Green Energy Noise Affects Sea Life, Research Finds

Recent research co-conducted by Dr. Louise Roberts of the University of Liverpool focuses on the noise generated by marine energy converters, or MECs, such as tidal turbines and wave energy converters.

Situated in shallower waters than offshore wind farms, MECs interact directly with the seafloor. This interaction might be causing disturbances to our marine life.
 

The Silent Impact on Fish

 
MECs might seem silent on the surface, but underwater, numerous fish and aquatic invertebrates have an innate ability to “feel” sound through water particle motion and ocean floor vibrations.

With MECs vibrating the ocean floor as they operate, the resultant noise could severely affect bottom-dwelling creatures.

Dr. Louise Roberts commented on the significance of the issue: “With a climate emergency we are quite rightly exploring green energy sources. However, we must consider the impact of these solutions on the environment in which they are placed.”

Several studies have shed light on the behavioural changes in fish due to noise pollution. Some fish migrating or recruiting could become disorientated because of the noise from MECs, leading them away from their migratory paths or stopping them from settling in benthic habitats.

Such disruptions can bring about a domino effect of stress responses in fish, including increased heart rate, alterations in feeding habits, and disturbances in social interactions.

Even more concerning is that the stress from MEC noises might reduce a fish’s ability to respond to predatory attacks or even impact their ability to handle food items.

The consequences don’t stop at immediate behaviour alterations. Disturbances can affect the very development, reproduction, and survival of these species.

As Dr. Roberts further shared, “Fishes and invertebrates are fundamental to marine food webs, and are often overlooked when investigating the impacts of sounds in the environment.”
 

Invertebrates and Noise Interference

 
Invertebrates, too, haven’t escaped the sonic interference. Most studies on them have centred around impulsive noise sources, leaving a knowledge gap about the impact of continuous noise sources like MECs.

Some initial findings suggest that continuous noises, similar to those from sea-going vessels, might induce stress in invertebrates. Other documented behavioural changes include altered locomotion, feeding behaviour changes, and variations in antipredator behaviour.

This information, albeit limited, paints a picture that the consistent drone from MECs might be disrupting marine life ecosystems.
 

Research Caveats and Interpretations

 
Researching marine life, especially in their natural habitats has its difficulties, and interpreting behaviours observed in controlled environments, like tanks, might not accurately present the genuine reactions of marine life in the wild.

This is because captive animals often have different behavioural patterns from their wild counterparts.

Studying marine life in their habitats also proves tricky. Many species cover across regions, making them difficult to observe, particularly when assessing the effects of devices like MECs.

Even in laboratory settings, replicating the exact acoustics of the wild isn’t an easy task. Hence, while laboratory research remain an important process, especially for physiological measures, it’s important to ensure the sound field is well-defined and controlled.
 

A Plea for Greater Insight and Awareness

 
The findings from the research emphasise the need for a deeper understanding and increased awareness. The marine ecosystem, with its complex interdependencies, deserves consideration and care, especially when introducing newer green energy technologies.