Rivers

Rivers come in many sizes and provide habitat for many fish species.  Different stretches of the same river can have contrasting personalities and different fish species assemblages.  For example, a young, clear, coldwater river plunges downhill, flowing over and cutting through solid rock.  Here, trout thrive but certainly not largemouth bass.  As a river matures, it becomes increasingly fertile, flows more slowly, and begins to meander.  A coolwater, moderate-flow environment favors walleyes and smallmouth bass.  Finally, a river winds through a floodplain as it approaches the coast or its confluence with a larger river.  This slow-flowing, warmwater environment supports excellent largemouth and smallmouthbass populations that inhabit backwaters, oxbows, and slower sections of the main river, as well as many other species of game and nongame fish.


Current

Current is like liquid wind. It blows food in the direction it’s flowing. Predator fish know this, and they rely on current to carry food to them.

Currents in rivers and creeks are steady, although they may get stronger after heavy rains or weaker during prolonged dry periods. On the other hand, currents in tailwaters and power-generation reservoirs are highly variable. Currents may be slow or nonexistant, but when power generators are turned on, currents pick up. When this happens, fish usually get very active, since moving water means better feeding conditions.

Slow-flowing, shallow rivers with broad floodplains offer complex backwater areas with abundant cover in the form of stumps, fallen trees, and aquatic plants.  Side channels provide connections to other prime spots, and largemouth bass use them for travel during all seasons and for feeding during the warmer months.

The force of water is constantly remodeling the riverscape.  Over time, rivers change their course.  It is this change that constructs adjacent flood plains.  If a river stretch does not have an extensive adjoining flood plain, it means that its bed is stable or the river is geologically very young.  Water is a universal solvent; given time, it can chew away granite, dissolve iron, and move mountains!

In streams, the action of water along with the meandering effect cuts materials on the outside bend where current flow is swift and deposits other materials on the inside bend where current speed and force is reduced.  Notice how the current has created a tongue-like structure.  The deepest part of any river stretch is always on the outside bend.