Whales and other marine organisms are being harmed by the unregulated use of military sonar.
There is a war being waged against whales, and it is being fought with noise. Originally exposed after unusual mass strandings of whales, this new war has left scientists and conservationists concerned about the potential impact of military noise on the wider marine ecosystem as a whole. And it has prompted the question of whether naval activities are bound by environmental norms, or whether this form of warfare is set to continue in the name of national security.
The original war against whales
It’s a catchy phrase. Historically it was used to conjure the activities of whalers, bravely chasing their prey, wrestling against the wind and waves before they fired explosive harpoons into the body of a fleeing whale. It was a symbolic image, recalling ‘Moby Dick’, and when transferred into the 21st century, it spoke of the archaic hunt that influenced thinking about the ‘man and the sea’ romanticism. But, the symbolism had a twist, in that it also described the unscrupulous hunt of an animal which grew in our collective consciousness from a beast into an intelligent beauty. The ‘war’ was eventually seen as unjust, serving the lust for a delicacy in high-priced restaurants. The prey grew into a symbol of our need to save the planet. In between the period of romanticism and brutal modern reality, there was a century of insanity, when whales were industrialised for their oil – the Big Oil of its time.
Whaling officially came to an end when the member governments of the International Whaling Commission (IWC) declared a ban on commercial whaling in 1982, which came into force four years later. Since then commercial whaling has been prohibited, leaving only a handful of industrial countries that still use loopholes in the IWC to continue their practices. And the protest remains.
Since the whaling ban, our knowledge of another threat to whales has grown. Another ‘war’, which when fully understood, goes beyond our imagination of destruction and harm.
A world of sound becomes a noise-filled hell
When we use the term ‘whale’, we actually mean ninety different species of cetaceans (whales, dolphins and porpoises). Within the family of cetaceans, there are many extremes, from the tiny vaquita, less than one and a half meters long, to the record-breaking thirty-metre blue whales. Cetaceans can be the ultimate divers, foraging in deep oceanic canyons; others live in shallow, muddy, rivers. Some have family bonds that last their whole lives; others live in completely different social units. But they all have something in common: they live in an acoustic world.
The ocean is filled with natural sound from animals and physical processes, and sound is everything to ocean wildlife. Through sound they maintain their bonds with relatives and mates, they pass information to each other, they teach their young, they search for prey, or use sound to find their way on some of the longest migrations on Earth. Evolution has helped ocean animals to see their world with sound. It’s their essence.
Sadly, ocean wildlife are not alone in reaping the merits of sound in water. Without care or concern, we’ve unleashed noise-generating technologies that serve the biggest and most powerful players on the planet: the oil and gas industry, and the military. Humans have turned a wonderful world of sound into a noise-filled hell for whales and all other marine wildlife.
From moving in sympathy to a lethal dance
Imagine standing in front of a loudspeaker in a rock venue during a sound check. Sound levels for the drummer are being set. The drummer is sounding his kick drum two beats per second: “TOMM, TOMM, TOMM”. The sound waves radiating from the speaker enter your body causing it to vibrate. What is happening is your body’s molecules are distorting, in sympathy, with the sound waves. Like a concertina. The sensation is tingly, similar to a mild electric shock, two times a second.
Now imagine wading chest height in vigorous beach surf. As a new wave approaches, your body is drawn towards it. You enter the wave, and your body is pushed in the opposite direction with considerable force. You feel your feet move around a metre and a half in one direction, and then back again. The duration, or frequency, of the complete cycle is about six seconds. During this time, your body experiences that same concertinaed transition, just on a bigger scale.
Individually, both experiences are considered pleasant to exhilarating. However, if both are combined, the outcome is a wave, in water, which has the same energy potential of the six-second cycle condensed to a half second cycle continuously. This outcome has now changed from pleasant to lethal.
Water is approximately 1,500 times denser than air and does not have the forgiving compressibility characteristics associated with air. So when an organism is exposed to a sound wave under water, the air pockets within the organism will distort first. As the noise level is increased (amplitude), there comes a point where the organism’s cells will no longer maintain their structural integrity and will break down. This is what is happening to many marine animals when they are exposed to the very loud noise generated by humans.
If we go back to the drummer’s sound check and think of the sound intensity level in the venue, military sonar (low, medium, and high), is perceptually three times louder, and it is lethal.
Whale strandings: the tip of the iceberg
The active sonar systems employed by the military – in particular noise in low- or mid-frequencies – to search for submarines, and actively screen whole ocean basins, generate devastating noise levels (see box).
Researchers and conservationists have expressed concern about the use of military sonar for decades, but it was the stranding of 17 whales in the Bahamas, involving four different species, in March 2000 that paved the way for an international discussion.
The US Navy initially dismissed claims about their responsibility, benefiting from the complexity of the issue and the almost impossible task of proving the cause of death. But, after exhaustive investigations by researchers, the Navy was eventually forced to admit that the only reason left was the employment of their low-frequency active sonar. As time has progressed, it is now apparent that almost all documented unusual mass strandings, often involving more than one whale species, correlate with naval activities.
Actual whale strandings are the tip of the iceberg – a chance circumstance where many factors, such as the occurrence of animals, tide and space, cause the animal wash up at the shore. Many more animals will have been severely impacted by the noise, for example fleeing their important habitats; experiencing extreme stress or disturbance; having their communication masked; impacts on their prey; or temporary or long-term hearing loss. The combination of these factors can lead to lethal consequences for the animals exposed. Others have suffered decompression sickness, as they flee towards the surface, and dissolved blood gases form into bubbles, affecting their joints, lungs, hearts, and brains.
Low, mid and high frequency active sonar
Active sonar comes in many forms for many uses: low frequency active sonar, used for locating depth and distance of an object, through to high frequency active sonar, used for underwater mapping of the sea floor.
Active sonar does not have a ‘one size fits all’ characteristic. The simple rule of thumb is the lower the frequency the longer the range of detection but with limited information in the return signal. The higher the frequency, the shorter the range of detection but with greater information in the return signal.
Low frequency active (LFA) sonar, as the name suggests, generates a very loud, low frequency pulses that can detect submarines at long distances. Each pulse can last tens of seconds, and up to minutes. The return signal, however, offers limited information – distance, depth and speed of a target (submarine).
Mid frequency active (MFA) sonar generates a very loud pulse between 1,000 – 5,000Hz with a pulse duration of approximately 18 seconds. It is used for submarine detection less than 10km away. The return signal of MFA offers more detailed information than LFA.
High frequency active (HFA) sonar generates a very loud pulses around 12,000Hz, for deep water, and between 400,000 – 700,000 Hz, for shallow water. HFA is used for mapping (imaging) the sea floor, producing very detailed images.
Continuous Active sonar generates a loud 100 percent duty cycle, in a frequency range between 500 – 3,000Hz. It is used for submarine detection and provides rapid continuous detection updates.
All in the name of national security
In reality, we are not even close to understanding the full scope of the impact of military sonar. This is made worse when we understand that most of this impact comes from mock battles and exercises, rather than actual combat operations, justified by arguments over national security.
In the past few years, the international community has recognised the importance of taking appropriate action to reduce the impact of noise in the ocean, including time-area closures, the establishment of exclusion zones, the propagating of best available technology and environmental practices, as well as deep assessment procedures and mitigation measures. But as a rule, military activities tend to be exempted from environmental provisions in legislation.
Ocean noise is subject to a number of international agreements and decisions adopted by states through the Convention on Migratory Species (CMS), the Convention on Biological Diversity (CBD) and others. The EU has also called for conservation measures to protect protected species from harassment, which includes acoustic disturbance, by recognising ocean noise as one out of eleven descriptors for assessing the status of the marine environment under its Marine Strategy Framework Directive (MSFD).
Defence ministries are often quick to point out that Article 2.2 stipulates that: “this directive shall not apply to activities the sole purpose of which is defence or national security”, even though the provision continues: “Member States shall, however, endeavour to ensure that such activities are conducted in a manner that is compatible, so far as reasonable and practicable, with the objectives of this Directive”.
There are likely many experts and people involved in military activities who care about ocean wildlife, and who try to find ways to better protect the environment, but how far can they go, and would we even know?
The country with the largest and strongest military power in the world – the US – only recently bowed to civil society. In 2016, the Natural Resources Defense Council (NRDC), together with other NGOs, successfully challenged the government’s failure to adequately protect marine mammals from the Navy’s use of the Low-Frequency Active (LFA) sonar for the third time. In prior district court cases (2002 and 2007) plaintiffs and the Navy reached a court-ordered settlement allowing the use of the system in significantly reduced areas of the world’s oceans, with the promise of sufficient protections under future permits. The government failed to meet that promise.
In 2016, the Ninth Circuit court ruled in favour of the NRDC and the other challengers. In its decision, the three-judge panel found that the lead government agency had unlawfully ignored reasonable safeguards recommended by the government’s own scientists to reduce or prevent harm from the sonar system, resulting in a ‘systematic under-protection of marine mammals’ throughout ‘most of the oceans of the world’. It found, among other things, that protecting marine mammal habitat from Navy sonar is ‘of paramount importance’ under the law.
Before this ruling, in September 2015 the US Federal Court silenced the US Navy’s active sonar systems ‘in areas around Southern California and Hawaii during certain periods of the year when marine mammal populations are most vulnerable’.1 The agreement further stipulates that important habitats for whales, dolphins, seals and sea lions are off-limits to both mid-frequency sonar and explosive training and testing.2 Accordingly, the “…settlement aims to manage the sighting and timing of Navy activities, taking into account areas of vital importance to marine mammals, such as reproductive areas, feeding areas, migratory corridors, and areas in which small, resident populations are concentrated”.3 More specifically, the Navy is prohibited from using mid-frequency active sonar for training and testing in Santa Catalina Island and San Nicolas Island; two habitats considered vital for the survival of beaked whales.
These cases show that there are examples where environmental and species protection provisions can and do restrict military activities. So why do navies operating in European waters fail to engage in an equally transparent framework?
It’s not ‘just’ whales
In recent decades it’s become apparent that ocean noise impacts many species, including fish, crustaceans and cephalopods, pinnipeds (seals, sea lions and walrus), sirenians (dugong and manatee), sea turtles, the polar bear and marine otters, as well as cetaceans (whales, dolphins and porpoises).
In 2017, OceanCare commissioned a review of the potential impact of noise specifically on fish and invertebrates. The review looked at 114 studies, 104 from peer-reviewed journals, about a range of ocean noise sources, which identified 61 species of fish and 26 species of invertebrates that were impacted. The findings are alarming, documenting impacts that include body malformations and mortality, internal injuries, disorientation, temporary and permanent hearing loss, impacts on immune systems and reproductive rates, behavioural changes, and even damage to the integrity of DNA.
The report suggested that a failure to incorporate noise into responsible ocean management policies therefore risks undermining progress on the UN Sustainable Development Goals, threatening the food security of coastal communities.
A way forward for ocean wildlife in the Mediterranean
At the 6th Meeting of the Parties of the Agreement protecting whales in the Mediterranean and Black Seas (ACCOBAMS), taking place in autumn 2016 in Monaco, one delegate told the plenary about his own experience on a research vessel when hydrophones were used to record signals of wildlife, and in particular marine mammals, in the region. The researchers heard a lot. But, it wasn’t the beauty of whales singing, crustaceans clicking their claws, and wind on the sea surface. What they heard was the cacophony of underwater warfare from vessels in the eastern part of the Mediterranean.
Compelled by the evidence, the states adopted a resolution on marine noise calling for a workshop: “…inviting NATO and national navies to show how the ACCOBAMS Scientific Committee can provide advice and assistance with respect to mitigating adverse effects on cetaceans for any future exercises”. The idea was for the workshop to lead to constructive dialogue with a common objective.
This regional decision was followed by an international decision of much wider scope, through the Convention on Migratory Species (CMS) in 2017. CMS Resolution 12.14 endorsed the CMS Family Guidelines on Environmental Impact Assessment for Marine Noise-generating Activities. These Guidelines provide comprehensive and consistent guidance on the assessment of noise-generating activities, providing specific advice for different activities, including military active sonar systems. The ball is again with governments to act, but will they?
While writing these closing lines, NATO had just undertaken another manoeuvre -DYNAMIC MANTA, in the Mediterranean Sea. Ten nations, nine warships and six submarines were involved in a ‘high-end multi-national exercise designed to sharpen existing NATO Anti-Submarine-Warfare skills in the Mediterranean Sea’. What was happening to ocean wildlife in the region? In the name of national security, we will never know.
Minimising harm to the marine environment from military noise pollution
It is of utmost importance that naval exercises are subjected to comprehensive environmental assessments and display appropriate levels of transparency. There is better practice than the usual “behind closed doors” policies on the occasions where naval exercises are subject to public commenting processes, or when mitigation measures are put in place.
The guidelines on marine noise developed under the framework of the Convention on Migratory Species (CMS), which have been endorsed by more than 120 state parties, show how proper environmental impact assessments should be undertaken, and provide a government agreed toolkit to be followed. Their application should be strongly encouraged globally, as they also deal with noise generated by military activities.
There is also a need for time-area closures for intense noise generating activities. This approach needs to be guided through the involvement of expert scientific bodies, which can provide accurate information on the distribution and occurrence of noise-sensitive species, including those that are endangered, or of vital importance to the marine ecosystem.
Such approaches require close collaboration between representatives from national navies, scientists and conservationists. An example of a regional starting point for a stakeholder collaboration of this kind could be a workshop proposed by the Range States to the Mediterranean and Black Seas: a workshop that we urge the secretariat to arrange.
For more information: https://www.oceancare.org/en/our-work/ocean-conservation/underwater-noise/
- NRDC, 2015a, Please Silence Your Sonar: https://www.nrdc.org/onearth/please-silence-your-sonar
- NRDC, 2015b, Navy Agrees to Limit Underwater Assaults on Whales and Dolphins: https://www.nrdc.org/media/2015/150914
- Ibid. 2015a