Christoph Humborg,^* Daniel J. Conley,^** Lars Rahm,^*** Fredrik Wulff,^**** Adriana Cociasu,^***** Venugopalan Ittekkot<sup>******


*</sup>Christoph Humborg, PhD, is studying the impacts of changes in nutrient composition in rivers on coastal biogeochemical cycles. His address: Department of Systems Ecology, Stockholm University, SE-106 91 Stockholm, Sweden. christoph@system.ecology.su.se
^**Daniel J. Conley, PhD, works mainly on the consequences of a major relative decline in silicon supply for marine food webs. His address: Department of Marine Ecology and Microbiology, National Environmental Research Institute, P.O. Box 358, DK-4000 Roskilde, Denmark. DCO@DMU.dk
^***Lars Rahm is professor in oceanography. He is working on large-scale fluxes and distribution of biogeochemical elements in the coastal zone. His address: Department of Water and Environmental Studies, Linköping University, SE-581 83 Linköping, Sweden. LarRa@Tema.LiU.SE
^****Fredrik Wulff is professor in marine systems ecology. His main interest is to use integrated models of marine systems for coastal zone management strategies. His address: Department of Systems Ecology, Stockholm University, SE-106 91 Stockholm, Sweden. fred@system.ecology.su.se
^*****Adriana Cociasu is head of the marine chemistry and oceanography department at the Romanian Institute of Marine Research. She is mainly working on long-term changes of nutrients in the Black Sea. Her address: Romanian Institute for Marine Research, Blvd Mamaia 300, 8700 Constanta, Romania. acociasu@alpha.rmri.ro
^******Venugopalan Ittekkot is professor in biogeochemistry and marine chemistry. He is currently coordinating a new SCOPE-Project: Land Ocean Nutrient Fluxes: the Silica Cycle. His address: Institut für Biogeochemie und Meereschemie, Universität Hamburg, Bundesstr. 55, 20146 Hamburg, Germany. ittekkot@dkrz.de