1. Rivers, Streams, and Lotic Ecosystems

2. Stream Classification
1st order
Small non branching stream/creak
2nd order
Two 1st order streams combine
3rd order
Two 2nd order streams combine
A 1 plus a 2 doesn’t equal a 3
True headwaters of Mississippi
River is named for the largest order.
True name of Mississippi?

3. Watershed Watershed/Drainage New stream Old Stream Area a river drains
High grade
Large fall
Fast flowing
V channel
Strait
Old Stream
Meanders
Oxbow Lakes
Back waters
U shaped Valley/channel

4. River Structure Bottom structure Scouring Flooding
Changes in rivers
Hard/soft
Scouring
Washing away of river bottom
Flooding
When river overflows its banks
Can scour
Ice Dams (Red River)

5. River Structures (continued)
Run
Straight main body of river
Riffle/Rapids
Fast flowing usually shallow
Caused by equal volume must go through less area
Pool
Deep slow flowing
Waterfall
Hard rock over soft
Erosion rates differ
Back waters
Flooded area usually not part of river

6. Biota Adaptations Fish Behavior adaptations Anatomy Adaptations
Must overcome constant current
Fish
Trout and salmon but also walleye, bass and others
Behavior adaptations
Hide behind rocks
Wait for food don’t chase it
Breed in shallows (dig holes)
Lay eggs upstream why?
Anatomy Adaptations
Very streamlined body
Great sense of smell
Feast on hatches

7. Biota (continued) Micro and Macro Invertebrates Mass hatchings
Base of food chain
Nymphs: Mayflies, dragonflies, stoneflies
Mass hatchings
Why?
When?
Where?
Roads and Cars
Indicator Species
Tell health of ecosystem

8. Biota (continued) Adaptations: Stream lined body Suction cups Hooks
Filter Feeders
Predators
Net Makers
Shredders

10. The End