The project aimed to create a proof-of-concept for the active reintroduction of offshore flat oyster beds, demonstrating whether a viable population of flat oysters could exist in an offshore wind farm, and developing novel methods, including predictive models. To do this, an innovative oyster cage was designed and tested (the WERC-dock) in the Offshore Test Site.

Oyster activity in the Gemini wind farm was measured by a valve gape monitor, and larval counts were done by traditional sampling as well as DNA-analysis (qPRC), which is easier to use than the traditional visual analysis by microscope (though high variability was still found). A model was made to determine oyster mobility on the seafloor, and a temperature prediction model was used and improved to predict larval peak production in the Dutch North Sea. Furthermore, survival and growth of the adult flat oysters was measured, as well as larval settlement success on substrate provided in the reintroduction system and on other substrates in the environment (shipwrecks and natural rocky reefs).

To get an impression of the (fish) biodiversity of the environment, environmental DNA (eDNA) sampling was done. Trials with bait cams and a consumer type underwater drone (ROV) were also conducted. Both methods proved to work (after some adaptations in the bait cam set-up) to get an impression of the fish and benthic community present

• Placement of oysters is critical to their survival.
• Customize your budget to suit your research needs. Expensive does not always equal best. For example, smaller ROVs can perform as well as commercial ones. In some cases, investments will save you down the line—for example, rather than using lightweight frames for oysters, larger and heavier structures may cost more but are more reliable to stay on the sea floor.
• Combine objectives with vessels to maximize research and monitoring time.

GEMINI wind farm had permits needed to use the wind farm. Permits are also required to enter the wind farm and deploy oysters. Additionally, health and safety measures are crucial to using a wind farm. Crew members are required to have medical examinations, a basic offshore safety course is required, and a risk assessment method statement (RAMS) is critical for many steps in this type of project.