Study the brief breakdown of marine life in the face of human noise
– Travel and economic slowdowns due to the COVID-19 pandemic have combined to curb boating, seabed exploration and many other human activities in the ocean, creating a unique time to begin a chronological study of the impacts of sound on marine life.
Our community of scientists has identified over 200 non-military ocean hydrophones around the world and hope to make the most of the unprecedented opportunity to pool their recorded data in the 2020 Calm Ocean Assessment and help to watch the ocean soundscape long into the future.
Our goal is a network of 500 hydrophones picking up signals from whales and other marine life while assessing levels of human activity. Combined with other methods of monitoring marine life such as tagging animals, the work will help reveal the extent to which noise in “anthropocene seas” affects ocean species, which depend on sound and natural sonar to keep them alive. mate, navigate and feed across the ocean.
Sound travels far out into the ocean, and a hydrophone can pick up low frequency signals hundreds or even thousands of miles away.
To assess the risks of underwater noise to marine life, it is necessary to understand which sound levels cause harmful effects and where in the ocean vulnerable animals may be exposed to sounds in excess of these levels.
In 2011, experts began to develop the International Quiet Ocean Experiment (IQOE), launched in 2015 with the Scientific plan for international experimentation on the calm ocean. Among our goals: to create a time series of ambient sound measurements in many locations in the ocean to reveal the variability and changes in intensity and other properties of sound at a range of frequencies.
The plan also called for 2022 to be designated the “Year of the Calm Ocean”. Due to COVID-19, however, the oceans are unlikely to be as calm as they were in April 2020 for many decades to come.
COVID-19 has reduced sound levels more than we ever imagined possible. Therefore, the IQOE is focusing project resources to encourage the study of changes in sound levels and effects on organisms that have occurred in 2020, based on observations of hundreds of hydrophones around the world in 2019-2021.
Of the 231 non-military hydrophones identified up to February 2021, the highest concentrations are found along the North American coasts – Atlantic, Pacific and Arctic – Hawaii, Europe and Antarctica, with some scattered throughout the Asia-Pacific region.
Several agreed to have their geographic coordinates and other metadata posted on the IQOE website (https://www.iqoe.org/systems).
The sparse and sporadic deployment of hydrophones and obstacles to integrating measurements have severely limited what we know for sure.
We are therefore creating a global data repository with contributors using standardized methods, tools and depths to measure and document ocean soundscapes and the effects on the distribution and behavior of vocalizing animals.
New software, MANTA (at https://bit.ly/3cVNUox), developed by researchers across the United States and led by the University of New Hampshire, will help standardize collaborators’ ocean sound recording data , facilitating their comparability, pooling and visualization.
In addition, an Open Underwater Sound Portal (OPUS) is being tested at the Alfred Wegener Institute in Bremerhaven, Germany, to promote the use of acoustic data collected around the world, thus providing a easy access to data processed by MANTA. The aggregated data will allow maps of the soundscape of entire oceans.
Meanwhile, scientists over the past decade have developed powerful methods to estimate the distribution and abundance of vocalizing animals using passive acoustic monitoring.
The all-new hydrophone network contributes to the Global Ocean Observing System (GOOS), a network of observing assets monitoring currents, temperature, sea level, chemical pollution, waste and other issues around the world.
Rarely has there been such a chance to collect calm ocean data in the seas of the Anthropocene. COVID-19 has dramatically reduced shipping, tourism and recreation, fishing and aquaculture, naval and coast guard exercises, offshore construction, dredging of ports and canals, and exploration and energy extraction. The concomitant price war that brought oil prices down to zero has further calmed maritime energy activities.
The last comparable opportunity followed the terrorist attacks on the United States in September 2001, which not only disrupted air travel; they also resulted in slower navigation and reduced ocean noise, prompting biologists to study stress hormone levels in endangered North Atlantic right whales in the Bay of Fundy.
With their 2001 data, the research found higher stress hormone levels in September over the next four years, as the whales prepared to migrate to the warmer southern waters where they calved, which suggests that the industrialized ocean causes chronic stress in animals.
We’re on track to secure timely, reliable, and easy-to-understand maps of ocean soundscapes, including the exceptional April 2020 period when the COVID virus gave marine animals a brief break from human noise.
Let’s learn from the COVID pause to help achieve safer operations for shipping industries, offshore energy operators, navies and other ocean users.
Additional information on MANTA is available at https://bitbucket.org/CLO-BRP/manta-wiki/wiki/Home, and on the IQOE at https://bit.ly/3sDTkd
We invite Parties in a position to contribute to join us in this global effort to assess the variability and trends in ocean sound and the effects of sound on marine life.
* Jesse Ausubel is the initiator of the IQOE project and director of the human environment program at Rockefeller University, New York City; Edward R. Urban Jr of the Scientific Committee for Ocean Research is the IQOE Project Manager