Arctica islandica

Iceland clam ( Arctica islandica )

The Iceland clam ( Arctica islandica ) is a common from the coasts of North America to the Baltic clam heterodonte from the order of Veneroida. The describer Linnaeus called it Venus islandica, later Cyprina islandica, after which it was as monotypic species into its own family, the Arcticidae found. In Iceland, the United States and Canada, up to 12 cm large shell is considered a delicacy in Europe, it plays no role in the fishing industry.

Age determination

The study of the growth lines in the shells of shellfish Iceland allows the determination of age. In this case, an age of several hundred years was found in some shells. The potential of the Iceland clam for Paläoklimaanalysen has been demonstrated for the first time already in the 1990s. It seems not unlikely that very old specimens of this species are found whose growth time series can be as in dendrochronology to link chronologies spanning the periods from centuries to millennia and climate variability of the past - released annually by seasonal - inform.

Oldest mussel

A research team from the British " Bangor University 's School of Ocean Sciences " collected in 2006 about 6,000 copies north of Iceland, including living that were frozen for later analysis. In October 2007, one of those still living at catching shells were dated at a first count to an age of 405 years. On the assumption that this was a new record, a separate press release was published. The Sunday Times claimed in its reporting it incorrectly, the scientists have given the name of the shell Ming, thereby attaining better known under this name and was so entered in the Guinness Book of World Records. In a later review, the first count equally made out to be false and which reached age is now given as 507 years. This shell is older than that copy, which was recovered by U.S. researchers in 1982 off the American coast.

Climate Archive

Previously, an international research group had already presented under German auspices of a 374 years old specimen, examined isotopengeochemisch and confirmed their importance for paleoclimate analyzes in 2005. The research team led by Prof. Beautiful ( University of Mainz) has demonstrated the practical application of the climate archive Iceland shell in various works. Thus, a relationship between annual growth and the North Atlantic Oscillation (NAO ) was found, inter alia. Furthermore, it was shown that the water temperatures of the North Sea over the past 120 years ( 1880-2001 ) have increased on average by about 1 ° C, global climate change has therefore not made ​​even stop here. The warming of the surface water (above the thermocline ) was placed by a factor of four over the deep water. In addition, a significantly accelerated rise in temperatures has been observed since 1960.

Chris Richardson, a professor at Bangor University, suggested that all cells renewed at an ideal pace. However, there are much older expectant animal species; see about Scolymastra joubini, a type of the class of glass sponges.