Conclusions

The variations observed over the study period (May, July, August, September and March) suggest that thecamoebians respond rapidly to seasonal variables such as temperature, light penetration, primary production and precipitation. Little variation in the relative abundance of total difflugiid vs. centropyxid thecamoebians was observed during the annual seasonal cycle, validating the use of this metric as an aquatic environment monitoring tool. However, the relative abundance of living thecamoebians (stained tests) and the species composition (particularly within the difflugiid taxa) varied substantially throughout the study. Depending on the time of year, some thecamoebian species appear to be more susceptible to predation or to have a low preservation potential as they were mainly observed as stained (live) tests. Paleoecological studies using thecamoebians should focus on the species with high preservation potential, however finding a thecamoebian with low preservation potential in the fossil record would be an indicator of a very specific environment.

Current environmental conditions should be gauged based only on the living population during time of collection. Looking at the total population is useful for paleoenvironmentalists who are typically interested in the overall marine lacustrine environment and not as interested in seasonal perturbations. The total population is a more accurate indicator of the general environmental conditions.