A Critical appraisal of the Torrey Canyon oil spill and the Remediative Response - Coursework Example

?A Critical appraisal of the Torrey Canyon oil spill and the Remediative Response The Torrey Canyon was an oil supertanker that became the source of what is today considered Britain’s most disastrous oil spill. This spill was disastrous not only because of the 119,328 tonnes of crude oil it released into the Cornwall region of the Atlantic Ocean (Barkham 2010), but because the British government’s response to it caused more long term danger to the local ecosystem than was caused by the oil itself. Traditional British Petroleum (BP)-manufactured detergents were not effective on the huge blocks of oil that formed on the ocean’s surface. Neither were other measures aimed at sinking the ship, limiting the spread of the oil, and removing the oil slick. The decision to burn the surface oil with napalm and bombs, and to disperse the oil with the heaviest bombardment of detergents ever applied to a spill led to the deaths of thousands of birds and untold numbers of many species of marine animals. Hampered by limited knowledge about the behavior of oil in diverse aquatic conditions, the effectiveness and toxicity of chemical solvents, and the parameters that suggest the optimal response to spills, ill-equipped authorities and officials from the navy and government made decisions that have tragic effects on the area wildlife and ecosystem even in this decade. What lessons have we learned from the Torrey Canyon tragedy that can be used to mitigate the disastrous effect of future oil spills? This paper addresses some of the responses to oil spill scenarios since the 1967 event. It examines why oil alone is so destructive to ecosystems, focusing particularly on PAH, one of the most highly toxic components of oil. This paper also looks at the history of oil dispersal and its effects on marine life. Finally, it addresses and the newer work being done by the scientific community and environmental groups that have led to innovative ideas for preventing- or at least lessening the impact of - oil spill disasters of the future. Exposure to Oil: The problem of PAH Studies have shown that wildlife contaminated by oil suffer a variety of health concerns, such as lowered fertility and fecundity, slower growth, and even death (Boyd, Scholz & Walker 2001). Studies show that many experts have been wrong to focus on dispersants as the main source of toxins involved in oil spill events, because oil itself has toxic effects that can outweigh the dangers of low-level dispersant use (Boyd et al 2001). Oil’s bioavailability to marine life is possible through four main pathways: 1) direct contact with the oil, such when birds dive through oil to catch fish 2) ingestion through eating prey covered with oil or that has recently eaten oil-contaminated food, or through preening their oil covered feathers 3) breathing in fumes or oil particulates suspended in the air, and 4) absorption, whereby toxins leach into the skin of sea creatures or the membranes of plants. Of particular concern is PAH, a highly toxic compound found in almost all oils that has a known association with cancers in both wildlife and humans. Polycyclic aromatic hydrocarbons (PAH) are formed when organic compounds are not completely burned off during combustion (Srogi 1997). PAH contamination of the environment occurs through many of our everyday activities both at the personal and industrial levels, such as motor vehicle emissions, asphalt and aluminum production, oil refining, waste burning, and the combustion of fuels in ships and aircraft (Srogi 1997). When in gaseous form, PAHs enter the water system through precipitation and other atmospheric conditions. Oil leaks and municipal and industrial waste and are other sources of aquatic contamination (Srogi 1997). PAH is toxic in both fresh oil and in “weathered” or decomposed oil that has been exposed to natural atmospheric conditions over time (Neff et al 2011). Researchers have found that oil continues to leach from sedimentation under the water’s surface years after a spill. French, Banta and Swiss discovered that PAH is made accessible to sea life from such percolation (2009). When oil enters the aquatic ecosystem, attempts are made to either remove it, disperse it, or both. Oil that is not dispersed can collect into sheets of various thicknesses. Over time, this older oil can sink to the floor and create a toxic coating that makes PAH available to the sea creatures that live or forage there. Dispersal is the act of breaking oil into small droplets that can be easily mixed into the surrounding body of water. PAH is problematic for organisms whether oil has been dispersed naturally or chemically. For example, in shallower areas under these conditions, mussels filter tidal water through their gills and collect PAH in the process. Sea lettuce, a type of alga, collects a coating of PAH on its slippery surfaces. Some forms of clams and sea worms have also been found to accumulate PAH on their surfaces in a similar fashion. PAH from oil spills has long reaching effects. The food chain is one method of transmitting toxic hydrocarbons between species. Certain types of fish, crabs, and whelks that consume sea lettuce and other PAH-covered organisms are introduced to these compounds primarily through their diet. These creatures, in turn, are consumed by certain types of birds (Neff et al 2006). Diet is also a method of PAH exposure for humans. The US Environmental Protection Agency (EPA) has identified over a dozen PAHs as compounds deserving high attention due to their role in cancers and birth (Srogi 1997; French et al 2009). Researchers are not in total agreement about the long term bioavailability of PAH or about the effects of PAH on marine species. Many factors must be taken into account when studying oil spillage and wildlife. Neff, et al identified three methods for wildlife exposure to PAH from the Exxon Valdez oil spill in Prince William Sound, Alaska, in 1989: directly through the water, by consuming animals contaminated with oil, or through contact with oil residue beneath the ocean surface (Neff et al 2011). They also identified three factors on which marine animal exposure to oil-related PAH depend: “the natural distribution, behavioral patterns, and activity of the wildlife in the vicinity of the spill; the geographic overlap between the location of spill remnants and the distribution and activities of the animals; and the geo-morphological state (location and physical form) of the spill remnants that defines their degree of sequestration, weathering, and persistence, and controls their bioavailability to wildlife” (Neff et al 2011). Studies by Neff et al contradict findings of previous researchers who asserted that that harlequin ducks and sea otters in Prince William Sound have lower populations due to high levels of PAH-contaminated oil seeping from shoreline rocks. Findings by Neff et al suggest that the foraging practices and habitat preferences of these species do not expose them to lingering oil. Furthermore, Neff et al caution that direct comparisons of species that inhabit different locations will not provide accurate information because of the effect of geography (Neff et al 2011. The geography of Prince William Sound and the location of the oil spill have not only allowed the maintenance of residues in the area for years, but are the reason that the PAH contained in the oil is less available to local wildlife, according to findings by Neff et al (2011). In other words, the conditions that keep the oil from dispersing are the same conditions that prevent accessibility to PAH, as oil that is able to disperse would have weathered away by now (2011). Continued studies by experts in different fields allow new findings such as these to enrich the body of knowledge about the long term effect of oil spills on marine life. The Added Problem of Detergents and Dispersants Industrially, emulsifiers and solvents had been used to “clean” small spills by dispersing oil into the water, under the notion that manmade dispersal methods as quickly as possible are better for the environment than allowing nature to take its own course through sea energy. In highly active waters, oil is naturally broken into small particles which are then easily biodegraded by micro-organisms (EMSA 2010). A dispersant’s effectiveness is based on “the amount of oil that the dispersant puts into the water column compared to the amount of oil that remains on the surface” (Fingas 2002, p2). Generally, dispersants must be applied within one or two days of a spill to be most effective (White & Baker 1999). Dispersants work best in optimum conditions that depend upon an interplay of oil components, water temperature and salinity, wave action and current strength, the level of oil decomposition, and the type and amount of dispersant used (Fingas 2002, p2-3). Dispersal prevents oil from forming a sheen or turning into slicks on the water’s surface, and also helps prevent oil from weathering into harder slabs that trap wildlife. The tradeoff of dispersal is that a more marine organisms have a higher risk of coming in contact with toxins from the widely spread droplets (EMSA 2010). The two main concerns about dispersants are the poisons they introduce to the local ecology and whether they are more effective than natural atmospheric processes in dispersing oils. Before the 1967 Torrey Canyon accident, detergents had been used to disperse oils into the surrounding waters. The overuse of these toxic chemicals and tragic effects on the environment attracted global attention and led to extensive research. This first generation of detergents has never again been used for large scale spills (EMSA 2010); in the early 1970s the UK introduced regulations for maximum toxicity and minimum effectiveness levels of dispersants. There has been little shared knowledge about the use of dispersants, partially because they are not widely used. While Britain fully supports the use of dispersants, it is almost alone among European countries. The only other countries in Europe who permit their use are Norway and France, but there are no records of those countries actually applying them" (Fingas 2002, pV). Several states in the United States have approved their use. As of 2002, the US had employed dispersants three times, all for spills occurring in the Gulf of Mexico (Fingas 2002, pV). Unfortunately, the decision to use certain chemicals for oil removal is influenced by more than effectiveness. For example, ionic surfactants are suggested for dispersant use even though they work better as “surface-washing agents” (Fingas 2002, 2). The choice to use them to disperse oil is based on their cheaper price. In response to concerns about the dangers and usefulness of dispersants, many countries have banned them outright (Fingas 2002, p2). SL Ross Environmental Research Ltd., a firm specializing in oil spill research, says that before a spill response is implemented, officials should consider whether the affected local habitat plays a significant role in the ecosystem as a whole, and should compare the productivity of ocean wildlife to near shore wildlife. They should also consider whether the method chosen will make PAH accessible to wildlife, and should understand how the method will affect the resources available within the habitats" (French et al 2009, 6-7). It is crucial to understand the fertility processes of species in affected environments. Knowing when and where species of fish mate and spawn, and how species migrate must influence the decisions made (French et al 2009). The European Maritime Safety Agency (EMSA) cautions that thorough knowledge of aquatic conditions is crucial to a proper response. Water that is shallow and enclosed, with little freshwater exchange, will respond more slowly to treatment. Bodies of water that are energetic will naturally disperse oils, so treatment will increase the concentration of oil droplets. Like SL Ross, EMSA cautions experts to ask themselves whether using dispersants, which protect shore and near-shore wildlife, is worth the greater risk to marine life (EMSA 2010). For some types of oils, dispersants are not recommended at all. Oils made up mostly of saturates can be naturally dispersed, for example. Oils containing mostly waxes, resins and asphaltenes do not respond to dispersants (Fingas 2002, p3). Research continues to improve both dispersant technology and the decision-making process involved in deploying them. Today’s dispersants do a better job at breaking down oils while presenting less danger to natural habitats (Lin & Mendelssohn 2005). Two classes of dispersants have been introduced for application either from ships or from aircraft, as each method presents unique conditions that influence effectiveness. In addition, three types of dispersants exist. A third class is used for shoreline cleanup (EMSA 2010). New chemicals have been introduced to remove the oil slicks that form on the water surface. These “oil herders” have proven effective in quickly clearing thin slicks that cover large areas (SL Ross 2010). Studies suggest that modern dispersants cause no more damage to the environment than an untreated oil spill (Fingas 2002). Placing The Torrey Canyon in Context The general public would likely be shocked to learn of the number of large oil spills that have occurred since Torrey Canyon event. There have been twenty major accidental spills involving the loss of over 35,000 tonnes of oil per incident. Many more tonnes have been lost during war. One of the most famous accidents is the Exxon Valdez, which lost 37,000 tonnes of crude oil to Alaskan waters in 1989. The UK has experienced two major incidents: the 1993 Braer spill in which 85,000 tonnes of crude oil were lost off the Shetland Islands, UK, and then three years later loss of the Sea Empress sent 72,000 tonnes of oil into the waters off Milford Haven (ITPOF 2011). The Exxon Valdez spill occurred in a non-temperate zone during the winter. Many species of wildlife were harmed by the spill. Of the 435,000 birds killed, 66% were alcids, a family including puffins, auks and murres (Dorfman & Hillenbrand 1983, French, et al 2009). The great majority of the alcid deaths were murres. 15% of the total birds killed were seabirds: gulls, petrels and terns. Very few shorebirds were lost (French et al 2009). Research reveals that the death of the seabirds is related to their foraging and preening habits. As they dove repeatedly into oiled waters they accumulated oil on their feathers, which they then ingested during preening (French et al 2009). Because the birds are diving through oil droplets, the toxic PAH compounds within the droplets are biologically accessible to these birds and to other marine species (Neff, Bence, Parker, page, Brown & Boehm 2006, 948). Severe weather helped to disperse 90% of the surface oil from turbulent shorelines, and up to 50% from calmer areas. In July, 1989, the U.S. Environmental Protection Agency approved the use of bioremediation for further cleaning. The technique involved the introduction of fertilizers to the environment to encourage the growth of native bacteria which would consume particular types of toxic hydrocarbons present in the oil. The EPA recommended fertilizers to clean sediments along the shoreline, but cautioned that this may not remove all of the oil that had seeped into stone. The EPA did believe that slow-release nutrients and oleophillic fertilizers would work with tidal forces to reach “less accessible areas” (EPA 1989). The EPA recommended monitoring of PAH levels, and urged Exxon to work with the National Oceanic and Atmospheric Administration for necessary information about the geography and atmospheric conditions.Additional recommendations were to physically clean heavily oiled portions of the shoreline (EPA 1989). Despite these measures, decomposed oil that permeated the soil and rocks in the area has persisted to this day due to low wave and tidal activity (Neff, et al 2006). Researchers have also found non-decomposed oil from the Exxon Valdez in Prince William Sound well over a decade after the event (French et al 2009). Oil continues to leach from sediment, but tests reveal that PAH levels are below the danger zone (Neff, et al 2006). Neff et al are not concerned about dangerous residues, observing that only 0.1% of the shoreline is contaminated and that there is little bioavailability. Their summation is that there is little risk to area wildlife today from the Exxon Valdez spill (Neff, et al 2006). Even though the 1993 Braer dumped more than double the amount of oil into the ocean, the spill was assessed to have caused less damage to the open Atlantic waters surrounding the Shetland Islands than the Exxon Valdez spill caused to Prince William Sound. The Braer was grounded on rocks in stormy weather that eventually led to the splitting and sinking of the tanker. Fortunately, the combined effects of geography, atmospheric conditions and oil type mitigated the consequences of this spill. While over 700 seabirds died from becoming coated with oil, dead fish washed up along the beaches, and several species of caged fish were found to have acquired toxic levels of PAH during the first few months after the spill, the fact that the event occurred during low marine activity prevented much higher wildlife deaths (Dorfman & Hillenbrand 1983). The gusting winds which prevented manual oil removal also created such highly active waters that the toxic oil quickly dispersed. The geography of the area prevented contamination of the beach areas and did not permit the development of the oil slicks that form in still waters. The type of oil carried by the tanker was of a light variety that behaved differently from other oils in that it didn’t “stick” to beaches or form thick, sticky balls of tar (Dorfman & Hillenbrand 1983). The 1996 Sea Empress spill near Wales was the third largest spill experienced in the UK. It took place in a high energy area and caused heavy deposits of oil along the shoreline, along with oil “pellets” that reached Ireland (Edwards, Kirby & Norton 1996). Mechanical oil removal was implemented for both sea and shoreline oil, but only recovered a small amount of the oil. 445 tonnes of dispersants were applied, but large oil slicks formed (Edwards, Kirby & Norton 1996). To avoid harming wildlife, dispersants were not allowed within one kilometer of the shoreline, however, decomposed oils along economically significant beaches were treated with dispersants. According to an assessment undertaken by the Sea Empress Environmental Evaluation Committee (1996), over 6,900 birds were oiled- mainly species who are often found at the sea surface. Some of these birds were dead but 3,000 of the surviving oiled birds were able to be cleaned and released back into the environment. Fish were not found to be dangerously contaminated, but mussels and cockles were (Edwards, Kirby & Norton 1996). A rare type of starfish suffered a loss of 87% of its population. Hundreds of urchins and other species washed up on shores. Grey seals were oiled but none died. A year after the incident, tar balls were occasionally found on beaches. Studies of area fish revealed low levels of PAHs (Edwards, Kirby & Norton 1996). ). Although the Deepwater Horizon oil spill (also known as the BP oil spill) stemmed from an oil rig explosion in the Gulf of Mexico rather than from a grounded tanker, the concerns about environmental impact and appropriate remediative responses are similar to those described above. A discussion of the Deepwater disaster is appropriate because, as the latest and largest oil spill, it presents an opportunity to gauge the status of oil spill remediation processes. Already scientists are learning that the 2.1 million gallons of dispersants applied to the ocean surface and near the sea floor between May and June of 2010 may be killing marine life and changing the environment in negative ways. In order to break down the oil more quickly than natural processes would allow and thereby prevent large amounts of oil from reaching the shores, BP officials decided to use dispersants to treat the Deepwater Horizon spill. This choice was made despite the fact that no data existed on the effectiveness of dispersant use in deep water, nor the ecological impacts that might occur under such conditions (Kujawinski, Soule, Valentine, Boysen, Longnecker, & Redmond 2011). While federal investigators have stated that the dispersants pose no more danger to the environment than the oil itself presents, some scientists are concerned that too little knowledge exists to make that determination. The EPA has justified the use of dispersants by weighing its potential effects against the effects on ecosystems along the shore, and claims that the trade-off is worth the risk (McGowan 2010). A local toxicologist has charged that this tradeoff protects some wildlife at the expense of others- including species that are on endangered lists ((McGowan 2010). Studies conducted by Kujawinki et al could not state with certainty that the chemicals have successfully dispersed and helped spread the oil. They question whether the water’s depth may have rendered components of the dispersants inoperable (2011). Although the EPA approves of the use of the dispersant, it is aware of its toxicity and is continuing to study its impact (McGowan 2010). New Directions in Handling Oil Spills Safely Experience and research are leading the science community and environmentalists in new directions in terms of oil spill responses. Microbial degradation of oil droplets is one area of research that may lead to more environmentally friendly cleanup procedures. Researchers are aware that all natural environments contain bacteria that degrade bacteria. Microbes adapt to their environment; areas with regular spills due to ship traffic have local led developed microbe populations that live off the oils (Biello 2010). Many types of these oil-eating microbes work together to break down the diverse compounds found in crude oils and other spilled substances. Researchers have attempted to genetically engineer microbes to enhance their hydrocarbon-eating capacity in future oil spills. Others have created experiments designed to encourage faster biodegradation of compounds, but these have so far failed (Biello 2010). Laboratory modeling and testing allows scientists to predict what might happen in the field. For example, the Sea Empress Environmental Evaluation Committee (1996) estimated that approximately one third of the oil spilled near Wales would evaporate from the surface of the water, while half of the oil would be successfully dispersed through chemical agents and natural processes (White & Baker 1999). Scientists modeling the Deepwater conditions were able to predict that oil would sink to the depths that it has currently reached. Predictions like these are important because temperatures are cooler at lower depths, and microbial processes happen more slowly. Predicting oil plume depths can help scientists to understand how long natural dispersal and degradation processes might take. No manmade dispersal methods are available at the current depths of some of the plumes. The bioremediation techniques used in Alaska for the Exxon spill are not successful in the ocean because there is no way to control the interaction between fertilizers and oil in the open waters, and the lack of both oxygen and storm winds creates a completely different environment (Biello 2010). While science has led researchers in new directions, a social response has developed as well. Environmental groups are studying the effects of oil spills and dispersant use and sharing their knowledge. They are working with other agencies with expertise in various arenas associated with oil spill impact. An example is OSRL/EARL, made up of Oil Spill Response and East Asia Response Ltd, a non-profit cooperative with aviation expertise founded in the 1980s and owned by the oil industry. Its purpose is to ensure a rapid and appropriate response to oil spills. They have combined with another group called Sea Alarm Foundation (SAF), which is primarily concerned with saving oiled animals. The new collective aims to respond rapidly to global oil emergencies by maintaining a cadre of experts in aviation and ecology, a reserve of cleanup equipment, and response plans developed with prominent groups around the world. SAF has announced its goal to foster cooperation amongst governmental and nongovernmental organizations to create a multi-pronged approach to oil spill cleanup and wildlife preservation (Holland, James, Coates, Clements & Nijkamp 2008). Groups such as The Prince William Sound Regional Citizens' Advisory Council (PWSRCAC) are politically active and lobby for regulations that limit or ban the use of chemical dispersants in favor of mechanical oil removal techniques. The Torrey Canyon spill continues to kill wildlife to this day. Birds land on thick concentrations of oil and die because they cannot extract themselves from the gooey tar. The area exudes an unpleasant, pungent aroma and oil continues to seep from sedimentary rock (Barkham 2010). Torrey Canyon is a constant reminder that the human response to oil spills can be more disastrous to an ecosystem than the ecosystem’s natural response. Today researchers know that a standardized response to oil spills isn’t feasible because of the many unique factors involved in each event, such as geography, atmospheric conditions, water quality and action, oil composition and volume, and local flora and fauna. Knowledge about the dangerous biological effects of the toxins found in both oils and dispersal chemicals have also influenced oils spill reactions. The literature is filled with new lab research employing modeling, experimentation and calculations to understand and predict the behavior of oils and dispersants. A better understanding of the habitation, foraging and propagation habits of wildlife has led experts to think twice about how and where to deploy chemical dispersants, if they are to be used at all. Knowledge of natural dispersion has allowed certain types of spills to be left to disperse naturally. While the U.S. maintains open-mindedness about the use of chemical dispersants, most of the world, rejects non-chemical oil removal in favor of mechanical methods. It is worth noting that the International Tanker Owners Pollution Federation Limited (ITOPF), which produces an annual report on accidental oil spills finds that over the past four decades there has been a decrease in the number of large oil spills (ITOPF 2011). Unfortunately, we seem to have far to go in figuring out how to prevent them altogether, however, when we use experience and science to handle spill events more intelligently, we may begin to see less disastrous consequences from our response to spills in the future. References Barkham, P. 2010. Oil Spills: Legacy of the Torrey Canyon. The Guardian. 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