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Ocean Research


September 2013 Issue

Whalebone-Eating Worms Found Deep in Antarctic
Two new species of rare, whalebone-eating worms have been found in deep Antarctic waters, according to research published in Proceedings of the Royal Society B.

The discovery of red-plumed Osedax antarcticus and Osedax deceptionensis are the results of investigations by an international collaboration of marine biologists, including experts from the University of Aberdeen, led by London’s Natural History Museum and the University of Gothenburg in Sweden.

Their findings also revealed Osedax’s wood-eating cousins—the Xylophagainae molluscs—were nowhere to be found, leading the scientists to believe famous shipwrecks such as Shackleton’s Endurance could remain entirely preserved in the depths of the Antarctic.

Researchers deployed and recovered a deep-sea lander, laden with large whale bones and planks of wood. The team then examined the bones and wood, which had been left on the seafloor for more than a year.

The dramatic contrast between the heavily consumed bone and the pristine wood upon recovery was indicative of how the Antarctic is relatively isolated from other ocean basins. The tiny larvae of the wood-eating worms could not reach the Antarctic from nearby continents, according to Dr. Adrian Glover from the Natural History Museum in London.

A new DNA analysis of the Osedax worms also revealed that the seven described species in the genus are most closely related to the tiny mud-dwelling beard worms that use specialist bacteria to consume chemicals in oxygen-poor muds.

This provides new clues as to how these animals evolve. Perhaps at some point after whales first appeared in the oceans, ancestral worms were able to make the evolutionary leap from sulphidic-muds to whale carcasses, Glover said.

AML Supplies CTD to Solar-Powered Vessel
AML Oceanographic Ltd. (AML), based in Sidney, Canada, has supplied a CTD instrument to the vessel MS Tûranor PlanetSolar for use in oceanographic research. AML was able to deliver a calibrated Minos•X CTD vertical profiler in less than 24 hours while the vessel was docked in Halifax, Canada.

AML’s Xchange field-swappable sensor heads enable instruments to be configured in the field to meet the specific requirements of the application at hand. Such an approach also allows AML to expedite delivery of instrument orders by drawing tested instruments from stock and configuring them to meet application-specific requirements.

MS Tûranor PlanetSolar is the world’s largest solar-powered vessel conducting oceanographic research in the Atlantic Ocean. In May 2012, the MS Tûranor PlanetSolar became the first ever solar electric vehicle to circumnavigate the globe. Now, the PlanetSolar DeepWater expedition is enabling researchers from the University of Geneva to conduct a unique campaign of physical and biological measurements along the Gulf Stream, with no carbon emissions.

Mangroves Build Up Soils, Protect Against Sea Level Rise
A new report by The Nature Conservancy and Wetlands International shows that mangroves can adapt to rising sea levels by building up soils in some locations.

Mangroves can protect human lives and property by reducing the impacts of storm surges and waves.

Past evidence suggests that some mangrove soils have built up at rates between 1 and 10 millimeters per year. Currently, global mean sea level is rising at a rate of 3 millimeters per year. This suggests that in some places, mangrove soil surfaces will be able to keep up with rising sea levels. This is key, as mangrove trees cannot survive if their aerial roots are submerged for a long period of time.

This latest report highlights the need to maintain, restore or enhance sediment supplies to mangrove areas. The sediments contribute to the buildup of soils, but the supply of sediment to many mangrove areas has been reduced because of dams built on rivers. Mangroves also need protecting from pollution and the felling of trees: the underground roots of healthy trees can push the soil up, while the roots of trees weakened by habitat degradation are less able to hold soils together, potentially leading to erosion and loss of surface soils. Restoring mangrove areas and safeguarding the health of trees can help mangrove soils to build up and so keep pace with sea level rise.

By building up soils, mangroves also help to lock up greenhouse gases such as carbon dioxide.

New Viruses Infecting Marine Bacteria Discovered
Researchers of the University of Arizona’s Tucson Marine Phage Lab have discovered a dozen new types of unknown viruses that infect different strains of marine bacteria.

Bacteriophages—viruses that prey on bacteria—control processes of global importance. For example, they determine how much oxygen goes from the oceans into the atmosphere in exchange for carbon dioxide, they influence climate patterns across the Earth and they alter the assemblages of micro-organisms competing in the environment. 

The researchers have deciphered the genetic makeup of 31 phages infecting a bacterium from the Baltic Sea known as Cellulophaga baltica. This bacterium and its relatives, collectively known as Bacteroidetes, play key roles in complex carbohydrate cycling in environments ranging from the oceans and sea ice to the human gut. The results are published in Proceedings of the National Academy of Sciences.

Bacteria like Cellulophaga account for many of the micro-organisms that make up marine and freshwater phytoplankton, where they control global cycles of oxygen and carbon, and their boom and bust cycles directly translate into the abundance/shortage of nutrients, which sustain global food webs and fisheries, for example.

By understanding the viruses, scientists can develop models that can help to improve understanding of the consequences of processes ranging from algae blooms to fish stock assessments to carbon storage in the world’s oceans.


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