Applications of planar oxygen optodes in biological aquatic systemsDissertation zur Erlangung des Doktorgradesder NaturwissenschaftenDem Fachbereich Biologie/Chemieder Universität Bremen vorgelegt vonUlrich FrankeBremen im Januar 20052Die vorliegende Arbeit wurde in der Zeit von Oktober 2000 bis Januar 2005 amMax-Planck-Institut für marine Mikrobiologie in Bremen angefertigt.GutachterProf. Dr. Gunter Otto KirstProf. Dr. Bo Barker JørgensenPrüferProf. Dr. Friedrich WiddelDr. Dirk de BeerWeitere Mitglieder des PrüfungsausschussesDipl. Biologin Susanne HinckStud. rer. nat. Nina LindeDatum des Promotionskolloquiums: 18. April 20053AcknowledgementsI would like to thank Prof. Bo Barker Jørgensen for accepting me as a PhD student and forsupporting this work.I am grateful to my mentor Dr. Gerhard Holst, who greatly supported me in numerousways during the first 1.5 years of my PhD and introduced me into the “secrets” of theplanar optode technique.Dr. Markus Hüttel is thanked very much for a lot of help and for sharing his greatexperience in the field of sandy sediments from the planning of wave tank experiments,fruitful discussions all the way to critical manuscript reading.Dr. Dirk de Beer is thanked for valuable discussions as well as numerous ideas concerningplaning and enforcement of several studies.