Wave energy devices may exert a range of effects on the environment, not all of which will necessarily lead to relevant or negative changes in the marine environment. The deployment of wave energy devices can effect the environment in which they are sited primarily in two ways:
Reductions in nearshore ocean energy may change current patterns and water mixing, potentially affecting organisms by altering food delivery patterns or rates, the mixing of eggs and sperm, the dispersal of spores and/or larvae, and how temperature varies throughout the water column. Changes in water movement also can affect how sand is moved along the coast. Since sediment grain size often determines which animals can live in the sand, changes to sand movement may affect the distribution of organisms. These wave, current and sediment transport effects will be technology- and location-specific.
The second environmental effects to consider are those that arise simply from having a device in the water. Because these devices are large and likely to be deployed in large groups, the presence of these devices also may alter current flows, having effects similar to those described above. The effects of structures can further be divided into localized effects and those on migratory species. Local effects stem from the introduction of artificial hard substrate, which could be colonized by a variety of organisms, including non-native species. Larger and migratory species may be at risk for entanglement in cables associated with the structures. Noise and electromagnetic fields could interfere with communication or navigation and lighting of the surface elements of the devices may affect sea birds in that they may be attracted to the area, avoid the area, or be confused about their location relative to shore. Avoidance of the area may result in longer migration or forage times.
Pictured here, Dr. Sarah Henkel measures a starfish off the coast of Newport, Oregon.