Seismic acquisition and its impact on marine life: a review and ethical aspects



There is a growing interest in understanding the effect of human-caused sounds such as ships, sonars and seismic air guns on the marine life. Fish and marine mammals use sound to communicate, sense the environment and find food. Marine mammals sense the environment by listening to sounds from natural sources, for example, surf noise, which can indicate presence and direction of a shoreline, or noise from an ice edge. Toothed and sperm whales use echo sounds to sense presence and location of objects, such as prey. Therefore, if a human-caused sound is within the animals’ auditory range, it might affect marine life in a way that could potentially prevent the animals from hearing important sounds, or cause the animals to alter their behavior.

We have a responsibility to protect the marine species against our human-induced noise. Indeed, this perceived responsibility is reflected in current concerns expressed through major campaigns for environmental organizations such as Oceana and Greenpeace, as well as through the increased regulations and guidelines during the planning phase and eventual sonar and seismic activity. In Norway, this concern has turned into an important question related to the oil industry, since environmental organizations use seismic acquisition and its impact on sea life as one of the largest anchor points towards the industry. However, ambiguity in science together with different ethical values, interests, and engagements has led to a carousel of discussions among experts on the issue and where the boundary defining what is right and wrong should be set.

As a marine geophysicist studying climate change, I have a special moral responsibility and curiosity about the effects that geophysical methods (e.g. seismic) can have on marine life. Throughout studies and work, I have participated on ~10 seismic acquisition cruises in arctic waters, almost all of them among whales and large schools of fish, without knowing much about the impact the operations can cause and potential mitigation procedures we apply to mitigate interference. Here, I will discuss the ethical challenges arisen by seismic airgun shooting.


Figure: Illustrative animation picture from: 

This relatively long essay is written by me, Malin, as a part of the course “Philosophy of Science and Ethics” at UiT.  The public interest for the issue made me wanting to share it with you.  Please do not hesitate to let me know (in the comment field below) if there is any comments or concerns regarding the text. 

What responsibilities do we have to the environment and why?

We use environmental ethics to discuss and determine what is right and wrong in the relationship between humans and the nonhuman environment, i.e. what things are valuable in the nonhuman environment, why and how they are, and how we should consider these values in principles, actions, practices and law (Palmer et al. 2014). Different values and possibly normative frameworks among societies and social groups cause different ethical perspectives and approaches. Hence, environmental ethics have branched into human-centered, animal-centered, life-centered and eco-centered environmental ethics. The different positions can further be discussed from a consequentialist or deontological point of view. Using the work of Elliot (1991) and Palmer et al. (2014), I give a short overview of the different ethical environmental positions, which have been necessary to use when attempting to clarify and unravel arguments in the debate of seismic impact of marine life.

(1) According to Human-Centered environmental ethics, humans have dominion over nature, meaning humans are more morally significant than what nonhumans are. In a strong human-centered viewpoint, only humans have intrinsic value (value in itself).

(2) Other philosophers claim that human beings have a moral responsibility to nature for the sake of nature itself, not its benefit to us. Humans are obligated to protect and promote the well-being of all living beings, including plants, algae, single-celled organisms and even perhaps viruses because they all have intrinsic value. This is so-called Life-Centered environmental ethics.

(3) An Animal-Centered perspective is something between (1) and (2) and considers only non-human animals as moral objects that deserve moral consideration.  One can distinguish between strong animal-centered ethics, where the rights of humans do not override those of animals, and, lighter animal-centered ethics, those who argues that animals that have more psychological capacities, such as sentience, have higher moral significance than others do.

(4) From an eco-centered perspective (holism), our moral focus should not be on individual living beings but on ecological communities, e.g., ecosystems. “—things is right when it tends to preserve the integrity, stability, and beauty of the biotic community.” (Quote: Aldo Leopold).  Many eco-centered ethicists also defend holism with respect to species. Species have values, but not necessary each individual. We, as moral agents have an obligation to prevent them from going “extinct”, locally or globally, from human causes.

(5) Consequentialism is result-based ethics, which focuses on whether an act is right or wrong purely depending on the result of the act, and, the more good consequences an act produces, the better or more right the act is. What good thing that should be maximized depend on the ethical positions.

From a (6) deontological perspective, there are certain imperatives. Certain things you should never do, e.g. an action that interferes with the duties of another moral agent for example. Whom the moral agents are, and what rights and values they have, differ between ethical perspectives (e.g. human, animal, ecosystem).


What is the deal with seismic air guns?

Airgun seismic surveys (marine seismic), widely used in the oil industry and research, emit low-frequency high sounds. They facilitate compressed air of about 2000-3000 psi (~140-170 bar) fired by one or several air guns every 3-15 seconds towed behind a slowly moving ship. The release of compressed air generates sound waves that travel through the water column. Directly by the source, the peak level of the chain of air guns can have peak levels as high as 250 dB* [1]. The geological data appears as the sound waves bounce back from different layers in the sediments and rocks underneath the seafloor, this way, one can map the geology underneath the seafloor that is otherwise hidden from mankind (Caldwell and Dragoset, 2000).

The intensity and amplitude of sound waves decrease rapidly from the source because sound waves spread out in all directions. Goertz et al. (2013) tested and modeled source decay from a 3090 cu in. source array with a peak sound level of 230 dB and a single airgun of 30 cu. in with a peak sound level of 190 dB. In both cases, a decrease of 20 dB occurred within the first 100 m from the source. At this distance, the noise level for the large source array was measured 170 dB and from the small air gun 150 dB.  Larger sources have a slower decrease in sound per distance and vice versa. At the University of Tromsø, we use one to two small air gun sources so-called GI airguns at totally 30 to 150 cu in volume. In other words, one would have to be within a couple of meters range to be within the peak sound level for such small airguns.


Scientific studies and ethical discussions

If and how much human-caused sound sources affects marine life depends on many factors such as the power, intensity, duration and frequency of the seismic equipment, as well as the distance from the sound source and depth. Biological communities prevailing in the area also make a difference, since different species have different tolerance towards sounds.

The severity of sea life impacted by human-caused sound including seismic air guns is still, and have been under discussion for decades. In 2005, biologists, acousticians, geophysicists and governmental regulatory technical managers gathered to discuss the effect of sound on marine life generated by oil and gas exploration and production activity. They did not agree on a simple and definite answer. Therefore, an international E&P Sound and Marine Life Joint Industry program (JIP) was formed in 2005 with the aim to gather data and do research work that is more valid on sound and source, physical and physiological effects, behavioral reactions and mitigation and monitoring methods [2]. In 2016, the program finished with 30 reports and 70 peer-review papers.

The National Marine Fisheries Service (NMFS), a division of NOAA, also just finished a 15-year research program gathering expert advice on how marine mammals are disturbed, and damaged by sound [3]. Based on experiments and available scientific data, they have developed a single comprehensive document, the “Technical Acoustic Guidance” with various marine animals sound threshold levels (above which marine mammals are predicted to experience changes in their hearing sensitivity either temporary or permanent), to use as a tool to evaluate the effects of proposed operations of human-caused sound. Depending on species, their results indicate sound threshold levels between 170 and 230 dB*. Hence, marine animals have to be within 10s or 100s of meters from the single small or large array, respectively, to experience high sound levels close to the upper hearing thresholds. We can also conclude that the peak sound level of UiT’s GI airguns is relatively “friendly” in relation to conventional seismic sources.

The Center for Marine Science and Technology at Curtin University executed an extensive study on various marine animals’ threshold response to nearby seismic air guns, (McCauley et al., 2000). According to their study, all baleen whales, sea turtles, finfishes, and squids showed a common high-end hearing response/general avoidance of the seismic operating source at 156-168 dB*. Fewtrell and McCauley (2012) indicate somewhat similar results on a study of captive fish (alarm responses at slightly lower, ~150 dB*). Contrary, Wardle et al. (2001) conducted a study above an inshore reef off Scotland where fish showed no responses other than a transient startle reaction that did not change the pattern of movement of the fishes when exposed to seismic sound levels of as much as 195 to 218 dB*. The study concluded that air gun shooting had little effect on the daily behavior of fish (including Pollack fish). Contrary, another study, conducted in Norway in 2009, indicated that Pollack, but also Greenland Halibut, Redfish, Ling, and Saithe increased swim level likely due to higher stress as a reaction to the sound of seismic airguns (Løkkeborg, 2010). A study of gray whales, adjacent to a feeding area near the Sakhalin Island, Russia, show a seismically affected distribution of five out of ten whales but the total number of gray whales present in the area remained stable during the seismic activity (Yazvenko et al., 2007).


Figure: Example of hearing thresholds of some different marine species.  from:

One of the problems regarding effects on fish is that studies are ambiguous partly because “fish species are numerous and highly variable and because no easy method exists for measuring the behavior of wild, unrestrained fish” [2]. The fact that there are about 500 000 to 1 million known marine species in the world oceans, and we only know ~1/3 of them, does not make the issue simpler. The mentioned studies above and many more indicate that there is diversity but also contradictory behavioral effects of seismic air-gun impact among species. However, there are some broader conclusions one can attempt to draw.

For example, at spawning or feeding areas, and at reefs, fish will either be scared away, or, “forced” to stay put and tolerate a stimulus they might otherwise avoid if the benefits in terms of feeding, mating or other factors out-weight the negative aspects of the stimulus (Council et al., 2003). In the worst case, they can be “forced” to stay in areas that exceed their threshold of sound, in such case; they are within the danger zone of risking hearing damage.

From an animal-centered or life-centered perspective, fish and mammals are moral objects since they are sentience, that is, they can experience suffering and pleasure, and should, therefore, be morally considered for the sake of themselves (Palmer et al. 2014). According to Palmer et al. (2014) sentience in itself is a sufficient condition for moral significance is widely accepted in environmental ethics in general. Strong animal- and life-environmental perspectives would claim equality, that is, the rights of humans do not override those of animals. This would certainly prohibit any animals of coming closer to seismic source than their threshold of sound since the risk of hearing damage can lead to stranding and death and if any risk deaths, it would be murder and therefore illegal. This is certainly, however, on the far end of the scale of potential negative consequences, but perhaps the only obvious evidence we, humans, can see, unless examination the ears of the animals before and after seismic activity (which might be too much of interference).  The dilemma becomes complicated when trying to distinguish between severe disturbance and casual insignificant disturbance. Amongst humans, it would be easy, since we could just ask the ones involved.  Unfortunately, we cannot communicate with the animals and so, there exists an obvious gray zone, which is subjective and interpreted differently amongst different people and ethical perspectives.

However, such concerns have contributed to the development of specific requirements of extensive mitigation procedures now well established within seismic companies. Within conventional seismic activity, surveyors must follow strict guidelines, so-called mitigation programs, to protect the marine life in the area. Commonly, mitigation programs include planning the activity outside areas and periods of feeding and spawning, pre- and post-seismic observations, marine mammal observers, passive acoustic monitoring, and sound propagation modeling and soft-start-step-up procedures of the source to signalize the future activity-to-come to animals. If marine life is observed or heard within a pre-determined distance from the source, operations stop immediately and restart when the area is clear again. Different regions, countries, and companies have different mitigation regulations and practices aimed at species and environment in the specific areas.

According to sources here at the department of geoscience at UiT, during the planning phase of seismic research operations, a document must be delivered to authorities, containing information about the operation and areas that it supposed to be executed in, in order to consider any interference with other activity such as, fisheries and environmental aspects. However, due to the small volume of air being released from the air gun – which causes lower sound levels than typically conventional seismic air gun arrays – we are exempted from using certified, “whale watch”. Instead, the crew on the bridge must keep an eye on potential animals coming too close.

A common basis for most regulation and guidelines (i.e. risk-benefit analysis) are human-centered consequentialism. One should strive to “create a security that is mutual for individuals, groups and nations”.  Using mitigation programs have pros and cons that will influence a human-centered perspective, and should, therefore, be taken account for when trying to calculate the best outcome among humans and in human relation to nature. The benefit of mitigation procedures – in addition to protecting the environment – is that it generate research, increase compliance with the government. However, the challenge is that it increases workload, costs, and part collaboration of parties and inhibits (Lewandowsky, 2016). Human interests will be account for when deciding what is right and wrong from a human-centered perspective. For the seismic operation in itself, this may be protests and oppositions regarding our relationship to nature, interference with fisheries, the affection of fish stocks and other interests.   If the overall benefits of seismic activity among humans have a greater outcome of happiness or welfare among us, humans, it should be ethically accepted according to a human-centered perspective, and the other way around.

The reason for the seismic acquisition is therefore also significant, for example, for the cause of climate science or alternatively oil exploration. One could argue that oil exploration would benefit humans the most (e.g. economically growth and investment, but also human happiness and wealth) but at the same time, more extraction will lead to increased climatic changes, which are a clear danger to human society. The human-centered ethical perspectives can radically differ based on different values; i.e. environmental organizations would value more the potential threat of climate change rather than “benefits” of oil exploration, which would be important values for oil companies.

There has however been an increased dissatisfaction of this kind of governance. Nowadays, a lot more emphasis has been placed on that science should demonstrate how it contributes to solving the “grand challenges of our time” (e.g. climate change, poverty alleviation, transport and green energy etc.). Oil and gas industry has a negative reputation due to its negative feedback on climate.  This negative attitude from the public and environmental organizations grows even stronger when geophysical methods have the potential of causing damage and interference in the environment and threaten marine life. It might be easy to blame the oil and gas industry for being ethically incorrect. However, in that case, the seismic activities might be more justified if it contributes to a better world for people learning about climate change etc.

Most research indicates that seismic activity using air guns can alter the behavior of marine animals (Caldwell and Dragoset, 2000; Wardle et al., 2001; Slotte et al., 2004; Dalen and Knutsen, 1987). However, in areas where animals are not restricted to, research has shown that avoidance behavior occurs well beneath their threshold of sound, commonly around 150 dB for various species (Fewtrell and McCauley, 2012). Khyn and others (2011) go further and conclude that “outside spawning grounds, fish, and mammals are probably not disturbed, unless dealing with extremely vulnerable species such as northern right whales and bowhead whales of the Spitsbergen stock…”. Whether or not current evidences are strong enough to draw such conclusions, is another discussion. However, it suggests that animals can alter their behavior so they swim away from the source, but that it does not have to mean that they are significantly disturbed by the seismic airguns it. This statement certainly sheds another light on the ethical discussion, which now turns into a discussion of who has the right to be in the area during the seismic activity. Strong animal-centered and life-centered ethics does not differ between rights of humans and animals, whereas most other perspectives consider humans of higher moral significance, therefore should accept temporary displacement of marine life. It should also give rise for questioning the neediness of mitigation programs outside spawning and mating areas because if it’s likely that the risk of disturbing the animals is not present, then should we care and use extensive time and money on mitigation programs?

When it comes to research work, one of the main points in the Guideline for research ethics in science and technology (2016) [4] is; “Research must be in accordance with sustainable development and respect for the environment, which means that it should promote biodiversity and in accordance with the Precautionary Principle”. The precautionary principle is clearly a deontological perspective i.e. you should never perform an activity in such way that the risk and uncertainties are too high and the potential outcome unforeseen.

Furthermore, sperm whales themselves generate clicks comparable sounds to the loudest sound levels generated by seismic that is 238 dB (Mohl et al., 2003). Moreover, blue-whales low-frequency calls have been measured at 190 dB and can travel for thousands of kilometers (Richardson et al., 1995). In general, whale’s moans and songs can reach 170-190 dB. The small pistol shrimp compete with the whales in producing load sounds, snapping of its claws create a cavitation bubble that generates an acoustic pressure peak of 218 dB. The pressure itself is strong enough to kill small fish (Richardson et al. 1995).   These facts indicate that seismic operations cannot cause hearing issues for these types of whales, but it can indeed confuse them.

Strong attitudes against seismic shooting from false, unscientific information?

The 10th of February 2017 about 416 pilot whales stranded at the beach of Farewell Spit in Golden Bay, New Zealand. About 300 were already dead during the time they were discovered [5].  One of the first questions that arise in the media was if seismic blasting had caused the stranding of the whales. Due to a lack of seismic activity in the area, this was quickly ruled out. Still, what made people think so? In an interview, Dr. Oliver Boisseau, a scientist at the Marine Conservation Research, says that there are now increased indications that seismic activities, for example, have caused serious injuries and standings to marine life. A headline in champions for cetaceans [6] (a shared information site for supporters of whales and dolphins), says; “Atlantic Seismic Survey Promises Death and Devastation for Dolphins, Whales, and other Sea Life”. In this article, they write “These dynamite-like blasts—which are repeated every ten seconds, 24 hours a day, for days and weeks at a time—are 100,000 times more intense than a jet engine. Langeth will be towing an 18 gun array of 160-190 Db of deadly sound”. The environmental organization Oceana even claims that seismic air guns are much more intense than jet engines [7]. In other interviews, various sources parallel the seismic effect on fish and whales as “going in and bombing some one’s home or backyard” (for example Matthew Huelsenbeck, a marine scientist at Oceana to National Geographic [8]).


Figure: Campaign poster used by Oceana. 

The fact is that sound from seismic is actually quieter than a jet engine considering intensity. Measured in dB, the sound from a jet engine is about the same sound as air guns release. However, the power (or intensity) from a jet engine is considerably higher than air guns due to its longer duration compared to the short impulsive nature of air guns [9].

Similarly, false statements about effects of seismic activity are also claimed in the media in Norway.  For example, in a debate in Stavanger Aftenblad in 2009 of seismic and fishery, Bjørnar Nicolaisen, a prominent and well-known fisherman and economist, used false arguments and statements regarding marine life effect on seismic shooting. Ingebright Gausland wrote later a disclaimer in the same newspaper (Bjørnar Nicolaisen fører oss bak lyset) where he also implies that Nicolaisen most likely knows that his statements are false but use them anyway. Gausland finished the text by writing that if fishermen’s attitude towards seismic is based on his “opinions” it is clear that coexistence will never happen [10].  People might not have the resources to research the fact behind what Gausland said and then, it might become an issue of belief. Most likely, some will also react to the strong claims of Gausland.

Clearly, the media, individual activists, and environmental groups tend to reflect a distinctively strong attitude against seismic shooting, and that often leads to protests in the weeks ahead of planned seismic operations. Unfortunately, it seems like a lot of the strong attitude originates from false, unscientific information. To date, seismic surveys have never been proven to be a cause of stranding events or deaths yet according to Sea Shepered NZ director Michael Lawry in an interview with newshub [11]). Unscientific scaremongering might have influenced the general view and attitude towards seismic activity and causation of stranded whales.


It is clear that sounds well above the hearing threshold of many marine species occur close to the source of active seismic air guns. Even so, seismic activity has been documented to have caused minor harm. The risk of injuring marine animals is regarded as negligible, especially i.e. outside spawning and mating areas, since there is time to move away from the source. Slower build-up of pulses compared to explosives and generally small continuous exposure time (less than one second) cause less intense signals than, for example sonar and multibeam echo sounder. Despite excessive research in various fields of expertise on seismic air guns impact on marine life, scientists still seem to struggle to come up with final answers of behavioral effects and sound threshold level among different marine species. Different research practices, environmental settings and contradictory behavioral affects among equal species complicates the research results. Even though some parties have amplified, actual consequences of seismic air gun effect of marine life, therefore caused questionable ethical aspects, animal welfare and protection of ecosystems increase in value among humankind, and we should consequently strive to act more correct according to animal-centered and eco-centered values.

The controversy on this topic is about not only the ambiguity within and about science, but also different arguments that are based on different values and possibly different normative frameworks, play a role. More likely, though, it seems that these movements and opinions prioritize values and beliefs that are not necessarily based on scientific studies on sea life harm caused by seismic activities. When seismic activities are used as an anchor point to stop oil exploration it seems like a waste of resources if this is based on the false argument that it is harmful for sea life. Rather, I think one should focus on the reason for the existence of the activity itself (i.e. the industry), or for a less drastic change – potential mitigation programs.

The article of Lewandowski (2016)  “Getting of the decision carousel: The case study of Marine mammals and sound” seems to capture the core of the debate quite neatly:  “Ultimately,  the  wickedness  of  the  issue  is  not  about  the  science,  nor  will  the  science ever tame the  issue  on  its  own.    Rather,  the  issue  is  intractable  because  of  the conflict between people about  the  most  appropriate  path  forward.    It  is  then  imperative  to  understand,  address,  and transform   this   conflict   in   order   to   move   off   the   decision   carousel   and   toward   improved conservation  outcomes  and sustainable  decisions”. Lewandowski hereby cuts to the heart of this and many ethical dilemmas within society, namely the different values, norms and beliefs underlying controversial issues such as seismic activity for sea life.

So how do we get off the decision carousel? It seems clear that knowledge across fields to generate mutual understanding will enhance the decision-making processes. Can more knowledge and better precautions resolve the conflicts? Yes, perhaps, to a certain extent. However, the different oppositions are also about values ​​and about how seismic is connected to other issues (conflicts of areas, fishery regulations, climate change, etc.). Moreover, the fact that current research is ambiguous related to risk and uncertainty. Therefore, the precautionary principle is and will be important. In that case, depending on different values, norms and beliefs, the core of this issue might be risk assessment and risk management (e.g. the comprehensiveness of mitigation programs), the legitimacy for maintaining the industry it contributes to (e.g. whether to stop seismic activities or not), or a discussion about animal rights (e.g. the duty for humans to refrain from any kind of interference with their habitat). Going into detail in studies and specialize mitigation programs might lead to more confusion.  It seems however easier to draw broader conclusions and more general guidelines. Perhaps a more general approach of mitigation rules that might involve using the upper boundary of acceptable threshold sound level for the species with lowermost sound threshold.

Because seismic activity will continue as long as hydrocarbon exploration and geophysical research continue. However, it should be noted that seismic operations have shown to become more and more environmental friendly with time, particularly as technology advances. Seismic systems become more efficient, which have led to less powered source, and new air gun technology (the eSource) filters out excess high sound frequency’s (i.e. the most disturbing to marine life) before it is emitted from the source.  A victory for many, followed by the oil industry`s currently hard time, seismic activates have also drastically decreased in Norway (and likely other countries) the last couple of years. Data from NPD show that amount of 3D seismic surveys completed in Norway during 2015 to 2016 has declined 45 % compared to the previous two year period [12].


In this essay, I attempted to unravel and clarify the arguments used in the debate about how seismic activity interfere with marine life by use of different philosophical perspectives. Even though extensive amount of research exist on the impact of seismic air guns on marine life, researchers seem to struggle compiling the information and coming up with general conclusions, perhaps due to the ambiguity within science, different arguments in debate and the fact that it touches upon our relationship to nature.  Increasing understanding of how human kind affects nature is likely to cause stronger animal- and eco-centered views in us. In order to avoid tension between social activists and industry, the latter have to come up with stricter rules and guidelines, and act with more precaution than earlier.  However, on the other hand, contradictions between public and industry often root from causes of seismic of oil and gas. Since the social activists often target oil and gas industries at large rather than specific seismic surveys that are just precursors to oil and gas extraction, it is believable that oppositions and discussions will continue to the end of the green shift.

The ethical values I propose, originate from a mixture of eco-centered, animal-centered and human-centered deontological perspective, where precaution is important. I believe we should not consider science as an excuse for damaging nature; contribute to unnecessary  pollution, interfere with nature because it pleases us somehow, but do all necessary to keep the nature in an undisturbed state, aim towards a sustainable and respectful attitude towards the nature and so that we, wildlife and future generations have possibilities of a good life together.  With this, I will continue my research work with better knowledge of possible and necessary  mitigation procedures, deeper understanding of risks that our seismic  sources possess and confidence that  we are able to prevent damages of marine  life.


*Decibel values in water column are “dB re 1 µP”. For simplicity, I use “dB”.


For further reading about this issue, we recommend the new book “Introduction to Exploration Geophysics with Recent Advances”; chapter 3: Marine Seismic Sources and Sounds in the Sea. The book is freely available here.



Featured image from:

CALDWELL, J. & DRAGOSET, W. 2000. A brief overview of seismic air-gun arrays. The Leading Edge, 19, 898-902.

COUNCIL, N. R., STUDIES, D. O. E. A. L., BOARD, O. S. & MAMMALS, C. O. P. I. O. A. N. I. T. O. O. M. 2003. Ocean Noise and Marine Mammals, National Academies Press.

DALEN, J. & KNUTSEN, G. M. 1987. Scaring Effects in Fish and Harmful Effects on Eggs, Larvae and Fry by Offshore Seismic Explorations. In: MERKLINGER, H. M. (ed.) Progress in Underwater Acoustics. Boston, MA: Springer US.

ELLIOT, R. 1991. Environmental Ethics, in Singer, P. (Eds.), A companion to ethics. Blackwell: Oxford.

FEWTRELL, J. L. & MCCAULEY, R. D. 2012. Impact of air gun noise on the behaviour of marine fish and squid. Marine Pollution Bulletin, 64, 984-993.

GOERTZ, A., WISLØFF, J. F., DROSSAERT, F. & ALI, J. 2013. Environmental source modelling to mitigate impact on marine life. pgs, Vol. 31, 2013.

KYHN, L. A., TOUGAARD, J., JOHANSEN, K., BOERTMANN, D. & MOSBECH, A. 2011. Guidelines to environmental mitigation assessment of seismic activities in Greenland waters. Danish Center for Environment and Energy (DCE)

LEWANDOWSKI, J. 2016. Getting off the decision carousel: The case study of marine mammals and sound. Proceedings of Meetings on Acoustics, 27, 032004.

LØKKEBORG, S. O., EGIL; VOLD, AUD; PEÑA, HECTOR; SALTHAUG, ARE; TOTLAND, BJØRN; ØVREDAL, JAN TORE; DALEN, JOHN; HANDEGARD, NILS OLAV 2010. Effects of seismic surveys on fish distribution and catch rates of gillnets and longlines in Vesterålen in summer 2009:. Havforskningsinstituttet, Fisken og havet 2-2010.


MOHL, B., WAHLBERG, M., MADSEN, P. T., HEERFORDT, A. & LUND, A. 2003. The monopulsed nature of sperm whale clicks. J Acoust Soc Am, 114, 1143-54.

PALMER, C., MCSHANE, K. & SANDLER, R. 2014. Environmental Ethics. Annual Review of Environment and Resources, 39, 419-442.

RICHARDSON, J., JR., C. R. G., MALME, C. I. & THOMSON, D. H. 1995. Marine mammals and noise. Academic Press.

SLOTTE, A., HANSEN, K., DALEN, J. & ONA, E. 2004. Acoustic mapping of pelagic fish distribution and abundance in relation to a seismic shooting area off the Norwegian west coast. Fisheries Research, 67, 143-150.

TECHNOLOGY, T. N. N. C. F. R. E. I. S. A. 2016. Guidelines for research ethics in science and technology.

WARDLE, C. S., CARTER, T. J., URQUHART, G. G., JOHNSTONE, A. D. F., ZIOLKOWSKI, A. M., HAMPSON, G. & MACKIE, D. 2001. Effects of seismic air guns on marine fish. Continental Shelf Research, 21, 1005-1027.

YAZVENKO, S. B., MCDONALD, T. L., BLOKHIN, S. A., JOHNSON, S. R., MEIER, S. K., MELTON, H. R., NEWCOMER, M. W., NIELSON, R. M., VLADIMIROV, V. L. & WAINWRIGHT, P. W. 2007. Distribution and abundance of western gray whales during a seismic survey near Sakhalin Island, Russia. Environmental Monitoring and Assessment, 134, 45-73.


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