Invasion Dynamics of Red Shiner in Southeastern Rivers

Objective:

Identify landscape, genetic, and behavioral components of red shiner colonization and dispersal. Model vulnerability of river systems to invasion by red shiner.

Approach:

Combine field study with historical fish collection and landscape data to develop vulnerability model for stream colonization.

Characterize genetic components of an expanding "hybrid swarm" in an invaded river.

Conduct experimental tank studies to identify behavioral and genetic components of hybridization.

Why This Research Is Needed:

Biological invasions are one of the foremost threats to the integrity of aquatic ecosystems in the U.S., but little is known regarding the invasion dynamics of non-indigenous fishes in streams. Southeastern streams, renowned for their exceptional levels of fish endemism and diversity, harbor the largest number of non-indigenous species (NIS) in the U.S. The invasion of red shiner (Cyprinella lutrensis) exemplifies the threat NIS pose to Southeastern stream ecosystems. Red shiners are native to naturally flashy, midwest Prairie streams and have recently invaded many southeastern rivers, primarily through bait bucket introductions. Red shiners excel in the degraded habitats of urban and agricultural streams and readily hybridize with congenerics (21 species in Southeastern rivers). Hybridization commonly leads to extirpation of congenerics, so red shiners pose a serious threat to the diversity and integrity of these systems. The rate of dispersal and mechanisms for genetic "swamping" of congenerics are currently unknown.

Expected Outputs/Outcomes:

This research will identify key characteristics of ecosystems that make them susceptible to invasion by this nuisance species. Understanding these factors will allow us to (1) accurately assess regional vulnerability of streams to invasion and (2) develop science-based management plans to curb the spread of red shiners into biologically sensitive areas.

Partners: NERL Athens

Contact: David Walters (walters.davidm@epa.gov) and Mike Blum (blum.mike@epa.gov) (Cincinnati, OH)

Ecological Exposure Research Home

Invasion Dynamics of Red Shiner in Southeastern Rivers

Local Navigation