SAVANNAH, Ga. (AP) — Scientists watching for baby right whales off the Southeast U.S. coast have yet to spot a single newborn seven weeks into the endangered species' calving season — the longest researchers have gone without any sightings in nearly 30 years.

Bad weather that has limited efforts to look for whales could be to blame, rather than a reproductive slump. But scientists also worry it could point to another low birth year for the imperiled whales after a grim 2017, when 17 confirmed right whale deaths far outpaced a scant five recorded births.

"We basically right now should be at the...