The Alfred Wegener Insitute has maintained a long time interest in the composition of phytoplankton communities in the North Sea. The phytoplankton data are based on the work of Dr. G. Drebes (Helgoland and Sylt), Dr. M. Elbraechter (Sylt) and Dr. M. Hoppenrath (Helgoland and Sylt). The species composition is recorded in the context of two long term sampling programs. The Helgoland Reede Station has been sampled daily since 1962. Water-bottle samples are fixed in Lugols iodine and phytoplankton taxa are counted mainly to estimate carbon contents - see Pangaea project. In addition to net samples for quantitative analyses, species identification information has also been collected. Since the species survey of Drebes between 1966 and 1971, there has been no continuous species composition record from net-samples from Helgoland. At Sylt, the taxonomic composition and life cycles of phytoplankton have been investigated weekly since 1987 by Dr. Drebes and Dr. Elbraechter again using live cells from net samples. Over the period 2001 - 2003, Mona Hoppenrath has reinvestigated the Helgoland phytoplankton species composition. Net-samples were taken with two plankton nets (20 and 80 ?m). Living organisms were identified by light microscopy. Fixed cells were investigated by scanning electron microscopy. This work was part of the Helgoland phytoplankton time-series, which is coordinated by Karen Wiltshire, who supported the creation of this database and took over the responsibility for it. J. van Beusekom is responsible for the Sylt phytoplankton time-series and the Drebes-data and he kindly supported the database. The phytoplankton checklist comprises 172 diatoms, 108 dinoflagellates, 5 prymnesiophytes, 2 raphidophytes and 6 other species, all together 293 taxa. Data on 137 species of zooplankton found around Helgoland are also available.
This material provided by Mona Hoppenrath, Alex Kraberg, Tanya Morozova and David Patterson. This image provided bu AWI. Image copyright: AWI, used under license to MBL (micro*scope), image taken by Karl Petermann.