Summary
The strip count method of determining fish densities was investigated for a small lake in a series of inshore sites that differed in their physical and biological characteristics and in the communities of fishes present. Overall total numbers of fish, number of species, ratio of commonest to total species, and 2nd commonest to total species, were investigated. Counts were made during time of the feeding peaks.
Methodology
Studies on small lake faunas carry with them the inherent problem of small population size. To remove an appropriate number of fish for stomach analysis may reduce the population level to an unacceptable degree. The stomach pump technique can, unfortunately, only be used with larger fish. Accordingly, the present study was designed as a three year project based on only limited numbers of fish (objective 20-25) per month for each year class being taken in each year. Grouping of such results to produce a ‘composite’ diet is a liberty. However, it is felt appropriate in view of the predictability and successional nature of the abundance peaks of the major prey invertebrates, allowing that monthly samplings had to be sufficiently spread out to ‘dampen’ year to year variations. Hence the emphasis here is on developing ‘average’ diets and using this to calculate ‘average’ diet overlaps between the year classes.