A comparative study between two different artificial substrate samplers and regular sampling techniques

One of the major problems confronting aquatic biologists in locating and sampling ecologically comparable habitats both exposed and not exposed to the variable one wishes to study (e.g. pollutional stress). This not only entails finding areas with comparable physico-chemical characteristics, but should also include samplibility and proximity of sites to each other to provide valid comparative data for proper evaluation of the similarities and differences. One solution to this problem is the use of artificial substrate devices which insure habitat similarity and may be placed where one wishes.