A government-commissioned study has concluded that escapes from fish farms in Scotland pose a “major threat” to the nation’s wild fish population. According to Friends of the Earth, about 1 million salmon have escaped from Scottish fish farms in the last five years. If just 1 percent of the farmed population escapes each year, the government report says, wild stocks will suffer severe losses in genetic variability and be overwhelmed. The study also looked at other environmental effects of fish farms, such as the impact on the ocean and marine life of nutrients and chemicals used on the farms. But industry defenders called the findings “inconclusive” and said the risks associated with salmon farming are insignificant compared to the employment gains, export increases, and dietary improvements that it provides. The report comes two weeks after an international aquaculture conference held in Edinburgh sounded similar warnings about fish farms.