CULTURE

Tales of a Warming Ocean, Told By Seashells 

Collecting shells on the beach is as much a part of summer as barbeques, fireworks and corn-on-the-cob. But we rarely pause to think about how they were made or the health and welfare of the mollusks that built and lived in them.

In a new book, The Sound of the Sea: Seashells and the Fate of the Oceans, environmental journalist Cynthia Barnett says that seashells have much to tell us, revealing our planetary past and warning us of dangers that lie ahead.  

Barnett said she decided to focus on seashells, delicate objects constructed by soft-bodied mollusks from particles in seawater, for what they say about the ocean itself. 

“We love seashells for their beautiful exterior rather than for what’s inside. In that same way, we love the oceans as a beautiful backdrop rather than the very source of life,” Barnett said. “I started to see seashells as really good ambassadors for helping people understand the chemical changes underway in the oceans.”

Climate change is threatening both shells and the creatures that make them. Ocean acidification caused by a greater concentration of carbon dioxide has increased by 30 percent since the Industrial Revolution, according to the National Oceanographic and Atmospheric Administration (NOAA). That can decrease the amount of calcium carbonate molecules, the building blocks of seashells, in seawater. Plus, the higher acidity also can dissolve shells that mollusks have already built. And warming ocean waters are  threatening shellfish, as temperatures exceed what their biology can handle.

“As we see them beginning to struggle to build their shells in the acidifying seas, and as we see them have difficulty living in the parts of the oceans warming, they’re the proverbial canaries in the coal mine for the oceans,” Barnett said. 

SOLUTIONS

A Carbon Market Powered by Blockchain

An Estonian company is using the same technology that powers cryptocurrencies like Bitcoin to turn nature into the new gold—precious, tradable and highly valued.

Single Earth partners with landowners around the world who want to preserve their biologically diverse lands, such as forests or wetlands, rather than harvest resources from them. The company uses blockchain technology to create digital tokens that represent the carbon sequestration value of a piece of land, one token per 100 kilograms of carbon dioxide. The landowner can keep the token as an investment or sell it to a company or another investor. That investor can keep the token or use it as a carbon offset to help reach their climate goals. Once the token is used as an offset, it is taken out of the market. 

“The point of having a blockchain is to make it super transparent and traceable,” said Single Earth co-founder Merit Valdsalu. “This is something that current carbon markets lack and are often criticized for.” 

Participating landowners have an incentive to keep their land intact rather than monetizing it through logging, agriculture, mining or other destructive practices, because for every 100 kilograms of carbon the land sequesters, they earn another token that can be sold. 

Private landowners face barriers in current carbon markets, like complicated and expensive certification procedures, Valdsalu said. “So we want to make these processes a lot easier for them.”

Single Earth just secured $7.9 million in seed funding to get the digital marketplace launched by the fall. Those interested in investing can sign up now to get in when the tokens come online. Valdsalu anticipates that the price per token will be similar to the current average global price of carbon. 

“Once tokens become available, we hope to see that a lot of new money will go to protecting nature. This has been our goal all along,” Valdsalu said. “We want to go to the landowners themselves to make sure they have the financial incentive to make real change, so that land use will become a lot more sustainable.”

SCIENCE

Coming Way Too Soon: A Shark Week Without Sharks

Next week is Shark Week, the annual seven-day extravaganza of shark content on the Discovery Channel. But despite the hype these apex predators get on TV every year, sharks face a dire future, amid overfishing and climate change.

“Unless there’s some serious intervention soon, there’s probably not going to be future Shark Weeks, because they’ll have no content,” said Luke Warwick, director of the Wildlife Conservation Society Sharks and Rays Program. 

The biggest problem sharks face is overfishing, he said. Sharks are harvested for their meat and for their fins, for shark fin soup. They’re often the top predator in the ecosystem, so shark populations are not adapted to bounce back from big losses, Warwick said, and climate impacts will just compound this. Sharks are already disappearing from hard-hit ecosystems like coral reefs. And some species are migrating to cooler waters as their native ranges heat up. 

“We will not be able to showcase the amazing diversity of animals that we see on Shark Week in even two or three decades time,” Warwick said. “These are the key indicators of biodiversity in the world’s oceans and they will effectively disappear. So the time to support better action to stop that is now.” 

SCIENCE

What Makes a Dragonfly Change its Spots? Rising Temperatures, a Study Suggests

Male dragonflies in hot climates tend to lose the dark spots that dot their wings, a new study has found. The spots are important for female dragonflies, helping them find males of their same species to mate with. But the markings also absorb solar radiation and can increase dragonflies’ body temperatures. 

The study, published this week in the Proceedings of the National Academy of Sciences, found that male dragonflies had less heat-absorbing dark color on their wings in hotter climates. This was consistent between and within species and across space and time, said lead author Michael Moore, a postdoctoral fellow with the Living Earth Collaborative at Washington University in St. Louis, Missouri.

Moore and his colleagues examined 3,000 photos of dragonflies on iNaturalist, a citizen science app where people can submit images of the plants and animals they spot. The researchers correlated each dragonfly’s coloration with the climate conditions of their environment. 

“Our focus on using citizen science observations was born out of necessity from the pandemic last summer,” Moore said. “But this is one of the first large-scale demonstrations of the application of this method to do these kinds of research questions. I think my colleagues and I are excited about the promise of citizen science initiatives for informing ecology and evolutionary biology research.”

Moore’s research did not go into the consequences of a potential shift away from coloration in dragonfly populations. But if these climate-driven changes cause dragonfly mating to decline and populations to suffer, insect ecosystems could lose an important predator, Moore said.

“Dragonflies have this really interesting role that I don’t think all that many people know,” he said. “Adults are important predators of the kinds of bugs we don’t like—mosquitoes, gnats, black flies—so we want to have these robust populations of dragonflies because they’re really important for us and our well-being in terms of eating the bugs that are annoying to us.”