A new study has found that seabird population has dropped by about 70 percent since the 1950s, based on a global database devised by a team of researchers.
The finding presents the decrease in these birds' numbers and also indicates the unfavorable status of the marine ecosystems. Because the samples used represent a large number of seabirds all around the globe and declines were highly noted among wide-ranging pelagic species, a pan-global population may be more at risk compared to the group with shorter-ranging species in the coastal areas.
Researchers Michelle Paleczny, Vasiliki Karpouzi and Daniel Pauly from the University of British Columbia, and Edd Hammill, a lecturer at the University of Technology, Sydney in Australia devised a global bank of information containing data about seabird populations from 1950 to 2010.
The total number of breeding populations collated were 3,213 from 324 species of seabirds, documented in 357 coastal areas. The researchers obtained the information from books, unpublished reports and journal articles and the entire data collated accounted for approximately 19 percent of the global seabird population.
The findings of the study, published in the journal PLOS ONE, showed that the general population of seabirds dropped by 69.6 percent, which can be translated to approximately 230 million birds in a span of 60 years.
According to the researchers, the alarming decrease is brought about by different causes, such as the overfishing of fish species that seabirds feed on; entrapment of birds in fishing equipment; exposure of the seabird colonies to non-native predators; oil pollution; modifications of habitats; and climate change-induced ecological and environmental alterations.
"Seabirds are particularly good indicators of the health of marine ecosystems," said Paleczny. "When we see this magnitude of seabird decline, we can see there is something wrong with marine ecosystems. It gives us an idea of the overall impact we're having."
Seabirds have a tendency to travel across the oceans of the world throughout their lives to look for food then return to their habitat for breeding purposes. With this new study, experts are given insight into the status of the oceans, which these seabirds regard as their home.
The results of the study uncover the necessity of formulating and implementing actions to conserve the population of seabirds in an international scope, believes Paleczny. The decline of seabirds may result in numerous consequences for the ecosystems of coastal and marine habitats.
Photo: Bert Knottenbeld | Flickr