Remembering The Cost of Oil Spills
A recent study published by veterinarians at the National Marine Mammal Foundation in San Diego compared 46 dolphin deaths in the region of the 2010 Deepwater Horizon spill with 106 bottlenose dolphin deaths from unaffected regions. The researchers discovered that Gulf dolphins had weaker lungs with leisions and abnormal adrenal glands; health problems identical to issues found in living Gulf dolphins in 2011, and similar to a study where oil was fed to mink with the result of shrunken adrenal glands.
Dolphins from the Gulf were four times more likely to have died from opportunistic infections compared to dolphins from North Carolina, South Carolina and the untouched parts of Texas and Florida costal areas. This susceptibility may be the result of reduced cortisol, a hormone produced by the adrenal glands, that protects an animal from stressors such as infection and cold temperatures.
Pneumonia often occurs in humans who inhale hydrocarbons during an oil spill. Dolphins breathe higher concentrations of hydrocarbons as their breaths come from the surface of the water where the chemicals are the most concentrated. Dolphin respiratory systems also lack filters, like human nose hairs, to filter out hydrocarbons.
It is not completely certain that these health issues in Gulf dolphins are the result of the oil spill; not much is known about the health of dolphins in that region prior to the spill, a region where all manners of sea life would likely have higher instances of exposure to petroleum due to the heavily industrialized operations taking place there. BP disputes a connection between the spill and dolphin health.
This study was published around the time of the report that the Plains All American Pipeline in Santa Barbara had ruptured and spilled oil into the ocean. As of 3pm this afternoon, the LA Times reported that 105,000 gallons of crude were released, with likely tens of thousands entering the ocean. Cleanup is only expected to take a matter of days however. To put things in perspective, the Deepwater Horizon spill released 210,000,000 gallons of crude into the Gulf. There is concern however, as endangered whale species such as humpbacks migrate through the Santa Barbara channel at this time of the year, a region that is also home to other endangered species and rare birds. While it is being downplayed as a minor event, the environmental impacts of oil spils are discernible decades later, making it very hard to predict the amount of harm caused by an event like this.
Additional Source: Scientific American
Image by NASA/GSFC, MODIS Rapid Response AND demis.nl AND FT2 [Public domain], via Wikimedia Commons