Keywords

10.1 A Synthesis of Key Issues of the Marine Environment in Qatar

Boomed by a high economic development since the oil boom of the 1970s, all eight nations bordering the Arabian Gulf, including Qatar, have witnessed a major and sustained increase in their demographic indicators (van Lavieren et al., 2011). This economic and social growth did not come with no impacts to their marine environment (Burt et al., 2017). Coastal reclamation, pollution, and overexploitation of natural resources are the major pressures and have often outpaced environmental conservation, policy, and regulations (Sale et al., 2011). The resulting anthropogenic changes, mainly occurring in the coastal and nearshore zones, exacerbated the already naturally stressed environment. Indeed, the Arabian Gulf has harsh environmental conditions (i.e., shallow depths, high salinity and temperature regimes, slow hydrodynamics) that make its marine ecosystems unusually fragile and susceptible to impacts from human activities (Fanning et al., 2021).

While marine fauna and flora around Qatar are adapted to these conditions, the extreme nature of the environment puts this biota at the margins of their physiological tolerance, and any further stress—such as from human activities—can push these species over the edge, and result in mass mortality of organisms across whole ecosystems. Given the importance of coastal systems such as coral reefs and seagrass in supporting the biodiversity and economy of Qatar, it is critical that Ecosystem Based Management practices be instituted to limit the addition of man-made stressors to these fragile ecosystems.

Among major man-made environmental pressures in the region is the development of the oil and gas industry, relying mainly on extractions made offshore. The Arabian Gulf has the highest density of oil platforms among all seas of the world, with more than 800 oil platform structures (Sheppard et al., 2010), and the number of well-head platforms in the Arabian Gulf is estimated to be between 2000 and 3000 (Stachowitsch et al., 2002). These structures cause acute and chronic impacts on natural ecosystems during their drilling and installations (Albano et al., 2016); during operations due to chronic pollution caused by residual oil spills and discharges of produced waters (Bakke et al., 2013; Tornero & Hanke, 2016; Zhang et al., 2019); interaction with bird’s migrations (Ronconi et al., 2015); or major loss of biodiversity and habitat destruction during decommissioning (Claisse et al., 2015). Nonetheless, several recent studies highlighted the positive effects of offshore oil platforms on the local and regional biodiversity and productivity (Meyer-Gutbrod et al., 2020; Van Der Stap et al., 2016) and recently in the Arabian Gulf around the Qatar EEZ (Torquato et al., 2017, 2021). Indeed, the growing body of evidence showing the useful ecosystem functions and services, habitat diversity, as well as the connectivity provided by these structures motivated the decision taken by some countries to allow these platforms to be converted into artificial reefs under the so-called Rig-to-Reef (R2R) program (Bull & Love, 2019).

In this chapter, the authors investigate the potential issues that may rise by implementing the R2R approach during decommissioning of Qatar’s offshore oil platforms. We applied a systematic analysis framework, the DPSIR (Driver-Pressure-State-Impact-Response) (Gari et al., 2015; Lewison et al., 2016) to revise empirical scientific information and support understanding by stakeholders of appropriate actions to be taken, in order to maximize positive impacts of reefing obsolete oil platforms.

10.2 Justification, Benefits with a Historical Context

Facilities used to develop offshore oil and gas fields are found on continental shelves throughout the world’s oceans. When the oil or gas reservoir reaches the end of its economic life the facilities are decommissioned, which usually requires the removal of all the installed facilities (platforms and wells). The world’s offshore oil and gas infrastructure is aging, and the industry is rapidly approaching a decommissioning crisis (Fowler et al., 2014). In fact, a large proportion of the more than 12,000 active offshore installations is operating beyond or approaching the end of their designed life (Ars & Rios, 2017).

Nevertheless, oil and gas platforms are known to provide habitat for marine benthic species, as well as increase the diversity and productivity of marine ecosystems. They can also act as stepping-stones for these species, by connecting patches of natural habitats that were previously unconnected (Fowler et al., 2020; Torquato et al., 2019).

In recognition of the growing body of evidence showing the useful ecosystem functions, services, habitat diversity, and connectivity provided by these structures, some countries allow these platforms to be converted into artificial reefs under R2R programs. Subsequent international agreements introduced some exceptions to complete removal (the so-called partial removal options) if obligations associated with navigational safety and environmental protection were met. This allowed the R2R concept to be applied in the United States, Brunei, and Malaysia (Bull & Love, 2019).

10.3 Political, Economic, and Regulatory Framework Context

The decommissioning of redundant oil and gas facilities is a process which is regulated internationally, regionally, and nationally. Decommissioning regulations and guidelines in various countries and regions have been reported on and assessed extensively in the literature (Van Elden et al., 2019). Complete removal was first mandated in the 1958 Geneva Convention on the Continental Shelf to ensure that the oil and gas industry was liable for their infrastructure following cessation of production. The OSPAR Commission’s Decision 98/3 requires complete removal of offshore installations, with some exceptions that fulfill purely technical criteria (Fowler et al., 2018). In Qatar, as well as the whole Arabian Gulf region, the current regulatory framework provides no other alternative, apart from the complete removal of obsolete offshore platforms. The intention of these regulations is clear, namely, to protect the marine environment and ensure proper management of redundant resources.

10.4 Reefing Obsolete Oil Platforms, a DPSIR Analysis

10.4.1 Rationale

Over 60% of global oil reserves are found within the jurisdiction of the Arab Gulf Nations (OPEC, 2018). In addition to oil, Arab countries just a decade ago were home to approximately 55 trillion m3 of reserves (Fattouh & Darbouche, 2011). These huge reserves have allowed unparalleled economic growth and development in the region (Din, 1990; Calder, 2015). This oil and gas rich economy has led to the construction of 800+ offshore platforms as well as 25 large terminals containing some of the largest oil and gas infrastructures to date (Sheppard et al., 2010). While some of this oil is transported through underwater pipelines to Harbor’s in the Red Sea and Mediterranean regions, most of it leaves through the Strait of Hormuz, transported via tankers which distribute this oil to different parts of the globe, such as Western Europe and Japan (Din, 1990; Calder, 2015).

Qatar is no different from the other Gulf countries; according to the US Energy Information Administration (2015), Qatar’s mainly hydrocarbon economy was responsible for almost half of its revenue in 2014. Its large oil and gas reserves are the main driver behind the construction of multiple oil platforms in the North and East of the Peninsula. Since some of them are reaching the end of their lifetime, they need to be decommissioned.

Recent studies however revealed, using remotely operated vehicles (ROV) footages, some promising findings, where the artificial reefs seem to support a very well-established ecosystem with a variety of fouling macroinvertebrates (Torquato et al., 2021) and rich fish assemblages (Torquato et al., 2017). These studies open the doors to explore the possibility of reefing the rigs. While it is widely known that coral reefs are among the most diverse and productive ecosystems in the world, they have been degraded, and their coverage is only a fraction of what they used to be. However, amidst the Gulf’s extreme environmental conditions of ocean surface temperatures above 36° during the summer months and salinity levels above 45 psu (Range et al., 2018), the fact that these corals are able to survive at different depths on these platforms is very promising. According to Torquato et al. (2021), the videos were taken et al.-Shaheen oilfield during the monitoring surveys conducted from 2007 to 2014. Using underwater Remotely Operated Vehicles, they analyzed 4510 videos and found 17 functional groups categorized by morphology, among which they found hard corals. They conducted this study from the surface to a depth of 60 m, where they found that the coral communities increased in abundance at depths exceeding 30 m as well as on older platforms (Torquato et al., 2021).

The most interesting finding was the identification of a new species of coral belonging to the family Caryophylliidae which was seen for the first time in Qatar. As a result, this study is of paramount importance as it shows that not only there is a well-established ecosystem attached to the oil platforms consisting of reef building corals, but also that they can potentially compensate for the loss of reefs and associated flora and fauna elsewhere (Range et al., 2018; Torquato et al., 2021).

These ecosystems provide various functions and services. Approximately 912% of global fisheries are associated with coral reefs (Smith, 1978), and up to 25% in certain regions (Cesar, 1996).

Scientists have also discovered anticancer and anti-inflammatory substances in corals and their associated flora and fauna for the pharmaceutical industries (Carté, 1996). In addition, coral associated flora, such as seaweed, is used to extract agar (Birkeland, 1997), as well as to produce manure (Craik et al., 1990). Corals themselves seem to be useful in bone surgery (Spurgeon, 1992). According to Tsounis et al. (2010), red corals were sold for up to 50.000 US$ kg−1.

The presence of corals prevents coastal erosion caused by natural events such as strong currents and storms. In Indonesia, Cesar (1996) estimates that up to a million dollars are lost per kilometer of eroded coast, while in the Maldives, it cost twelve million dollars to replace the lost reefs with an artificial barrier (Weber, 1993).

Reefs are also beneficial to fisheries by exporting nutrients into the pelagic food web, which in turn provides nutrients to plankton, leading to increased productivity and helping fisheries (Sorokin, 1990). Moreover, they clean the water by sequestering human waste and detoxifying it, such as breaking down hydrocarbon pollution to CO2 and H2O (Peterson & Lubchenco, 1997).

The decommissioning of these rigs would result in loss of the biodiversity, ecosystems, and their provided services (Torquato et al., 2021) justifying the prospect of their conservation through the R2R approach instead of a complete removal during decommissioning.

10.4.2 Qatar Oilfields

The Arabian Gulf is recognized as a youthful sedimentary basin which is found in the subtropical area. The Gulf area ground was nearly entirely exposed in the last glacial maximum (LGM) since the level of the sea was about 120 m less than the current level (Sheppard et al., 2010; Torquato et al., 2021). Presently, the Arabian Gulf seawater floods show a maximal width of 350 km with 35-m mean depth, hardly surpassing 100 m of depth (Seibold, 1973; Vaughan & Burt, 2016). The exchange of water with the open ocean in that region is restricted to the Hormuz strait. The climate in the Arabian Gulf is allied with the desert condition since the area is encircled with arid land, which generates extreme environmental conditions resulting in hypersaline conditions where water which usually exceeds 42 psu (Swift & Bower, 2003) and extremely seasonal variations in sea surface temperatures (Nesterov et al., 2021). During the summer months, the Gulf is characterized as being the hottest sea on earth with sea surface temperatures exceeding 36 °C (Vaughan & Burt, 2016). However, during the winter season, the temperature can drop as low as 13 °C (Coles, 2003; Torquato et al., 2021).

This manuscript is critically analyzing risks associated with the implementation of the R2R to the oil platforms pertaining to the different oilfields into the Exclusive Economic Zone of Qatar.

Qatar’s offshore oilfields are located mainly toward the northeast and East of the peninsula. They comprise, from South to North, El Bunduq, Al-Karkara, Idd El Shargi, Bul Hanine, Maydan Mahzam, Najwat Najem, Al-Khalij, Al-Shaheen, and Al-Rayyan oilfields. The latter two fields are inserted in the Qatar’s North Field, the world largest single natural gas field (Fig. 10.1). All oilfields under operation are located at 60 km or more off Qatar’s mainland and are therefore away from direct exposure of anthropogenic pressures generated at the coastal zone. Each oilfield will comprise 5– 33 oil rigs or platforms, each weighing several thousands of tons and the submerged rig is usually made of austenitic stainless steel.

Fig. 10.1
The map of the north fields of Qatar represents the offshore oil and gas fields. Qatar Petroleum is highlighted.

Source Qatar Petroleum

Map of the offshore oil and gas fields in the Exclusive Economic Zone of Qatar (delimited by the dotted border).

Full size image

Most of the agreements signed by the different operators of these offshore structures with the State of Qatar last for more than 20 years, and thus, oilfield platforms play a crucial role as a long-lasting artificial habitat for several marine organisms in the offshore environment in the Arabian Gulf (Torquato et al., 2021).

10.4.3 The Rig-to-Reef Approach

Rig-to-reef (R2R) is considered as the reusing and conversion process of offshore submerged platform structures into artificial reefs that consist of similar characteristics and functions of natural reefs. The main objective of this process is to protect and regenerate the production of marine organisms to enhance the conservation of aquatic environment and fisheries (Verbeek, 2013). The conversion of oil platforms into the environmental and economic valuable structure after decommissioning can be achieved through the re-utilization of the rig structure and its associated fouling biological communities which in turn enhance the biological production, preserve the marine ecological resources, and form a well-established habitat for marine organisms (Bull & Love, 2019; Kaiser, 2019; Nugraha et al., 2019).

The increase in offshore oil exploration, the construction of oil platforms, and the decommissioning after reaching the end production period have led to the exploitation of the artificial reefs resulting from the structure of the rig, left after the platforms closure (Nugraha et al., 2019). This would provide environmental and economic benefits:

  • Habitat restoration, loss compensation, and resources conservation: rig-to-reef supports the production and development of different marine organisms that enhance the ecological connectivity.

  • Fisheries: production of valuable marine organisms such as algae, crustaceans, molluscs, and pelagic and benthic fishes.

  • Recreational activities: attract divers and recreational fishermen and increase the economy of the tourism sector.

10.4.3.1 Methods of Rig-to-Reef

The conversion of oil platforms into artificial reefs is considered as a sustainable solution, and it occurs following three different methods: (1) partial removal, (2) topple-in-place, and (3) tow and place (Fig. 10.2). Each method requires different levels of sea work interventions on the rig jacket, including use of explosives and heavy mechanical processes (Kaiser, 2019). A jacket represents the support structure of the oil platforms which are produced from steel and placed offshore where it extends from the seafloor up to the sea surface (Bull & Love, 2019). The following methods were mainly used to establish the artificial reefs (Bull & Love, 2019; Kaiser, 2019; Macreadie et al., 2011).

Fig. 10.2
The methods of platform reefing. First is the Tow-and-place, it goes straight. The second is Topple-in-place, which bends a little, and the third is Partial removal.

Platform reefing methods. a. Tow-and-place platform reefing. b. Topple-in-place platform reefing. c. Partial removal platform reefing. Methods a and b often use explosives to severe steel jacket legs below the seafloor. Methods b and c often use mechanical tools to severe steel jacket legs either below or above the seafloor. Method c may or may not include placement of shallow water severed jacket on the seafloor as additional reef material (Bull & Love, 2019)

Full size image
10.4.3.1.1 Partial Removal Method

The upper part of the rig jacket is severed through mechanical process and placed next to the bottom part without using explosive materials. This method can reduce the disturbance of marine habitat (Bull & Love, 2019). The bottom part remains in the same place of the rig without any movement providing a habitat for marine organisms (Kaiser, 2019).

10.4.3.1.2 Topple-in-Place Method

The oil rig jacket is laid down in a horizontal position using some explosive materials on the seafloor.

10.4.3.1.3 Tow-and-Place Method

The oilrig jacket is pulled up from the sea floor and towed using heavy lifting vessels after which it is placed vertically or horizontally on the sea floor (Kaiser, 2019).

10.4.3.2 Outcomes of the Rig-to-Reef Approach

10.4.3.2.1 Benefits of Rig-to-Reef

Rig-to-reef is considered as a beneficial project since it provides a habitat for marine organisms to spawn, grow, and aggregate which improves the carrying capacity of the ecosystem which in turn increases biomass production (Macreadie et al., 2011; Verbeek, 2013). Also, it develops and augments the marine ecosystem functions that provide energy and nutrients for the aquatic environment (Verbeek, 2013). In addition, it offers several ecosystem services such as provisioning services, cultural services, and supporting services, where rig-to-reef improves the marine biodiversity and biomass production through the change of food webs, and provides recreational activities (Jagerroos & Krause, 2016). Furthermore, artificial reefs play a significant role in the development of new habitats in the aquatic environment, restoration, protection, and conservation of the habitats (Becker et al., 2018; Jagerroos & Krause, 2016). The main goals of rig-to-reef approach are:

10.4.3.2.1.1 Creation of New Habitat

Rig-to-reef can produce new habitat that develops and matures with time which in turn increases the abundance of biofouling communities and marine organisms including macro-algae, fishes, and most invertebrate taxa such as corals and sponges (Jagerroos & Krause, 2016). In addition, it attracts the endangered species, for instance Eretmochelys imbricata which is considered as endangered turtle that was obtained in the artificial reefs in Borneo (Tisen et al., 2002).

10.4.3.2.1.2 Restoration of Habitat

Rig-to-reef can restore the damaged sites through the maximization of larval recruitment and its distribution. Moreover, it provides an alternative habitat for the impacted marine areas, for instance, coral bleaching (Jagerroos & Krause, 2016). In addition, it enhances the presence of commercially valuable marine organisms (Jorgensen, 2009).

10.4.3.2.1.3 Protection and Conservation of Habitat

Rig-to-reef represents a barrier to prevent active fishing, for instance, trawl fisheries that will enhance the conservation of marine organisms, and to achieve this, regular monitoring should be conducted in artificial reefs area to avoid any illegal fishing methods and reduce overfishing (Jagerroos & Krause, 2016).

10.4.3.2.2 Implementation Determinants of Rig-to-Reef

The implementation of the rig-to-reef scenario could be hindered with several obstacles potentially affecting its success including, legal compliance, the overall costs of cleaning, severance of platforms, maintenance, and regular surveillance (Jagerroos & Krause, 2016; Ounanian et al., 2020). According to the Gulf of Mexico case, 10% of the oil platforms have been reefed; however, some decommissioned platform's structure has been fully removed and brought onshore because of the prohibitive costs of maintenance (Kaiser, 2019). Moreover, the liability problems of platforms leakage, the pollution level of the artificial reef installation site, and the abundance of invasive species can motivate their complete removal (Ounanian et al., 2020).

Additional criteria should be also considered for the implementation of the R2R approach in the Qatar oilfields such as the location of the different oil platforms, determining their connectivity with natural, and other artificial reefs and its exposure to differential hydrodynamic forcings (Jagerroos & Krause, 2016).

Perhaps the most significant obstacle toward the implementation of the R2R approach in Qatar is the lack of a regulatory framework for such decommissioning scenario. The United Nations Convention on the Law of the Sea (UNCLS), to which Qatar is a signatory, recognizes the need for artificial structures developed on the sea, either for commercial purposes or protection of the territorial integrity of a state. According to Byrd et al. (2018), the state of Qatar established regulations that sought to ensure the safety of all those accessing the country’s seabed which may impact the future implementation of the R2R approach. Accordingly, reefing oil platforms in the EEZ of Qatar will lead to several legal challenges (da Fonseca et al., 2020). This is due to the possible disruption of marine transport due to the many accidents likely to be reported by having reefs beneath the sea. In Qatari law, oil and gas companies that fail to comply with the set of regulations on marine operations risk being decommissioned. Any move by the operators of oil and gas companies to establish rig-to-reef is seen as a violation of a country’s regulations on marine transport (Van Elden et al., 2019). This is in accordance with Law No. 29 of 1966 together with Law No. 8 of 2017 on the conduct of marine works in Qatar which collectively require oil and gas companies to provide seamless passages to marine transportation companies using both the inland and offshore waters.

Lim (2021) noticed that one key challenge at offshore Qatar oilfield is the lack of a natural reef that can provide a safe breeding ground for fish. In this case, the fundamental idea is that once the entire oil exploration is completed, there will be a need to remove the top part so that the reef underneath will not be affected. However, according to da Fonseca et al. (2020), this represents a set of challenges to maritime navigation. In most cases, such ambitious projects are prone to accidents due to the reefs already existing under the water hindering the free movement of cargo across the sea (Van Elden et al., 2019).

On the technological front, there are logistical challenges of time, manpower, and resources, both financial and non-financial, to fully realize the objective of a rig-to-reef system (Lim, 2021). Moreover, not all the platforms can be used for reefing. Transforming a platform to a permanent artificial reef requires engineering and environmental criteria. The size, complexity, structural integrity, and location of the platform are all important factors to consider when assessing its reefing potential. Platforms that are complex, stable, durable, and clean are good prospects for reefing. Reefing is not an option for platforms that have tipped over owing to structural breakdown (BSEE, 2021).

Rig-to-reef is meant to offer favorable environmental conditions for fish and other macroinvertebrate communities to thrive but with the increased oil and gas exploration, the project would pose significant legal, logistical, and environmental challenges to stakeholders (Lim, 2021). Byrd et al. (2018) noted that the development of artificial reefs on any oilfield requires the removal of the top structures while leaving behind those buried deep in the sea.

In the following sections, we are considering the DPSIR framework to critically analyze the risks associated with reefing oil rigs in Qatar from different perspectives, such as leaving an artificial structure in place, implementing marine protected areas, pollution that is likely to occur, the effect on fisheries, and expert knowledge regarding the case.

10.4.4 The Driver-Pressure-State-Impact-Response (DPSIR) Framework

The complexity of the marine environment is mainly generated from the interaction of its morphological and physical structures which creates a continuous variation between the physico-chemical processes and the ecological structure and function (Elliott et al., 2017).

Recently, several comprehensive assessments based on conceptual models have been utilized for problem structuring and facilitating empirical research in coastal regions (Lewison et al., 2016). The Drivers-Pressures-State-Impact-Response (DPSIR) framework remains one of the most widely adopted comprehensive approaches in some of the coastal regions around the globe. Although there are various frameworks which are available and accessible for exploring the components interactions and the integrated assessments of the different systems (Lewison et al., 2016; Potschin, 2009). DPSIR is a powerful framework which was initiated by the economic co-operation and development organization (OECD, 1993) in order to offer an integrated reporting strategy related to the environmental assessment (Kelble et al., 2013). This framework is effective in organizing and compiling various sets of information to manage the system; therefore, it unambiguously illustrated the causal relationship to the stakeholders (Maxim et al., 2009). In addition, this conceptual model can distinguish addressed issues by associating and recognizing the causal relationship, which will facilitate the definition and the study of the system, and to further analyze the issues in order to generate potential solutions for the same (Daniels, 2010). DPSIR framework can be successfully implemented for the evaluation of environmental variations in the coastal regions and marine ecosystems, to make predictions for the future challenges, and to enhance the managemental practices (Goble et al., 2017; Kaur et al., 2020; Lin et al., 2007; Miranda et al., 2020; Newton & Weichselgartner, 2014). Moreover, this straightforward approach has the ability to form a link between pressures and impacts for evaluating objectives by mainly directing the risk assessment and the major pressures which are altering the state and thus impacting the ecosystem services and benefits which will eventually impact “us” as humans (Atkins et al., 2011; Smith et al., 2016; Smyth & Elliott, 2014). Within the marine context, managing marine ecosystems by implementing the DPSIR framework is coherent with the ecosystem approach (Cooper et al., 2013; de Jonge et al., 2012; Elliott et al., 2017). Therefore, due to the effectiveness of this conceptual model, the risks associated with the rig-to-reef approach in Qatar’s platforms at the different oilfields will be evaluated and critically analyzed via A DPSIR framework analysis.

10.4.4.1 Evidence Search and Review

A systematic literature review (Booth et al., 2021) was performed in order to critically analyze the risks associated to reefing approach of the Qatari platforms by using A DPSIR framework. Science Direct and Scopus databases were used, by searching specific syntaxes:

  • “DPSIR framework, AND marine, (artificial structures OR sustainability)”. Total papers found were 98.

  • “MPA Marine DPSIR” (yielded 73 results out of which the relevant papers were chosen).

  • “Rig-to-Reef” (yielded 7 results).

No refinement was done based on any specific titles, abstracts, or date limitations. Additional references were also manually added due to their relevance to the topic.

10.4.4.2 DPSIR Framework Set-Up and Analysis

A DPSIR framework was generated to identify, evaluate, and critically analyze the risks associated with the rig-to-reef approach implementation in Qatar oilfields (Fig. 10.3). This approach is potentially applicable to all similar oilfields in the Arabian/Persian Gulf. Potential risks of impacts are reported here as a result of a cascade of effects starting from a set of pressures driven by primarily societal changes resulting in changes of environmental features triggering impacts for which policy- and decision-makers are required to remedy with technical and non-technical set of responses.

Fig. 10.3
A schematic of the D P S I R framework. The relationship between drivers, pressures, states, and impacts, as well as the subsequent responses to all the other factors are classified.

Schematic representation of the generated DPSIR framework

Full size image
10.4.4.2.1 Pressures
10.4.4.2.1.1 Chemical Pollution

The driver for this activity is that pipelines attached to the main structure may be classified as remaining materials left on site and can be considered as litter since they are alien objects to the natural environment and may eventually breakdown and disperse into the local environment. There are two options regarding the issue. First is pipeline abandonment, which, as the name suggests, is the activity of leaving the pipeline within the environment after disconnection and purging. Second is the physical removal of a pipeline installation from within the environment intended to be turned into a marine-protected area. The first issue that arises is in terms of chemical and radioactive pollution in the form of naturally occurring radioactive materials (NORMs), since a buildup of barium and strontium compounds within pipelines is commonplace. This may be due to transportation of crude and incompatible water injection which results in a barium/strontium, sulfate, and calcium carbonate co-precipitate (Hamlat et al., 2001). Trace amounts of precipitate may leak into the environment via degradation of pipeline if it is left within the environment. Trace amounts may also be released into the environment during purging and decommissioning process which can lead to adverse effects.

NORM as well as other elements can indeed be made directly accessible to lifeforms on site or via discharge into the adjacent seabed ecology by hydrocarbon granulation (Ossai et al., 2020). Although pipeline precipitate is not a soil pollutant, it will settle on and combine with the surface layer of soil after the pipeline erodes. Through nutritional absorption of particulates and soluble particulates or physical adsorption through carapace, benthic and pelagic ecosystems may well be subjected to related pollutants. The relationship of marine animals with NORM precipitate-based pollutants is influenced by suspended particulate quantities, as well as the dietary habits and biochemistry of the biota. Organisms living in close proximity to pipelines or other hydrocarbon sediments linked toxins can bioaccumulate chemicals and experience eventual ecotoxicological impacts due to the precipitates biochemical and radioactive characteristics (Kennish, 1997).

10.4.4.2.1.2 Physical and Biological Pollutions

Coral reefs provide habitat for aquatic creatures but determining the ecosystem functions or impacts on the local plant and animal life is challenging. As artificially deployed coral reefs age and expand, this introduced environment leads to an increase in the population of creatures by luring surrounding species to the suitable environment, as well as the creation of biomass. The first problem created may be introduced in the form of alien and potentially invasive species as individuals that do not belong to the original habitat potentially leading to a shift in the trophic structure. Furthermore, the substrate provided by the rig is responsible for attraction of invasive species as it forms a perfect anchoring point. Secondly, the richness of local marine fauna that can also be accessed by fishermen is undeniably increased by increased coral habitats. As a result, increased fishing pressure may result in lower fish populations in the long term. Artificial reefs attract fish and other species because they provide protection from waves and predation, reproductive and incubation locations, and a substrate that allows for more accessibility to phytoplankton and sunlight.

The habitat now existing on and around the rig will undoubtedly be impacted by the total removal of subsea structures following dismantling, but the long-term environmental effects of artificial reef installation are less obvious. Most sessile marine creatures, in contrast to migratory species, are unable to be attracted to artificial reefs owing to their confined or sessile lives (Reed et al., 2004). As a result, colonization and expansion of such individuals will almost certainly result in only minor gains in biomass at first (Reed et al., 2004). Acquisition of invertebrates via larval colonization contributes to improvements in secondary production of these organisms as the reef grows and matures.

However, there are multiple forms of pollution that can invariably affect creation and operation of a rig to a coral reef that may have varying effects on the local community that has formed over the course of the rig’s lifetime with one of these stressors being noise pollution. The activity of converting an oilrig to a reef is bound to introduce large amounts of sound into the immediate environment. Since most aquatic species utilize sound as a vital function of their physiology, the excessive input can likely result in deformations, juvenile, and clutch mortality, slowed growth and furthermore it is determined that zooplankton are directly affected with a higher mortality rate when exposed to excessive auditory input (Weilgart, 2007). This will result in key ecosystem services being provided by inhabitants of the existing ecosystem to be disrupted. In a similar manner, a higher exposure to sunlight into an otherwise benthic community that is used to a lowered light concentration can also result in a modification of the physiological performance of the community. Artificial illumination has been shown to introduce changes in species abundance since it disrupts the natural predator prey interactions that an ecosystem develops which results in a disruption of the trophic equilibrium (Davies et al., 2012).

10.4.4.2.1.3 Fisheries

From a fishing perspective, the main causes of pollution are fishing gears such as nets and anchorage. Mangi et al. (2007) applied the DPSIR analysis on the reef fisheries management in Kenya and found out that the destructive fishing gear was one of the pressures affecting the reefs. Similarly, Ojeda-Martínez et al. (2009) in their study of the conceptual framework for the integral management of marine protected areas found that the gears effect, gear lost, and wastes were the main pressures for the management of the protected areas. This is also expected in the rig-to-reef case, as many nets may be lost while fishing and the use of fishing gears (e.g., gargoor or fishing traps) that falls on the seafloor, affect the living communities, or may be lost where the fishermen cannot locate it again.

10.4.4.2.2 State of the Environment

All the previously mentioned pressures resulting in the implementation of the R2R approach will cause several changes in the structure and functions of the natural ecosystems and thus modifying their state. These pressures and human activities have adverse effects in altering the marine ecosystems since it mainly creates a potential biological loss and damage to the ecology, hydrodynamics, and ecosystem services (e.g., suffocation of the benthos, sediments resuspension, and thus the release of the contaminants) (Li & Hu, 2021). In addition, there is a potential change in the physical and chemical nature of the water column and seabed (Tarr, 2014). All of these changes will eventually lead to a disruption in the food web due to habitat destruction and loss of the biological diversity.

Regarding fisheries activities, studies have shown that there can be changes in the species abundance, species richness, and habitats (Mangi et al., 2007; Ojeda-Martínez et al., 2009). In the case of the rig-to-reef of Qatari oilfield platforms, we are expecting these changes to be in the contrary affecting the status of environment in a net positive manner, due to the relatively low productivity recorded nearshore and offshore of the EEZ of Qatar in most of the seasons (Rakib et al., 2021).

10.4.4.2.3 Impacts

Since several pressures are altering the state of natural ecosystems by causing changes in their structure and functions, these changes may lead to various impacts. Maintaining the rigs in place will change the originally existing seabed’s nature affect the benthic populations and their predators. The physical and chemical changes in the water column can affect sea mammals and fishes. Furthermore, marine mammals in general are potentially endangered via offshore operations (i.e., boat propeller accidents) leading to a loss of biodiversity (Tarr, 2014). In addition, food web disruption due to pollution will potentially lead to a loss of food sources and medicine (e.g., corals mortality). Moreover, changing the structure and functions of the natural ecosystems will eventually lead to the loss of the ecosystem services provided by these ecosystems (Smyth et al., 2015).

Previous studies found that some impacts on the fisheries industry are the changes in the habitat’s spatial structure and declining fish catch, which will show reduced livelihood benefits that will be a change in socioeconomic relationship (Gebremedhin et al., 2018; Mangi et al., 2007; Ojeda-Martínez et al., 2009). Since the rig-to-reef is expected to boost fisheries, its implementation in the Qatari oilfields would inversely benefit the fisheries and tourism.

Climate change plays a negative role in the success of rig-to-reef, namely, due to the impacts resulted, increase of temperature, and acidification rate that accelerate physical breakdown of the artificial reefs (Jagerroos & Krause, 2016).

10.4.4.2.4 Responses

In order to tackle the potential navigational safety issue of the remaining structure, many regulations were developed for the achievement of an equilibrium between international agreements which tackle navigational safety, protection, and preservation of the created marine ecosystem (Smyth et al., 2015). Navigational aid (NAVAID) may be installed to assist navigators in determining safe course and/or warn of the existence of underwater structures. In addition, a set of regulations and environmental management solutions needs to be set in order to protect the biodiversity and connectivity with adjacent natural reefs, such as restoring and rehabilitating habitats (e.g., relocation of coral reefs) and thus preventing the loss of habitats, food source, and ecosystem services. Implementing all of these responses will tackle the main risks associated with the rig-to-reef approach in Qatar oilfields, taking into consideration the monitoring process in order to modify these measures based on their efficiency.

As a response to the previously mentioned impacts, past experiences have suggested that certain steps can be implemented to mitigate potential impacts. These mitigation measures include proper policy implementation, changes in the legislation, environmental impact assessments, education, and awareness especially for fishermen, restriction on the number of recreational and professional fishermen and fishing gears, and monitoring and control for the newly established artificial reefs (Gebremedhin et al., 2018; Mangi et al., 2007; Ojeda-Martínez et al., 2009). Furthermore, a regulatory management needs to be developed including policies and monitoring plans that should be implemented by the governmental regulation system to ensure the sustainability and successful work of artificial reefs over long term (Jagerroos & Krause, 2016).

In the case of Qatar, there is already a good environmental law that is constantly updated and that should include the new established rig-to-reef and would have a dedicated policy and legislation. Also, all the fishing activities are licensed, and monitoring using Automatic Identification System (AIS) using radar technology would allow a prompt control of the access to reefed rigs and activities around.

An ecosystem-based approach for management of the newly artificial reefs is necessary to efficiently manage their uses. Declaring these areas as Marine Protected Areas (MPAs) is to be considered. MPAs provide protected zones for fish reserves, underwater parks, as well as wildlife sanctuaries (National Research Council, 2001).

As a result, management responses are required to tackle the changes that can take place due to applied pressures, changes in the status of the environment, and their associated impacts. Regarding decommissioning of oil platforms in these potential marine protected areas, the impacts of decommissioning activities on the conservation objectives need to be included, by incorporating mitigation, adaptation, and compensation measures to minimize negative consequences, as well as to utilize management measures to further enhance gains in goods and services (Burdon et al., 2018).

The selection of the type of MPA as fully protected; highly protected; lightly protected; or minimally protected (Grorud-Colvert et al., 2021) for the reefed rigs should be purely based on the desired outcome from the MPA. Since the aim here is to protect the ecosystem but at the same time promote human development, the precautionary approach would consist of keeping the area fully protected until studies can be conducted to understand the carrying capacity of the established system to human utilization. Once the capacity of the system to cope with disturbances is assessed then an increasing usage can be implemented at a later stage.

10.4.5 Conclusion

The prosperous economy of the State of Qatar, as all other Arabian Gulf neighboring countries, is based on a foremost oil and gas industry established in the second half of the twentieth century. Most of today’s production is conducted offshore using oil platforms, that during the last decades have been colonized by a thriving biological fouling assemblages and visited by rich fish and megafauna communities. Decommissioning these man-made infrastructures in the upcoming decades, through a complete removal, will imply a major loss of the established biodiversity and associated ecosystem functions and services. The rig-to-reef approach, successfully implemented in other seas of the world, provides an attractive alternative to the complete removal by reefing the underwater oilrig structures and theoretically provide positive environmental, economic, and social benefits to a wide range of stakeholders. We thoroughly assessed and reported environmental and technical risks associated to the implementation of the rig-to-reef in Qatar, following the Driver-Pressure-State-Impact-Response (DPSIR) framework. Considering risks associated with navigation, pollution, fisheries, and enforcement of the protection status of the reefed structures, potential impacts and needed mitigation response measures have been identified and linkages with pressures revealed. Obstacles to the effective implementation of the rig-to-reef approach in Qatar have been reviewed and appeared to be mainly connected with the existing regulatory framework and the limited knowledge of conservation value of the oil platforms to be reefed. Hazardous outcomes of the implementation of the rig-to-reef approach in Qatar, and potentially in the region, are of low risk and should be outweighed by the potential benefits achieved by analogous projects and logically expected by the conservation of functional ecosystems, contributing to the maintenance of local biodiversity and regional productivity and connectivity.

10.5 Future Options

The rig-to-reef alternative to complete removal during decommissioning has a potential successful outcome if implemented to Qatar and the Arabian Gulf oil platforms. Its successful implementation will be contingent of the following considerations:

  • Ensure stakeholder engagement with clear definition of liability and compensation schemes under a consistent policy and regulatory framework.

  • Consider asset integrity and risks from corroding structure to the safety of maritime navigation, surrounding habitat destruction and release of contaminants.

  • Thoroughly assess how important are these platforms to ecological productivity and diversity, fisheries sustainability, or the development, use, and enjoyment of marine fisheries in Qatari waters. The State of Qatar should consider this in the proposal of new MPAs toward the 30-by-30 (protection of 30 percent of national marine environment by 2030) as a commitment for the Sustainable Development Goals (SDGs).

  • Anticipate and mitigate risks associated with spread of invasive species and changes in the marine food webs.

  • Implement monitoring programs and enforcement actions to ensure sustainability of the artificial reef and its safe use.

All these actions should be integrated through space (single or multiple oil platforms and/or oilfields) and time (a timeline for decommissioning and reefing) for the effective implementation of a national rig-to-reef strategy roadmap.