Biology 3800 Aquatic Ecosystems
The course deals how freshwater aquatic ecosystems function. It deals with
the topics of energy flow and nutrient cycling, how they involve aquatic
organisms, and how they are shaped by physical processes in lakes, rivers and
watersheds. The course also outlines problems in conservation and
management of aquatic ecosystems, and outlines how ecological principles are
applied to these problems.
Learning objectives:
 understanding the diverse ways that aquatic organisms (ranging from
prokaryotes, to algae, plants and animals) contribute to the functioning of
aquatic ecosystems.
 application of mathematical models to make predictions, and solve
management problems pertaining to lakes, rivers and watersheds.
 Learning the techniques used to quantify key aquatic ecosystem processes,
and to sample and study aquatic organisms.
Time: Monday/Wednesday/Friday 10:00-10:50 AM, Jan 09 –Apr 19, 2012
Place: B730 University Hall
Instructor: Dr. Joseph B. Rasmussen—office hours by appointment
Professor, Department of Biological Sciences
Canada Research Council Chair in Aquatic Ecosystems
Office: WE1050 Water and Environmental Sciences Bldg
Phone: (403) 382-7182
Email: joseph.rasmussen@uleth.ca
Textbook: no textbook, reading material will be posted as needed on the
class website
Grading will be based on two in-class exams (worth 30 % each), and
five tutorial assignments (8 % each)
Exams will include multiple choice, fill in the blanks, matching, short
answers and paragraph answers.
Note—If you miss one of the exams due to illness, and have a medical
note, the remaining exams will count for the missing increment
Lecture Topics
Lecture 1 Jan 9.
Introductory lecture: What is Aquatic Ecology about?
Human demands on aquatic ecosystems and their impacts on them.
Ecosystem services: water purification, food production, pollutant assimilation,
recreation
Management and Conservation issues facing aquatic ecosystems
Lecture 2-3 Jan 11-14.
Watersheds and the Landscape
The Water Cycle and the flux of water across the landscape
TheWatershed, water movements above and below ground
Alberta watersheds
Hydrological balance equation, R = P - E - S
Types of Aquatic ecosystems on the landscape
Lotic (streams, rivers, flood plains)
Lentic (lakes, oxbows, ponds, reservoirs, wetlands)
Streams and Rivers, relationships of discharge, velocity, stream width, and depth to
drainage area
Stream order –Examples of Alberta streams of various orders
Lecture 4-7 Jan 16-23. Stream habitats
The pattern of stream flow, pools riffles, meanders
The flood plain, oxbows, wetlands and abandoned channels
The variability of runoff in streams over different time scales
Management of flow in rivers
River conservation and restoration.
Lecture 8-9 Jan 25-28: Lakes and ponds/standing water
How lakes and wetlands form on the landscape
Glacial processes and their role in forming lakes and wetlands
Tectonic processes and their contribution to lakebasin formation
Some of the oldest lakes in the world are tectonic lakes, and they have evolved
endemic flora and fauna
Lecture 10-11 Jan 30-Feb 1. Physical processes and habitat zonation in lakes and rivers
Hydraulic flux and water residence time
Mixing and waves
Thermal stratification (epilimnion/hypolimnion),
Sediment deposition in lakes/the profundal
Light extinction/photic zonation, the littoral
The light absorption and the colour of water
Lecture 12-13 Feb 4-6. Physical properties of water, Hydrodynamics
The Aquatic Medium and its effects on organisms:
viscosity, density, currents and drag—the Reynolds number
sedimentation and Stokes Law
Lectures 14-15 Feb 8-11. Primary Producers
Cyanobacteria, Protista, and Aquatic plants
Major taxa and examples of important species
Species causing nuisance blooms, toxicity, taste and odour
Communities of running water/attached algae, the periphyton community
Communities of standing water/ phytoplankton and littoral vegetation
Lectures 16-17 Feb 13-15
Measuring Primary Productivity in standing and flowing water
The oxygen method
Dark and light bottles
The harvest method
14
C tracer method
Midterm Break Feb. 18-22
Lecture 18-19 Feb 25-27
Nutrient limitation and Primary Production
Photosynthesis and the nutrients that support it/nutrient limitation
Measurement of 1o productivity using dissolved oxygen flux or nutrient uptake
C, P, N, Fe, and Si limitation in aquatic environments.
Testing for nutrient limitation
Eutrophication—anthropogenic enrichment with nutrients
Inorganic carbon dynamics and pH in water
Midterm Examination Mar 1
Lecture 20-21 Mar 4-6
Modelling phosphorus dynamics in lakes
Mass balance models for nutrient export and flux
Using mass balance models in the management of lake eutrophication
Successful and unsuccessful attempts to restore lakes
Lecture 22-23 Mar 8-11
Nitrogen dynamics and the N-cycle in Lakes
Oxidation-reduction reactions and the forms of N available
N-cycling in the hypolimnion and sediments of lakes
N-fixers and their role in the lake community.
Lectures 24-25, Mar 13-15
Microbial processes, oxidation reduction
Anaerobic environments
Methanogens, Sulphate reduction, Nitrate reduction
Lectures 26-27 Mar.18-20
Secondary Production and Bioenergetics of aquatic animals
Ecological efficiencies of consumers
The energy and biomass pyramid
Energy allocation by aquatic animals
Lectures 28-29 Mar 22-25 Energy flow in rivers
Allochtonous inputs of energy and nutrients to rivers
The concept of the river continuum
Lectures 29-31 Mar 27-Apr. 5 Aquatic Foodwebs
Relationships between fish predators and prey
Bottom up vs top down interactions in food webs
Lectures 32-34 Apr.8-12 Fish in lakes and streams
Prey defenses against predators
Vertical migrations
Lecture 35-36 April 15-17
Conservation and Management of fish in Aquatic Ecosystems—how are fisheries managed?
Aquaculture vs wild fisheries
Impact of stocking, species invasions and biomanipulation on community dynamics.
History of species invasions and their impact on the Great Lakes
Mountain lakes and the introductions of Mysis shrimp
Bass stocking in Ontario lakes and their impact on lake trout populations
Examination II—April 19 (written in class)
Lab exercises: Tuesday E640, Friday E646
2 weeks on each topic, assignments handed in the week following.
I : The watershed and stream dynamics—Week of Jan 23 and Jan 30
II. Morphometry and dynamics of lakes—Week of Feb 6 and Feb 13
III: Primary production: calculation of 1o productivity—Week of Feb 27 and Mar 5
IV. Phosphorus loading models and eutrophication—Week of Mar 12 and Mar 19
V. Secondary producers: fish productivity and management—Week of Mar 22 and April 2.
Assignments will be graded by TA—8% each.
Grading
Exams and assignments provide a way for instructors to assess the degree to which each student
has accomplished the course goals. The goal of education is learning, not the attainment of
certain grades. Exams and assignments are means by which you can demonstrate to instructors
that you have learned the course material and understand the principles of ecology. Marks are a
way to represent this degree of learning on a standard scale.
Letter grade conversions (approximate)
Percent
Letter
91-100
A+
86-90
A
80-85
A77-79
B+
74-76
B
70-73
B67-69
C+
64-66
C
60-63
C55-59
D+
50-54
D
49 or less
F
Excellent
Good
Satisfactory
Poor
Minimal Pass
Failure
Student Conduct
Unless otherwise indicated, all assignments and exams in this course must be original work
completed by individual students. Academic offences (plagiarism and cheating) or nonacademic offences committed by students in the context of this course will be dealt with
according to the policy of the University of Lethbridge as indicated in the 2006/07 Calendar
(see pages 70-74).
Missed Exam and Assignment Policy
Missed exams and assignments earn a grade of zero. Students who miss exams or assignments
will be allowed to perform make-up work only if they provide documented evidence of an
acceptable excuse (e.g. note from physician). Do not make travel arrangements that conflict
with exams, assignments or the final exam schedule!