Internship Experimental assessment of meroplankton grazing rates
Zooplankton grazing rates on phytoplankton are very variable and depending on life stage, abundance and environmental variability (Lizárraga et al., 2017; Sommer et al., 2000). During zooplankton blooms, these organisms can exert top-down control by grazing on phytoplankton, which reduces phytoplankton abundance and affects the structure of the primary producer community. Grazing rates of major zooplankton species have previously been investigated. However, main effort has been focused on holoplanktonic species (Ratnarajah et al., 2023). The holoplankton community includes all zooplankton permanently suspended in the free water column. However, overall, a decline of holoplankton linked to changing temperature regimes and phytoplankton availability can be observed in the North Sea.
Description
In the marine trophic food web meroplankton abundance is considered to be on a comparable level to holoplankton. Meroplankton is defined as species only spending part of their life cycle as plankton (e.g. bivalve, echinoderm and polychaete larvae). The grazing pressure on phytoplankton exerted by meroplankton is strongly understudied as compared to holoplankton. With increasing abundances of meroplankton it is important to understand their grazing impact on primary producers.
To investigate grazing rates of meroplankton in the North Sea mesocosm experiments are planned at NIOZ Yerseke as part of the MONS project. This internship includes practical experimental work, lab processing of samples and statistical analysis.
Requirements & Application
The proposed starting date is mid-April and the internship should last 4-6 months.
For further information and to apply, please contact Rebecca Buring (rebecca.buring@nioz.nl).