Gwybodaeth Modiwlau

Module Identifier
Module Title
Freshwater Biology
Academic Year
Semester 2
Other Staff

Course Delivery

Delivery Type Delivery length / details
Lecture 3 x 1 hour lectures per week (33 hours)
Practical 6 x 4 hour practicals (24 hours)


Assessment Type Assessment length / details Proportion
Semester Assessment Practical Test.  25%
Semester Exam 3 Hours   75%
Supplementary Assessment Students must take elements of assessment equivalent to those that led to failure of the module.  25%
Supplementary Exam 3 Hours   Students must take elements of assessment equivalent to those that led to failure of the module.  75%

Learning Outcomes

On successful completion of this module students should be able to:

1. demonstrate a sound understanding of the nature of living systems in freshwater environments

2. explain the processes which control the functioning of lake and river ecosystems

3. identify the principal groups of freshwater invertebrates

4. describe the feeding habits and habitat requirements of the major groups of freshwater organisms.

Brief description

This module aims to introduce students to the organisms and processes that characterize freshwater ecosystems, through an integrated series of lectures and practical classes. It covers a range of freshwater habitats from the smallest rivers to the largest lakes, and a range of organisms from viruses to vertebrates. It also takes account of the impact of human activity on all of these.


The module assumes no prior knowledge of inland waters, although some students may have a little background from physical geography or from field work undertaken at school or college. It starts with the water cycle and the factors determining the availability and chemistry of water in inland drainage. It covers the structural aspects of freshwater systems, including the origin of lakes and drainage systems, and physical habitat characteristics at a variety of spatial and temporal scales in lakes and rivers. An overview of the freshwater biota and its adaptations to the medium follows.

The section on lake biology includes a review of primary producers and their principal characteristics. It covers seasonal variation in relation to stratification, the role of the microbial and bacterial/viral loops. The section also deals with zooplankton, their place in open water trophic webs, including bottom-up and top-down controls on the functioning of open water systems. It concludes with the biology of the benthos, including macrophytes.

In dealing with river systems, the theme is the spatial pattern imposed by changing conditions from the headwater to the estuary. The nature of, and factors affecting, biofilms/ periphyton in rivers is covered with some discussion of macrophyte production. Relationships between physical conditions and biological assemblages are described, together with the role of biotic interactions in determining the structure of stream invertebrate assemblages. Physical disturbance is discussed as is the concept of patch dynamics at a variety of of spatial scales. A section on the dynamics of organic matter in streams provides a link with the section on lakes. Vertebrate assemblages in freshwater systems and the longitudinal zonation of vertebrates along European rivers is described in relation to abiotic factors.

The final section of the course deals with human impacts, paying particular attention to organic pollution, eutrophication and their treatment. This links with earlier discussions of primary productivity. The course concludes with examination of methods of monitoring river water quality.

The practical classes are based on investigation of the invertebrate communities of a local river and the littoral habitat of a small lake. These provide experience of simple techniques for sampling in the field and handling and preserving material in the lab., serving to illustrate many of the topics covered in the preceding lectures.

Module Skills

Skills Type Skills details
Application of Number Using basic analytical techniques to assess and interpret data from practical classes
Communication Reading from a variety of sources in support of course content. Providing written responses to examination questions. Listening effectively in class.
Improving own Learning and Performance Self-testing of taxonomic skills in the final practical session
Information Technology Accessing and interpreting class data provided in electronic format. Appropriate use of internet and e-journals.
Personal Development and Career planning Gaining confidence in understanding key concepts in freshwater biology, and through developing awareness of personal interests and skills in relation to potential career paths
Problem solving Through an understanding of the principal factors influencing the functioning of freshwater ecosystems
Research skills Experience of basic methods of data collection in freshwater habitats, assessment and evaluation of results
Subject Specific Skills Basic taxonomy of freshwater organisms. Understanding of precautions and safety issues in freshwater field and laboratory work
Team work Through co-operating effectively in groups during the practical classes in the field and laboratory


This module is at CQFW Level 5