Nicole Welle | February 8, 2021
A new scientific review confirmed that human-made noise is disrupting the ocean soundscape and harming marine life.
Anthropogenic sound from sources like ships, seismic surveys, pile drivers, dynamite fishing and drilling platforms threatens the countless marine species that rely on sound to navigate and communicate. The new review, published last week in the journal Science, combined the work of 25 authors in various fields of marine acoustics to form a more complete synthesis of evidence on the effects of noise pollution. While past studies have outlined the effects noise pollution has on individual large marine animals, this study includes many groups of marine life and aims to increase global awareness of the issue, according to a New York Times article.
The study shows that increasing levels of anthropogenic noise not only negatively affect large mammals like whales and orcas, but also groups like zooplankton, jellyfish and clownfish. After clownfish are conceived in coral reefs, they drift in the open ocean as larvae until they have grown enough to swim against the tide. They then use the sounds coral reefs make to find their way back to the reef where they will live out the rest of their lives. However, high levels of human-made noise sometimes prevent baby clownfish from hearing the popping and snapping of reefs, and they never find their way back, according to the article.
The authors also found that some species of whales, killer whales and porpoises will permanently evacuate areas where noise pollution levels are too high. However, these forced evacuations can lead to population decline, especially in species that have limited biogeographical ranges like the Maui dolphin. Even when marine life can escape, they don’t have anywhere to go that is free of noise pollution.
While the study’s results are worrying, the authors say that noise pollution is the easiest pollutant to control in the ocean. Reducing ships’ speed, developing quieter propellors, avoiding sensitive areas and moving shipping lanes could all help to reduce its impact. Many animals also have the ability to quickly rebound. For example, some large marine mammals immediately began repopulating areas that had been vacant for decades when pandemic-related lockdowns reduced noise pollution by just 20% last year. The authors hope their review urges policymakers to enact policy changes that address noise pollution and raise awareness of the issue.