Ancient seagrass holds secrets of the oldest living organism on Earth

It's big, it's old and it lives under the sea -- and now an international research collaboration has confirmed that an ancient seagrass holds the secrets of the oldest living organism on Earth. Ancient giant Posidonia oceanica reproduces asexually, generating clones of itself. A single organism -- which has been found to span up to 15 kilometers in width and reach more than 6,000 metric tonnes in mass -- may well be more than 100,000 years old.

2011 shark attacks remain steady, deaths highest since 1993

Shark attacks in the US declined in 2011, but worldwide fatalities reached a two-decade high, according to the a new report.

Satellite tracking reveals sea turtle feeding hotspots

Satellite tracking of threatened loggerhead sea turtles has revealed two previously unknown feeding "hotspots" in the Gulf of Mexico that are providing important habitat for at least three separate populations of the turtles.

Global extinction: Gradual doom is just as bad as abrupt

Around 250 million years ago, most life on Earth was wiped out in an extinction known as the "Great Dying." Geologists have learned that the end came slowly from thousands of centuries of volcanic activity.

Scientists coax shy microorganisms to stand out in a crowd

Scientists have advanced a method that allowed them to single out a marine microorganism and map its genome even though the organism made up less than 10 percent of a water sample teeming with many millions of individuals from dozens of identifiable groups of microbes.

Heat and cold damage corals in their own ways

Around the world coral reefs are facing threats brought by climate change and dramatic shifts in sea temperatures. While warming has been the primary focus for scientists and ocean policy managers, cold can also cause significant damage. Scientists have shown that cool temperatures can inflict more damage in the short term, but heat is more destructive in the long run.

Are nuisance jellyfish really taking over the world's oceans?

Evidence is lacking that populations of jellyfish and similar gelatinous plankton are surging in numbers globally and will likely dominate the seas in coming decades. Rather, increasing scientific and media interest as well as the lack of good baseline data seem to explain the widespread perception of an increase.

Global experts question claims about jellyfish populations

Blooms, or proliferation, of jellyfish have shown a substantial, visible impact on coastal populations -- clogged nets for fishermen, stinging waters for tourists, even choked intake lines for power plants -- and recent media reports have created a perception that the world's oceans are experiencing increases in jellyfish due to human activities such as global warming and overharvesting of fish. Now, a new study questions claims that jellyfish are increasing worldwide and suggests claims are not supported with any hard evidence or scientific analyses to date.

Are jellyfish increasing in world's oceans?

A global study has questioned claims that jellyfish are increasing worldwide. Blooms, or proliferation, of jellyfish have shown a substantial, visible impact on coastal populations -- clogged nets for fishermen, stinging waters for tourists, even choked intake lines for power plants -- and recent media reports have created a perception that the world's oceans are experiencing increases in jellyfish due to human activities such as global warming and overharvesting of fish. Now, a new global and collaborative study questions claims that jellyfish are increasing worldwide and suggests claims are not supported with any hard evidence or scientific analyses to date.

Southern Indian ocean humpback whales found singing different tunes

Humpback whales on both sides of the southern Indian Ocean are singing different tunes, unusual since humpbacks in the same ocean basin usually all sing very similar songs.

Mammals shrink at faster rates than they grow: Research helps explain large-scale size changes and recovery from mass extinctions

It took about 10 million generations for terrestrial mammals to hit their maximum mass: that's about the size of a cat evolving into the size of an elephant. Sea mammals, such as whales took about half the number of generations to hit their maximum.

What do killer whales eat in the Arctic?

Killer whales are the top marine predator. The increase in hunting territories available to killer whales in the Arctic due to climate change and melting sea ice could seriously affect the marine ecosystem balance. New research has combined scientific observations with Canadian Inuit traditional knowledge to determine killer whale behavior and diet in the Arctic.

Detecting detrimental change in coral reefs

Over dinner on R.V. Calypso while anchored on the lee side of Glover's Reef in Belize, Jacques Cousteau told Phil Dustan that he suspected humans were having a negative impact on coral reefs. Dustan -- a young ocean ecologist who had worked in the lush coral reefs of the Caribbean and Sinai Peninsula -- found this difficult to believe. It was December 1974. But Cousteau was right. During the following three-plus decades, Dustan, an ocean ecologist and biology professor at the University of Charleston in South Carolina, has witnessed widespread coral reef degradation and bleaching from up close.

Ecologists capture first deep-sea fish noises

Fish biologists conducted one of the first studies of deep-sea fish sounds in more than 50 years, 2,237 feet under the Atlantic. With recording technology more affordable, fish sounds can be studied to test the idea that fish communicate with sound, especially those in the dark of the deep ocean.

Life beyond Earth? Underwater caves in Bahamas could give clues

Discoveries made in some underwater caves by researchers in the Bahamas could provide clues about how ocean life formed on Earth millions of years ago, and perhaps give hints of what types of marine life could be found on distant planets and moons.

Viruses con bacteria into working for them

Researchers have discovered that certain photosynthetic ocean bacteria need to beware of viruses bearing gifts. These viruses are really con artists carrying genetic material taken from their previous bacterial hosts that tricks the new host into using its own machinery to activate the genes, a process never before documented in any virus-bacteria relationship. The con occurs when a grifter virus injects its DNA into a bacterium living in a phosphorus-starved region of the ocean.

Microbubbles provide new boost for biofuel production

A solution to the difficult issue of harvesting algae for use as a biofuel has been developed using microbubble technology.

Attack or retreat? Circuit links hunger and pursuit in sea slug brain

If you were a blind, cannibalistic sea slug, living among others just like you, nearly every encounter with another creature would require a simple cost/benefit calculation: Should I eat that -- or flee? In a new study, researchers report that these responses are linked to a simple circuit in the brain of the sea slug Pleurobranchaea.

Where there's a worm there's a whale: First distribution model of marine parasites provides revealing insights

Each year around 20,000 people are infected by nematodes of the genus Anisakis and suffer from illnesses ranging from gastrointestinal diseases to serious allergic reactions as a result. For the first time, parasitologists have gathered data on the occurrence of the parasitic worm and have modeled the worldwide distribution of individual species in the ocean. The resulting maps not only enable statements to be made on the occurrence and migration behavior of certain hosts of the parasites, such as Baleen or toothed whales, but also provide conclusions on the risk of human infection.

Turtles' mating habits protect against effects of climate change

The mating habits of marine turtles may help to protect them against the effects of climate change. The study shows how the mating patterns of a population of endangered green turtles may be helping them deal with the fact that global warming is leading to a disproportionate number of females being born.