Lake sturgeon thriving in Coosa River after reintroduction project
Lake sturgeon were once abundant in Georgia's Coosa River before disappearing altogether. Now, an initiative to bring them back is showing major progress, according to a new study from the University of Georgia.
The lake sturgeon's lineage can be traced back millions of years, all the way to the time of the dinosaurs. But due to a mix of pollution and overfishing, they were completely wiped out in the Coosa River.
In 2002, the Georgia Department of Natural Resources began a project to bring these ancient fish back. Every year, eggs from lake sturgeon in Wisconsin were brought to Georgia before being hatched and released into the Coosa River.
UGA researchers were tasked with monitoring the project's progress, conducting an intensive netting study to capture and tag as many fish as possible.
"There was kind of a big question mark as to whether fish with the genetics of fish from up north would survive," said Martin Hamel, lead author of the study and an associate professor in UGA's Warnell School of Forestry and Natural Resources. "And even if they did survive, would they be able to reproduce on their own and have a self-sustaining population?"
The scientists now believe they have the answer.
"Not only are these fish surviving, but we're showing evidence that they are capable of reproducing and that the young are able to survive on their own."
Birds found thriving in a very large commercial forest in Maine
North America has lost an estimated 3 billion birds since 1970—a nearly 30% drop across species—mostly due to habitat loss and degradation. So when a team of researchers repeated a bird population study they did 30 years earlier in a very large commercial forest landscape in Maine, they were stunned to find more birds than before.
"When we started this project, we expected to add to the pile of bad news," says Michael Reed, a professor of biology in the School of Arts and Sciences at Tufts University and co-author of the study. "So we were very pleasantly surprised to find that, for most of the bird species in our study, things were actually looking up."
The research team wanted to see if bird populations and habitat use had changed over the decades, particularly given a shifting forest landscape. "Forest management practices in Maine have changed significantly since the early 1990s," says Reed. Due to social pressure, clearcutting has become much less common in Maine. Today, most logging operations remove fewer trees per acre—returning to spots every decade or so—and spread their activity across a broader area.
The
study, published in
Biological Conservation, found that 26—or more than half—of 47 species counted by the researchers had significantly increased in numbers since the early 1990s, while populations for 13 species (or 28%) had remained stable. That's contrary to what happened across much of the continent, with the North American Breeding Bird Survey showing that 35—or 75%—of the same species analyzed had seen their numbers decline, both regionally and continentally, for the same timeframe.
Chagos study highlights value of vast Marine Protected Areas
Large ocean animals can be protected throughout much of their lifecycle by huge Marine Protected Areas (MPAs), new research shows.
Scientists tracked sea turtles, manta rays and seabirds—all of which travel far and wide to forage, breed and migrate—in the Chagos Archipelago MPA in the Indian Ocean.
In total, 95% of tracking locations were recorded inside the MPA's 640,000-square-kilometer area—suggesting it is large enough to protect these wandering animals.
The study—by a team including Exeter and Heriot-Watt universities and ZSL—also assessed the impact of a smaller 100,000-square kilometer MPA and found seabirds would be less well protected in this scenario. The paper, published in the Journal of Applied Ecology, is titled: "Large marine protected areas can encompass movements of diverse megafauna."
"Very large Marine Protected Areas (VLMPAs) are seen as essential for meeting international goals, such as the target for 30% protection by 2030," said Dr. Alice Trevail, from the Environment and Sustainability Institute at the University of Exeter's Penryn Campus in Cornwall.
"However, the conservation value of VLMPAs—defined as anything over 100,000 square kilometers—is debated.
"Our results provide clear evidence for the value of the Chagos Archipelago VLMPA for protecting a diverse range of large and mobile marine species."
Molecular hope: Tiny ocean crustaceans use genetic and epigenetic tools to weather climate change
In a first-of-its-kind experiment tracing evolution across 25 generations, scientists have discovered that marine copepods—the tiny crustaceans at the heart of the ocean food web—rely on a largely unknown biological toolkit to survive the stresses of climate change.
Published July 15, 2025, in the Proceedings of the National Academy of Sciences, the study reveals that it's not only genetic changes (permanent alterations to DNA) that help these animals adapt to warming and acidifying ocean conditions. In addition, little-known epigenetic changes (temporary "on/off" chemical modifications to parts of DNA) play a crucial role too. Remarkably, the researchers discovered that the two mechanisms operate independently but in concert, offering what they call a "two-pronged strategy" for long-term resilience.
"This is a story of molecular hope in the face of a rapidly changing planet," said senior author Melissa Pespeni, associate professor of biology at the University of Vermont. "We found that evolution is not working from one toolbox, but two—and they're complementary."
Until now, few studies have tracked genetic and epigenetic changes in tandem over many generations. This experiment is one of the first to do so in a long-term, replicated evolution study—offering some of the strongest evidence yet that epigenetic change can help populations survive and perhaps even allow future genetic adaptation.
Which means that copepods may be tougher under the stresses of a warming ocean than scientists previously would have predicted. And that could be good news for the many fish species who eat copepods as their primary prey—and for the many other creatures, including humans, who eat fish.
Tiny as they are, Acartia tonsa and other copepods play a massive role in the ocean ecosystem and global carbon cycle. They're the base of the marine food web, sustaining fish, whales, and seabirds. They also help cycle nutrients and carbon in the ocean.
"Without copepods, you don't have fish, you don't have whales, you don't have the ocean system we know," said Pespeni. "And they are arguably the most abundant animal on Earth."
The fact that copepods can survive and quickly adapt across generations—say, during a short, intense heat wave—could make a long-term difference in maintaining biodiversity and ecosystem function in a warming world.
