the
presence of another group of bacteria
which is capable of respiring carbonate.

In contrast to the sediments of oceans
that do not lack oxygen in their deeper
waters, the sediment of the Black Sea is
very rich in certain organic materials.
Some of them are most probably products
of fermentation, still another form of mic-
robial life without free oxygen.

Complete Cycle

The transformation of sulfur, that is so
important for the maintenance of life in
the anoxic water of the Black Sea, might
even turn into a complete cycle. This
happens directly in the intertace where
suinde comes into contact with oxygen-
containing surface water. Here we found
sizable populations of aerobic bacteria that
take the necessary energy for growth from
the oxidation ot sulfiae. They produce
sulfur that might settle down to the sedi-
ments in tiny particles, or it might be
further oxidized to sulfate. The presence
of these organisms has never been shown
before in large quantities.

A puzzle is, why these bacteria could
also be found m the deep anoxic waters. If
they are representatives of the known
sulnde-oxidizing type, they are not ex-
pected to survive tor long in this hostile
environment. But, isolated and studied in
pure cultures, they do not exactly fit that
well known type, and we may have found
a new metabolic form of marine bacteria.
It is not too uncommon in microbiology
that an unknown type of organism pre-
dicted by mere speculation, was later
found to exist. The extreme conditions
of the Black Sea present a particular
"environmental stress ' that may nave pro-
duced still more strange and highly inter-
esting forms of life.

One of the microbiologisf s views of the
Black Sea therefore, is not far from that
of the "exo-biologist" who is probing Mars
for new and unusual forms of life.

40

WHOI LIBRARY

Index Errata

1 HE Editor began to see volumes and numbers swim before his eyes during the
preparation of the index volume. Please note that on page 13 are shown the
Contents of Volume XIII and on page 14, the Contents of Volume XIV. Self-
sticking corrections were made in most cases; if this was not done and fastidious
readers do not wish to mar their copies with their own handwriting, such stickers
are available upon request.

About the authors

J_yR. J. M. HUNT is Chairman of our Chemistry Department. Drs. Manheim
and Bukry are with the U.S. Geological Survey, respectively at Woods Hole and at
La Jolla, Cal. The other authors are all staff members of the Woods Hole
Oceanographic Institution.

New Atlas

J. WO of our staff members have pre-
pared an atlas: "The Water Masses of the
North Atlantic, A Volumetric Census of
Temperature and Salinity", by W. R.
Wright and L. V. Worthington. Folio 19,
Serial Atlas of the Marine Environment.
The American Geophysical Society, 1970.
$10.00.

This makes the third atlas in this series
prepared at this Institution. The others:
Folio 2 by Elizabeth H. Schroeder and
Folio 7 by D. F. Bumpus and L. M.
Lauzier were discussed in Oceanus (see
Index). We understand that these folios
are considered "best sellers".

Associates of The Woods Hole Oceanographic Institution

President TOWNSEND HORNOR

Executive Assistant L. HOYT WATSON

IVlEMBERSHIP inquiries are invited. They should be addressed to Mr. L. Hoyt
Watson, Woods Hole Oceanographic Institution, Woods Hole, Mass. 02543.

Vol. XV, No. 4, July 1970

ON 'ATLANTIS II' CRUISE No. 49 TO THE BLACK SEA

by J. M. Hunt 4-10

FROM METER TO MILLIMETER TO MICRONS AND FINALLY
TO ANGSTROM UNITS

by E. J. Degens, S. W. Watson and C. C. fiemsen /// 11-15

GEOPHYSICAL STUDIES

by D. A. Ross, £. Uchupi, C. O. Bowin and K. E.Prada 17-19

COCCOLITH INTRUSION-
by D. Bukry

TRACE METALS

by P. G. Brewer, D. W. Spencer ond P. 1. Sachs
RECENT SEDIMENTS

by D. A. Ross, E. T. Degens, J. Mcllvaine
and R. M. Hedberg

FOSSIL WATER

by F. J. Manheim

STABLE ISOTOPE GEOCHEMISTRY
by W. G. Deuser

BOTTOM PHOTOGRAPHY

by A. C. Vine 36-38

A MICROBIOLOGIST'S VIEW
by H. W. Jonnoscri

Features

LITTLE DEFINITIONS

Published by the

WOODS HOLE

OCEANOGRAPHIC

INSTITUTION

WOODS HOLE,
MASSACHUSETTS

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