A long-term plan for managing noise in shallow parts of the ocean such as Falmouth Bay is needed to protect the environment, experts have said.

Man-made noise in the marine environment can increase stress in animals, alter their behaviour, and displace them from habitats important to their daily lives. There has so far been limited scientific research on methods to assess long-term trends in marine noise in coastal regions, but engineers and biologists from the Universities of Exeter and Bath, have been investigating how best to monitor this increasing human influence in our seas. They used underwater sound recorders in Falmouth Bay for 14 months at a marine renewable energy test site and have found managing noise in shallow coastal environments will likely require a very different strategy to other, deeper ocean environments.

Lead author of the research, Dr Joanne Garrett, from the University of Exeter, said: “We found considerable variation in noise throughout the year. As well as anthropogenic noise sources such as shipping, we found that natural environmental conditions, such as waves and tide, also affect the sound levels. “Both of these factors highlight the need for tailored and long-term monitoring to develop a robust understanding of our effects on the marine environment”.

Dr Matthew Witt, from the University of Exeter’s Environment and Sustainability Institute, said: “This work underlines the need for continued and focused research in the area of human noise, both on techniques to collect, analyse and interpret data, and on the biological implications of noise on marine species and consequences for marine ecosystems upon which we are so very much dependent.” Click here to read more

ICES launches underwater noise data portal

All licensed impulsive underwater noise events in EU waters to be found on new data portal.

Published: 14 June 2016

The EU’s Marine Strategy Framework Directive (MSFD) lists input of energy including underwater noise as descriptor 11 in its list of Descriptors, which can be used to describe what the marine environment will look like when good environmental status (GES) has been achieved.

The ICES underwater noise data portal will not record all sounds in the seas, just the human caused impulsive noise that occur due to activities such as pile driving, seismic surveys, controlled explosions and from some naval operations. The ICES impulsive noise data portal assembles data supplied by OSPAR (North East Atlantic) and HELCOM (Baltic Sea) and will register noise events collated nationally from registers of licenced events. As there is currently inadequate knowledge on the effects of underwater sound and the effects of impulsive noise especially to quantify effects on ecosystem and population levels, the data portal aims to increase our knowledge of trends in these sounds. The ICES underwater noise data portal is available through the ICES Data Centre.

ICES FEATURE ARTICLE – Underwater noise

Nathan Merchant, Cefas The latest piece in our series of features looks at the world of underwater noise and the associated impacts and assessment. Published: 4 July 2016

ICES   ‘For many marine animals, the ocean is an ‘acoustic habitat’. Sound can penetrate dark or murky seas and travels much further than light underwater. Many marine organisms have evolved ways of using sound for communication, navigation, and detection of predators and prey. Baleen whales warble low-frequency calls over tens or hundreds of kilometres; in the mating season, aggregations of fish grunt and croak in chorus; dolphins click at high frequencies to echolocate fish; snapping shrimp make loud pistol shots with an oversized claw –­ this sonic wonderland is far from the ‘silent world’ of Jacques Cousteau.

In the modern era, humans have also learned to use sound underwater. From ship-borne depth sounders to underwater communication systems and seabed mapping to antisubmarine warfare, acoustic signals underpin the sensor technologies we use to measure, detect, and navigate in the oceans. Many human activities also generate sound as an unwanted by-product: the slow rumble of ship traffic, the repetitive thump of pile driving, the occasional boom of an explosion. How do marine animals react to these noisy newcomers? Could this affect marine ecosystems? If so, how might we monitor manmade sound and assess its possible impact? And what might we do about it? 

The evidence

Mass strandings of cetaceans linked to military sonar activity are the most dramatic example of our acoustic impact on the oceans – and first raised the issue in the public consciousness. However, subtler effects of man-made sound on marine animals are increasingly being discovered¹, and at lower sound levels, which implies that these effects are more widespread and potentially more detrimental to populations. Behavioural and physiological reactions to man-made sound have now been observed in marine mammal, fish, and invertebrate species. For example, harbour porpoises have been displaced from pile driving of offshore wind turbines by more than 20 kilometres,² lab experiments with shore crabs have found ship noise playback to disrupt feeding behaviour³, and European seabass have shown stress responses when exposed to in situ pile driving⁴.

Researchers are now looking beyond the impact on individual animals to consider how noise might affect the wider ecosystem, through effects on interactions between animals, effects on species which perform ecosystem functions, and the consequences of individual disturbance at the population level. Studies have demonstrated the reduced ability of fish to avoid predators in the presence of motorboat noise⁵, reduced nutrient cycling activity in langoustine exposed to noise⁶, and a probable low risk of population-level effects from disturbance by boat traffic and dredging activities based on modelling of a bottlenose dolphin population⁷.’ To read more click here