A review of potential impacts of submarine power cables on the marine environment: Knowledge gaps, recommendations and future directions

Abstract

Submarine power cables (SPC) have been in use since the mid-19th century, but environmental concerns about them are much more recent. With the development of marine renewable energy technologies, it is vital to understand their potential impacts. The commissioning of SPC may temporarily or permanently impact the marine environment through habitat damage or loss, noise, chemical pollution, heat and electromagnetic field emissions, risk of entanglement, introduction of artificial substrates, and the creation of reserve effects. While growing numbers of scientific publications focus on impacts of the marine energy harnessing devices, data on impacts of associated power connections such as SPC are scarce and knowledge gaps persist. The present study (1) examines the different categories of potential ecological effects of SPC during installation, operation and decommissioning phases and hierarchizes these types of interactions according to their ecological relevance and existing scientific knowledge, (2) identifies the main knowledge gaps and needs for research, and (3) sets recommendations for better monitoring and mitigation of the most significant impacts. Overall, ecological impacts associated with SPC can be considered weak or moderate, although many uncertainties remain, particularly concerning electromagnetic effects.Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

Electroreception in marine fishes: chondrichthyans

“…The global increase in subsea electrical cable deployment from marine renewable energy installations and the expansion of communication cable networks has raised interest in whether electroreceptive marine fishes will be affected by the associated EMFs (Gill et al . a, Gill et al, ; Taormina et al, ).…”

“…Electromagnetic fields (EMFs), can be emitted over large spatiotemporal scales by electric trawl fishing (Desender et al, 2017), subsea high-voltage cable networks, transoceanic marine vessels, mineral prospecting and metallic infrastructure, such as railways and bridges . The global increase in subsea electrical cable deployment from marine renewable energy installations and the expansion of communication cable networks has raised interest in whether electroreceptive marine fishes will be affected by the associated EMFs (Gill et al 2012Taormina et al, 2018).…”

Wave Energy in Tropical Regions: Deployment Challenges, Environmental and Social Perspectives

“…These effects depend on the body size and flexibility of the fauna and its feeding behavior, as well as its ability to detect the risk [24]. In addition, underwater noise, vibrations, and electromagnetic emissions have also been highlighted as major concerns, as they can disrupt the communication, feeding, and navigation of many marine species [79]. Even though potential impacts of underwater noise are widely recognized, the uncertainty over the variability in baseline noise levels makes it difficult to establish limits [80].…”

Risk Retirement—Decreasing Uncertainty and Informing Consenting Processes for Marine Renewable Energy Development

“…Concerns around EMF have been raised increasingly throughout the MRE and offshore wind industry progression [57]. Despite the presence of many electricity-bearing cables in the oceans for over a century, this is a relatively new issue of concern that has been raised in the marine domain [77]. Without any standards or regulatory thresholds, EMF risk from MRE cables must be addressed through a growing research base, comparisons with cables carrying electricity for other industries, and laboratory studies that indicate the risk to not be significant [77].…”

“…Despite the presence of many electricity-bearing cables in the oceans for over a century, this is a relatively new issue of concern that has been raised in the marine domain [77]. Without any standards or regulatory thresholds, EMF risk from MRE cables must be addressed through a growing research base, comparisons with cables carrying electricity for other industries, and laboratory studies that indicate the risk to not be significant [77]. The present evidence base appears to be sufficient to determine that for the low power modes generated by single MRE devices, the risk to susceptible marine animals is very low.…”