The marine environment is under threat from a variety of dangers. From rising ocean temperatures causing coral bleaching, to plastic pollution poisoning the bird, fish, and mammal population, the impact humans are having on the oceans is becoming increasingly obvious.
One devastating consequence of engineering progress is oil spills, which have occurred to varying degrees across the globe throughout the 20th and 21st centuries. So what does this mean for wildlife?
The Deepwater Horizon oil spill in April 2010 was the largest offshore marine oil spill in the world, covering 112,100 km2. It resulted in unprecedented loss of human life and significant economic and environmental impacts. The active spill continued for several months, resulting in repeated sub-lethal exposure to oil along 2,100 km of the US shoreline in Louisiana, Mississippi, Alabama and western Florida.
It has been suggested that the damage to wildlife was lessened by the fact that the oil was more biodegradable and less toxic than other oils due to its chemical makeup. However, various studies have shown that birds exposed to the oil experienced effects on multiple organs, including the heart, feather damage, increased heat loss and greater energetic demands.
Researchers at the University of Wisconsin-Madison and the US Department of Agriculture National Wildlife Research Center used one-dimensional proton nuclear magnetic resonance (1D 1H NMR) spectroscopy to assess the impact of the Deepwater Horizon oil spill on double-crested cormorants. Metabolomic studies, which analyze metabolites in a biological cell, tissue, organ or organism, reveal changes in metabolites of energy metabolism in the birds exposed to the sub-lethal oil, as well as fatty acid and amino acid metabolic pathways and can help reveal important effects on reproduction, migration and, ultimately, survival of the cormorants.
Magnetic resonance spectroscopy is used across a range of fields related to environmental science and beyond. Access to state-of-the-art technology like NMR enables researchers to reveal the true impact of oil spills on marine life and show that damage assessments are likely to underestimate the true cost to animal populations. Using this information, scientists can more accurately predict the physiological impact of sub-lethal oil exposure and improve clean-up and rescue methods.