The document introduces limnology as the study of inland waters, including their physical, biological, and chemical aspects. It notes there are three main branches: physical limnology covers properties like water movement and basin geology. Biological limnology focuses on photosynthesis and productivity. Chemical limnology examines inorganic and organic compounds. The document provides examples of limnology studies on lakes, noting their formation, depth, residence time, zones, and trophic classification. It outlines the importance of limnology for conservation and understanding impacts of changes to watersheds.

2. Presented By
Nusrat Jahan (MUH1819039F)
Arnima Aich (BKH1819014F)
Shatabdi Dhar Bithi (BKH1819019F)
Shahadat Hossain (ASH1819043M)

3. Our Presentation Topic

4. Introducing To Limnology
• Limnology is the study of
inland waters and their
many aspects
• It covers all inland waters,
which may be lakes, rivers
and streams but also
reservoirs, groundwater
and wetlands.

5. Branches of Limnology
There are three Branches of
Limnology
1.Physical limnology
2.Biological limnology
3.chemical limnology

6. Physical Limnology
Unique properties of water-important role in
penetration, distribution of light, heat.
Water movements( waves, currents)
Geology of basin(origin, morphology, leaching,
minerals).

7. Biological Limnology
 Base is photosynthesis-primary productivity.
 Regulated by and may regulate,physical and chemical factors

8. Chemical Limnology
 Inorganic,Organic compounds
 Closely allied to geology(leaching)
 Distribution often related to water movements

9. Example of Limnology
 We can describe lake.There are three types of Lake.
1. Glaciated lake
2. Reservoirs
3. Oxbows.
 The lake differs from 2 sides
1. Depth
2. Residence Time

10. Formation of Lakes
 Most natural Midwestern lakes
were formed by glaciers>10000
years ago
 Glaciers scoured out lake basins
Ice
 Blocks formed depression that
filled and became lakes(kettle or
ice block lakes)

11. Chemical Aspect
The importance of chemical factors, is owing to
their lethal and sublethal effects on cultural
organisms, and also owing to their effect on
biological productivity.
productivity of the organism in the food chain.
This aspect is discussed separately under ''
Biological Productivity ‘’.

12. Nutrition Aspect Of Limnology
Nutrients are redistributed from the upper
water to the lake bottom as the dead plankton
gradually sink to lower depths and
decompose.
In contrast to DO, essential nutrients such as
the bioavailable forms of phosphorus and
nitrogen (dissolved phosphate, nitrate and
ammonium)

13. The Ecological Pyramid

14.  Producers : producers is primary productivity of lakes.the major threat to
lakes involves the excessive growth of primary producers due to nutrient
inputs caused by poor landuse management
 consumer: the best known group of aquatic consumers is fish.tertiary
consumers that prey on the smaller fish include larger fish and other
carnivorous animals(loons,grebes,herons and otters)
 Decomposer : Decomposers are organisms such as bacteria and fungi
that break down the organic matter in the dead bodies of plants.
Decomposers are hetetrophic, meaning that they use organic subtrates to
get their energy, carbon and nutrients for growth and development

15. Lake Zone
 A typical lake has three distinct from zones.
1. Limetice
2. Littoral
3. Benthic
 This zones are usally determind by depth and distinct from the
shoreline

16. Trophic Classification

17. Importance Of Limnology
 Cconversation from manmade lentic
reservoirs to natural lotic rivers
 Dam removal completely alters watershed
biogeochemical processes.
Large- scale distributance that results in
variety of ecosystem impacts.