ZOO401 Handouts

ZOO401 Limnology

Diversity of aquatic ecosystems, Comparison of fresh, brackish and marine ecosystems. Unusual and extreme habitats, hydrology, physiography and physical properties like temperature, light, turbidity, currents, density, their interactions and relations with aquatic life. Chemical properties like dissolved oxygen, carbon dioxide, pH, alkalinity, hardness, inorganic and organic substances, their distribution, dynamics and influence on aquatic ecosystem. Status and forms of nutrients like nitrogen, sulphur, phosphorus and carbon in natural waters; nutrients use and remineralization with special reference to processes controlling the levels of nitrogen, phosphorus and sulpher in aquatic ecosystem. Stichiometry of autographs and heterotrophs; concepts of trophic state, aquatic productivity & eutrophication. Managing eutrophication in freshwater habitats. Biodiversity of fresh waters. Ecological classification of aquatic biota. Limnological importance of biota. Adaptations and characteristics of aquatic life. Quantitative and qualitative changes in spatial and temporal distribution of aquatic biota.

Textbook: Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems, Third Edition.

Academic Press

Course Notes

Lecture 1 - Introduction

I. Introduction; Syllabus Review/Background

II. What is limnology and why study it?

1. Limnology – study of inland waters

1. Standing waters – lentic

Q2. Flowing waters – lotic

1. Interdisciplinary science -- geology, chemistry, physics, biology
2. Greater diversity of freshwater systems than of oceans

1. Size
2. Origin
3. Temperature
4. Age
5. Color

H. Lakes are good places to study ecology

1. easier boundaries
2. easy to sample
3. shorter-lived organisms
4. field experiments easier to perform than in oceans

III. History of Limnology (don't worry about the names!) A. F.A. Forel, " Father of Limnology"

1. Lac Leman (Lake Geneva) -- began biological studies

Q2. Influenced by oceanography

1. S.A. Forbes, Illinois Natural History Survey (1887)

1. " Lake as a Microcosm"

Q2. Beginnings of ecosystem ecology

1. US -- Birge and Juday -- Wisconsin school of limnologists

1. sampled many lakes -- comparative approach

Q2. 'the data will speak' versus hypothesis testing

1. Europe -- Thienemann and Naumann

1. Lake classification
2. Continuation of ecosystem ecology

E. G.E. Hutchinson

1. Treatise of Limnology (1957 first volume)
2. theories and processes; modeling
3. influential in founding modern ecological thought
4. fight between Wisconsin school and Hutchinson

F. Current -- integration of research on lakes, streams, rivers and their watersheds --

ecosystem approaches; human influences on freshwater systems

IV. Limnology and the development of Ecology A. Standing crop, biomass, productivity

1. ' Dynamical ecology'

Q2. Not just what's there, but how fast it's growing

1. Ecosystem Ecology
2. Paleoecology
3. Trophic dynamics (Lindeman) -- Food webs and energy flow

Origin of Lakes

I. General background A. There are a few large lakes, but ponds dominate numerically (85%)

B. Lake districts

C. Necessity of positive water balance

Precipitation + Inflow > Evaporation + Outflow

C. Processes in lake formation

1. Constructive

2. Destructive

Q3. Obstructive

1. Significance of lake formation