Seabirds, which spend most of their lives soaring over remote oceans, have long attracted the attention of scientists. A study at the University of Washington has shed light on the grim effects of sea heat on these bird populations. Published in the journal Marine Ecology Progress Series, the study describes how seaside heat waves are leading to an alarming number of seabird deaths.
Seabirds play a crucial role in the marine ecosystem as guardians of the coastal marine environment. A study conducted by Julia Parrish, professor of aquatic and fisheries sciences, asks a global question about the effects of global warming on seabirds. The answer to this question from the study is alarming – global warming does have a significant impact on seabirds.
One of the most striking discoveries made by the researchers is the lagging effect of sea heat on seabird mortality. Rising ocean temperatures, especially during El Niño, or sea heat waves, cause hundreds of thousands to millions of birds to die within one to six months of the temperature rise.
Sea heat waves, such as the “blob” observed off the Pacific Northwest in 2014-2016, have been a concern for scientists and environmentalists. They were the subject of an extensive study that analyzed data from 1993 to 2021. Surveys of beaches from central California to Alaska tracked the number of dead seabirds washed ashore. The study assessed the severity of the deaths regardless of bird species.
The results of the study showed that catastrophic seabird mortalities, where the number of dead exceeds a quarter of a million, occur about once a decade. However, there were five such events between 2014 and 2019, which is unprecedented.
Timothy Jones, the study’s lead author, compared this type of mass extinction to a catastrophic storm, which usually occurs once a decade. In this case, however, catastrophic deaths continued to occur year after year, like storms that hit every year.