River Otter Recovery

 PGC Photo: Joe Kosack

River Otter Sightings

Your chances of seeing a river otter in the wild have always been slim to none due to their elusive behavior. Today, viewing opportunities are at their greatest in many parts of Pennsylvania.

Once widely distributed and relatively abundant, otter populations entered a period of very low numbers beginning in the mid-1800s. Habitat destruction, in the form of water pollution, caused the extirpation of river otters from most of Pennsylvania, and much of the entire country, more so than any other factor.

Toxic Streams

Toxic stream conditions were produced by drainage from tanneries, mines, oil wells, chemical works, factories and foundries. Deteriorating water quality quickly eliminated fish and other aquatic life from waterways nationwide, leading to a 75 percent decline in North American otter populations.

The last recorded otter in the Allegheny River was in 1899. The last in Pymatuning Swamp was in 1908. River otters were never completely extirpated from Pennsylvania, but their numbers were vastly reduced. The Pocono region always supported otters, especially the counties of Wayne, Pike and Monroe.

Improved Habitat and Reintroduction Efforts

As a result of dedicated efforts of concerned biologists and state wildlife agencies throughout the country, reintroduction efforts, improved habitat quality, legal protection and regulated harvest bolstered otter populations during the mid- to late 1900s.

Nationwide, 21 states implemented river otter restoration projects during 1976-1998, releasing 4,018 river otters. During 1982-2004, the Pennsylvania River Otter Reintroduction Project released 153 river otters in central and western Pennsylvania.

Otter restoration efforts in Pennsylvania and similar efforts in neighboring states resulted in significant range expansion. Pennsylvania’s otter population has been protected and growing for more than 30 years since otter restoration was initiated. Restoration efforts, range expansion of native population, and influx from Ohio, New York and Maryland restoration efforts led to successful population recovery.

Increasing Otter Population

All data suggest that otter populations are currently increasing in density and expanding geographically throughout Pennsylvania. Otter populations occupy all major river systems.

The Delaware, Susquehanna, Allegheny and Youghiogheny Rivers support sustained otter populations and act as travel corridors from which new populations disperse and expand geographically. The Potomac and Lake Erie watersheds maintain less dense populations, and continue to increase in otter numbers annually.

In all states surrounding Pennsylvania, river otters are harvested annually. As Pennsylvania otter populations increased and expanded, monitoring efforts have determined that a highly-regulated harvest is feasible. Careful planning and sound harvest management will safeguard Pennsylvania’s healthy otter population for future generations to enjoy.