ANN ARBOR — Like salmon in reverse, long-snouted Bandringa sharks migrated downstream from freshwater swamps to a tropical coastline to spawn 310 million years ago, leaving behind fossil evidence of one of the earliest known shark nurseries.
That’s the surprising conclusion of University of Michigan paleontologist Lauren Sallan and a University of Chicago colleague, who reanalyzed all known specimens of Bandringa, a bottom-feeding predator that lived in an ancient river delta system that spanned what is today the Upper Midwest. (more…)
Scientists use satellites, underwater robot to study Atlantic sturgeon migrations
More than a century ago, an estimated 180,000 female Atlantic sturgeon arrived from the coast in the spring to spawn in the Delaware River and fishermen sought their caviar as a lucrative export to Europe. Overfishing contributed to steep population declines, however, and today numbers have dwindled to fewer than 300 adults.
Researchers at the University of Delaware and Delaware State University are using satellites, acoustic transmitters, an underwater robot and historical records to pinpoint the ocean conditions that the fish prefer during migrations — and potentially help fishermen avoid spots where they might unintentionally catch this endangered species. (more…)
In a joint research effort between the University of Hawaiʻi at Mānoa’s Hawai‘i Institute of Marine Biology (HIMB), University of Tokyo, the Japanese National Institute of Polar Research, and the University of Florida, scientists have shed new light on the hunting behavior of tiger sharks by studying their swimming dynamics off the west coast of Hawai‘i Island. (more…)
