07/10/2024
Billions of dead jellyfish have washed up around the world:
The dead jellies form a 'crunchy carpet' of corpses, one expert said.
The jellyfish, known as Velella velella, thrive in large colonies boasting millions of members— or more. But they can be stranded en masse when seasonal winds change, washing up on beaches worldwide.
A 2006 event in New Zealand involved millions of jellyfish. In 2015, about a billion washed up on West coast beaches in the United States, prompting researchers to investigate the factors behind such massive die-offs.
Once stranded, these jellies dry up and die, leaving behind a "crunchy carpet" of corpses on the sand.
A study, based on 20 years of citizen-science observations along the U.S. Pacific coast, revealed that the largest Velella strandings occurred from 2015 to 2019, coinciding with a marine heat wave known as "the blob."
This period of unusually warm ocean surface temperatures likely fueled the jellyfish's population growth by extending the spawning season of certain fish, providing more food for the jellies.
While the blob may have helped Velella populations thrive, it disrupted the marine ecosystem, causing die-offs in other species. As climate change increases the frequency of marine heat waves, Velella may become more common, resulting in even larger stranding events in the future.
Image: Tiffany Boothe, Seaside Aquarium
