The long tusk of the male narwhal earned these whales their fanciful nickname. But there's more to these Arctic mammals than their unique spiral tooth.
How did whales that feed on tiny prey evolve into the largest creatures on Earth? And why don't they get even bigger?
Regulations have lowered mercury emissions globally, but the risks to ocean ecosystems and human health may be getting worse.
We don't know for sure which one is smarter, because not everyone agrees on what "intelligence" means. Both have their own special behaviours and skills and we can't say who is more intelligent.
Diving animals are incredible athletes.
North Atlantic right whales are headed toward a traumatic extinction, but could rebound if humans can get out of their way.
Russia isn't the only nation suspected of training marine mammals for military use – the US, UK, and Ukraine have all done so in the past.
Protecting forests and wetlands, which absorb and store carbon, is one way to slow climate change. Scientists are proposing similar treatment for marine animals that help store carbon in the oceans.
Climate change is shrinking Arctic sea ice and opening the region to ship traffic. Whales, seals and other marine mammals could be at risk unless nations adopt rules to protect them.
How can marine preserves best protect sea creatures that move in and out of them? Two ocean scientists describe new thinking about designing marine protected areas.
A new report will supply some information needed for science based conservation measures in the Red Sea.
For 50 years California has used laws and policies to manage development along its 1,100-mile coastline and preserve public access to the shore. Climate change will make that task harder.
Marine mammals are often referred to as sentinels of the ocean and research on whales and dolphins in particular contributes important knowledge about the health of our seas.
Humpback whales are deterred from their migration routes by the noise of air guns used to survey the ocean floor for oil and gas deposits, a new study has found.
As the Discovery Channel and National Geographic Wild unleash a week of dueling shark programs, a biologist advises viewers to take what they see with a large grain of sea salt.
There are plenty of mammals that have adapted to life in water, some more than others. That meant they also had to adapt the way they feed.
A new US seafood import rule requires supplier countries to control accidental bycatch of whales, seals and other marine mammals – showing that global trade and conservation can reinforce each other.
Size doesn't always matter when it comes to the pitch of your voice, especially if you're an aquatic mammal.
Ships in Australian waters are getting bigger and more numerous all the time. We need a plan to help them avoid crashing into whales and other large sea creatures.
Indian Ocean humpback dolphins, which live close to the shore, need protection. The total population is estimated to be just 10,000, with fewer than 1,000 of them off the coast of South Africa.