Balmy temperatures can lead to conditions perfect for the spread of infectious diseases, Sanderson said. When sea ice melts too early in the season, seal pups must enter the water before they are ready to be weaned, leaving them weaker and more vulnerable to disease. Vanishing sea ice also means that seals and sea lions in cold regions will have less space to emerge from the water to rest, breed, or escape predators, forcing them to crowd more tightly together.
What we commonly see accumulating at the sea surface is “less than the tip of the iceberg, maybe a half of 1% of the total,” says Erik Van Sebille, an oceanographer at Utrecht University in the Netherlands.
This loss of oxygen in the ocean is significant enough to affect the planetary cycling of elements such as nitrogen and phosphorous which are, “essential for life on Earth,” Dr. Laffoley said.
Although Arctic-wide warming during the 20th century is well documented, little is known about the response of sea-ice to abrupt warming and it is unclear when the sea-ice decline started. Data coverage in this region is highly restricted, with observation-based satellite data only available since the 1970s, too short to accurately calibrate climate models.
Most of the trash in the ocean comes from land, and most of it is plastic. An estimated 4.8 to 12.7 million tons of plastic leaves the shorelines into the ocean globally each year, and there are now over 5.25 trillion pieces of plastic are floating in the ocean currently.
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.
The Ocean Cleanup, which has raised $35 million in donations to fund the project, including from Salesforce.com chief executive Marc Benioff and PayPal co-founder Peter Thiel, will deploy 60 free-floating barriers in the Pacific Ocean by 2020.
She says understanding how plastic gets into fish matters not just to the fish, but to us. “We eat fish that eat plastic,” she says. “Are there things that transfer to the tissue? Does the plastic itself transfer to the tissue? Do the chemicals associated with the plastic transfer to the tissue?”