Admittedly, the last entry is a catch-all, but only because it's impossible to know, at this early stage, which populations will be affected by the threat. In early 2017, President Donald Trump ordered the Environmental Protection Agency to review the Clean Water Rule, as well as the Stream Protection Rule, with the intent of revising or scrapping the measure, which would roll back protections for certain streams and wetlands. Before the rule had taken effect, it was expanded to encompass river headwaters, and conservationists fear losing it would pose a grave threat to trout species living in both headwaters and in the larger waters they feed. In 2015, under the Obama Administration, the EPA released a report stressing the relationship between large rivers and the smaller streams the Clean Water Rule would protect, such as headwaters and seasonal streams. According to Trout Unlimited, these waters account for nearly 60 percent of America's streams. Thus, because of the relationship between big and small streams, trout could be at risk without the protections of the Clean Water Rule. Immediately following the executive order to review, and likely scale back, the Clean Water Rule, a group of sportsmen and conservationists released a statement condemning the decision.