Seagull Blood Shows Promise For Monitoring Oil Spills

Sea Technology, Feb 2008

Like the proverbial coal miners' canary in the cage, seagulls may become living sentinels to monitor oil pollution levels in marine environments, reported scientists in Spain.

Researchers have known for years that large oil spills can increase levels of polycyclic aromatic hydrocarbons (PAHs) in marine environments.

Studies have linked these compounds to cancer in humans. While oil spills quickly kill large numbers of seabirds and other animals, scientists do not fully understand the nonlethal biological effects of these spills, the researchers said.

The researchers measured PAH levels in the blood of yellow-legged gulls living in the vicinity of the oil spill caused by the 2002 shipwreck of the Prestige, one of Europe's largest oil spills.

Gulls exposed to the oil showed twice the levels of PAHs in their blood compared to unexposed birds, even though these levels were measured 17 months after the initial spill, the researchers said. The findings "give support to the nondestructive use of seabirds as biomonitors of oil pollution in marine environments," the report states.