Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cockles and mussels reveal all

01.04.2004


Cockles and mussels harvested on the shores of the Irish Sea may have provided a staple diet for Molly Malone and her fellow Dubliners, but for scientists at the University of Wales, Aberystwyth they are, along with longer living species such as the clam Arctica islandica*, a detailed record of pollution extending back over two centuries.



The shells of molluscs are made up of layers of calcium carbonate which grow in regular cycles. With each cycle a layer is added causing an effect similar to the rings formed as trees grow. As layers are formed pollutants such as heavy metals become incorporated or trapped into the shell.

Led by Dr Bill Perkins of Centre for Research in Environment and Health at the Institute of Geography and Earth Sciences, the Aberystwyth team have been working on a technique that enables them to extract samples from the individual layers on a shell in minute quantities. Once analysed the extracted shards of shell reveal their chemical composition including trace metals in very low concentrations – parts per million.


The technique (Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS)) involves firing a laser at the shell that leaves a hole measuring between 20 and 30 microns across. Such accuracy is essential as the layers are not unsually distinguishable to the human eye. The samples are analysed in a matter of minutes whilst other techniques can take hours to achieve such low levels of detection. .

According to Dr Perkins the sea has been the ultimate ’sink’ for waste since man started mining and processing metals.

“The oceans have been used to wash away man’s dirt for thousands of years and there are many techniqes that allow scientists to monitor the levels of pollution and to look at long term changes in concentrations,“ he said.

“However, there is an increasing need to pinpoint when a pollution incident takes place and the likely source of the contamination, as people become more aware of the effects of pollution on the environment and their lives.“

“The technique we have developed at UWA, coupled with our increased understanding of how shells are formed, means that we will soon be able to pinpoint a pollution incident to a particular day and even identify the source. Longer living species such as Arctica islandica* provide information on naturally occuring levels whilst the shells of shorter living species such as cockles provide a much more detailed record of pollution levels from day to day,“ he added.

Environmental Forensics

The work of the Aberystwyth team has attracted the attention of scientists working in the relatively new field of Environmental Forensics.

Driven primarily by litigation in the US, where instances of ground water becoming contaminted by fuel from petrol stations and refineries is on the increase, the need to prove who is responsible and when a particular incident happened is ever more pressing.

In March 1989 the Exxon Valdez ran aground in Prince William Sound, Alaska, polluting hundreds of miles of pristine coastline. Scientists investigating the spill were able to prove that the area had a level of naturally occurring pollution as well as oil from the tanker spill. According to Dr Perkins, the work at Aberystwyth should in future enable scientists to map in much more details the presence of various pollutants in a particular marine environment, and provide important information that would be available in the event of a future spill and the ensuing legal action.

Dr Perkins presented the findings of his work to the International Society of Environmental Forensics at a meeting of the society held in Italy in May 2003

Parys Mountain

The team are currently looking at shell fish off the coast of Anglesey, north Wales. Over 200,000 cubic meters of heavily contaminated water from disused mine works on Parys Mountain are currently being dumped untreated into the Irish Sea. Working on the shells of limpets, mussels and whelks collected prior to, during, and for a period following the dumping, they will be able to build up a pollution profile.

Dr Perkins said: “The samples collected will enable us to build up a complete picture of any pollution caused by this work. Our technique works in a mater of minutes and, as the samples need very little preparation, there is little risk of contamination once they are removed from their natural habitat.“

*Shell fish of Ceredigion Bay

Ceredigion Bay is home to a rich and diverse shell-fish community, amongst them one of the longest living organisms on the Earth today, the clam Arcitca islandica. Measuring up to 120mm across, Arctica islandica can typically live for anything between 150 and 225 years, developing new layer of shell every year. During its „youth“ the shell can grow at a rate of several mm per year but the rate slows as the clam reaches „old age“. Unsuprisingly it has also become known as the tree of the sea. At the opposite end of the longevity spectrum are welks, limpets and mussels which live for between 4 and 5 years, and cockles whose shells develop a new layer with every tidal cycle.

Arthur Dafis | University of Wales
Further information:
http://www.aber.ac.uk/aberonline/uwa104.shtml

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>