Updated: 11:14 AM EDT Jun 3, 2021 By Seth Borenstein One of the giants of the deep is shrinking before our eyes, a new study says.The younger generation of critically endangered North Atlantic right whales are on average about 3 feet shorter than whales were 20 years, drone and aircraft data show in a study in Thursday s journal Current Biology.Scientists say humans are to blame. Entanglements with fishing gear, collisions with ships and climate change moving their food supply north are combining to stress and shrink these large whales, the study says.Diminishing size is a threat to the species overall survival because the whales aren t having as many offspring. They aren t big enough to nurse their young or even get pregnant, study authors said.These marine mammals used to grow to 46 feet on average, but now the younger generation is on track to average not quite 43 feet, according to the study. This isn t about short right whales, it s about a physical manifes