First NO-REGRETS Research Cruise at HKZ offshore wind farm

The first research expedition of the NWO-funded NO-REGRETS project has successfully concluded, marking an important milestone in the project's efforts to understand the environmental effects of offshore wind farms in the Dutch North Sea on board the Wim Wolff vessel (NIOZ-Royal Netherlands Institute for Sea Research).

Led by chief scientist Henko de Stigter (NIOZ), the two-week campaign brought together researchers from multiple disciplines to test monitoring methods and collect data in and around the Hollandse Kust Zuid offshore wind farm.

A key focus of the expedition was to examine how wind turbines may influence water column mixing. Researchers deployed lander moorings equipped with sensors measuring temperature, salinity, currents, turbulence, and underwater sound. These instruments will help determine whether offshore wind farms enhance the movement of nutrient-rich deeper waters toward the surface, potentially stimulating plankton growth and affecting the wider marine food web.

The cruise also included fish monitoring using acoustic echo sounders, underwater sound recordings through hydrophones, and the deployment of an advanced CTD imaging system that combined traditional oceanographic measurements with high-resolution imaging of plankton and suspended particles throughout the water column.

In addition, water samples were collected to analyse phytoplankton communities and their pigments. These data will be compared with satellite observations to improve the ability to monitor ecological changes across the North Sea using remote sensing technologies.

While laboratory analyses are only beginning, the expedition has already provided valuable insights into both the scientific and operational challenges of conducting multidisciplinary research at sea. The datasets collected during this first campaign will contribute to a better understanding of how offshore wind farms interact with marine ecosystems and help inform sustainable management of the North Sea's growing offshore energy sector.

The cruise represents the first step in a series of NO-REGRETS field campaigns that will continue to investigate the ecological consequences of offshore wind development and support evidence-based decision-making for the energy transition.