March 4, 2023 | Issue 23-3 | |
Sunflower Sea Stars Could Help Bring Back Kelp Forests |  | |
The average sunflower sea star, also known by the scientific name Pycnopodia helianthoides, can eat almost 5 purple sea urchins a week. That's good news! The now-endangered predator may be returned to their former habitat so they can keep hungry sea urchins in check and possibly help restore kelp forests.
A team led by Aaron Galloway and Sarah Gravem at Oregon State University discovered that these very large scaled sea urchins couldn't have developed in the presence of the sunflower sea stars. He states "Our findings indicate that if Pycnopodia recovers, it should suppress these urchin barrens and help the kelp forest recover."
Healthy bull kelp are extremely important in our oceans ecosystems. They can stretch more than 50 feet up from the ocean floor, creating underwater forests. The kelp provides valuable habitat and food for mammals, fish and invertebrates. However, climate change is warming the ocean and that is putting a lot of stress on the ecosystem.
Alongside sea otters, sunflower sea stars kept the sea urchin population in check. Sadly, sea otters were almost hunted to extinction. And over the past decade, sea star wasting disease wiped out almost all the sunflower sea stars in Oregon and Washington.
Galloway's team collected sunflower sea stars at sites in the San Juan Islands, where small populations of sea stars have managed to avoid the wasting disease. They found that with all their studies, the sunflower sea star could help save the kelp forests even without the sea otter.
Read more about this kelpful sea star here.
| Source: “Sunflower sea stars could help bring back kelp forests," PHYS.org, 02/22/23 | |  |
Chemical Signals From Fungi Tell Bark Beetles Which Trees To Infest |
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The Eurasian spruce bark beetle (Ips typographus) is responsible for killing millions of trees in forests across Europe and researchers now believe they had the help of fungi. These fungi take the trees' chemical defenses and warp it to create an aroma that attracts the bark beetle.
Although several species of bark beetles have aggressively attacked forests from Northern America to Australia, the trees aren't defenseless. You know that delightful smell of a Christmas tree? That's actually a chemical the tree produces to trap and poison invaders! Well, that's what its supposed to do anyway.
Jonathan Gershenzon, a chemical ecologist at the Max Planck Institute for Chemical Ecology in Jena, Germany, and his colleagues compared chemicals released from these trees. Some of the trees were infested with the fungi known as Grosmannia, and the others uninfected. The team found that the trees with the fungi had a different chemical profile. These studies suggest that the fungi-made chemicals tell the beetles where to feed and breed, and to advertise that the trees defense has been taken down.
While the fungi perfume might doom the trees, it might actually be the secret ingredient to a more effective beetle trap. Currently, beetle traps in Europe are only using beetle pheromones to attract their victims. But by mixing the pheromones with the fungi-derived chemical might attract even more beetles to the traps.
Read more about this pesky problem here.
| Source: “'Chemical signals from fungi tell bark beetles which trees to infest,” ScienceNews, 2/21/2023 | | | | |
