Breakthroughs, discoveries, and DIY tips sent every weekday. It is in these waters that marine mammal ecologist Ari Friedlaender shuts off the inflatable boat's engine and waits. This is the edge of the world--remote, hostile, and stunningly alive. Beneath the hull, the dark sea churns with wonder abound. A humpback whale (Megaptera novaeangliae) emerges, slow, deliberate, and gentle in its curious demeanor, casting a ripple across the surface.

Killer whales – also known as orcas – have complex social structures including close'friendships', a new study reveals. Scientists at the University of Exeter used drones to film the animals – one of the world's most powerful predators – in the Pacific Ocean. The team found killer whales (Orcinus orca) spend more time interacting with certain individuals in their pod, and tend to favour those of the same sex and similar age. Results from the new study are based on 651 minutes of video filmed over 10 days. Orcas are the largest member of the dolphin family.

The increased freshwater from melting Antarctic ice sheets plus increased wind has reduced the amount of oxygen in the Southern Ocean and made it more acidic and warmer, according to new research led by University of Arizona geoscientists. The researchers found Southern Ocean waters had changed by comparing shipboard measurements taken from 1990 to 2004 with measurements taken by a fleet of microsensor-equipped robot floats from 2012 to 2019. The observed oxygen loss and warming around the Antarctic coast is much larger than predicted by a climate model, which could have implications for predictions of ice melt. The discovery drove the research team to improve current climate change computer models to better reflect the environmental changes around Antarctica. "It's the first time we've been able to reproduce the new changes in the Southern Ocean with an Earth system model," said co-author Joellen Russell, a professor of geosciences. The research is the first to incorporate the Southern Ocean's increased freshwater plus additional wind into a climate change model, she said.