Monitoring of anthropogenic and biological sounds in the ocean
Characterization and quantification of anthropogenic, biological and ambient sounds in the oceans are important for a range of marine industries as well as for enhancing our understanding of marine ecosystem.
In this project we work with passive acoustic measurements performed in Norwegian waters, mainly from the Lofoten-Vesterålen cabled ocean observatory. In addition to the passive acoustic recordings we use auxiliary data from the ocean observatory and other data sources to characterize the acoustic baseline, and implement methods for continuous monitoring of the marine soundscape.
Characterization and monitoring of underwater sounds is important for a range of industries and scientific purposes including
- Oil and gas exploration, construction and operation
- Offshore renewables (e.g. offshore wind), construction and operation
- Marine mammal observations
- Dredging for shipping lanes
- Shipping (e.g. trade and tourism)
The project is motivated by the EU Marine Directive, in which the goal is to achieve Good Environmental Status of EU marine waters by 2020, including that the “Introduction of energy (including underwater noise) does not adversely affect the ecosystem”.
Example recordings from the Norwegian coast (biophony):
Humpback whale – Knølhval (Megaptera novaeangliae)
Humpback whales are one of the most studied large baleen whales, and have one of the most diverse acoustic repertoire. Humpbacks are famous for their songs, primarily produced in lower-latitude breeding waters.
Fin whale – Finnhval (Balaenoptera physalus)
Fin whales produce at least two types of calls (“20 Hz” and “40 Hz” calls). Both types of calls are generally 1 s long downswept pulses, with the 20 Hz calls sweeping from approximately 23 to 18 Hz. These calls can be produced in regular and irregular sequences. The 20 Hz calls are often accompanied by a high frequency component at 130 Hz. The file shows three 20 Hz downswept calls played back at 10x the original speed.
Example recordings from the Norwegian coast (anthrophony):
Vessel noise; a 124 m tanker passing at close range (excerpt).