Royal Netherlands Institute for Sea Research

Changing North Sea

The North Sea is a hotspot in transition: a shallow highly productive, heavily fished and increasingly turbid sea with a changing species composition. Species. Effects of global change are noticeable such as acidification, rapid warming and northward migration of Southern fish species whereas Northern species are disappearing from the coastal zones. Also, a spatial mismatch is found between seabirds and their food takes: while fish populations migrate,  many birds are bound to their breeding places.


Turbity
Turbidity of  the water has increased with likely detrimental impacts on the carrying capacity of the system. How these changes affect the functioning and the trophic dynamics of the North Sea food webs remains largely unknown. NIOZ will undertake multidisciplinary studies of the North Sea ecosystem in which the functioning of the entire food web is the central theme. 

Turbidity in the North Sea. Photo: Jacco Kromkamp.

The PULS project - Impact of fisheries on ecosystem functioning
Tickler chains dragged over the sediments and electrical pulses are two techniques used to startle sediment-inhabiting organisms such that they can be caught in fishermen’s nets hovering over the bottom. In the PULS project, a cooperation with Wageningen Marine Research, we investigate the effect of these fishing methods on the sediment ecosystem functioning. We perform lab experiments where we mimic fishing-induced perturbations in small-scale settings. We also perform a number of field campaigns where we measure ecosystem functioning in designated areas that are experimentally fished. Finally, modelling will be used for upscaling our results.

The SANDBOX project – biological-geomorphological interactions.
Natural protection of coasts starts underwater with barriers such as sandwaves, emerging up to 5 meters from the sea bottom, and up to several hundred meters long. These submerged, dune-like structures are maintained by localized small-scale current patterns that form as a result of the topography. Some key animals living in these sandwaves may either stabilize or destabilize the sediments, and therefore also affect the size, shape and mobility of these bedforms. In the SANDBOX project, in cooperation with TU Delft and University of Twente, NIOZ EDS investigates the three-way physical-geomorphological-biological interaction in the underwater geomorphological landscapes.