The Laboratory of Applied Bioacoustics warns that noise pollution is threatening the natural balance of the oceans

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Michel André, the only researcher from Spain on this expedition

Within the programme The Winds of Change, the Swiss Ocean Mapping Expedition is making a four-year (2015-2019) journey round the world in the wake of Magellan on board the Fleur de Passion sailing boat. The expedition has already identified many zones of high emission of methane and carbon dioxide between Mactan in the Philippines and Singapore, where the expedition arrived on 13 March. Another project, 20,000 Sounds Under the Seas, is being carried out on board the boat by the Laboratory of Applied Bioacoustics (LAB) of the Universitat Politècnica de Catalunya (UPC). One of this project’s findings is that the only area of the globe free of noise pollution is between French Polynesia and Australia.

Mar 23, 2018

The Winds of Change, a pioneering programme that continuously monitors greenhouse gases on the ocean's surface, was launched in Mactan in the Philippines in December 2017. It is being carried out on board the Swiss Fleur de Passion sailing boat in collaboration with the University of Geneva, within the framework of the Ocean Mapping Expedition. The participants in the project gathered continuous real-time data on methane and carbon dioxide concentrations on the journey to Singapore, where the boat arrived on 13 March after stopping in Brunei and Kuching. The programme has also identified the first hot spots of greenhouse gas emissions, whose dynamics require special vigilance by the scientific community.

The aim of the programme is to provide the scientific community with field data that will improve their understanding of the role of oceans in global warming. Scientists on the expedition warn that, in view of the worrying evolution of the climate and the acidification of the oceans, it is becoming increasingly urgent to revise our concepts of the global carbon cycle. “Methane and carbon dioxide concentrations are clearly higher near cities and islands and in shallow seas—in other words, in areas that are influenced by human activities or that experience higher algal growth” explains Professor Daniel McGinnis, head of the Aquatic Physics Group at the University of Geneva, who is in charge of the project. “The programme has already revealed several emission hot spots that warrant further investigation,” he adds. “For example, the methane level was more than six times higher than background levels at Mactan.

The 33-metre Fleur de Passion sailing boat is an old German Navy minesweeper built in 1941 and converted into a ketch to carry out the four-year mission (2015-2019) in the wake of Magellan. It is equipped with a greenhouse gas analyser connected to an air intake device located 16 m above the sea surface on the aft mast. The analyser automatically collects methane and carbon dioxide readings every minute. The boat will continue its mission until it reaches Seville in August 2019, at the end of its round-the-world journey.

Threat of noise pollution in the oceans
The Ocean Mapping Expedition, which aims to raise awareness of the challenges of sustainable development, includes two other new programmes. One is the ocean noise pollution project 20,000 Sounds Under the Seas of the UPC's Laboratory of Applied Acoustics, led by researcher Michel André, the only Spaniard on this expedition. “Marine noise pollution is recognised today as one of the greatest disrupters of marine ecosystems and as a threat to the natural balance of the oceans" says André.

This pollution, little known to the general public because it is invisible and inaudible, at least to human ears, increases with industrial activities at sea and spreads at high speeds to all the corners of the planet. Nowhere is free of it, except maybe between French Polynesia and Australia, where levels of noise measured by the expedition in some deep-ocean areas were close to the ocean’s natural levels—that is, zero noise pollution, equivalent to the level existing before industrialisation.” The first records can be consulted at http://omexpedition.listentothedeep.com/acoustics/.

In other regions of the world, such as the Great Barrier Reef, the situation is different. “Because most of the marine organisms found in coral reefs produce sounds, tracking the specific soundscapes is an efficient way to monitor and understand any changes,” explains André.

“The 20,000 Sounds Under the Seas programme has collected sound recordings at sample stations and is currently performing analyses and comparisons with the health status of the coral reefs. It is expected that the acoustic monitoring of biodiversity will significantly contribute to our understanding of the scale of the damage that this unique ecosystem is facing,” continues André. From Seville to Singapore, the crew has so far collected 148 surface water samples that are being analysed by biologists from the Oceaneye association of Geneva. The map of the samples analysed can be seen at http://www.oceaneye.ch/en/cartographie/.

The hydrophone system of 20,000 Sounds under the Sea detects and automatically classifies all sounds of natural or human origin during the Fleur de Passion’s journey around the world. It is an innovative device that integrates internet technology, so the crew on board only need to place hydrophones in the water and the LAB researchers can activate and operate the data collection and transmission remotely from the laboratory. Sounds and images taken with on-board underwater cameras fitted in the hydrophones are transmitted in real time to researchers at the LAB, which is affiliated to the Vilanova i la Geltrú School of Engineering (EPSEVG).

Two other projects
In addition to this project, the Micromegas programme on microplastic pollution is being carried out on board the sailing boat, in collaboration with Oceaneye.

In April 2017, the expedition also opened a second field of research on global warming, one of the three types of major human impact on the oceans along with pollution and overfishing. In collaboration with the CoralWatch project of the University of Queensland in Brisbane, Australia, the crew of the Fleur de Passion perform observations of the health status of corals, victims of bleaching caused by warming waters. By mid-March, more than 1,300 observations had been carried out in Australia, the Solomon Islands, Papua New Guinea, Indonesia and the Philippines, as the expedition advances on its journey in the wake of Magellan. This information, transmitted to CoralWatch, is added to a comprehensive database covering 77 countries that is generated by the project.

The UPC project 20,000 Sounds Under the Sea also helps to understand the health status of the Great Barrier Reef by measuring its soundscape.