The other major industry for the first and second generation of Italian immigrants to California was fishing. It had been a search for fishing grounds that brought the first Italians to California, and California's many harbors and pleasant climate convinced a large number of fishermen to stay. There were a variety of reasons that Italians captured the San Francisco fishing industry, but this did not mean that the domination did not come without a fight. The Italians who came to fish the San Francisco Bay already had experience as fishermen and had boats that were ideally suited for the Bay. They were able to adapt to improvements in technology, whether it was switching from sailboats to motorized ones, or their use of the paranzella net, which proved to be too efficient. Also key in their capture of the fishing industry was the general prejudice in California against their principal rivals, the Chinese. Italians built fishing colonies in other harbors as well. The Genovese built large communities in Santa Barbara and Santa Cruz, while the Sicilians flourished in Monterey.
It was in the fishing industry that most of the conflicts between the more established Genoese and the Sicilian newcomers came to light. Indeed, conflict was a recurring theme in the history of fishing in San Francisco Bay, as the more established and successful fishermen banded together and bought tugboats, allowing them to catch larger amounts of fish further out at sea. The 1900s and 1910s were decades in which independent fishermen were forced to fight for their economic lives against the Fish Trust of the wealthier fishermen and merchants. Most famous of these was Achille Paladini, who owned a company that included five boats, tow trucks, and had seventy-five employees by 1915. Although admired as an innovator for among other things, being the first to can tuna on the Pacific coast, he was reviled as a monopolist. His underselling of competition in order to drive them out of business got him in hot water with the government multiple times. But Paladini's legal problems were small compared with what other Italian-Americans were about to face.