India, Oct. 30 -- Imagine a plan to help a community that ends up hurting its own lake. That is part of the story of Lake Titicaca. According to Smithsonian magazine, the United States shipped about 500,000 trout eggs to the lake in the 1930s. Its purpose was to increase fishing. The trout flourished, and the report says they are now one of the most invasive species in southern Peru.

Lake Titicaca is situated on the border between Peru and Bolivia. It is the largest lake in South America by volume. It is also the world's highest navigable lake for large vessels. For the Inca, it was the birthplace of humankind. Many people who live on its shores still rely on it for their livelihoods, so it's easy to see why officials once viewed it as a...