New oil spill modelling research demonstrates potential risks and devastating effects on SA’s oceans

South Africa’s first oil spill model has been presented in a report by local and international researchers to provide an “independent assessment” of the risks and impacts of a potential blowout oil spill for offshore exploration and production drilling. This comes on the back of applications for exploratory and extractive drilling rights by oil and gas giants being approved for vast ocean expanses around the country. 

The researchers claim that at any given time, an average of 90% of the waters around South Africa’s Exclusive Economic Zone (EEZ) are under lease for oil and gas exploration or extraction, increasing the risk to the country’s marine biodiversity, natural resources, fisheries, tourism and coastal community livelihoods. 

The project’s ocean modeller, Dr Giles Fearon from the University of Cape Town, said: “Applications for exploratory and extractive drilling rights by oil and gas giants are being approved, yet at the same time are being objected to by many stakeholders, including NGOs, coastal communities and fishers. 

“Unfortunately, this pushback by stakeholders appealing against decisions to approve drilling or exploration has been compromised by the lack of an objective and independent oil spill model to evaluate risks and impacts.”

This is where the motivation behind the “Oil Spill Model for South Africa’s Exclusive Economic Zone” report came from. The report presents oil spill modelling undertaken to predict the trajectory and impact of oil released into the marine environment from potential blowout spill scenarios of proposed offshore oil exploration wells within South Africa’s EEZ. It focuses on spill scenarios off the east, south and west coasts.

Model spills

WILDTRUST, a South African non-profit conservation organisation, is heading the oil spill model project with funding from the Energy Transition Fund.

The report was authored by Fearon, Rory Laing from WILDTRUST, Professor Annalisa Bracco from the Georgia Institute of Technology, Danielle Reich from Shoal’s Edge Consulting, and the South African Environmental Observation Network.

Each spill scenario used in the report is modelled 200 times to predict the range of possible outcomes.

Fearon said: “The focus of our study was a potential spill off the east coast of South Africa, offshore of Durban in a water depth of about 3,000 metres. This site was chosen as it is in a region [the east coast], which is actively being targeted by the oil and gas industry.”

The results of the scenarios in the report found that a 15-day blowout of light crude oil from a major well, in a proposed well site approximately 100 kilometres off the coast of Durban, is estimated to have an 80% chance of necessitating beach clean-up operations and a greater than 50% chance that oil concentrations could result in the death of shoreline life.

It also found that the fast-flowing Agulhas current along the east coast of South Africa would transport oil large distances, hindering predictions of where oil would make contact with the shoreline, further complicating clean-up efforts in the event of a spill. 

Other findings of the report indicate that the minimum time to shoreline impact could be as little as three days for the east coast of South Africa, increasing to about 10 days for the south coast and 30 days for the west coast. 

‘A tool to stop exploration and exploitation’ 

The report states: “Oil and gas exploration and extraction introduces the risk of various types of spills into the marine environment, such as surface spills of marine diesel, accidental releases of non-aqueous drilling fluid and blowout spills at the wellhead on the seafloor. Blowout spills pose the greatest potential ecological risk, as evidenced by the Deepwater Horizon disaster in the Gulf of Mexico in 2010.” 

The Deepwater Horizon spill released over four million barrels of oil into the marine environment over 87 days, leading to extensive ecological impacts within the water column, on the water surface, shorelines and seabed. It reportedly killed thousands of marine mammals and sea turtles and contaminated habitats.

This is according to the research article, “Impacts of the Deepwater Horizon oil spill evaluated using an end-to-end ecosystem model”, by Cameron Ainsworth from the University of South Florida College of Marine Science and other researchers. 

With the long-lasting detrimental impacts of this disaster, the researchers of South Africa’s oil spill model said the potential impacts of similar blowout spills within South Africa’s EEZ due to current explorative and extractive activities need to be properly considered.  

Dr Jean Harris, Strategic Lead of the WILDOCEANS programme at WILDTRUST, said this model was necessary because applications to explore and extract oil and gas are subjected to an environmental impact assessment that often under-represents the “likely negative environmental impacts, doesn’t assess climate risk, and is funded by industry applicants”. 

“This oil spill model for South Africa is a powerful tool to be used in the civil society campaigns underway in South Africa to stop exploration and exploitation of fossil fuels,” Harris said. 

“It will allow for better assessments of potential damage and create an environment where it is more difficult for approvals to be obtained by big industry for risky proposals that threaten marine biodiversity, marine protected areas, natural resources, fisheries, tourism and coastal community livelihoods.” 

Recent years have seen an exponential increase in civil society, coastal communities and small-scale fishers taking to the courts in attempts to prevent companies from carrying out oil and gas exploration activities along South Africa’s shores. 

Now this oil spill model for the offshore environment of South Africa provides a scientifically defensible reference for the assessment of risks when decisions are made and for future oil spill modelling studies in the region.

The National Oil Spill Contingency Plan

The increasing interest in South Africa’s oceans for potential oil and gas exploration and extraction has left a bitter taste in the mouths of many stakeholders, NGOs, coastal communities and fishers – and resulted in a number of legal challenges and battles to prevent these projects from going ahead. 

One persistent fear has been the impacts on the marine environment should an oil spill occur from these activities.

Spokesperson for the Department of Environment, Forestry and Fisheries (DFFE) Peter Mbelengwa said: “South Africa’s National Oil Spill Contingency Plan (NOSCP) outlines all the processes that should be followed in the event of an oil spill in the marine environment. 

“The department made a significant contribution to the drafting of the NOSCP and has designated roles in the response structure contained therein – known as the Incident Management Structure for an oil spill from a vessel or platform.”

In the NOSCP, the Marine Pollution Act of 1981 stipulates that the Department of Transport is responsible for responding to a national marine oil spill incident, and the South African Maritime Safety Authority (Samsa) administers these responsibilities on behalf of the minister. 

The NOSCP sets out the roles and responsibilities of most of the parties likely to be involved in a national response to a marine oil spill in South Africa. It also contains relevant information and recommended procedures on how to act in the event of an oil spill.

“The process for responding to an emergency incident would start with the detection of the incident, the relevant vessel owner or offshore installation operator activating its oil spill contingency plan and notifying Samsa. Should a polluter be unable to deal with an incident, it would then be handed over to the national maritime IM structure and the polluter would fulfil a supportive role,” the NOSCP states.

The DFFE agreed on the need for oil spill modelling capabilities and said it was addressing this under the Ocean and Coastal Information Management System project. 

The DFFE also maintains and updates regional oil spill contingency plans, provides oil spill training to local authorities and other interested stakeholders, and organises and participates in oil spill exercises.

A tool in activists’ arsenal

Desmond D’Sa is the coordinator of the South Durban Community Environmental Alliance (SDCEA), which has been challenging the government’s approval of offshore oil and gas exploration projects and fighting for environmental justice and health. D’Sa gave the SDCEA’s support for the implementation of this model.

D’Sa said the report will strengthen their fight against oil and gas exploration but pointed out that it does not mention all the domestic aspects that would be affected by an oil spill.

“This is another piece of all the tools that we would have in our armour to fight against oil and gas, because oil and gas in our ocean will destroy the millions of jobs created by small individual businesses on the coasts, of all races. It will destroy tourism in this country. It will destroy the livelihoods of people, and the people who use the ocean for their health will be denied access to clean ocean water. If there is a spill, the water will be contaminated.”

Inside the spill model

Fearon said: “At the heart of the oil spill model is an ocean model – a computer programme that solves a set of mathematical equations to predict how ocean currents change over time. Oil released into the model is transported by the prevailing ocean currents. Most of the oil reaches the surface, where it is additionally transported by the surface winds, while the properties of the oil change in response to the environment.”

He explained the primary model outputs are the expected thickness of oil on the ocean surface and the quantity and concentration of oil washed up onto the shoreline. These values are then compared with thresholds or indicators to relate the level of oiling they see in the model with potential impacts. 

Fearon says the strength of the model is that it represents an “independent assessment” of the risks and impacts of a potential blowout spill for offshore exploration and production drilling, and it is envisaged that the model can be used by industry and decision-makers as a benchmark against which future applications from the oil and gas industry can be compared.

The first phase of the oil spill model has been completed and the report is available here. 

The second phase of the study is under way and WILDTRUST is using the results of the model in an assessment of the expected environmental, social and economic impacts. DM

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