Hannelore Halliger

Thalassiosira species (Bacillariophyceae, Thalassiosirales) in the North Sea at Helgoland (German Bight) and Sylt (North Frisian Wadden Sea) – a first approach to assessing diversity

Thalassiosira species are an important component of phytoplankton populations in pelagic waters around the islands of Helgoland and Sylt in the German North Sea. This taxonomic study revealed the presence of at least 27 species, 21 at Helgoland and 21 at Sylt. Fifteen species had not been recorded previously for Helgoland (T. aestivalis, T. angulata, T. concaviuscula, T. curviseriata, T. delicatula, T. diporocyclus, T. hendeyi, T. kuschirensis, T. minima, T. minuscula, T. oceanica, T. pacifica, T. proschkinae, T. tealata, T. tenera) and 16 for Sylt (T. aestivalis, T. angulata, T. concaviuscula, T. constricta, T. curviseriata, T. delicatula, T. guillardii, T. hendeyi, T. lundiana, T. mediterranea, T. minima, T. pacifica, T. partheneia, T. punctigera, T. tealata, T. tenera). We provide brief descriptions with illustrations and document the seasonal occurrence of these species at the two stations. We also discuss investigation methods used for different levels of species recognition, namely Utermöhl counts, light microscopical observations of living net-samples as well as scanning electron microscopy of net-samples and isolated cultures. Clonal cultures of some species were established to facilitate the taxonomic investigations and 18S ribosomal DNA sequencing was carried out to complement the morphological studies. A perspective for a routine species-level assessment strategy is given.

First records of the benthic, bloom-forming, non-toxic dinoflagellate Thecadinium yashimaense (Dinophyceae) in Europe: with special emphasis on the invasion in the North Sea

Thecadinium yashimaense was recorded for the first time in France, Great Britain, The Netherlands, and Germany. The invasion and establishment of the species in the German Bight was documented reliably and is presented here. The geographic expansion of the species from the North Pacific to the North Atlantic Ocean is discussed. This bloom-forming, marine, sand-dwelling dinoflagellate was shown to be non-toxic. Also Thecadinium kofoidii, the type species of the genus, was analyzed for potential toxin production and turned out to be non-toxic as well.

Semi-quantitive microplankton analysis (Sylt Roads Time Series) in the Wadden Sea off List, Sylt, North Sea in 2002

See data in other version: 2002 - https://doi.pangaea.de/10.1594/PANGAEA.860409 / 2003 - https://doi.pangaea.de/10.1594/PANGAEA.860410 / 2004 - https://doi.pangaea.de/10.1594/PANGAEA.860411 / 2005 - https://doi.pangaea.de/10.1594/PANGAEA.860412 / 2006 - https://doi.pangaea.de/10.1594/PANGAEA.860413 / 2007 - https://doi.pangaea.de/10.1594/PANGAEA.860414 / 2008 - https://doi.pangaea.de/10.1594/PANGAEA.860415 / 2009 - https://doi.pangaea.de/10.1594/PANGAEA.860416 / 2010 - https://doi.pangaea.de/10.1594/PANGAEA.860417 / 2011 - https://doi.pangaea.de/10.1594/PANGAEA.860418 / 2012 - https://doi.pangaea.de/10.1594/PANGAEA.860419 / 2013 - https://doi.pangaea.de/10.1594/PANGAEA.860420