Ecology

There are more than 500 species of sharks in the world’s oceans, from the 7-inch dwarf lantern shark to whale sharks that can grow to over 35 feet long. They’re found from polar waters to the equator, at the water’s surface and miles deep, in the open ocean, along coasts and even in some coastal rivers. With such diversity, it’s no surprise that sharks serve many ecological functions. For example, the largest individuals of some big predatory species, such as tiger and white sharks, can have an oversized role in maintaining balances among species. They do this by feeding on prey and sometimes by just being present and scary enough that prey species change their habits and locations. In a newly published study, colleagues and I surveyed decades of research on sharks’ ecological roles and considered their future in oceans dominated by people. We found that because sharks play such diverse and sometimes important functions in maintaining healthy ocean...

When wildfire smoke is in the air, doctors urge people to stay indoors to avoid breathing in harmful particles and gases. But what happens to trees and other plants that can’t escape from the smoke? They respond a bit like us, it turns out: Some trees essentially shut their windows and doors and hold their breath. As atmospheric and chemical scientists, we study the air quality and ecological effects of wildfire smoke and other pollutants. In a study that started quite by accident when smoke overwhelmed our research site in Colorado, we were able to watch in real time how the leaves of living pine trees responded. How plants breathe Plants have pores on the surface of their leaves called stomata. These pores are much like our mouths, except that while we inhale oxygen and exhale carbon dioxide, plants inhale carbon dioxide and exhale oxygen. A highly magnified view of stomata in a maize leaf. Umberto Salvagnin/Fli...

Fishermen across the Gulf of Mexico are reporting that something is eating fish off their lines. What’s to blame? Many recreational anglers point a finger at sharks. This conflict has caught politicians’ attention. Congress has directed the National Oceanic and Atmospheric Administration, which regulates fishing in U.S. waters, to review shark and dolphin interactions with fisheries, and the U.S. House of Representatives recently passed the SHARKED Act, which would create a task force to address the problem. I’ve studied this conflict, which is formally called depredation, for the past decade. While some shark populations in the Gulf of Mexico, such as bull sharks, are increasing, my colleagues and I have found evidence that human perceptions are also an important factor. A Gulf angler races to land a fish before sharks take it. Sharky waters The Gulf of Mexico is home to more than 70 species of sharks – and those...

“Hey Rupam, open the door. Take this fish,” a woman yelled from outside. I was sitting in the kitchen at my friend Rupam’s house in rural northeast India. It was the heart of monsoon season, and rain had been falling since morning. The woman must have been shouting because the noise of the rain on the tin roof muted everything else. The aunty who lived next door stood outside with a large bowl of Boriala fish. Her husband had gone fishing on the Subansiri River, which flows next to the village, and he had fished all evening. “My husband cannot stay indoors in this weather,” she said in Assamese, the local language. “You can catch a lot of fish during this time.” The monsoon season has long brought a bounty of fish from May to September for people living downstream. However, this is likely to change once the Subansiri Lower Hydroelectric Project, one of the largest hydropower dams in India, is completed upstream. Expected to be fully op...

In July 2024, all eyes will turn to Paris for the Summer Olympic Games. Spectators from around the globe will converge on the City of Light to watch athletes compete and to soak in the culture, romance and history of one of the world’s most recognizable cities. But an iconic Paris landmark, the Notre Dame cathedral, will still be under renovation after a devastating fire that ignited in the cathedral and burned for 12 hours on April 14, 2019. When the last embers were extinguished, most of Notre Dame’s wood and metal roof was destroyed, and its majestic spire had vanished, consumed by flames. Notre Dame is nearly 1,000 years old and has been damaged and repaired many times. Its last major renovation was in the mid-1800s. The massive beams that framed the structure were fashioned from European oak trees harvested 300 to 400 years ago. Today, these trees are common throughout north-central Europe, but few are tall enough to replace Notre Dame’s roof lattice an...