On the Foraminiferida of the Plymouth region

The seasonal changes in the foraminiferid populations along the Tamar-Eddy-stone profile have been shown for the winter, spring and summer of 1962. No single environmental factor appears to be wholly responsible for these changes but temperature is considered to be important. Variable salinities are of secondary importance in the Tamar. These seasonal changes have been compared with those observed at Christchurch and found to be different, presumably because of the different temperature and salinity conditions prevailing in the two estuaries. A qualitative assessment of the energy input of the environment from the nature of the deposited sediment has shown a good positive correlation between the distribution of the Miliolacea and a high-energy environment. All other superfamilies show a negative correlation with high energy, but the Cassidulinacea show a preference for a moderate-energy environment during the summer. Foraminiferids, found not to be very abundant in the Plymouth region, show a trend toward greater numerical abundance and greater diversity in passing out o t sea. The shortage of living foraminiferids is tentatively correlated with a restricted food supply.