Biology Reference
In-Depth Information
vest its by-products and access its raw materials. Down in the South Bay,
the Leslie Salt Company brought together a dozen small operations to cre-
ate a 40-square-mile ring of salt ponds between Redwood City and Fre-
mont. This important bay industry, which had converted about 40 percent
of the bay's tidal marsh to salt production by the 1930s, took bay water
through nine stages of ever increasing salt concentration, from evapora-
tion to crystallization, then harvest. The entire process took a little over a
year, and it evaporated more than 90 percent of the bay water—producing
one pound of crude salt at the pond bottom for every five gallons of bay
water.
According to Gilliam, nowhere else on earth did the elements com-
bine in such perfect proportions to make salt as in San Francisco Bay,
with its long rainless season, warm sun, moving air to evaporate water
rapidly, and acres of sea-level marshland sealed by hard clay, creating a
watertight floor. “Unlike most places where man extracts wealth from
nature, here he has made little change in the ancient landscape. He has
put his levees around it and his power lines across it, but he has not
tamed it. A sense of the primeval remains, owing perhaps to the fact that
man's job here is not to conquer nature but to facilitate its work,” writes
Gilliam.
The proportions were just as harmonious for another type of industry
in the South Bay: the manufacture of cement. In the 1920s, dredgers with
snouts inhaled a mix of mud, water, and old oyster shells from the bay
A South Bay salt pond at Eden Landing. (Jude Stalker)
