Researchers are alarmed after noticing a significant drop in the number of vocalizations from blue whales.As National Geographic reports, scientists used specialized underwater hydrophones, meaning the aquatic version of microphones, to record and trace the sounds of marine life, allowing them to analyze the impact human activity is having on various species.However, as detailed in a study published in the journal PLOS One, devastating heat waves have triggered worrying changes over the past decade, allowing toxic algae to bloom and undermine food sources for whales."It caused the most widespread poisoning of marine mammals ever documented," coauthor and Monterey Bay Aquarium Research Institute biological oceanographer John Ryan told NatGeo. "These were hard times for whales."As a result, blue whale vocalizations dropped by almost 40 percent, according to the study, with populations of krill and anchovy collapsing."When you really break it down, it’s like trying to sing while you're starving," Ryan explained. "They were spending all their time just trying to find food."Scientists are still racing to understand the causes of devastating marine heatwaves. An ominous pool of warm water in the ocean, nicknamed "The Blob" following its discovery in early 2013, confounded scientists.By 2016, it had grown to a region spanning over 2,000 miles in the Pacific Ocean, NatGeo reports.The rising temperatures caused important sources of sustenance for blue whales to all but vanish.Scientists are still racing to understand the effects of rising ocean temperatures. And as climate change continues to rear its ugly head, scientists are worried about future extreme weather events, including marine heatwaves.Scientists have found that the duration of these heatwaves has tripled since the 1940s."There are whole ecosystem consequences of these marine heat waves," coauthor and Monterey Bay Aquarium marine biologist Kelly Benoit-Bird told NatGeo. "If they can't find food, and they can traverse the entire West Coast of North America, that is a really large-scale consequence."Worse yet, "fewer feeding opportunities" mean that blue whales "put less effort into reproduction," as Oregon State University ecologist Dawn Barlow added."Where they are, and what they’re doing can tell you a lot about the health of the ecosystem," Barlow explained. "The Blob really highlighted how long-term these consequences can be."Benoit-Bird voiced concerns of reaching a "tipping point," which could have devastating consequences on our climate, changing how the "ocean absorbs carbon.""Science shows that climate change is impacting the oceans," Barlow told NatGeo. "Listening and learning from these places is essential to our future. Now more than ever, it’s important to listen."More on marine life: Using the Ocean to Suck Up CO2 Could Come With the Small, Unintended Side Effect of Wiping Out Marine LifeThe post Scientists Alarmed as Whales Suddenly Going Silent appeared first on Futurism.