Hydrochemistry and phytoplankton abundance at time series station Helgoland Roads, North Sea, in 1981 - von Westernhagen, Hein; Hickel, Wolfgang (In: Wiltshire, Karen Helen; Carstens, Kristine; Ecker, Ursula; Kirstein, Inga V: Hydrochemistry at time series station Helgoland Roads, North Sea since 1873 [dataset publication series]. Alfred Wegener Institute - Biological Institute Helgoland, PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.960375 (dataset in review), 1999)