Navigation Links
Glass sponges take advantage of retreating Antarctic ice shelves
Date:7/12/2013

The breakup and collapse of the Larsen A ice shelf in the western Weddell Sea in 1995 has resulted in fundamental changes to life on the sea bed in less than two decades. As reported by biologists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in the cover story of the current issue of the scientific journal Current Biology, Antarctic glass sponges have been the prime beneficiaries of the disappearance of the ice shelf. To the surprise of the scientists, the density of these archaic filter-feeders has increased threefold between 2007 and 2011 despite only low plankton food supply and water temperatures of minus 2 degrees Celsius. The sponges had also grown remarkably quickly and had completely supplanted competitors for food. The results show that communities at the bottom of the western Weddell Sea react considerably more quickly to climate-related changes than previously thought.

Glass sponges (Hexactinellida), an archaic group of animals at the basis of the animal kingdom, dominate the shallow seafloor in the Antarctic. Many biologists believed that glass sponges grew so slowly that two-metre behemoths would have to be around 10,000 years or older. These assumptions have now been challenged in a new study led by scientists from the Alfred Wegener Institute (AWI) and published in the current issue of the scientific journal Current Biology.

During a Polarstern expedition to the poorly accessible region of the former Larsen A ice shelf, AWI biologists Laura Fillinger and Claudio Richter, together with colleagues from the University of Gothenburg and the Senkenberg Research Institute and Natural History Museum; succeeded in demonstrating that glass sponges can grow rapidly within a short period of time. "We were surprised by what we saw on our video screens in 2011 when we lowered our remotely operated vehicle onto the sea bed at a depth of around 140 metres. In an area, which had revealed large numbers of ascidians and only occasional glass sponges during an earlier expedition with the ice-breaking research vessel 'Polarstern' in 2007, four years later we found no ascidians at all. These pioneer species had completely disappeared, replaced by three times the number of glass sponges, including several juvenile individuals", reports Laura Fillinger, lead author of the study.

Until this time scientists had assumed that communities on the Antarctic sea bed only change very slowly because of the very low temperature (minus two degrees Celsius) and patchy supply of food in pack-ice covered waters. "We now know that glass sponges may undergo boom-and-bust cycles, allowing them to quickly colonize new habitats in a short period of time", says project leader Prof. Dr. Claudio Richter.

"To the organisms living on the sea bed, the disappearance of the hundred-metre-thick Larsen A ice shelf must have been like the heavens opening up above them", he adds. Where cold, darkness and food shortages had previously reigned, sunlight now allows plankton growth in surface waters and, hence, a rain of food comes down to the sea bed.

Glass sponges feed on the smallest plankton, which they filter from the water. The animals grow to a size of up to two metres, and their vase-like bodies provide perfect hiding, spawning and shelter opportunities for fish, invertebrates and many other sea dwellers. "Like corals, sponges create their own habitats. To an extent they are like cities on the sea bed. There is something going on wherever they grow, and this attracts other sea dwellers to them", says Claudio Richter.

New spaces are being created for such underwater worlds wherever the ice shelves on the Antarctic Peninsula are retreating or breaking up. However, scientists cannot yet definitively say whether this means that glass sponges will be one of the beneficiaries of climate change. Laura Fillinger: "There are still too many unknowns to make predictions. One example is the question of the influence of competitors: currently we are witnessing a fierce competition for space on the sea bed. Another concerns predators: in our dive in 2011 we hardly saw any of the snails and starfish, which feed on glass sponges. However, it is possible that these voracious predators will follow suit and wreak havoc."

Marine biologists at the Alfred Wegener Institute will continue to monitor the changes to communities in the western Weddell Sea. In January 2013, the planned dives in the area of the former Larsen A ice shelf had to be called off due to the solid pack ice in the Weddell Sea. However, Claudio Richter and his team hope for better pack-ice conditions during future Polarstern trips to this part of the Antarctic so that they can use new investigative methods to discover more about the life cycle of the glass sponges.


'/>"/>

Contact: Sina Loeschke
medien@awi.de
49-471-483-12008
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. Spinning up antibacterial silver on glass
2. From grains of volcanic glass to continental rifting: New Geosphere articles now online
3. Glass offers improved means of storing UKs nuclear waste
4. Feel-good glass for windows
5. NJIT, Chinas Bengbu Glass Institute sign agreement for R&D, training
6. Inspired by deep sea sponges: Creating flexible minerals
7. Bacteria on marine sponges can develop capacity to move and inhibit biofilm formation
8. Microbes, sponges, and worms add to coral reef woes
9. Toughened silicon sponges may make tenacious batteries
10. NOAA scholarship awarded to Jan Vicente to study the impact of ocean acidification on marine sponges
11. Nanosponges soak up oil again and again
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... -- Today HYPR Corp. , leading innovator in ... the HYPR platform is officially FIDO® Certified . ... that empowers biometric authentication across Fortune 500 enterprises and ... 15 million users across the financial services industry, however ... suites and physical access represent a growing portion of ...
(Date:4/4/2017)... , April 4, 2017   EyeLock LLC ... announced that the United States Patent and Trademark Office ... broadly covers the linking of an iris image with ... transaction) and represents the company,s 45 th issued ... patent is very timely given the multi-modal biometric capabilities ...
(Date:3/30/2017)... , March 30, 2017  On April 6-7, 2017, ... the Genome hackathon at Microsoft,s headquarters in ... competition will focus on developing health and wellness apps ... Hack the Genome is the first hackathon ... The world,s largest companies in the genomics, tech and ...
Breaking Biology News(10 mins):
(Date:5/22/2017)... ... May 22, 2017 , ... Stratevi, a boutique firm ... the East Coast. It has opened an office in downtown Boston at 745 Atlantic ... it increasingly more important to generate evidence on the value they provide, not just ...
(Date:5/21/2017)... ... May 19, 2017 , ... Ovation Fertility ... the American Association of Bioanalysts (AAB) and the College of Reproductive Biology (CRB) ... reinforces AAB’s commitment to excellence in clinical laboratory services and regulations. , ...
(Date:5/19/2017)... ... May 19, 2017 , ... The University ... researchers with technologies ripe for commercialization, and who are affiliated with the 21 ... to submit proposals. QED, now in its tenth round, is the first multi-institutional ...
(Date:5/18/2017)... ... , ... Clinical Supplies Management (“CSM”), a Great Point Partners II (“GPP”) portfolio ... CSM has doubled in size over the past six months with the acquisition of ... Gasper joins CSM as Chief Financial Officer. Roger has over 25 years of ...
Breaking Biology Technology: