Most fish and invertebrates use sound for vital life functions. This review of 115 primary studies encompasses various human-produced underwater noise sources, 66 species of fish and 36 species of invertebrates. Noise impacts on development include body malformations, higher egg or immature mortality, developmental delays, delays in metamorphosing and settling, and slower growth rates. Zooplankton suffered high mortality in the presence of noise. Anatomical impacts from noise involve massive internal injuries, cellular damage to statocysts and neurons, causing disorientation and even death, and hearing loss. Damage to hearing structures can worsen over time even after the noise has ceased, sometimes becoming most pronounced after 96 hrs. post-noise exposure. Even temporary hearing loss can last months. Stress impacts from noise are not uncommon, including higher levels of stress hormones, greater metabolic rate, oxygen uptake, cardiac output, parasites, irritation, distress, and mortality rate, sometimes due to disease and cannibalism; and worse body condition, lower growth, weight, food consumption, immune response, and reproductive rates. DNA integrity was also compromised, as was overall physiology. Behaviorally, animals showed alarm responses, increased aggression, hiding, and flight reactions; and decreased anti-predator defense, nest digging, nest care, courtship calls, spawning, egg clutches, and feeding. Noise caused more distraction, producing more food-handling errors, decreased foraging efficiency, greater vulnerability to predation, and less feeding. Schooling became uncoordinated, unaggregated, and unstructured due to noise. Masking reduced communication distance and could cause misleading information to be relayed. Some commercial catches dropped by up to 80% due to noise, with larger fish leaving the area. Bycatch rates also could increase, while abundance generally decreased with noise. Ecological services performed by invertebrates such as water filtration, mixing sediment layers, and bioirrigation, which are key to nutrient cycling on the seabed, were negatively affected by noise. Once the population biology and ecology are impacted, it is clear fisheries and even food security for humans are also affected. Turtles, sharks, and rays were especially underrepresented in noise impact studies. Research on an individual’s ability to survive and reproduce, and ultimately on population viability and ecosystem community function, is most vital. More long-term, realistic field studies also considering cumulative and synergistic effects, along with stress indicators, are needed.
The Impact of Ocean Noise Pollution on Fish and Invertebrates
Weilgart, L. (2018). The Impact of Ocean Noise Pollution on Fish and Invertebrates. Report by OceanCare and Dalhousie University. pp 36.