River otters are fish eaters, and fish populations are at risk from climate change  due to effects of sea-level rise. If fish populations start to decrease in number or begin moving elsewhere due to climate change, river otters would lose their major food source.
River otters are also threatened by habitat destruction . Historically, they were hunted for their pelts. Today, there is no major threat from commercial harvesting, but local populations can be affected by illegal hunting. The otter’s aquatic habitats are being influenced by human contact. Water is depleted, water quality is lowered, timber and other cover is being cleared, vegetation is becoming scarce and more. Most of the problems are caused by water pollution.
Reasons for Hope
River otters once thrived throughout much of the United States. Trapping caused the decline or extinction of many state populations. Fortunately, 21 states have actively worked to restore or reintroduce otters and they are doing well in most of these areas.