The Helgoland Roads long-term plankton monitoring programme
The Biological Station Helgoland holds one of the largest and longest marine plankton time series in Europe, named 'Helgoland Roads' after the sampling location. This time series has been running continuously, with samples taken on a work-daily basis since 1962. As far as possible species counts are carried out at species level. This has allowed us to show long-term changes in abundance and seasonality of different organisms, but also to reliably demonstrate the appearance of species entirely new in the Helgoland Roads phytoplankton community. More complex analyses have also shown long-term shifts in diversity and delays in the start of the spring bloom after warm autumn/winter seasons. The latter was shown using a simple index: The mean diatom day.
Zooplankton samples have been collected and analyzed regularly since1975. This data series is an invaluable tool for investigations of zooplankton diversity, trophic interactions and the phenology i.e. the annual timing of occurrence and abundance of individual species. The time series could also be used to document the appearance/invasion of new species such as the ctenophore Mnemiopsis leidyi.
In addition to the phytoplankton, the time series also includes physico-chemical data. Inorganic nutrients (silicate, nitrate, nitrite, phosphate, ammonium), temperature, salinity and secchi depth are all measured and are also available from 1962 onwards (exception: silicate is available from 1967 onwards.)
All data are archived in Pangaea: Click here for list of data
Fig. 1 Location of the sampling site for the Helgoland Roads long-term datasets, including the Helgoland transects ('Schnittfahrten).