nermost shelf. The American ship, 
R/V Oceanographer (from NOAA, 
Seattle), was to be responsible for de- 
ploying several arrays of current me- 
ters on the shelf, for taking hydro- 
graphic measurements of waters on 
the middle and outer shelf (at times 
coordinated with the observations 
made by the Chinese ships), and for 
carrying out most of the geophysical 
and geomorphic studies. 
This was to be the first cooperative 
oceanographic field program between 
scientists of two countries that had 
been antagonists for the preceding 
thirty years, and as might be expected, 
many areas of potential conflict had 
to be straightened out prior to the 
departure of the ships from Shanghai. 
Some points of contention (such as 
who would ultimately retain the origi- 
nal data) were not agreed on until 
a few hours before the ships sailed. 
Moreover, the exchange of equipment 
and personnel between ships presented 
countless problems. For instance, con- 
sider the difficulties of trying to op- 
erate U.S. instruments on Chinese 
ships wired for different electrical 
power and equipped with different 
ocean winches. Nevertheless, our 
agreement on the ultimate objectives 
of the project made us optimistic 
about the forthcoming cruise. 
The three ships sailed from Shang- 
hai on June 9, 1980, marking the be- 
ginning of what was the first inter- 
national cooperative study of the 
Chang Jiang River and its adjacent 
waters. Sailing out the Chang Jiang 
from Shanghai is an intriguing expe- 
rience for scientists and nonscientists 
alike. As we approached the mouth 
of the river, the tan waters turned 
brown near the ever present shoals. 
Where ship propellers stirred the bot- 
tom, the water became dark brown, 
creating a patchwork of tan, brown, 
and chocolate. Across this mosaic 
sailed a wide variety of craft — modern 
cargo ships, junks, fishing boats, and 
even the occasional passenger liner — 
most of them go short distances to 
and from Shanghai, but some go as 
far upriver as Chungking, more than 
a thousand miles from the coast. 
During high river runoff in the sum- 
mer, the tan-colored freshwater plume 
can extend many miles offshore. 
About thirty-five miles from the coast, 
however, the bottom deepens, the wa- 
ter becomes more saline, and the sus- 
pended sediment settles from the sur- 
face. The increased clarity of the wa- 
ter stimulates the growth of plankton 
in the nutrient-rich, river-derived wa- 
ter, turning the offshore water green. 
This proliferation of plankton ulti- 
mately results in a high production 
of fishes, which, in turn, attract hordes 
of fishing boats of all sizes, most of 
them from China, Japan, Taiwan, and 
Korea. (When towing scientific instru- 
ments from an oceanographic ship, 
one must always keep a lookout for 
small fishing boats that might dart 
across the wake and cut the towing 
cables.) 
The Shu Guong # 6 carried eighteen 
Chinese scientists and technicians and 
five American, and its work was re- 
stricted to the river and estuarine wa- 
ters. Among other tasks, this ship was 
assigned to anchor at a series of speci- 
fied stations for 27-hour periods, so 
that variations in temperature, salin- 
ity, currents, and dissolved and sus- 
pended loads could be monitored. As 
the tide rises and falls, the discharge 
of river water decelerates and accel- 
erates correspondingly. Maximum 
currents are associated with ebb tide 
and minimum currents with flood tide. 
During the maximum outflow, we 
found suspended sediment present in 
amounts that periodically exceeded 
four grams per liter — concentrations 
100 to 5,000 times higher than those 
recorded in offshore waters. Perhaps 
even more interesting was the obser- 
vation that most of the water and sedi- 
ment from the river hugs the southern 
coast as it leaves the river mouth, 
apparently little of it escaping directly 
offshore or to the north. 
The team on the Xiang Yang Hong 
#9 included thirty-five Chinese and 
seven Americans. Despite the consid- 
erable problems the Americans en- 
countered in working with Chinese 
equipment, this group was able to ob- 
tain numerous geologic and biological 
samples from the bottom. In nearshore 
areas, the fine-grained bottom sedi- 
ment was highly laminated, suggestive 
of rapid accumulation. Interestingly, 
farther offshore the sediment was 
coarser, but also laminated. D. C. 
Rhoads of Yale University feels that 
these sands are periodically resus- 
pended by currents. This would pre- 
vent colonization by benthic organ- 
isms, thereby giving the sediment its 
laminated character. 
The team on the Oceanographer 
also included more Chinese (thirteen) 
than Americans (five) and its work 
was concentrated in mid-shelf areas. 
Profiles of the water column, using 
conductivity, temperature, and depth 
probes, showed the offshore waters to 
be a two-layered system, with warmer, 
less saline waters overlying colder, 
more saline waters. The density gra- 
dient between the two is remarkably 
sharp. Suspended particles above the 
gradient are composed primarily of 
biologically produced material, while 
the bottom waters mostly contain sedi- 
ment from the river, suggesting that 
the two layers are almost decoupled 
from one another. Occasionally, plank- 
ton concentrate at the density discon- 
tinuity — a phenomenon that has often 
been observed elsewhere. 
Mapping the sea floor revealed that 
much of the bottom of the East China 
Sea consists of well-rippled sand, al- 
though some areas were unrippled or 
included only scattered outcrops. Sub- 
surface seismic profiles crossed a num- 
ber of areas in which filled channels — 
possibly those of the Chang Jiang — 
could be detected. The depth of the 
channel indicates that it was probably 
riverine until about ten thousand years 
ago, after which it became filled with 
about eighty-five feet of sediment. 
Further profiling in the area should 
delineate the extent of this buried 
channel. 
Only a few months have passed 
since the U.S. scientists returned 
home and an even shorter time has 
elapsed since all of our samples ar- 
rived. Clearly, it is too early to draw 
any far-reaching conclusions about the 
significance of our observations from 
this one cruise and there is no question 
that further cruises are needed. One 
is already planned for the summer 
of 1981, during flood season, and one 
for the late autumn of 1981, when 
runoff should be far lower. Observa- 
tions made during the initial 1980 
cruise will help define areas of special 
interest that should be studied further. 
It is already apparent that the region 
of the East China Sea immediately 
south of the Chang Jiang, where most 
of the river water appears to escape, 
warrants such attention. Now that 
Chinese and U.S. scientists have 
worked successfully together once, fu- 
ture efforts should go more smoothly. 
It is perhaps fitting to note than even 
with the problems of logistics and 
equipment and a variety of bureau- 
cratic snags, all the U.S. scientists 
are eager to continue the studies next 
year. Considering that for most of us 
our first introduction to China and 
its oceanography took place less than 
a year ago, we have moved very far 
very quickly. □ 
74 
