Otters are predators that feed on amphibians, and their populations can sometimes have a negative impact on amphibian populations. In areas where otters are present, they may consume a significant number of amphibians, which can lead to a decline in the amphibian population. For example, in one study, otters were found to consume over 50% of the adult amphibians in a pond. In addition, otters may also prey on amphibian eggs and larvae, which can further reduce the amphibian population.

However, it is important to note that otters are not always a threat to amphibian populations. In some cases, otters may actually help to maintain amphibian populations by controlling the populations of other predators, such as snakes and fish. In addition, otters can help to improve water quality by removing pollutants and excess nutrients, which can benefit amphibians.

Overall, the impact of otters on amphibian populations can vary depending on a number of factors, such as the abundance of otters, the abundance of amphibians, and the availability of other food sources for otters. In some cases, otters may pose a threat to amphibian populations, but in other cases, they may actually help to maintain them.