Succession of marine epipelagic communities

Abstract

The changes occurring in the structural-functional characteristics of plankton communities (assemblages) in the course of their development have been repeatedly described and modelled for various oceanic regions. However, the tracing of a particular con~munity through the whole course of its successional development is practically unattainable and the comparison of the serial stages in different communities reflects neither the duration of each separate stage nor their strict sequence. We propose here a method of ranging of the communities observed according to the value of Q = Ig D/P, (maturity index); this makes it possible to follow changes in the community's characteristics in the course of its quantitatively assessed development. The scale comprises designated intervals corresponding to different community-development stages and their coincidence with the trophicity gradations of the waters that these communities inhab~t. The influence of frontal zones on the development of plankton communit~es is discussed and a comparison is given of the quantitative charactenstics of communities at different stages of development in the eastern tropical Paciflc Ocean and in the Black Sea.