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FW: red abalone shells research
Wow! Mass specs and carbon dating? "Radiocarbon" released from nuke weapons? Hmmmm...
> To All Flipper Dippers:
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> This e-mail message came in via our Club's Web site.
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> There may be some of you "older" divers who might be able to help out in this investigation of red abalone.
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> Regards,
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> http://www.SJFlipperDippers.com
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> Dear San Jose Flipper Dippers,
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> My name is Robert Leaf and I am a graduate student at Moss Landing Marine Labs in Moss Landing, California. My thesis work and interest involves studying the ecology and life history of red abalone on in Sonoma and Mendocino counties. My work thus far has been concerned with using archived California Fish and Game tag and recapture data to determine natural mortality, age and growth relationships, and their variability in time and space. I have used these data to construct a variety of computer models that will help managers, such as the California Department Fish and Game, to make informed decisions about proper size limits and what strategies may be effective to enhance the recreational fishery.
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> One of the major factors in maintaining the sustainability of the red abalone fishery is an understanding of how old can get. Abalone growth has been shown to be very slow at large sizes and the maximum longevity of red abalone has not been validated. Colleagues of mine in the ichthyology lab at Moss Landing Marine Labs have done some pioneering work using radiocarbon derived from nuclear testing, referred to as 'bomb carbon', as an independent chronometer to describe the age of a variety of sharks and rockfishes. I would like to apply a similar technique to red abalone.
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> Radioactive carbon was released into the atmosphere by nuclear testing during the 1940's and 1950's and this radiocarbon was incorporated into shell material. When analyzed using a mass spectrometer, a machine that can detect very low concentrations of an element, the concentration of radiocarbon in the birth material can be used to determine the date of birth of the abalone. This information can be combined with the date that the abalone was killed to get the age of the animal.
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> I am writing you and the members of your dive organization to ask if anyone may have red abalone shells collected during the 1950's and 1960's whose date of collection is known to within about 3 to 5 years. Obviously this is a difficult task and that is why I am appealing to you and your organization. I am looking to collect 5 to 10 shells of red abalone harvested in California during this time and will sample the birth material for radiocarbon. As I mentioned above the date of harvest must be known approximately. It is also necessary to use shells that are in good condition they must have the outside calcite layer (the part that often erodes, especially on older specimens).
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> Please let me know if you or any member of your organization would be able and willing to help me by providing their old shells for my project. I will remove some shell material from the outside of the shell and would be happy to return the shell if the owner would like it back. I would very much appreciate any help you may be able to provide me. I have included a link to similar work done by researchers in Oregon on red sea urchin using the same technique for your information.
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> Thank you very much for your time.
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> Sincerely,
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> Robert Leaf
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> <http://oregonstate.edu/dept/ncs/newsarch/2003/Nov03/urchin.htm>
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> --
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> Carl V. Tuttle
> President
> Tuttle Communications
> Marketing Communications / Advertising Design / Public Relations
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