2. What we will cover
Theory
Aquatic Ecosystems
What conditions determine life in an aquatic environment
Creating our own aquatic systems
Practical
Pond building
3. Rivers- Rain Fed
Head Waters-Upper Reaches Middle Reaches-Un spoilt Lowland Rivers
Spring-Fed Rivers
Lake Fed Rivers
Short Mountain Rivers
Estuaries
7. What determines The Plant and Animal
Biota ?
•Nutrient Content
•Depth and light penetration
•Acidity
8. Nutrient Content
A nutrient can be defined as a food substance for an organism.
The level of nutrients in the water underpins the existence of all
life, plant and animal.
The nutrient content is affected by
The geology of the catchment.
The topography of the catchment.
Intensiveness of agriculture in the surrounding area
Size of surrounding human population (sewage)
9. Nutrient Content
Nutrients and Light = Phytoplankton and Plants
Phytoplankton and aquatic plants are the primary
producers on which the entire food web relies
upon.
Algae-Diatoms-Cyanobacteria
12. Depth and light penetration
A high density of phytoplankton quickly absorbs the light and reduces the
depth at which the light can penetrate to approx 2m ,below this point nothing
can grow and animals cannot live.
13. Acidity
Some species only live in PH 4-6 and some species only exist in slightly alkaline
waters pH >7. Most species prefer 6 - 7.5.
14. An Optimum Aquatic Habitat
A good supply of Nutrients supporting a high diversity of Plant and Animal life
A balanced level of phytoplankton (PRIMARY PRODUCERS) so that light can penetrate
through the water
A water body deep enough for plants to grow on the floor utilizing the filtered light
Moderate pH
We can easily design this optimum Habitat.
22. Floaters
Lemna minor- Duckweed
USES
Forage for Fish
Shade the water
Edible –great for Chickens
The dried plant repels mosquitoes
Medicinal properties
23. Common Carp - Cyprinus carpio
Uses
High Protein food
Tolerance of a lack of oxygen
Rapid growth
Easy to feed
Info
•Common carps feed on small plants and
zooplankton, molluscs, detritus and dead
plants.
•The deep water is needed for winter
hibernation
•Logs and rocks with cavities for young fish
to shelter
24. Toads and Frogs
Uses
Frogs and Toads will keep pest populations low
A single adult toad can eat as many as 10,000 insects per
summer. Including Mosquitoes
Frogs legs, taste a bit like chicken apparently:- Rana esculenta
Water quality control :they need clean water ,if you have them
around you can be assured your water is clean. If they start
growing extra legs be concerned.
.
Position
The ideal pond for frogs and toads includes plenty of shallows for
toads to rest and breed.
A deep area of at least 1.3 meters for overwintering frogs, and
plenty of vegetation around the edges to hide out in.
Provide shallow, not steep, edges so frogs and toads can easily
climb in and out, or add a couple logs partly in and partly out of the
water.
Both frogs and toads will also really appreciate some rocks around
the edges for sunning themselves
Edible Frog
Rana esculenta