Ambushed! Japanese pygmy squid have been filmed releasing ink when hunting shrimp – using it both as a smokescreen and distraction.

“This is the first report that cephalopods use ink for predation,” says Noriyosi Sato of Aberystwyth University, UK.

In 2014, Sato and his colleagues collected 54 specimens of Japanese pygmy squid (Idiosepius paradoxus) from the waters of the Chita Peninsula in central Honshu, Japan, and transferred them to two lab aquaria.

Species: The southern sand octopus (Octopus kaurna)
Habitat: The seafloor on the south-eastern coast of Australia

The southern sand octopus has taken hide-and-seek to a whole new level. It shoots jets of water into the seafloor creating quicksand that allows it to vanish.

A skilled architect, the octopus can build a mucus-lined home – complete with a chimney –20 centimetres down into the seabed, where it holes up during the day. It only emerges from its underground burrow at night to crawl over the seafloor and snack on small crustaceans.

Now, its unique burrowing technique has been revealed for the first time.

Almost every person has an appreciation for natural environments, say San Diego State University scientists. Most people find healthy or pristine locations with high biodiversity more beautiful and aesthetically pleasing than environmentally diminished places. In a new study which computed ‘aesthetics’ as it relates to coral reefs, researchers have shown that computer analysis of underwater photos can be used to accurately assess the health of a coral reef.

Working together, mathematicians, biologists and art historians created a tool to computationally measure the aesthetic appearance of coral reefs. The results show that visual cues generated from random underwater photos can be used to reliably assess both the beauty and health of reefs around the world.

The collaborators compiled and modified a list of 109 visual features that can be used to assess the aesthetic appeal of an image, such as the relative size, colour and distribution of discernable objects within the image, as well as texture and color intensity. They then created a computer program capable of assessing these features in images and used it to analyse more than 2,000 random photos of coral reefs from 9 locations across the Caribbean and central Pacific. The program produced a “beauty” score for each reef ecosystem.

Thriving ecosystems are abounding with bright colours. Underwater, coral reefs surpass all other ecosystems in their display of colour. The diversity and colorfulness of fauna and flora living in healthy reef systems is unmatched on this planet. This diverse and intense display of color is, however, not only an indicator of high biodiversity, but also of a “clean” system.

SAN DIEGO, CA – In celebration of World Oceans Day, the La Jolla based Waitt Foundation and the Marine Conservation Institute announced the launch of a new online tool at MPAtlas, dedicated to bringing the importance of ocean parks into the public eye.

The world’s oceans are facing enormous adversity from environmental degradation, overfishing, and pollution. Science has shown that the establishment of ocean parks, or marine protected areas (MPA), can mitigate these harms, thereby restoring and revitalizing fragile marine ecosystems. MPAtlas is the foremost database of global MPAs. It is an online digital map that assembles key information on marine protected areas around the world. An interactive and user-friendly platform, MPAtlas is geared towards providing a comprehensive scope of data for conservation advocates, scientists, policy makers, and the interested public alike.

While working on a reference article on pressure-depth relationships, I was reminded of divers I had a few years ago. This couple has a creative way of finishing a dive. After maintaining a reasonably well-controlled safety stop, they both reached for their inflator hoses and pffffffffttt held down their inflate buttons and shot to the surface from 15 feet. When I chatted with them about this dangerous habit, they told me that their open water instructor taught them to ascend this way.

Why does this scare me so much? For the sake of simplicity, let's consider just one of the reasons that a fast ascent during any part of a dive is dangerous. Increased pressure underwater causes a diver's body tissues to absorb more nitrogen gas than they would normally contain at the surface. If a diver ascends slowly, this nitrogen gas expands bit by bit and the excess nitrogen is safely metabolized and released.