Planned seismic survey by Shell has kicked up a storm in South Africa. Here’s an explainer

The planned seismic survey off South Africa’s Wild Coast by energy company Shell has unleashed public outrage in the country and beyond. The survey’s aim is to search for oil and gas deposits. Environmental and human rights organisations and fishing communities are trying to block the move in court. The Conversation Africa asked researchers to share their insights on seismic surveys.

What is a seismic survey?

Seismic surveys have been used for at least 50 years in both onshore and offshore mineral and oil exploration. The concept is relatively simple: measure the time it takes for a compression wave (“sound”) to move through solid material, strike a reflecting surface and return to a recorder. This allows the orientation and thickness of layers hidden below the Earth’s surface to be measured, so hidden ore deposits and gas or oil trap structures can be identified.

This negates the need for costly drilling and makes seismic surveys a fast and cost-effective tool in exploration for natural gas or mineral deposits.

Offshore seismic studies use an array of airguns towed on a cable behind a ship to create loud sound pulses, which move through the water to strike and pass into the ocean floor. Though this sound pulse is extremely loud to human ears, it is of far lower amplitude than earthquakes and explosions, and the pulse is not sufficient to cause any physical disruption to faults or structures on the ocean floor. Therefore, it is considered geologically safe.

If a detailed seismic survey confirms the likely presence of gas or the mineral deposit of interest, then it might be followed by drilling test wells.

Is this one unusual?

Seismic surveys are not uncommon along the South African coast. The Petroleum Agency of South Africa keeps records of all seismic surveys, and it is clear from this map that many seismic surveys have been done in South African waters, and beyond, since 1967.

Superficially, there does not seem to be anything technically unique about this particular survey, but these details need confirmation from the company that is working with Shell, Impact Oil & Gas.

The main difference is that it has provoked a large public outcry. The concerns are wide and varied, and some of them are in the process of being tested in court. Some have not been successful, while others wait on an outcome.

Seismic surveys have a direct impact on the marine environment – which we unpack below. More importantly, they can also be the precursor of much larger and systematic impacts if the exploration leads to further offshore operations such as drilling.

South African marine biodiversity is unique and valuable in many ways, and the Wild Coast is an especially rich part of that heritage. It’s therefore understandable that people wish to protect it and ask questions about who the true beneficiaries are.

In addition, projects to find new fossil fuel sources are inconsistent with staying within planetary boundaries for a sustainable future. They are at odds with promises made by the South African government during the 2021 United Nations Climate Change Conference (COP26).

What are the effects of marine acoustic seismic surveys?

Seismic surveys, and the subsequent exploitation of oil and gas reserves in much of the world’s oceans, focus on continental shelves, those areas closest to the coast. Here the seafloor is fairly shallow, making it easier (and cheaper) to access oil and gas reserves.

Continental shelves are also productive regions where marine life is the most diverse, where predators hunt for food, or creatures mate and give birth or lay eggs, where corals grow, and ultimately where the most productive fisheries are. Surveys can therefore lead to wide-scale disruption of marine ecosystems, and the value that humans derive from them.

There is a growing body of evidence of the effects of seismic surveys on marine wildlife. These effects are pervasive in marine ecosystems, from the smallest organisms to the largest.

Plankton are very small organisms that form the basis of a healthy marine ecosystem. They consist of phytoplankton (small plants) and zooplankton (small animals). Zooplankton are severely affected by seismic surveys, leading to wide-scale die-off in the vicinity of blasting sites. Since other marine species survive by feeding (directly or indirectly) on zooplankton, this has an effect on the entire aquatic food web.

The critically endangered leatherback turtle, which frequents some areas to be surveyed, is similarly affected by seismic surveys. The Wild Coast is an important area where the young future-breeding individuals spend their time.

Whales and dolphins rely on sound to communicate, navigate and hunt. Generally, the dominant frequencies of seismic airguns (typically below 100 Hz) overlap with those of the communication signals of large baleen whales (10 Hz–1 kHz).

Some seismic surveys also use high frequency sonar mapping, which has been linked to the mass strandings of deep-diving toothed whales. For example in Madagascar 100 melon headed whales stranded and died. The strandings occur because the sonar interferes with their navigational system (echolocation), causing the whales to surface extremely fast. Gas bubbles form in their bloodstream and expand, resulting in decompression sickness, similar to “the bends” that human divers get.

Furthermore, the sound waves generated by seismic surveys may lead to temporary outward migration of wildlife. In another study conducted in the Bass Strait of Australia, it was found that noise exposure during larval development of scallops produced body malformations in nearly half of the larvae and their overall development was delayed.

So how dangerous is this survey?

Despite the examples we’ve given above, the science on the direct and long-term impacts of seismic surveys has not yet provided conclusive answers on many facets of marine ecosystems. But that doesn’t mean there is no basis on which to act. Decisions are often made in the absence of scientific certainty to avoid potentially catastrophic changes in the environment.

The global scientific community has a specific method to assess the state of knowledge in a particular area, to support decision making. It is called a scientific assessment. Among the best known examples are the scientific assessment reports of the International Panel on Climate Change, regularly used in climate policy and decision making.

The same method has also been applied locally to assess the impact of fracking in South Africa’s Karoo region. It is clear that we need a scientific assessment on the impact of seismic surveys to inform the current gaps in South Africa’s National Environmental Management Act and guide the development of new policies.

Until we have the outcomes of such an assessment, the act provides for the application of the precautionary principle in environmental matters and states that:

… a risk-averse and cautious approach is applied, which takes into account the limits of current knowledge about the consequences of decisions and actions.

Other countries have also grappled with seismic survey impacts. Norway, for example, amends its management guidelines in response to findings from ongoing studies. The country does not rely on impact assessments that are years out of date.

Although still needed, it would be short-sighted to focus research on marine environmental impacts and seismic surveys only. The focus should be on the danger to humanity from additional fossil fuel exploration, and the associated increase in the impacts of climate change.

Climate science has matured to the point where there is very strong evidence for the links between life-threatening extreme events such as floods, fires and droughts, and climate change. There are also several new studies that map out feasible and just transitions to reduce our carbon footprint. There really are no good excuses left to continue with any fossil fuel exploration, and certainly not seismic surveys that have an impact on unique and rich marine ecosystems.

Mia Wege, Marine Predator Ecologist and lecturer in Zoology, University of Pretoria; Barend Erasmus, Dean and Professor, University of Pretoria; Christel Dorothee Hansen, Lecturer, University of Pretoria; Els Vermeulen, Research Manager, Mammal Research Institute Whale Unit, University of Pretoria; James Roberts, Associate Professor, Geology, University of Pretoria; Jean Purdon, Marine Biologist, University of Pretoria, and Michael John Somers, Professor, University of Pretoria

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Researchers

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  Dr Christel Hansen

  Dr Christel Hansen holds a BSc in Geoinformatics from the University of Pretoria (UP), and has been doing research at the University since 2018.
  
  The focus of her work is to understand how the landscape is affected by natural and anthropogenic processes. “By understanding how the landscape changes – such as through a landslide or a river flooding – we can better plan and manage for the effects of such occurrences,” Dr Hansen explains. “Geographic information science allows me to do this quickly, at a fairly low cost, using the computing and data power that is currently available.”
  
  Her research centres on how geoinformation science can be used to improve the well-being and health of the urban citizen. This is done by modelling an individual’s energy expenditure, and using information from the health sciences and the natural world (such as difficulty of the terrain or gradients). This information can be made available to the public on online platforms such as web maps. Dr Hansen works to improve access and the user-friendliness of these platforms so that information can be disseminated more effectively.
  
  Geoinformation science is important, she says, because everything has a geospatial component. “Geomorphology matters because if we do not understand how the landscape works and evolves, we will not understand our place within it very well. Our decisions are always partly influenced by the physical world around us.”
  
  Dr Hansen is passionate about what she does and says she is inspired by people who are focused, dedicated and innovative. “I want to do good work that I am happy with. Students enjoy it when I teach them aspects of geoinformation or use examples drawn from my research.”
  
  Her advice to school learners or undergraduates who are interested in her field is to investigate something that they are interested in. “Don’t be afraid to ask questions. There is an exciting world out there with many mysteries still to be solved. Next time you think a question will make you look ‘stupid’, remember that all answers require a question, and all solutions require a problem. There are no stupid questions.”
  
  In her free time, Dr Hansen enjoys being in nature. “I love walking or hiking among the amazing landforms and landscapes that I study.”

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  Professor Michael J Somers

  Wildlife researcher and lecturer Professor Michael J Somers is recognised internationally as an expert in his field, and currently serves on four International Union for Conservation of Nature specialist advisory groups: African wild dogs, otters, wild pigs and small carnivores.
  
  Born in Pietermaritzburg, he studied zoology, botany and wildlife management at the University of Natal (now University of KwaZulu-Natal) and the University of Pretoria (UP) before obtaining his PhD in zoology from Stellenbosch University.
  
  Currently an Associate of the Mammal Research Institute at UP and a core team member of the Centre for Invasion Biology in the University’s Department of Zoology and Entomology, Prof Somers’ main research focus is on carnivore ecology, conservation and wildlife management.
  
  Following a four-year stint in the field studying wild dogs in Zululand, he returned to teaching in 2001, a passion he discovered during his PhD studies.
  
  His research output has also been prolific, having published 129 papers in peer-reviewed journals and book chapters, 40 other publications and two books (with a third book in press). He has also supervised or co-supervised 42 honours research projects, 21 research MSc and eight PhD students.
  
  Research conducted with his students have covered a wide variety of subjects, including the impact of fencing on wildlife; studies on species ranging in size from spiders and crabs to predator species such as lion, cheetah and leopard, and whales; as well as studies on aphids, seed dispersal or the impacts of fire.
  
  Last year, Prof Somers co-authored a paper voicing strong concern about the Animal Improvement Act (1998), cautioning that reclassifying several South African wildlife species as farm animals would not “improve” the genetics of the species and would instead have considerable negative genetic consequences and pose ecological and economic risks.
  
  Prof Somers has also served as Editor-in-Chief of the South African Journal of Wildlife Research, Academic Editor of PLOS One and PeerJ, associate editor of Mammalian Biology and African Journal of Wildlife Research, and sits on the editorial boards of Koedoe and Nature Conservation Research.
  
  Of the many wildlife species you have studied, is there one animal that fascinates you most?
  African clawless otters, which I did my PhD on. Although you do not see them often, every encounter with them is memorable.
  What attracted you to teaching?
  I instantly liked teaching, and the students seemed to like my approach. Students want their lecturers to be engaging, humorous, wise and informative. At the start, I was young and naive, with no formal teaching training or the advantage of having read good books on teaching and learning, but I still got good feedback, which convinced me to follow an academic path. By the time the students graduate, they should also be able to use the knowledge, think independently, gather information themselves and be able to assess new knowledge.
  
  With the rapid growth of Africa’s human population and disappearance of wild landscapes, are you optimistic that wild animals have enough space to survive?
  It is context dependent. An increasing amount of land has been put under conservation, which is encouraging. An example of this is the Transfrontier parks. However, even in many African conservation areas, the numbers of animals are declining owing to the overuse of resources within these areas. We have a new project in West Africa, and I have been shocked to learn how few of even the large charismatic species such as lions and wild dogs are left there. Wildlife still needs more space and protection in that space.
  You co-wrote a book on the pros and cons of fences for wildlife. Will fences ever disappear?
  Although the preferred scenario is to have fences disappear, I do not believe they will go for the most part. Present reserves will continue to drop barriers to join others or become part of more extensive reserves. This is good for ecosystem functioning. Many reserves in Africa do not have fences but rather buffer zones, which sometimes work. As the human population expands and needs more resources, the reserves are put under increasing pressure, the buffer zones are not appropriately managed and the animals in the reserves are overharvested. Although not ideal, but as shown to be somewhat effective in South Africa, fencing some new areas, maintaining the fences and having effective law enforcement may be needed.
  
  As a lecturer, what is your approach to instilling ethical behaviour in your students?
  As we often see in the media, the wildlife sector (like any industry, really) is plagued by corruption and unethical behaviour. This includes poaching, wildlife theft and the poor treatment of animals. Our students are likely to encounter this after leaving university, so it is essential to alert them to this and try to instil in them a good work ethic and respect for wildlife as a whole, as well as for individual animals.
  
  What do you do in your spare time?
  I still enjoy game drives to watch animals, often in our local Rietvlei Nature Reserve. I also try to play the guitar.
  

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  Prof James Roberts

  Professor James Roberts is a senior lecturer in igneous and metamorphic petrology at the University of Pretoria (UP). He has been a UP staff member since 2007; he previously did contract teaching at the University, in 2006.
  
  Prof Roberts holds a BSc (Hons) degree from Rhodes University, an MSc and a PhD in Geology from the University of the Witwatersrand, and a BA in History and Ancient History from the University of South Africa (Unisa).
  Prior to joining UP in 2007, he worked for AngloGold Ashanti and Anglo American; he also worked as a researcher at the SAPS Forensic Science Laboratory.
  
  Prof Roberts specialises in igneous and metamorphic petrology, though has published in a variety of fields, including ore geology and coal petrology. He has more than 25 publications to his name.
  
  He describes the subject he studies as a “very academic aspect of geology”. “However, the rigorous training I give my postgraduate students allows them to apply their skills to a wide variety of industry applications.”
  
  He has supervised more than 30 master’s students and eight doctoral students.
  
  With the aid of a research grant, Prof Roberts is currently collaborating with a group of researchers from Texas Tech University in the US on a project that involves magnetite pipes in the upper zone of the Bushveld Igneous Complex.
  
  He regards the C3-rating he received from the National Research Foundation (which was “based on eight years of hard work”) as a highlight.
  
  In his spare time, Prof Roberts enjoys war-gaming, and has run his own martial arts school for 20 years.

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  Dr Els Vermeulen

  Dr Els Vermeulen has been a researcher at the University of Pretoria (UP) since her postdoctoral appointment in 2015. A Belgian national, she did her undergraduate studies at the University of Antwerp.

  In 2017, she took the reins as research manager of the Whale Unit at UP. The unit is part of the University’s renowned Mammal Research Institute (MRI) and is an internationally established whale and dolphin research hub. “Considering the unit’s extensive knowledge base, I feel fortunate to be able to lead its work forward,” Dr Vermeulen says.

  The Whale Unit was established in 1985 and has become a globally recognised leader in cetacean (whales, dolphins and porpoises) sciences. Researchers there investigate the ecology, population dynamics and behaviour of cetaceans from southern African waters into the Southern Ocean, with the principal objective of providing knowledge that will promote their conservation.

  “The Whale Unit has a database on whales and dolphins that spans over 50 years,” Dr Vermeulen says. “These long-term databases on large mammal species are unique in the world, and provide a critical tool to study long processes such as climate change and its effect on wildlife. Making use of these databases ensures that they continue to grow, and allows me to assist in gaining a better understanding of anthropogenic impacts on the marine environment.”

  Over the past 36 years, the unit has built a wealth of expertise, considerable long-term intellectual property and well-established knowledge bases, making it the most established cetacean research group in Africa. Being able to continue with this legacy gives researchers at the unit the opportunity to make a significant contribution to whale and dolphin conservation and management in a broad geographical region.

  In terms of cross-faculty research, Dr Vermeulen collaborates with a UP genetics laboratory headed by Prof Paulette Bloomer, as well as the Department of Geography, Geoinformatics and Meteorology.

  She regards the Whale Unit’s most recent research ­– which has shown the effects of climate change on the health, reproductive success and migration patterns of South Africa’s southern right whales ­– as a research milestone. Much of this research has been highlighted on the Research Matters website.

  Dr Vermeulen has always been inspired by established academics in marine mammal research, as it is a highly competitive field and a difficult one to pursue

  She looks up to Prof André Ganswindt, her line manager and Head of the MRI. “I admire the way he manages the MRI, creates a family feeling within the group, finds balance between work and personal life, and the way he provides guidance to students and other academics like myself. He is an effective and extremely qualified professional, yet a gentle, patient, down-to-earth person with whom it is a pleasure to work and collaborate with.”

  Dr Vermeulen hopes to secure a permanent appointment within the Whale Unit and be able to grow the unit to the next level.

  Her advice to school learners or undergraduates who are interested in her field is to follow their dreams. “Live the life you have imagined – in the end, it is not what you want, but how much you want it. Also remember, it is not always what you know, but who you know. So never cease to be a friendly, gentle person. It will stand you in good stead.”

  Outside of work, she says she loves spending time outdoors with her two little children and her dogs. “Nothing brings more joy to my heart than seeing them play in nature.”

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