The recent palaeoecology and conservation status of Balkan Lake Dojran

Abstract

Lake Dojran is a Balkan lake which is host to a number of endemic species and is of high conservation concern. We report the results of research into the present ecological status of the lake and its comparison with palaeolimnological data for recent human impact, based on modern zoobenthology, diatom and ostracod palaeoecology, sedimentology and 18O/ 16O and 13C/ 12C stable isotope ratios from shells of Darwinula stevensoni (Ostracoda) and Anodonta cygnea glochidia larvae (Mollusca). The results of the modern survey indicate that benthic faunal composition has changed substantially in recent years. However, in spite of documented eutrophication and major, human-induced fluctuations in lake level since the 1950s, the results of palaeoecological analyses indicate that Lake Dojran is still buffered from major ecological impact. The palaeolimnological datasets suggest, however, that an ecological threshold may have been reached, and remedial measures should now be considered. Ecological problems include not only a major decrease in water depth through water abstraction and the diversion of source waters for agricultural purposes, but also recent climatic aridity and anthropogenic pollution. However, geopolitical problems presently conspire against the formulation of a management strategy for the preservation of the lake and its endemic fauna and flora.