TNO develops knowledge and collaborateswith industry to make this practicable. We findsolutions today for problems that appearedunsolvable yesterday and we tackle the pro-blems that will confront our customers tomor-row. We take a multidisciplinary approach tocomplex issues, clustering knowledge form dif-ferent core areas in groundbreaking research.We stimulate cooperation with other know-ledge institutes both at home and abroad.TNO stands for open innovation, sharing know-ledge to create new knowledge. In this way wehelp people, organisations and the gover-nment to perform better.

Frank van den BergT+31 (0)1526 92420

Oude Waalsdorperweg 63P.O. Box 968642509 JG The HagueThe Netherlands

frank.vandenberg@tno.nl tno.nl

Defence, Security and Safety

offshore activities are a source of underwater sound and there are major

concerns on how to deal with these anthropogenic underwater sound sources and their

possible effects on marine life. A recent TNO project for the Ministry of Transport, Public

Works and Water Management showed that the main contributions to anthropogenic sound

in the North Sea come from shipping, seismic surveys (airguns), underwater explosions and

pile driving. Hence, regulation of underwater sound is explicitly mentioned in the European

Union's ambitious Marine Strategy Framework Directive for 2012. Furthermore, the

European Bird and Habitat directive requires impact assessment from all planned offshore

economical activities on flora and fauna. In the Netherlands alone, this concerns tens of

major offshore development projects such as the construction of offshore wind farms (the

Dutch government aims at a 6000 MW capacity by 2020), the extension of several harbours

such as Mainport Rotterdam with Maasvlakte 2, the Eemshaven etc.

While governments have started taking necessary steps towards regulation of underwater

sound, more and more key players in the offshore industry are looking into more sustaina-

ble processes and are therefore seriously concerned with the underwater sound issue.

ContextSeas and oceans have become a major economic

asset and the modern battle grounds of the 21st

century. Examples of this are offshore exploration

for oil and gas, wind farms, extension of har-

bours, canals and busy transport routes, responsi-

ble fishing and defence activities, etc. This means

that the world has to face a crucial economical

and environmental challenge: how to promote

offshore economical growth while protecting the

underwater environment. This challenge transla-

tes into many aspects, underwater sound pollu-

tion being one of them:

Underwater sound and itsimpact on marine lifeHow TNO can help you innovate towards more sustainable off-shore activities

TNO | Knowledge for businessmodels that assess potential acoustic impact zones for various marine species. For the biologi-

cal and ecological aspects TNO collaborates with (inter)nationally recognized institutes such

as IMARES (Institute for Marine Resources and Ecosystem Studies), SMRU, NPL (National

Physical Laboratory) and WHOI. Relevant examples are consultancy projects for industrial con-

sortia during the planning and impact assessment phases for large offshore/coastal construc-

tion projects (offshore wind farms, extension of harbours), research projects for the Dutch

Ministry of Transport, Public Works and Water Management such as such as the project

'Assessment of natural and anthropogenic sound sources and acoustic propagation in the

North Sea' (figure below) and the above mentioned international 3S programme

Simulated broadband noise distribution (received sound pressure level) for (a) a dredger near the

Rotterdam harbour, (b) a wind farm northwest of Amsterdam.

Development of risk mitigation tools

TNO has built up a research programme supported by the Royal Netherlands Navy (RNLN) to

focus on the mitigation aspects related to sonar operations and environmental risk asses-

sment. Within this programme TNO developed the SAKAMATA software tool to support the

mission planning and the calculation of risk mitigation measures. This tool will officially be

introduced in the RNLN in the beginning of 2010. Further development of the tool will conti-

nue until at least 2013.

And also…

Within the various core centers of TNO, complementary expertise is available that contributes

to the development of more sustainable offshore activities. This expertise includes for exa-

mple ship and air acoustics, dynamic behaviour of maritime structures, sound reduction via

optimization of a vessel's acoustic signature, corrosion aspects, etc..

There are still many uncertainties regarding the imminent environmental regulations on

underwater sound and its consequences for the offshore industry. Are you interested in

understanding the real issues of underwater sound for your activities?

TNO can help you in identifying them and prepare you towards more sustainable offshore

activities.

Noise level distribution in dB re 1 μ Pa 2

Longitude [deg E]

Latitude [deg N]

3 3.2 3.4 3.6 3.8 4 4.2 4.4 51.5 51.6 51.7 51.8 51.9

52 52.1 52.2 52.3 52.4

90 95 100 105 110 115 120 125 130 135 140 145 Noise level distribution in dB re 1 μ Pa 2

Longitude [deg E]

Latitude [deg N]

3.4 3.6 3.8 4 4.2 4.4 4.6 4.8 52 52.1 52.2 52.3 52.4 52.5 52.6 52.7 52.8 52.9

90 95 100 105 110 115 120 125 130 135 140 145

How our expertise in underwater sound impact assessment can help you

The so-called SESAME (Shallow water Extendible

Stand-alone Acoustic Monitoring SystEm) is

robustly designed to perform in high sea-state

and is placed on the seabed, where it can with-

stand pressures up to 20 bar (200 m water

depth). Hydrophones mounted to a vertical cable

record acoustic data in the frequency range 0.1-

180 kHz. This large frequency range allows for

both monitoring of underwater sound produced

during all sorts of offshore activities and/or

monitoring of marine mammals.

In situ acoustic monitoring of offshore activi-

ties, advanced data processing and analysis:

Relevant examples of acoustic monitoring are

measurements nearby offshore wind farms such

as the Princess Amalia wind farm (Q7), construc-

tion activities for Maasvlakte 2 being the in-sea

extension of Mainport Rotterdam, and the

Eemshaven. Furthermore, TNO has been asked

by the Ministry of Transport, Public Works and

Water Management to draft an underwater

sound measurement procedure and to help esta-

blishing a European consensus for measurement

standards regarding underwater sound, with

particular regard to sound in the North Sea.

TNO has thus built up a consequent track record

in the planning and performing of underwater

sound measurements in the vicinity of various

offshore activities.

TNO believes in an approach that combines stra-

tegic measurements and modelling, which in

time will enable the development of validated

prediction and risk mitigation tools when combi-

ned with ecological and bio-acoustical data. This

requires that sound should be measured at

several carefully chosen locations and at various

water depths in the vicinity of sound producing

activities. Each noise type must be registered

acoustically and should be linkable to its source

and operation stages. The background underwa-

ter noise should also be measured outside of

operational periods. The recorded data are analy-

sed in order to deduce the source level. With the

help of this source level, environmental parame-

ters (e.g. weather, bathymetry) and a sound pro-

pagation model, the sound level can be compu-

ted at any distance from the source and at all

depths. Such a complete model for underwater

sound only needs the correct environmental

parameters and strongly reduces the need for

future measured data.

Acoustic monitoring during pile activities on the construction site of the

offshore wind farm Princess Amalia Q7 off the Dutch coast in 2007. A

sample of the recorded sound pressure in kPa at 1 km distance.

Our underwater technology team also has a long expertise in passive

marine mammal monitoring and impact assessment trials for the

Royal Netherlands Navy and international sponsors such as the

American Organization for Naval Research (ONR), NURC (the NATO

Underwater Research Centre), etc.. One example is the international

3S programme, which currently involves four main partners: the

Norwegian research institute FFI, TNO, the SMRU research centre from

St. Andrews University and the American WHOI, the American Woods

Hole Oceanographic Institute. The 3S team conducted several

research trials between 2005 and 2009 in Norwegian waters to inves-

tigate behavioural reactions of killer whales, pilot whales and sperm

whales to Low and Mid Frequency Active Sonar (LFAS/MFAS) signals,

in order to establish safety limits for sonar operations. This research

is sponsored by the Dutch and Norwegian Ministries of Defence and ONR.

Underwater acoustic propagation modelling and impact assessment

TNO is able to combine sound source characteristics and environmen-

tal conditions in order to develop and validate acoustic propagation

models. When reliable information on animal behaviour (such as pop-

ulation distribution and migration routes) and hearing sensitivity

(audiograms) is available, these can be combined to propagation

Very little is known about the possible impact of underwater sound (both

natural and anthropogenic) on marine life. This is a complex and multi-

disciplinary issue that embraces not only technological but also non-tech-

nological aspects, and calls for a rigorous approach, a tight collaboration

between acousticians, biologists and ecologists and international consensus.

In order to provide some answers, the following preliminary steps are

necessary:

The rigorous characterization, in-situ measurement and modelling of

the produced underwater sound and background noise.

The processing, analysis and interpretation of the measured data

(with regard to sound propagation and characteristics).

The gathering of information on the underwater fauna distribution

and behaviour.

The study and inventarisation of the effects on individual animals,

and consequences for the population and finally the ecosystem as a

whole in both the short term and long term.

TNO was one of the early parties with acoustic expertise in the

Netherlands to start research on the impact of underwater sound on

marine life more than a decade ago. Our drive in that field is inherent to

the mission of TNO as a promoter of 'knowledge in sustainability' and

economy combined to a long history of expertise in all aspects of under-

water acoustics. It is also born from the following observations:

Measurement, modelling, reporting and interpretation of underwater

sound are not straightforward. Sound in water and in air are comple

tely different, but this is often not well considered.

Large gaps in ecological and bio-acoustical knowledge and the lack of

standardization have to be solved, to translate increasing concerns

about environmental impact of underwater noise into valid criteria.

Only then can a balance between economical growth and

sustainability be found.

One amongs many press realease & articles questioning the effects on under-

water sound... Is it true that a sonar can be "one billion times louder" than a

jet aircraft? Does it make sense to compare a sound in air with a sound in

water? If so, what is the correct way to make this comparison and what are

the possible pitfalls?

TNO has therefore taken the step to develop

and provide rigorous expertise and know-

ledge on the acoustic aspects of the impact

assessment. To provide the complete picture,

TNO embraces its multidisciplinary structure

to gather complementary technological

knowledge and has joined forces with

national and international experts in biology

and ecology. All together, TNO can provide a

wide portfolio of activities ranging from con-

tract research to consultancy, all directly con-

nected to the assessment process.

Fish, seals and porpoises are the main species at

stake in the North Sea

Design and development of innovative

underwater acoustic measurement systems:

TNO has developed a stand-alone measure-

ment platform for underwater sound that

enables autonomous measurements that can

last up to about one month.

The autonomous acoustic measurement system

SESAME before deployment during the monito-

ring of dredging activities during the construc-

tion of the 2de Maasvlakte in October 2009

A complex assessment process

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a)A glimpse in TNO's drive and expertise in

underwater sound and impact assessment