The effects of environment on Arctica islandica shell formation and architecture
Milano, S.; Nehrke, G.; Wanamaker, A.D.; Ballesta-Artero, I.; Brey, T.; Schöne, B.R. (2017). The effects of environment on Arctica islandica shell formation and architecture. Biogeosciences 14(6): 1577-1591. https://dx.doi.org/10.5194/bg-14-1577-2017
In: Gattuso, J.P.; Kesselmeier, J. (Ed.) Biogeosciences. Copernicus Publications: Göttingen. ISSN 1726-4170; e-ISSN 1726-4189, more
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| Authors | | Top |
- Milano, S.
- Nehrke, G.
- Wanamaker, A.D.
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- Ballesta-Artero, I., more
- Brey, T.
- Schöne, B.R.
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| Abstract |
Mollusks record valuable information in their hardparts that reflect ambient environmental conditions. For thisreason, shells can serve as excellent archives to reconstructpast climate and environmental variability. However, animalphysiology and biomineralization, which are often poorly understood,can make the decoding of environmental signalsa challenging task. Many of the routinely used shell-basedproxies are sensitive to multiple different environmental andphysiological variables. Therefore, the identification and interpretationof individual environmental signals (e.g., watertemperature) often is particularly difficult. Additional proxiesnot influenced by multiple environmental variables or animalphysiology would be a great asset in the field of paleoclimatology.The aim of this study is to investigate the potentialuse of structural properties of Arctica islandica shells asan environmental proxy. A total of 11 specimens were analyzedto study if changes of the microstructural organizationof this marine bivalve are related to environmental conditions.In order to limit the interference of multiple parameters,the samples were cultured under controlled conditions.Three specimens presented here were grown at two differentwater temperatures (10 and 15 ?C) for multiple weeks andexposed only to ambient food conditions. An additional eightspecimens were reared under three different dietary regimes.Shell material was analyzed with two techniques; (1) confocalRaman microscopy (CRM) was used to quantify changesof the orientation of microstructural units and pigment distribution,and (2) scanning electron microscopy (SEM) wasused to detect changes in microstructural organization. Ourresults indicate that A. islandica microstructure is not sensitiveto changes in the food source and, likely, shell pigmentare not altered by diet. However, seawater temperaturehad a statistically significant effect on the orientation of thebiomineral. Although additional work is required, the resultspresented here suggest that the crystallographic orientationof biomineral units of A. islandica may serve as an alternativeand independent proxy for seawater temperature. |
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