Anthropogenic Mixing of Seasonally Stratified Shelf Seas by Offshore Wind Farm Infrastructure

TL;DR

This paper discusses the environmental implications of offshore wind farm infrastructure in seasonally stratified shelf seas, highlighting potential impacts on stratification, ecosystems, and the need for further research.

Contribution

It introduces the first analysis of how offshore wind infrastructure may alter stratified shelf sea dynamics and ecosystems, emphasizing the importance of understanding these effects.

Findings

Offshore wind infrastructure can significantly increase mixing in stratified shelf seas.

Enhanced mixing may erode natural stratification, affecting primary production.

Further research is needed to quantify and manage environmental impacts.

Abstract

The offshore wind energy sector has rapidly expanded over the past two decades, providing a renewable energy solution for coastal nations. Sector development has been led in Europe, but is growing globally. Most developments to date have been in well-mixed, i.e. unstratified, shallow-waters near to shore. Sector growth is, for the first time, pushing developments to deep water, into a brand new environment: seasonally stratified shelf seas. Seasonally stratified shelf seas, where water density varies with depth, have a disproportionately key role in primary production, marine ecosystem and biochemically cycles. Infrastructure will directly mix stratified shelf seas. The magnitude of this mixing, additional to natural background processes, has yet to be fully quantified. If large enough it may erode shelf sea stratification. Therefore, offshore wind growth may destabilize and fundamentally change shelf sea systems. However, enhanced mixing may also positively impact some marine ecosystems. This paper sets the scene for sector development into this new environment, reviews the potential physical and environmental benefits and impacts of large scale industrialization of seasonally stratified shelf seas and identifies areas where research is required to best utilise, manage and mitigate environmental change.