At this time in human history, it is not controversial to assert that oil spills create a universal loss for all involved. As a society, we understand that an oil spill represents both an economic and environmental tragedy; it is an event that engenders one of our most valuable resources to slip from our grasp, to coat the surface of the oceans, and to envelop the manifestations of its biodiversity. Yet, while we are able to estimate the inherent costs of our dispossessed oil, rarely do we assess the indirect price of such human error, and incorporate forlorn ecosystem services into the red tallies that drive our actions.
Although we may see images of beach clean ups and videos of animal rescue, we tend to associate this facet of the issue with volunteers rather than dollar signs. However, as we begin to discover that worldly resources at our disposal are indeed finite, we must reevaluate the true cost of environmental contamination, its effects on marine ecosystems, and our holistic resource losses.
In order to understand the broader impact of oil spills, we must first understand the concept of cascading trophic effects. A trophic cascade defines a disruption to a keystone species in an ecosystem’s web or food chain that creates significant changes to the dynamic equilibrium of the area. An excellent example of this can be studied in the trifold relationship between jellyfish, fish stocks, and the endangered leatherback sea turtle. Leatherbacks are one of the few primary predators of jellyfish, so when the turtles are forced out of an area, the region may experience a rapid overabundance of the species called “jellyfish blooms.” This event can be extremely detrimental to an ecosystem, as these mesopredators, or creatures that fall into the middle of a food web, feed on the smaller creatures that sustain a varied array of organisms. The increased number of these mesopredators serves to decrease the population of fish in the region, and leads to food shortages for fisherman and coastal inhabitants. Yet, upon examination of the situational antithesis, an abundance of jellyfish prey typically points to a return of leatherback sea turtles, and congruently, an increase in fish stocks.
This principle, that a disruption to a single species may negatively impact entire ecosystems, can also be applied to oil spills. A major threat to specific organisms, such as the coastal otters and seabirds who are severely impacted by spills, can incite extreme damage to marine ecosystems and deteriorate essential resources for human prosperity and survival. To describe this cascading effect, if an oil spill eliminated sea otters from a coastal kelp forest, there would be an influx of the otters’ prey in the area. Otters happen to be critical in maintaining safe populations of sea urchins–a creature that feasts upon oceanic kelp. In the absence of their primary predator, sea urchins are known to devour kelp forests in totality. This in turn depletes local stocks of fish, as well as other wildlife populations that depend on coastal kelp forest habitats to survive. Humans may not feel the resonating effects of oil spills immediately, we may be able to ignore a local extinction of otters, yet subsequent food shortages and other notable effects are imminent nonetheless. Conversely, there is ample evidence that thriving ocean ecosystems absent of heavy pollutants like oil tend to support a greater abundance of fish.
Without even touching upon the incalculable benefits of ocean ecosystems as the world’s largest carbon sink, it is already evident that the damage caused by oil spills can wreak immense havok on human interests. With an ever-growing population and an ever-diminishing supply of arable farmland, we must become better stewards of the resources and ecosystems that sustain us. In essence, if ever there comes a day when our ocean ecosystems falter, access to oil will be the least of our concerns. We must adjust our priorities and protect the most fundamentally important aspects of our plane.
Citation
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