The phenomenon of a patch of abnormally warm water off the west coast of North America gained notoriety in 2014, when the first such “Blob” was spotted and given that name, after the horror movie creature that devoured everything in its path. That first Blob lasted years, from 2013 to 2016. It has been blamed for slicing some forage fish populations in half; starving seabirds; triggering a collapse in cod; shifting tuna as far north as Alaska; pushing whales into the path of crab fishing lines and ships; and allowing exotics, including glowing tropical sea pickles, to arrive in northern waters.
“We know marine heatwaves are on the rise globally, but policymakers, fisheries experts, aquaculture industries and ecologists need to know how this will play out at regional levels, especially in terms of where they will occur and how much hotter they will be,” said lead author from the ARC Center of Excellence for Climate Extremes Dr. Hakase Hayashida.
In a study published Wednesday in the journal PLOS ONE, a group of scientists from various state and federal agencies, universities and bird rescue organizations documented the die-off and concluded from the data that it was caused by a record-breaking ocean heat wave in 2014 through 2016 that triggered systemic changes throughout the ocean ecosystem.
The study, published Monday in the journal Nature Climate Change, looked at the impact of marine heat waves on the diversity of life in the ocean. From coral reefs to kelp forests to sea grass beds, researchers found that these heat waves were destroying the framework of many ocean ecosystems.
According to Rebecca Vega Thurber, an associate professor of environmental microbiology at Oregon State University, who was not involved in the study, “What’s really exciting about this paper is the really strong correspondence between this temperature anomaly that occurred during that year when the sea stars started dying.”
Everywhere the warming went, the sunflower stars sickened and died.
The study showed a correlation between warming temperatures and the spread of the disease, not a direct cause. But it corroborates a hypothesis that was initially questioned because the virus that researchers think is responsible also shows up in healthy sea stars.
As the oceans continue to heat up, those effects will become more catastrophic, scientists say. Rainier, more powerful storms like Hurricane Harvey in 2017 and Hurricane Florence in 2018 will become more common, and coastlines around the world will flood more frequently. Coral reefs, whose fish populations are sources of food for hundreds of millions of people, will come under increasing stress; a fifth of all corals have already died in the past three years.
At its peak, the blob stretched from Alaska to South America. In the Gulf of Alaska, the cod population plummeted by more than 80 percent.
From Science Daily Increased fluctuations in the path of the North Atlantic jet stream since the 1960s coincide with more extreme weather events in Europe such as heat waves, droughts, wildfires and flooding, reports a University of Arizona-led team. The… Read More ›