Marine Ecosystems Battling Oil ImpactsApr 18, 2014 03:49 pm
By: Ashley Tuggle
The Gulf of Mexico is one of the most active areas for oil drilling in the country. According to the U.S. Energy Information Administration, the Gulf accounts for 23% of total crude oil production and the Gulf coast contains over 40% of the oil refining capacity in the country. That much production and refining capacity centered in one region has made the Gulf a prime area for oil-related injuries. Galveston Bay in Texas, alone, has had an average of 285 oil spills annually since 1998.
The March 22 Houston Channel oil spill dumped 170,000 gallons of oil into the ecosystem. Image courtesy of National Geographic Staff.
Most recently, the Houston Ship Channel oil spill on March 22 disrupted not only the Gulf's ecosystem, but one of the busiest seaports in the nation, gaining national attention for the magnitude of the spill, 170,000 gallons of tar-like oil, and its commercial and environmental impacts. The Channel closed for 4 days and significant injuries to marine and coastal wildlife were reported.
Under the Oil Pollution Act of 1990, responsible parties must provide compensation for these natural resource injuries on top of the fines related to the spill itself. While the full magnitude of the Channel spill's impacts is still to be determined, it could be extensive as globally significant important shorebird habitat lining both sides of the waterway. The timing of the spill is especially concerning given that it comes just before peak shorebird migration season when tens of thousands of birds will pass through the area surrounding the Houston Ship Channel.
Compensation for environmental impacts from spills of this size typically comes from habitat restoration or creation. A tool called Habitat Equivalency Analysis can help translate environmental damages to wildlife and habitat into restoration acreage.
Spills from ships and pipelines are not the only culprits for oil impacts in North America's coastal waters. Widely-publicized major spills like the Houston Ship Channel spill typically account for only 8% of the petroleum inputs into the North American marine ecosystem. Natural seeps, cars, and other land vehicles, along with recreational boats are major contributors to oil pollution in the Gulf. It is death by a thousand paper cuts. None of these impacts are on the scale of oil spills, but taken in sum, they can add up to the more insidious and chronic injuries impacting our oceans.
Oil on the surface of the Gulf of Mexico, from the natural seeps. Image courtesy of the NASA Earth Observatory.
Natural seeps contribute the majority of the oil load in North American waters, about 60%. However, bacteria have evolved around these seeps that naturally break down the oil coming from them, which is why it is much more of an issue when an oil spill from a tanker occurs in an area that doesn't have these seeps or bacteria.
Cars and other vehicles constantly drip oil, further contributing to the problem. Many storm drains lead directly to the nearest water body without treating stormwater. This means that whatever happens to be on the street at the time may impact the nearby aquatic environment. This kind of pulse impact can lead to more chronic problems in the ecosystem as low-level influxes of oil occur continuously.
Recreational boating can result in small-scale spills that may go unnoticed or unreported. Some experts have noted that as many as 80% of small spills from recreational boats go unreported. This makes tracking the chronic impacts and the full magnitude of these types of spills complicated for regulators and researchers. In busy recreational areas, small spills may represent a much greater proportion of the impact from oil than large-scale spills since they occur on a more consistent basis. They may be the main source of oil for areas that have little to no commercial boat traffic or drilling activity.
Regardless of the source of oil, the impacts of spills, acute and chronic, on our marine ecosystems are extensive and an ongoing problem. When planning for restoration in compensation for major spills, the myriad sources of coastal pollution from oil and other sources must be taken into account for an effective habitat design that can withstand and sometimes even help to cleanse these environmental stressors from an ecosystem. Ending all oil spills is probably not possible, but designing restoration to try to combat their impacts is. Understanding the ecology of a system and the processes that make it more resistant and resilient to oil and other stressors can be the deciding factor in the success of a restoration project. With oil spills, large and small, and the other threats to our coastal waters, restoration success is something our marine ecosystems desperately need to survive.
Pay attention to the open skies, you never know what will be coming down.