Headwaters to Confluence: Matching the River Continuum Concept with Mesohabitats and Fish Communities

The River Continuum Concept (RCC) is a widely accepted concept that provides the framework for insight and a better understanding of ecology in lotic systems.  Although a very useful concept, limitations do exist.  The focus of this study was to investigate the relationship between fish assemblage characteristics and their reaction to habitat changes. Our objectives were to evaluate how fish communities and mesohabitats change through a lotic system and whether a fish community changes within a mesohabitat over an entire lotic system.  Site location was the relatively undisturbed Niobrara River, NE which extends approximately 900km from headwaters to mouth and drains a 3413km².  Sampling was conducted from 2010 to 2011 from June to September.  A total of 14 different habitat types were recognized throughout the entire river system.  A total of 51 different fish species were sampled using electroshocking sampling techniques.  Comparisons will be made between and within mesohabitats and fish communities from headwaters to the mouth.  Results from this study will help clarify how the RCC applies to a relatively undisturbed large river system and fish communities within that system.