Final answer:
The Peruvian government attributed the decline in the trout population to overfishing and implemented strict regulations to curtail the issue and promote sustainable fishing practices.
Step-by-step explanation:
The Peruvian government interpreted the decline in the trout population during the 1960s as being caused by overfishing.
In response, they sought to implement strict regulations to prevent the species from being fished to extinction and to achieve sustainability.
This included regulating the access to fisheries, setting fishing limits, and possibly requiring permits and adherence to catch limits.
Through these measures, the government aimed to balance the immediate economic benefits of fishing with the long-term health of fish populations and the environment.