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.
Extreme weather led to starfish mass strandings along beaches in Kent and East Yorkshire.
The CSIRO has provided new estimates of population sizes for White Sharks in Australian waters.
How many shark encounters have there been at your local beach? Explore our interactive map to see 20 years of incidents between humans and sharks in coastal waters around Australia.
Nightvision, ejectable stomachs and regrowable arms mean starfish are more than meets the eye.
Image from video of Mariana snailfish.
SOI/HADES/University of Aberdeen (Dr. Alan Jamieson)
The Mariana snailfish lives nearly 27,000 feet underwater, but has features that help it adapt to intense water pressure and cold. Physiological limits may prevent fish from surviving in deeper water.
An animal behaviour expert gives his view on finding that a killer whale can copy the sound 'hello'.
Author Tom Iliffe leads scientists on a cave dive.
Scientific fieldwork that happens underground and underwater in spectacular but dangerous caves opens a window on a largely unknown world.
Jellyfish have a lot more going for them than blobby bodies and a sting.
The sea remains the least explored habitat on our blue planet.
Luis Lamar / BBC NHU
Few fish can survive in these freezing waters, so invertebrates are the dominant predators.
Over 20 cephalopods crawled on to New Quay beach. What was going on?
Make yourself at home.
Scientists have just discovered an unusual symbiotic relationship between crabs and living corals.
Colleen Burge counts oysters on an oyster aquaculture lease in California.
Oysters grow in seawater and filter their food from it, so how do you shield them from waterborne diseases? Scientists are working to develop strains that are resistant to a fast-spreading herpes virus.
Hey, what about us? Whale shark (spotted) and manta ray, a close shark relative.
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.
The famous “faceless fish”, which garnered worldwide headlines when it was collected by the expedition.
Surveying the bottom of the ocean turns out to be far from easy. But there was something wonderful about seeing animals we have only read about in old books.
Some sea animals with smooth shells can dig themselves into the sand in just a few seconds.
Maëlle, 7, wants to know why some shells are smooth, while others are corrugated. It turns out that while corrugated shells are strong, smooth shells can move fast.
A tank can give a good idea of what will happen out in the wild.
A new study suggests the benefits of a boost to marine plant growth from increased carbon dioxide will be cancelled out by the increased stress to fish species.
Fish leave bits of DNA behind that researchers can collect.
Mark Stoeckle/Diane Rome Peebles images
Animals shed bits of DNA as they go about their lives. A new study of the Hudson River estuary tracked spring migration of ocean fish by collecting water samples and seeing whose DNA was present when.
Scientists have sequenced the seahorse's genome and found the genes that could explain male pregnancy.
Whitespotted surgeonfish (
Acanthurus guttatus), found in the Indo-Pacific, crop the upper portion of algae while feeding, preventing macroalgae from becoming established on reefs.
Plant-eating fish control the spread of seaweed and algae on coral reefs. New research explaining why populations of these fish vary from site to site could lead to better reef protection strategies.