User:Cullen328/sandbox/SF bay shrimp

History of the San Francisco Bay shrimp fishery
Italian fishermen began catching shrimp in San Francisco Bay around 1869, followed by Chinese fishermen in 1871, using traditional bag nets imported from China. Soon, immigrant Chinese fishermen from Guangdong dominated shrimp fishing in Northern California. The Chinese also fished for shrimp in nearby Tomales Bay, but those fisheries were abandoned in the 1890s. Junks were built at several places along the West Coast of the United States by Chinese shipwrights using traditional techniques and local lumber.

By the end of the 19th century, dozens of traditional Chinese shrimp fishing junks built in California were operating on the bay. As many as nine to ten million pounds of shrimp were harvested from the bay annually before restrictions on the fishery were imposed.

Although a small quantity of shrimp were sold locally, most were boiled and dried, resulting in a shelf-stable product that was exported to China and Hawaii. Drying resulted in two products: one third by weight the higher-grade product, called dried shrimp meat, which was used for human consumption, and two thirds the lower-grade product, called shrimp meal, which was used for fish food and plant fertilizer.

Political opposition to the fishery began in 1885, based on the assumption that bycatch in the Chinese nets was killing large numbers of desirable young fish, especially salmon and striped bass. The opposition was exacerbated by the prevalent anti-Chinese sentiment in California in the late 19th century. Studies showed that the concerns were greatly exaggerated, and that the fishermen ate or gave away the edible fish. A 1932 report concluded that "the average striped bass is too spry to be taken in any such rig." Restrictive regulations were implemented, beginning in 1901 with an annual four-month closure of the fishery during the height of the season, a ban on the export of dried shrimp in 1905, followed by a ban on Chinese nets in 1911, forcing a switch to beam trawl nets, which required motorized boats. Arrests of Chinese fishing crews were common in the first decade of the 20th century. The ban on exports was lifted in 1919, leading to a tripling in production in the 1920s.

California state fishery records show that in 1930, the catch was 2,687,831 pounds of shrimp from the bay, 35 boats were operating, and 72 men were employed. There were 12 shrimp fishing camps at Hunter's Point in San Francisco, and two in Marin County, including China Camp. Only a handful of traditional sail powered junks remained in service, and most of the boats were converted motorized junks or Western style fishing boats.

The fishery went into a steep decline in 1936, due to a collapse in the export market due to the ongoing effects of the Great Depression and the intensification of war and revolution in China.

After World War II, the fishery was limited to a much lower volume catch for local sale as fishing bait. Third generation Chinese-American shrimp fisherman Frank Quan has continued small volume shrimp fishing into the 21st century, and still lives at China Camp. He had his 90th birthday in 2015.

Environmental stresses
When exposed to sewage in a laboratory, the species shows behavior described as "avoidance of the toxicant". It is "sensitive to pollution in estuaries".

In the late 19th and early 20th century, San Francisco Bay became increasingly polluted. The Gold Rush, which proceeded commercial shrimp fishing, caused the first significant environmental damage to San Francisco Bay. Hydraulic mining techniques introduced tens of millions of cubic meters annually of rock and soil debris into the Sacramento and San Joaquin rivers, the main sources of fresh water input into the bay. The accumulation of sediment on the bottom of the bay reduced total water volume and changed tidal patterns. Hydraulic mining was banned by an 1884 court decision. The size of the bay shrank as dikes were built to create farmland and salt ponds, and areas of the bay were filled to create real estate, such as San Francisco's Marina District, Treasure Island and Foster City. The vast majority of the tidal marshes around the bay, where the shrimp thrive, were lost to development by the 1980s.

The Central Valley Project, which began in 1933, and the California State Water Project, which began in 1960, were efforts using dams, reservoirs and canals, to divert water from the Sacramento and San Joaquin river systems for use in agricultural irrigation and urban development. By the 1980s, the annual inflow of fresh water into the bay was reduced to about 40% of historic levels.

Following prolonged droughts, the shrimp population declines, and following wet years, it rebounds. In 1996, after two wet years, the shrimp population was 20 times larger than it was in 1980, following the severe drought of the late 1970s.