A female zebra shark in an Australian aquarium has astounded scientists by producing live offspring asexually, three years after being separated from her long-term mate. While scientists have previously observed “virgin births” in vertebrates such as sharks, rays and reptiles — a reproductive strategy thought to aid survival during periods of isolation — this is the first time a female shark has ever been observed reproducing asexually after previously mating with a male.

How humpback whales use marine habitats off the eastern coast of Africa is only partially understood, and that has become a conservation concern as offshore energy exploration expands in the region. However, a new study published in Marine Ecology Progress Series found that humpback whales that were satellite tagged off the coast of Madagascar during peak breeding season are traveling much further in the southwest Indian Ocean than previously thought. This research can help define potentially sensitive areas that should be protected from the disruption of seismic testing or other industrial development that could be destructive to the humpback population and this globally important marine habitat.

Behold the hyolith — a bizarre Cambrian-period creature that dwelt on the ocean floor alongside other armored invertebrates like trilobites more than 500 million years ago. Its body was encased in a pair of shells that resembled an ice cream cone with a lid like a trap door. Two tusklike spines protruded from the soft tissue near the hinge, and on top of its mouth was a row of fluttering tentacles. Since its discovery in the 19th century, the hyolith has puzzled paleontologists. Some thought it was a mollusk, like a snail or clam. Others said it belonged to its own group of animals.

New study finds that 10% to 50% of iceberg melting happens in the fjords, not in the open ocean as assumed by previous research. Icebergs contribute more meltwater to Greenland’s fjords than previously thought, losing up to half of their volume as they move through the narrow inlets, according to new research.
Greenland, the world’s largest island, is almost entirely covered by a permanent ice sheet that has been shrinking and melting as global warming increases temperatures. In fjords, narrow inlets where glaciers meet the sea, ice breaks off from glaciers to form dense packs of icebergs.

Pollution in the Arctic is so bad that chemicals are accumulating in polar bear mother’s milk and getting passed onto bear cubs. A new analysis of pollutants in the Arctic has found that polar bears are at a particularly high risk, compared to other animals like seals.

The study was published in the journal Environmental Toxicology and Chemistry in December and focused on a class of pollutants known as persistent organic pollutants (POPs). POPs are toxic, hang around for a long time, and tend to build up in the bodies of humans and animals.

Thirty years ago a mysterious disease wiped out long-spined black sea urchins across the Caribbean, leading to massive algal overgrowth that smothered already overfished coral reefs. Now, marine biologists at the Smithsonian Tropical Research Institute (STRI) report that smaller sea urchins and parrotfish may be taking the place of the large sea urchins, restoring the balance on degraded reefs.