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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | 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: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>