Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Seabed biodiversity of the Straits of Magellan and Drake Passage

28.01.2010
A study of animals visible to the naked eye and living in and on the seabed – the 'macrobenthos' – of the Straits of Magellan and Drake Passage will help scientists understand the biodiversity, biogeography and ecology of the Magellanic region.

"The biodiversity data are from my very first oceanographic cruise with the Chilean Navy in the Magellanic region in 1997, as an early undergraduate," said Dr Sven Thatje of the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre, Southampton: "The beauty of this dataset is the comprehensive diversity analysis with probably more than 10 per cent of species new to science." The cruise was part of the Chilean 'Cimar Fiordo III' expedition.

The soft sediments at the seafloor were sampled at depths ranging between 35 and 571 metres using a 'box corer' lowered from the Chilean navy vessel RV Vidal Gormaz. Samples were taken within the Straits of Magellan, the seaway separating mainland South America and the islands of the Tierra Del Fuego archipelago, and the eastern part of the Beagle Channel which separates South America from Antarctica. Samples were also taken from adjacent channels and fjords, some of which had been visited for the first time ever during the cruise.

A total of 173 species or morphological variants of species were identified, including crustaceans, molluscs and echinoderms. But polychaete worms, the group that includes ragworms dug by anglers for bait on sandy beeches at low tide, dominated both in terms of abundance and biomass.

At some locations the abundance of invertebrates peaked at more than 10,000 individuals per square metre, even without counting rare species that were missed or fast moving species that eluded capture. However, abundance, biomass and species richness all decreased with depth, consistent with reports from other regions such as the high Antarctic Weddell and Lazarev Seas.

The animals living at the seafloor depend for food on organic matter that rains down from the overlying ocean. "Variation in this flux of organic matter from the pelagic to the benthic is probably the major factor structuring these communities," said Dr Thatje.

It has been argued for the polychaetes of the Pacific coast of South America that shallow areas act as sources of colonisation, helping to maintain species diversity in deeper regions in the face of local extinction. "Such colonisation-extinction dynamics may also explain the patterns of diversity that we see in the Magellanic region," said Dr Thatje.

The Magellanic region was covered by ice 21,000 years ago, and the sea level was much lower than it is today. The Straits of Magellan probably did not fully open until approximately 7,000 years ago, after the ice had receded. The species now present in Magellanic waters must therefore have recolonised the region from adjacent Atlantic and Pacific areas, and indeed some of the polychaetes found in the Magellanic region are known from the Antarctic shelf.

The larvae of polychaetes can live as plankton for many months before resettling and developing into adults. "The dispersal of Antarctic species through larval transport in easterly circumpolar currents may explain their occurrence in the Magellanic region," said Dr Thatje.

Contact information:

For more information contact the NOCS Press Officer Dr Rory Howlett on +44 (0)23 8059 8490 Email: r.howlett@noc.soton.ac.uk

Images are available from the NOCS Press Office (Tel. 023 8059 6100).

Scientist contact

Dr Sven Thatje: email sven.thatje@noc.soton.ac.uk

The researchers are Dr Sven Thatje of the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre, Southampton, and his graduate student Alastair Brown.

Publication:

Thatje, S. & Brown, A. The macrobenthic ecology of the Straits of Magellan and Beagle ecology of the Straits of Magellan and Beagle Channel. Anales Instituto Patagonia (Chile) 37(2), 17-27 (2009).

The National Oceanography Centre, Southampton is the UK's focus for ocean science. It is one of the world's leading institutions devoted to research, teaching and technology development in ocean and earth science. Over 500 research scientists, lecturing, support and seagoing staff are based at the centre's purpose-built waterside campus in Southampton along with over 700 undergraduate and postgraduate students.

The National Oceanography Centre, Southampton is a collaboration between the University of Southampton and the Natural Environment Research Council. The NERC royal research ships RRS James Cook and RRS Discovery are based at NOCS as is the National Marine Equipment Pool which includes Autosub and Isis, two of the world's deepest diving research vehicles.

Dr. Rory Howlett | EurekAlert!
Further information:
http://www.soton.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>