Lake structure and terminology

1
The Structure of Aquatic Ecosystems

• Lake structure and terminology
• Stream structure
• Estuary structure

2
Lake Structure

• Water Mass
• WATER DENSITY CHANGES WITH TEMPERATURE

Temperature deg C
0
5
10
15
20
0
Epilimnion
20
Metalimnion
40
60
80
Depth m
Hypolimnion
100
120
140
160
3

• Chemocline

• ex Lake Nyos in the Cameroons

4
Monimolimnion in Lake Vanda, Antarctica
5
Lake Basin Structure

• Benthic Zones
• Littoral zone
• spray zone
• eulittoral zone
• sublittoral zone
• Profundal Zone

6
Lake Basin Structure

• Open Water Zones
• Littoral zone
• Limnetic/pelagic zone
• Production zones
• trophogenic zone
• tropholytic zone

7
Light Structure in Lakes

• Photic zone
• Compensation Depth
• Aphotic zone

8
Light Structure in Lakes

• Photic zone
• Compensation Depth
• Aphotic zone

9
Lake Communities

• limnetic/pelagic
• plankton
• nekton
• neuston
• pleuston
• psammon
• littoral
• benthic

10
Stream Structure

• By Age

Youth
Maturity
Old Age

• Substrate
• erosional
• depositional

11
Stream Organism Communities

• Binding algae (periphyton) and bacteria
• free living
• rotifers
• protozoans
• detrital feeders
• grazers

12
Estuary Structure

• Geomorphology
• submerged coastline
• glacial coasts
• modification