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Juvenile great blackbacked gulls. Credit: National Oceanic and Atmospheric Administration
Screeching, prancing, soaring seabirds are a standard feature of just about any day at the beach. Gulls, terns, pelicans, oystercatchers, and many others are common sights on American shorelines. But a recent study says that these birds are becoming a less-common sight around the world.
The study was conducted by researchers from the University of British Columbia. They looked at records of seabird populations from 1950 to 2010. They found good records for roughly 500 individual bird populations, representing about one-fifth of all seabirds. They found only spotty records for the rest, but used mathematical models to extrapolate changes in their populations as well.
Some small groups of seabirds saw their populations go up. But several larger groups saw their numbers go down — in some cases, way down. Overall, in fact, the number of seabirds dropped by about 70 percent during the study period. That represents a loss of more than 200 million individual birds.
The researchers say that most of the loss is the result of human activity. Coastal development destroys habitat, creates pollution, and introduces cats and other animals that can destroy eggs or chicks. Overfishing robs the birds of food supplies. And many birds get caught and drowned by fishing lines.
The researchers also say that the loss of seabirds gives us a good view into the overall health of coastal ecosystems around the world — ecosystems that are in decline.
