Abstract
MARINE renewable energy (MRE) developments, such as those harvesting wave or tidal energy, will need to grow towards large-scale arrays for the sector to successfully contribute toward the portfolio of sustainable energy alternatives and fight global climate change. However, this growth must be accompanied by the investigation of potential environmental effects at larger scales, and will require investigations of stressor-receptor interactions that may not be relevant at the scale of small numbers of devices, such as changes in oceanographic systems and displacement of marine animals [1]. In the MRE context, stressors are (parts of) a device that can produce stress, harm, or injury to receptors such as marine animals or habitats, and oceanographic or ecosystem processes [2].
Whether large arrays of MRE devices (i.e., 10-30 devices) will displace marine animals from their preferred or essential habitats remains to be examined [3]. Many marine animals undertake annual migrations, during which they could encounter MRE arrays, potentially altering their course and lengthening their routes to avoid the devices. Resident animals may be displaced locally if a complete or partial loss of critical habitats occurs due to the installation and operation of arrays. However, research around mechanisms and effects of displacement has been precluded by the lack of large-scale deployed arrays [4]. In addition, there is a lack of common understanding within the international MRE community about the definition of displacement, the mechanisms that cause displacement, as well as the consequences, species of concern, and methods to investigate the outcomes.
Displacement of marine animals is not specific to the MRE sector and lessons may be learned from other marine, or even terrestrial, human activities. These activities should be identified, as well as the relevant knowledge to transfer. Remaining knowledge gaps will need to be filled through targeted research studies, involving field-based approaches and/or numerical modeling.
A literature review on displacement of marine animals was undertaken across three offshore energy sectors: MRE, offshore wind, and oil and gas, and a workshop was organized with international subject matter experts to gather feedback and attempt to reach a consensus around the definition and mechanisms of displacement. This study aims to establish a definition of this stressor-receptor interaction, explore which groups of marine animals may be affected and how, and identifies pathways for investigating displacement through modeling and monitoring in the MRE context.