Where all the water in the ocean came from is a very good question. Scientists have been wondering about it for a long time.
The Big Bang created a cloud of dust and rocks that included a lot of rocks that were made of ice, like giant snowballs. That's where some of the water came from.
Bottlenose dolphins off the coast of New Jersey.
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.
Copepod with eggs (blue). Copepods are typically just a few millimeters long, but are important food sources for small fish.
DNA sequencing is making it possible for scientists to identify thousands of species of zooplankton – drifting animals that are key links in ocean food webs.
Marine heatwaves can kill off species and alter ecosystems.
Marine heatwaves have had little attention until recently, but they're already having large effects.
Lava flows from Kīlauea.
At Kīlauea in Hawai'i, a recent volcanic eruption has created some of the most spectacular sights in nature. But also danger for those around it.
Blooms of algae, like this growth in 2015 in Lake St. Clair between Michigan and Ontario, promote the formation of dead zones.
NASA Earth Observatory
Scientists have mapped a huge dead zone in the Gulf of Oman, without enough oxygen in the water to support life. This Speed Read explains why dead zones form in waters around the world.
A pelagic snail ensnares food with with a mucous web.
Linda Ianniello https://lindaiphotography.com
Biologists are finding new evidence that these ocean invertebrate grazers don't just ingest whatever they catch. They can actually be picky eaters – and their choices might influence ocean food webs.
A Kemp’s ridley hatchling makes its way to the water on Padre Island, Texas.
During sea turtle nesting season, scientists collect data and assess how turtles are doing. But they know less about how plastic pollution, fishing and warming oceans are affecting turtle numbers.
Sustained ocean warming could greatly reduce catches of fish like these herring photographed off Norway.
Fish are a key food source for millions of people worldwide. But a recent study finds long-term warming over the next 200 years could starve tiny plankton, with impacts that would ripple up food chains.
A plastic bag floats in the ocean in this 2016 photo.
Banning plastic bags in food distribution is complicated and not all municipalities are on board. Are bioplastics a solution?
Boat noise can interfere with the underwater communication of fishes and other marine animals.
The noise from motor boats, sonar and other industrial activity interferes with the underwater chatter of fishes.
Juvenile blue tang sheltering in restored staghorn coral.
With coral reefs in crisis around the world, many organizations are working to restore them by growing and transplanting healthy corals. A new study spotlights techniques that help restored reefs thrive.
The British First Fleet knew little of conditions in Port Jackson, later Sydney Cove, before their arrival.
George Edwards Peacock, State Library of New South Wales.
When the First Fleet sailed into Sydney Cove in 1788, they entered an ancient and unforgiving landscape. A new book charts Australians' relationship with one of the world's most volatile climates.
The increasingly bleached coral at Black Point on the Cobourg Peninsula is a worrying sign of what’s to come for other coral reefs in Australia.
Coral bleaching has struck the Northern Territory, adding urgency to the need for better national management strategies for our warming oceans.
‘Under’, Martina Amati.
© Martina Amati
Diving without oxygen tanks requires you to enact some very weird and very strange and not all that well understood physiological feats just to stay alive.
Yellow-bellied sea snake (
Coleman M. Sheehy III, Florida Museum of Natural History
Sea snakes spend their lives in the water, giving birth to live young at sea, so why are they only found in some of the world's oceans? The answer lies in a combination of climate and geography.
Sustainable swimwear shopping means that you don’t have to worry about the sea soaking in plastic from your bathers while you soak in the sun!
Summer may have come to an official end, but the plastics from your bathers might still be at the beach!
Farmed fish like these carp now make an important contribution to global food security.
Many critics say that fish farms mainly sell their output to wealthy countries and don't provide much benefit to poor people in producing countries. Three aquaculture experts show why this view is wrong.
Nightvision, ejectable stomachs and regrowable arms mean starfish are more than meets the eye.
A seal trapped in a mat of plastic pollution.
Millions of tonnes of plastic garbage winds up in our oceans each year. Voluntary pledges haven't worked. It's time for Canada to advocate for an international plastics treaty.