Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cockles and mussels reveal all


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:

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: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

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...

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

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>