DETERIORATION OF MARSH IN SAN FRANCISCO BAY 



Herbert L. Mason 



1190 Sterling Avenue 

 Berkeley, California 93306 



I was asked to discuss deteriora- 

 tion of ecosystems. This puzzles me be- 

 cause I have been rather critical of the 

 notion of the ecosystem all my life. 

 System belongs to mathematics and logic, 

 not to biology. You never will find a 

 pure example of the ecosystem because 

 nature is so variable. You will find a 

 pattern around which your data will 

 vary. However, the data is correlated 

 with the system; it is not the system. 



I have just been dealing with a 

 problem of the deterioration of an eco- 

 system, the delta system of the San 

 Joaquin and Sacramento rivers as they 

 flow into San Francisco Bay and join a 

 group of marshes. I discovered the dom- 

 inant effect of plundering one resource 

 and what happens to it. The primary 

 natural resource in the marsh is its 

 capacity to act as a living filter that 

 maintains the water quality of the sys- 

 tem. There were 777 to 1,036 km 2 (300 

 to 400 2 mi ) of delta marshes at the 

 mouths of the San Joaquin and Sacramento 

 Rivers. Someone discovered there was 

 land under those marshes that was worth 

 cultivating, so he drained the area and 

 got it out into the open. 



The first loss was the natural fil- 

 ter that maintained the water quality of 

 the San Francisco Bay. The second loss 

 was the fisheries of San Francisco Bay. 

 The loss of marshes included the salt 

 marshes of San Francisco Bay, and the 

 total destruction was between 95% and 

 97% of the marsh area. The area was 

 diked, the remaining water pumped off, 

 and the land left to dry out. So we 

 lost the filter system. I do not know 

 how you could evaluate that in terms of 

 dollars but it was an enormous thing. 

 Now there are no commercial fisheries in 

 San Francisco Bay. This change did not 

 occur instantly; the last fishery to go 

 was a tiny shrimp with a very nice fla- 

 vor. Oyster and shrimp fisheries, crabs, 

 and practically everything else disap- 

 oeared because the impurities that came 



into San Francisco Bay were no longer 

 going through a natural filter. 



The next loss was when the marsh 

 lands were exposed to the hot, dry 

 California air: the peat began to shrink 

 and it began to settle because of farm 

 equipment on it and the annual plowing 

 that broke up the soil. Plowing pulver- 

 ized the surface and it began to blow 

 away. A related problem was the tectonic 

 settling of land: the lowering of the 

 entire west coast 10.7 m (35 ft) in 

 10,000 yr. Land which was at tidal 

 level is now 6.4 m (21 ft) below sea 

 level. So the farmers lost the invest- 

 ment they had put in the land. When the 

 dikes broke, the farmer said, "I can not 

 afford to repair the dike because the 

 land is not worth it." He lost his land 

 and the State lost the land's agricul- 

 tural potential. The total loss involves 

 an enormous amount of money. 



Thus, man destroyed a whole series 

 of natural resource values that were 

 very important to us and resulted in the 

 deterioration of a gigantic ecosystem 

 which includes human beings. Not only 

 did drainage of the delta marshes affect 

 the San Francisco Bay, but the fisheries 

 along the coast of central California 

 also never recovered from that loss. I 

 suspect that if someone knew all the 

 facts, the losses would be traceable to 

 the decline in quality of water that 

 came into San Francisco Bay as a conse- 

 quence of losing the extensive marsh 

 system. 



Last week the Bureau of Water Qual- 

 ity control voted to allow the lowering 

 of the quality of water that is permit- 

 ted to enter Susson marsh because there 

 is not enough fresh water to supply the 

 needs of Los Angeles. Therefore, Susson 

 marsh will suffer. Susson marsh is 

 important to the ecosystem because it 

 has about 140 plant species whereas the 

 bay salt marshes have only 9 or 10 spe- 

 cies. No two plants of a given kind have 

 exactly the same range of tolerance for 



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