Zooplankton response to a warmer northern Wadden Sea

Abstract

Weekly

First report of the planktonic copepod Oithona davisae in the northern Wadden Sea (North Sea): Evidence for recent invasion?

“…There temperatures range between 8.9 and 28.2°C (Uye and Sano 1998), which is generally higher than in the studied Wadden Sea station (between -1.8 and more than 20°C (Martens and Beusekom 2008)). The warming of the Wadden Sea (Martens and Beusekom 2008) may have provided the right environment for O. davisae to settle. Reise and van Beusekom (2008) revealed that global warming is an important factor for species invasions in the Wadden Sea, since most of the introduced species originate from warmer regions than the North Sea.…”

“…Martens and Beusekom 2008), which is also true for its original habitat, the coastal waters of southwestern Japan (Nishida 1985;Uye and Sano 1998). There temperatures range between 8.9 and 28.2°C (Uye and Sano 1998), which is generally higher than in the studied Wadden Sea station (between -1.8 and more than 20°C (Martens and Beusekom 2008)). The warming of the Wadden Sea (Martens and Beusekom 2008) may have provided the right environment for O. davisae to settle.…”

“…In June 2014, the remaining three female specimens were first identified as O. davisae. To investigate whether the occurrence of O. davisae in the North Sea had been only a single event in 2010, samples of the time series (2007 in the List Tidal Basin were checked (Martens and Beusekom 2008) and a new non-quantitative sample was taken in August 2014 at the same station. This sample contained many copepodites, males and females with or without egg sacks.…”

“…The Wadden Sea may be a favourable habitat for O. davisae, a unique coastal environment subjected to a pronounced seasonality in temperature, phytoplankton, and zooplankton (e.g. Martens and Beusekom 2008), which is also true for its original habitat, the coastal waters of southwestern Japan (Nishida 1985;Uye and Sano 1998). There temperatures range between 8.9 and 28.2°C (Uye and Sano 1998), which is generally higher than in the studied Wadden Sea station (between -1.8 and more than 20°C (Martens and Beusekom 2008)).…”

“…1a). It is the location of a zooplankton time Martens and Beusekom 2008). At this station, plankton samples (Apstein net, 80 lm mesh size) were taken in October 2010 and 6 August 2014.…”