Oxygen- and carbon-isotope analyses of the articulate brachiopodLaqueus californianus: a recorder of environmental changes in the subeuphotic zone
Oxygen- and carbon-isotope analyses of the articulate brachiopodLaqueus californianus: a recorder of environmental changes in the subeuphotic zone
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关节腕足动物Laqueus californianus的氧和碳同位素分析：亚绿光带环境变化的记录者
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
H. Spero
中科院分区：
文献类型：
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作者：
N. Buening;H. Spero
这项研究是首次系统地尝试在现代腕足动物中使用氧和碳同位素来研究季节性和生长率。对从加利福尼亚州圣卡塔利娜岛附近 80 和 130 m 处挖出的加州拉奎斯活体标本的壳的氧同位素分析与现有的水文学数据进行比较表明，这种有关节的腕足动物分泌的壳与周围海水处于或接近氧同位素平衡。周期性氧同位素消耗似乎是由厄尔尼诺事件造成的。与 1983 年厄尔尼诺现象相关的 δ13C 值出乎意料地低，这可能是由于与这些温水脉冲相关的南加州湾细菌活动或有机负荷增加所致。根据 δ18O 记录中的年周期确定的增长率是可变的，但成熟个体的平均增长率通常在 2 至 3 mm yr−1 之间。因为L的寿命很长。 californianus,18O 剖面提供了跨越一到二十年的高分辨率季节性温度记录。我们的数据表明，腕足动物壳中的氧同位素可以用作亚真光带环境变化的监测器。
This study is the first systematic attempt to use oxygen and carbon isotopes in modern brachiopods to investigate seasonality and growth rates. A comparison of oxygen-isotope analyses of shells of living specimens ofLaqueus californianus dredged from 80 and 130 m off Santa Catalina Island, California, to available hydrographie data indicates that this articulate brachiopod secretes its shell in or close to oxygen isotopic equilibrium with ambient seawater. Periodic oxygen-isotope depletions appear to result from El Nino events. Unexpectedly low δ13C values associated with the 1983 El Nino may be explained by increased bacterial activity or organic loading into the Southern California Bight associated with these warm-water pulses. Growth rates determined from annual cycles in δ18O records are variable, but generally average between 2 and 3 mm yr−1 for mature individuals. Because of the longevity ofL. californianus,18O profiles provide high-resolution seasonal temperature records spanning one to two decades. Our data suggest that oxygen isotopes in brachiopod shells can be utilized as monitors of environmental change in the subeuphotic zone.