Freshwater Pollution
Derivation of the Biotic Indexes of Freshwater Pollution
You have been provided with long term biological data for the four different freshwater sites
routinely monitored by SEPA with potentially different levels of pollution. You have also been
issued with notes setting out the sensitivity of various species of invertebrates to pollution.
1- Deveron Cabrach, NJ 37855 29144
2- Water of Cruden, upstream of Morissons
3- Mains of Dyce at Pitmedden Industrial Estate
4- Burn of Noss
Your task is to use these materials to:
(i) derive biotic indexes that summarise pollution status of each site
(ii) compare different BI approaches,
(iii) calculate long-term ASPT scores for each site
(iv) Critically appraise the use of biotic indexes in freshwater pollution monitoring
Summarise your findings in a scientific report. The report should not exceed 2000 words and
should be of the following structure:
Title
Abstract
Introduction and Aims – a very brief review of what a biotic index is and why it is useful in
freshwater pollution monitoring. Some background information you can get on the specific
sites would also be useful. There should be at least 2 aims, one focusing on assessing the
ecological status of the 4 sites you got samples to work in class and one aim focusing on the
long term dataset.
Methods – a clear, concise account of what materials and methods have been used (i.e. what
BI methods have been used, etc.), how samples were collected
Results – tables/graphs summarising data and derived biotic indexes, including brief
commentary.
Discussion – an understanding of the assessment of the ecological status of your 4 sites; be
critical and innovative in discussion; has the recovery site recovered or not? Is the “clean” site
still clean? Provide potential explanations for the long-term fluctuations in the biotic index at
each site; account of the strengths and weaknesses of the biotic indexes; how useful are they in
general and how they could be improved.
