Fish

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...

Wetlands have flourished along the world’s coastlines for thousands of years, playing valuable roles in the lives of people and wildlife. They protect the land from storm surge, stop seawater from contaminating drinking water supplies, and create habitat for birds, fish and threatened species. Much of that may be gone in a matter of decades. As the planet warms, sea level rises at an ever-faster rate. Wetlands have generally kept pace by building upward and creeping inland a few meters per year. But raised roadbeds, cities, farms and increasing land elevation can leave wetlands with nowhere to go. Sea-level rise projections for midcentury suggest the waterline will be shifting 15 to 100 times faster than wetland migration has been clocked. Many wetlands, like these on Cape Cod, are now bordered by human infrastructure, including towns and roads. Lance Cheung/USDA I have been studying coastal g...

When people hear about underwater reefs, they usually picture colorful gardens created from coral. But some reefs are anchored to much more unusual foundations. For more than a century, people have placed a wide assortment of objects on the seafloor off the U.S. coast to provide habitat for marine life and recreational opportunities for fishing and diving. Artificial reefs have been created from decommissioned ships, chicken transport cages, concrete pipes, rail cars and more. We study how ocean-dwelling fish use artificial reefs in the U.S. and beyond. Through our research, we have learned that artificial reefs can be hot spots for large predatory fish such as groupers and jacks. They also can serve as stepping stones for reef fish expanding their range northward with warming water temperatures and as rest stops for sharks. Artificial reefs can be strategically designed and placed to optimize fish habitat. But although they provide valuable ecological services, no one has in...

Humans have sailed the world’s oceans for thousands of years, but they haven’t all reached port. Researchers estimate that there are some three million shipwrecks worldwide, resting in shallow rivers and bays, coastal waters and the deep ocean. Many sank during catastrophes – some during storms or after running aground, others in battle or collisions with other vessels. Shipwrecks like the RMS Titanic, RMS Lusitania and USS Monitor conjure tales of human courage and sacrifice, sunken treasure and unsolved mysteries. But there’s another angle to their stories that doesn’t feature humans. I have studied the biology of shipwrecks in the United States and internationally for 14 years. From this work, I have learned that shipwrecks are not only cultural icons but can also be biological treasures that create habitat for diverse communities of underwater life. The USS Monitor, which sank off Cape Hatteras, North Carolina, in a...

PFAS, the “forever chemicals” that have been raising health concerns across the country, are not just a problem in drinking water. As these chemicals leach out of failing septic systems and landfills and wash off airport runways and farm fields, they can end up in streams that ultimately discharge into ocean ecosystems where fish, dolphins, manatees, sharks and other marine species live. We study the risks from these persistent pollutants in coastal environments as environmental analytical chemists at Florida International University’s Institute of the Environment. Because PFAS can enter the food chain and accumulate in marine plants and animals, including fish that humans eat, the spread of these chemicals has ecological and human health implications. Biscayne Bay and nearby coastal areas are teeming with fish, including many varieties that people eat. NPS image by Shaun Wolfe I...