Download Stream Ecology 101ish - Conservation Corps Minnesota

Stream Ecology
Roland Sigurdson
Aquatic Education Specialist
Minnesota DNR - Division of Fish and Wildlife
MinnAqua Aquatic Education and Angling Program
What is a stream?
Body of water
moving under the
influence of
gravity, to lower
levels, in a welldefined natural
channel.
What is a stream – Take 2
Body of water
moving under the
influence of
gravity, to lower
levels, in a welldefined natural
channel.
Why study streams/rivers?
 Why does a river flow when there is no rain?
 Why do rivers look the way they do?
 What's in the water?
 Where does the energy come from to run the system?
 What kinds of organisms do you find in rivers?
 How are these organisms organized and distributed?
 How do humans affect rivers and their biota?
 And finally, how does it all fit together?
Time…is on their side
Water in a stream
is continually in
motion. It is the
erosional forces of
this moving water
that has sculpted
the landscape of
much of the earth.
The Watershed
 A watershed is the surrounding land area that drains
into a lake, stream, river system. It includes natural
and artificial drainage systems
It’s all about scale
 Minnesota has
nine major
watersheds.
 Minnesota is a
net exporter of
water, no
water enters
the state other
than by
precipitation.
Stream Order




First Order Stream – small, stony & shaded
Second Order – when two First Order streams combine
Third Order – when two Second Order streams combine
Etc (10th is about the maximum world-wide
Succession in Streams
Width and Depth
Substrate
Gradient
Temperature
Pool-Riffle Spacing
Meanders
Temporal – changes
taking place over
long periods at a
single site
Spacial – changes
from headwater to
mouth from a
‘snapshot’ in time
Reset by disturbance
River Continuum Concept
The structure
(numbers and kinds
of species) of
biological
communities
changes
downstream (ie the
numbers and
species of plants,
insects and fish
The function (what
they do) of
organisms change
downstream
according to
available food
resources
Stream food web
Heterotrophy
Allochthony – Materials from outside a
system, such as leaves and insects that fall
from terrestrial plants into a stream.
Autotrophy
 Primary
Productivity/Photosynthesis
 Primary producers in most
stream systems – periphyton
and macrophytes
Functional Feeding Groups
 Feeding Strategy Food Category








I.
II.
Shredders
Collectors
filter feeders
miners
browsers
III. Scrapers
IV. Piercers
V. Predators
dead leaves/live macrophytes
fine organic particles (live/dead)
particles in water column
buried particles
bottom surface deposits
live benthic algae (diatoms)
live filamentous algae
other invertebrates + small fish
Tough Bugs
Hey!! Who you calling ‘fish
food’ now frog face!!!
Invertebrate Biodiversity
 Flatworms
 Leeches
 Aquatic
earthworms
 Snails
 Mussels/Clams
 Water Mites
 Crustaceans
 True Bugs
 True Flies
 Water Beetles
 Dragonflies/Damselflies
 Stoneflies
 Mayflies
 Dobsonflies, Fishflies,
Hellgrammites, Alderflies
 Caddisfliees
Meet a few of them
Fish
Cold Water
- Brook Trout
- Brown Trout
- Rainbow Trout
- Sculpins
- White Sucker
- Dace
Warm Water
- Smallmouth Bass
- Walleye/Sauger
- Largemouth Bass
- White Bass
- Catfish
- Suckers
- Minnows
Number of fish species by
major drainage system
Red River
Rainy River
Superior Drainage
Upper Mississippi River
St Croix River
Minnesota River
Missouri River
Lower Mississippi River
82
73
83
75
106
95
42
127
Human impacts
Let’s talk…shall we?
Good, Bad, Ugly, Normal