Since 1988 free consultant: „LIMNOFISCH“, Büro für Gewässerbiologie und Umweltplanung, March, Germany
10/1995-03/1998: Fishes in Luxembourg. Mapping (270 water courses; 2 dams: 380 ha, 50 ha), Databank, Red List of endangered fish species, lampreys und crayfishes. Documentation and lay out. Administration des Eaux et Forêts, Luxembourg
04/1995-05/1995 Mapping of fresh water fishes and crustaceous of the River Uruguay, River Itajai und River Paraná, Santa Catarina, Brazil, in cooperation with the University Florianópolis Santa Catarina (UFSC) and “Museum Rosenstein”, Stuttgart, Germany
03/1993-05/1993 Mapping of fresh water fishes and crustaceous of the Iland of S. Catarina, Santa Catarina, Brazil, in cooperation with the University Florianópolis, Santa Catarina (UFSC) and “Museum Rosenstein”, Stuttgart, Germany
1999 Investigation of possibilities to reinforce the fish production at the upper Rio Negro with local species, São Gabriel da Cachoeira, Amazonia, Brazil. Estimation of support and local acceptance of new fisheries technologies and methods. Foundation „Entwicklungszusammenarbeit Baden-Württemberg“ (Stuttgart, Germany), Cities of Lahr a. Ettenheim, Germany)
02/1991-04/1991 Mapping of the fresh water fishes and crustaceous of the Dominican Republic in cooperation with the University of St. Domingo, D. R., Ministry of Agriculture, St. Domingo and “Museum Rosenstein”, Stuttgart and “Senckenbergmuseum” Frankfurt a. M., Germany
1991 "Liechtensteiner Binnenkanal“ and „Auwald Lettensteg-Ruggell", River Rhine channel. Assessing the impact of restoration activities. The principality of Liechtenstein.
11/1984-04/1985 Collection of Fishes in Algeria, Cameroun, Central African Republic and Zaire during a biological expedition to Kenia. “Museum Rosenstein“, Stuttgart, Germany.
06/1975-06/1977 Appranticeship at the fish hatchery of Dr. O. Müller, Fredelsloh, Germany with specialization on breeding and hatching.
1989-1992 Upper Danube, Fish faunistic and structural estimation of the Danube between the cities of Donaueschingen and Ulm, Baden-Württemberg (165 km). Administration of the District of Freiburg and Tübingen, Baden-Württemberg.
1992 Estimation and value of the fisheries of the comunity of Breisach, River Rhine: River Rhine (90ha), canalizated River Rhine (77ha) and its tributatries (60ha). Comunity of Breisach, Fed. State of Baden-Württemberg.
1993 History of the fisheries development (decrease) at the Upper River Rhine. Documentation about the last 100 years. Fisheries Research Station Langenargen, Lake Constance, Fed. State of Baden-Württemberg.
1994 Fish damage after a three years lasting impact in the Upper Danube (6 km). Calculation of the damage. Fisheries Association Sigmaringen, Baden-Württemberg.
1996 Recommendations to increase the ecolocical value of the Upper River Rhine (120 km). Administration of the District of Freiburg, Baden-Württemberg.
1996-1997 Management of the Lake Salza/"Süßer See"(270 ha): Limnological part of the whole report (plancton, fishes, sediment, nutrition load, inlet water: possibility of plant treatment), Fed. state of Sachsen-Anhalt, Halle.
1997 Fish fauna of the River Rhine (1995): Status-quo report of the International Commision for Protection of the River Rhine – IKSR/:CIPR: Integration of international collected Data from France, Switzerland, The Netherlands and Germany. IKSR/CIPR Koblenz.
2000 Restruction of the Water Way Main: Fish-ecological functions of new litoral structures (replacements) between the cities of Freudenberg and Lengfurt, Bavaria (13,42km). Water way administration, Aschaffenburg, Bavaria.
2000-2004 Food chain manipulation in an eutrophic backwater of the River Rhine. City of Kehl, Baden-Würrtemberg.
2001 Functional control of 6 different constructed fishways in the rivers Kinzig and Rench. Administration of Hydrography, Section Offenburg, Baden-Württemberg.
2001 Fish ecological aspects in by-pass channels of hydropower plants. Administration of the District of Freiburg, Baden-Württemberg.
2002 Ecological development of a river passing a Dam. City of Lauf, Black Forest. Administration of Hydrography, Section Offenburg, Baden-Württemberg.
2002 Evaluation of a structural improvement in the river Schutter; suitability as a spawning habitat. Administration of Hydrography, Section Offenburg, Baden-Württemberg.
2003 Conception to increase the ecological and fisheries value of the denaturalized river „Oberer Glan“. District of Neustadt a.d.W., Rheinland-Pfalz.
2004 Mapping crayfish between Freiburg and Baden-Baden (90 x 40km), in context to the obligation to the European Water Guide. Administration of Hydrography, Section Offenburg, Baden-Württemberg.
2004-2005 Functional control of 2 fishways in a tributary of the River Rhine. City of Kehl, Rhine, Baden-Württemberg.
2005 Biological conception for the river Wieslauter (French/German border). District of Neustadt a.d.W., Rheinland-Pfalz.
1988-2005 Elaboration about more than 120 other reports in different fields of fresh water aspects (fisheries, valuation, conceptions, ecology, environmental impacts, pollution, water ways, hatcheries; recommendation and advice).