[ti:Fast-Spreading Sea Urchins Destroying Sea Life in California, Oregon]
[00:00.04]Scientists say fast-spreading sea urchins have eaten away
[00:06.28]at huge underwater kelp forests in California and Oregon.
[00:14.32]The invasion by tens of millions of the sea creatures
[00:18.76]is causing the destruction of important forms of sea life.
[00:25.52]A recent count found 350 million purple sea urchins on one Oregon reef alone.
[00:34.60]That is more than a 10,000 percent increase since 2014.
[00:42.40]In Northern California, 90 percent of large kelp forests have been swallowed up by the urchins.
[00:52.84]Scientists have reported finding so-called "urchin barrens,"
[00:58.15]or huge stretches of the seafloor that contain nothing but sea urchins.
[01:06.00]Such growth has spread from California to waters off the state of Oregon,
[01:12.00]where kelp forests were once so thick that boats had trouble passing through.
[01:19.88]Scott Groth is a shellfish scientist with Oregon's Department of Fish and Wildlife.
[01:28.32]"We're in uncharted territory," he told The Associated Press.
[01:34.64]"You can't just go out and smash them. There's too many. I don't know what we can do."
[01:42.80]The explosion of purple sea urchins is one of the many problems
[01:48.37]now facing the Pacific Northwest's ocean environment.
[01:54.52]Kelp has already been struggling because of warmer-than-usual waters in the Pacific Ocean.
[02:02.68]In 2013, a mysterious disease began destroying tens of millions of starfish.
[02:11.40]One starfish species, called the sunflower sea star,
[02:16.24]is the only known creature that seeks to feed on the purple sea urchin.
[02:23.08]Also around 2013, the purple urchins had two very good mating years.
[02:30.25]With no animals feeding on the urchins, their numbers continued to grow.
[02:38.00]Steve Rumrill is a shellfish expert at Oregon's wildlife agency.
[02:44.41]He told the AP the huge growth is being driven by starvation.
[02:50.96]"You can imagine all of these small urchins growing up,
[02:55.27]each one of them looking for food, desperate for food," he said.
[03:02.08]Rumrill added that while he has seen major population changes in sea urchins before,
[03:09.29]nothing comes close to the latest explosion.
[03:14.56]Scientists say they are not yet sure if climate change is to blame.
[03:20.24]But they suspect it did play a part in the events
[03:24.79]that helped the purple urchins spread so quickly and widely.
[03:31.44]Norah Eddy is a director at the Nature Conservancy California's oceans program.
[03:38.76]She gave another reason for the explosion.
[03:42.55]She said the area's kelp, which has already been weakened by warming waters,
[03:48.96]is not able to regrow itself as well as in the past.
[03:55.16]"We're going to see climate change as a big driver of changes in kelp forests
[04:01.07]as we move forward, and we are already seeing that," Eddy told the AP.
[04:08.96]She is leading an effort to use drones to map
[04:12.56]and observe Northern California's remaining kelp forests.
[04:18.96]The destruction is also having economic effects.
[04:22.69]Until now, red abalone and red sea urchins, a larger and meatier species of urchin,
[04:31.15]supported strong fishing businesses in California and Oregon.
[04:38.04]A study released this week by the University of California, Davis found
[04:43.52]that 96 percent of red abalone had disappeared from California's northern coast.
[04:51.88]Last year, California closed its red abalone fishery,
[04:56.49]which had brought an estimated $44 million into the coastal economy every year.
[05:04.52]In Oregon, officials suspended permits for its 300 abalone divers for three years.
[05:12.90]I'm Bryan Lynn. 更多聽力請訪問51VOA.COM