Plankton Ecology in Relation to Flushing Rate in Four Newfoundland Ponds

Abstract

AbstractA seasonal quantitative study was conducted on the plankton of four Newfoundland ponds. There are indications that one pond received inputs of airborne pollutants emanating from a phosphorus plant. All ponds are characterized by high flushing rates. Highest numbers of both phytoplankton and zooplankton organisms tended to occur from late spring through summer, the period of greatest water retention. The phytoplankton was dominated for the most part by nano‐plankton forms. Large blooms of Anabaena flos‐aquae and Asterionella formosa occurred during summer in the pond located near the phosphorus plant. This did not occur in the other ponds. Dominant microcrustaceans encountered included Holopedium gibberum, Diaptomus minutus, and Epischura nordenskiöldi. Of the rotifers encountered, collectively the most important forms were Polyarthra dolichoptera, Conochilus unicornis, Keratella cochlearis, Kellicottia longispina, Kellicottia bostoniensis, Pleosoma truncatum, Synchaeta sp., and Trichocerca sp. Aspects of the ecology of the phytoplankton and zooplankton are discussed in the context of water retention characteristics. A comparison is made with a pond subject to pollution from rural and urban sources. This pond also possesses a high flushing rate.