Detailed Instructions: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Q: From the start of the 20th century through the 1970s, the American tuna fishing fleet and tuna canning industry were based in San Diego, "the tuna capital of the world". San Diego's first tuna cannery was founded in 1911, and by the mid-1930s the canneries employed more than 1,000 people. A large fishing fleet supported the canneries, mostly staffed by immigrant fishermen from Japan, and later from the Portuguese Azores and Italy whose influence is still felt in neighborhoods like Little Italy and Point Loma. Due to rising costs and foreign competition, the last of the canneries closed in the early 1980s.
A:
What nickname was San Diego given by the tuna canning industry in the 1970s?