Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Methane seeps of the deep sea: A bacteria feast for lithodid crabs

Photos and analyses reveal more about a highly specialized food web

The bottom of the deep sea is largely deserted. Oases occur for example at cold seeps where water transports dissolved elements from the seabed: Specialized microbes convert methane and sulfate from sea water to hydrogen sulfide releasing carbon dioxide.

This is a crab on a bacterial mat at mud volcano Mound 12, documented by a deep-sea observatory.

Credit: GEOMAR Helmholtz Centre for Ocean Research Kiel

Highly adapted bacteria, many of which live in symbiosis with worms and clams, use the hydrogen sulfide for their growth. In their cells, they incorporate carbon originating from the chemical reaction of methane. "The co-existence of organisms that have settled at the cold seeps is already well understood", says Dr. Peter Linke. The biologist at GEOMAR Helmholtz Centre for Ocean Research Kiel is lead author of the publication in the online journal PLOS ONE together with Dr. Helge Niemann from the University of Basel.

"We could give evidence that crabs subsist on the methane seeps. Thus, we came a bit closer to answering the question of which organisms benefit from the cold seeps: Versatile animals living on a mixed diet do so as well. "

In dives with the submersible ALVIN and the underwater robot QUEST off the coast of Costa Rica in the summer of 2005, the researchers observed lithodid crabs grazing at bacterial mats at a methane seep in the vicinity of the mud volcano "Mound 12". "As far as we know, deep-sea crabs feeding on bacterial mats were discovered only one single time before," Linke states.

"Our team was the first one to also generate a photographic documentation over a longer period which allows scientific interpretations." For this purpose, a deep-sea observatory was equipped with a camera and placed above a bacterial mat. During a period of about 400 hours, the camera automatically took a picture every 30 minutes. "On 184 images, crabs were seen crawling over the bacteria and apparently grazed the bacterial "lawn", Niemann describes the observations. "Afterwards, it took a few hours until the animals returned, so that new bacteria could grow."

With the submersible ALVIN, the marine biologists brought one of the crabs onboard their research vessel ATLANTIS. For the comparison with the bacteria, the diving robot QUEST took short sediment cores from the sea floor from the METEOR. "DNA and isotopic analyses at Max Planck Institute for Marine Microbiology later showed that the crabs actually feed on the bacterial mat and took up large amounts of chemically-produced carbon. In the body cells, we have also found traces of carbon, which was formed under the influence of light through photosynthesis", summarizes main author Niemann. "Therefore, we assume that cold seeps make an important but not the only contribution to the diet of migratory animals on the ocean floor and in this way enters into carbon, which is produced by chemosynthesis of methane in the marine food web."

Original publication: Niemann, H.; Linke, P.; Knittel, K.; MacPherson, E.; Boetius, A.; Brückmann, W.; Larvik, G.; Wallmann, K.; Schacht, U.; Omoregie, E.; Hilton, D.; Brown, K.; Rehder, G.: Methane-carbon flow into the benthic food web at cold seeps – a case study from the Costa Rica subduction zone.

Maike Nicolai | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Signaling Pathways to the Nucleus
19.03.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht In monogamous species, a compatible partner is more important than an ornamented one
19.03.2018 | Max-Planck-Institut für Ornithologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

A new kind of quantum bits in two dimensions

19.03.2018 | Physics and Astronomy

Scientists have a new way to gauge the growth of nanowires

19.03.2018 | Materials Sciences

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Science & Research
Overview of more VideoLinks >>>