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Introduction How Rivers Run Stories Value Of A River What We Can Do
Connections of a River - Connectivity
Longitudinal: River Continuum Concept (pg 4 of 9)

As the river grows (seventh through tenth order), energy inputs and organism functions continue to change. Terrestrial organic matter such as leaf fall is insignificant in comparison to the volume of water in a wide river. Increasing turbidity prevents sunlight from reaching the streambed, so there are few rooted aquatic plants in the main channel. In backwaters of floodplain rivers where turbidity has settled, aquatic plants may be abundant.

Energy is supplied by dissolved and ultrafine organic material drifting from upstream reaches. Drifting phytoplankton and zooplankton contribute to the food base. Energy is also provided during flood pulses that bring organic matter from the floodplain into the main channel.

Fish species commonly found in higher order rivers are omnivores and plankton feeders. Examples include carp, buffalo, suckers, and paddlefish. Catfish rely on their olfactory sense to find food in turbid water; sight feeders such as smallmouth bass may not do as well. Stream gradient is usually very low. Disruptions such as riffles and rapids are rare. Riffle-spawning fishes such as walleye migrate up tributaries to find suitable spawning habitat.


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Flow
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Longitudinal
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