Potomac Shenandoah Fish Kills

Fish Kill Hotline: (800) 642-3074


Intersex and Fish Kill History in Potomac and Shenandoah Watersheds

State and federal environmental, natural resources, agriculture and health officials are analyzing smallmouth bass in the South Branch of the Potomac and Lost rivers in West Virginia's Eastern Panhandle, trying to understand the cause of intersex conditions and fish kills. Over the past three years, DEP and all other agencies have undertaken an extensive effort to assess the extent and cause, whether natural or anthropogenic, of intersex occurrence in South Branch smallmouth bass.

Intersex is a condition in which a fish may exhibit characteristics of both sexes. The condition is believed to be caused by a fish's exposure to manmade sources of hormones or synthetic compounds that mimic hormones. Histopathologic examinations of smallmouth bass testes collected from the South Branch Potomac, Potomac and Cacapon Rivers in 2004 found intersex condition in up to 80% of the male fish sampled.

All available resources will continue to be applied. The agencies involved are currently focusing on studies concerning:

  • Relationship of intersex and fish kills
  • Causative pollutants associated with the fish kills
  • Reproductive ability of male bass with intersex, via assessment of sperm motility

Below you will find documents and links to information about the fish kills that have occured in the Potomac and Shenandoah River Watersheds. There were two workshops held at Cacapon State Park that included representatives of many state and federal agencies.


General Information and Resources


Virginia-West Virginia Fish Kill Research Status Meeting Held at Cacapon State Park on January 30, 2008


Virginia-West Virginia Fish Kill Research Workshop held at Cacapon State Park September 22-24, 2006