Wave energy harnesses the consistent motion of ocean waves to generate electricity. As a clean, renewable source, it offers a promising alternative to traditional fossil fuels. Understanding its potential interactions with the marine environment is essential for its development.
Effects on Marine Life
Wave energy converters (WECs) and their associated infrastructure can introduce changes to marine habitats and species. Underwater noise, from both construction and operational phases, is one factor. While construction activities produce significant noise, operational noise from WECs is often lower, sometimes barely audible to marine mammals. Research continues to assess the potential long-term effects of chronic, low-level noise exposure.
Subsea cables, necessary for transmitting power from WECs to shore, generate electromagnetic fields (EMF). These fields can affect marine species that rely on natural electromagnetic cues for navigation, hunting, and other biological functions. Sharks, rays, and certain fish like salmon are particularly sensitive to EMF, and exposure may lead to altered behaviors, reduced mobility, or changes in their distribution. The extent of these effects depends on factors such as field strength, species sensitivity, and the cable’s proximity to sensitive habitats.
The physical presence of WECs and their mooring lines introduces a potential for collision risk for marine animals. This risk is generally considered low for wave energy devices due to their slow-moving parts. However, concerns remain for large marine mammals and diving birds.
Wave energy installations can also lead to habitat alteration. The deployment of WECs and associated infrastructure may disturb or displace existing benthic (seabed) habitats during installation, potentially affecting organisms living on or in the seafloor. Conversely, the structures themselves can act as artificial reefs, providing new substrates and shelter that may attract and support certain marine species, potentially enhancing local biodiversity.
Changes to Physical Coastal Processes
Wave energy devices can directly influence the physical dynamics of coastal environments. Wave attenuation occurs as WECs absorb energy from incoming waves, reducing wave height and energy levels reaching the shoreline. This reduction has implications for coastal erosion. Studies suggest that WEC arrays, especially when positioned strategically, can decrease wave impacts on coastlines, potentially promoting sediment deposition and reducing erosion.
Changes in wave patterns can consequently affect sediment transport, the movement of sand and other particles along the seabed and coastline. A decrease in wave energy due to WEC operations may alter natural sediment movement, leading to localized areas of accumulation or erosion. Reduced wave action can encourage the deposition of sediment, potentially stabilizing beaches and dunes that might otherwise be vulnerable to erosion.
Localized changes in currents and water circulation, known as hydrodynamics, can occur around wave energy installations. These alterations could influence the dispersal of nutrients and the movement of larval stages of marine organisms. Changes in water flow patterns can have broader effects on the local marine ecosystem.
Wider Environmental Advantages
Beyond localized impacts, wave energy technologies offer broader environmental advantages by contributing to the global shift away from fossil fuels. As a renewable power source, wave energy displaces electricity generation that would otherwise rely on burning coal, oil, or natural gas. This leads to a significant reduction in greenhouse gas emissions, particularly carbon dioxide (CO2). The operational phase of wave energy conversion produces very few CO2 emissions, making its carbon footprint notably low.
The adoption of wave energy also helps reduce other forms of air and water pollution associated with fossil fuel combustion. Burning fossil fuels releases pollutants into the atmosphere. Wave energy avoids these atmospheric emissions. It also mitigates environmental risks tied to fossil fuel extraction and transport, such as oil spills and contamination from coal ash, protecting water quality and marine ecosystems.
Addressing Potential Environmental Effects
Developers of wave energy projects implement various strategies to minimize and manage potential environmental impacts. Careful site selection involves thorough assessments to avoid ecologically sensitive areas. This includes steering clear of marine protected areas, critical habitats, and established migration routes for marine species. Considerations also encompass water depth, proximity to shore, and existing shipping lanes to reduce conflicts with other ocean uses and environmental sensitivities.
Ongoing research and development focus on improving device design and technology to reduce environmental footprints. Innovations include designing WECs that operate more quietly, have a smaller physical presence, and generate minimal electromagnetic fields. Some designs incorporate bio-inspired flexible materials or wildlife-friendly mooring systems to reduce entanglement risks and allow for more natural interaction with marine currents.
Environmental Impact Assessments (EIAs) are a standard regulatory requirement before wave energy projects can proceed. These comprehensive studies identify and predict potential environmental impacts across various stages: construction, operation, and decommissioning. EIAs inform the development of specific mitigation plans designed to prevent or reduce adverse effects, ensuring environmental considerations are integrated into project planning.
Continuous monitoring and adaptive management practices are implemented throughout a project’s lifespan. Monitoring programs collect data on environmental parameters during operation, allowing for real-time assessment of actual impacts. Adaptive management is an iterative process where operations or mitigation measures can be adjusted based on monitoring findings. This approach helps to reduce uncertainties and refine practices, ensuring environmental protection alongside energy generation.