Operation, Performance and Measurements with the NESTOR Test Detector

NESTOR is a deep-sea neutrino telescope that is currently under construction in the Ionian Sea, off the coast of Pylos, Southwestern Greece, at a depth of approximately 4000 m. We outline briefly the layout of the telescope and summarize the present status of the project. The results of a one month continuous operation of a test unit using our standard detector modules is discussed. Data of the cosmic ray muon flux acquired with the help of an electro-optical cable during this period is presented. The data are in good agreement with earlier experiments at comparable depth. In addition we discuss our results of bioluminescence measurements and other site and technical aspects