Calcification and Photosynthesis Measurements for the JGOFS Equatorial Pacific Study

JGOFS 赤道太平洋研究的钙化和光合作用测量

• 批准号: 9022227
• 负责人: William Balch
• 金额: $ 19.61万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-10-15 至 1994-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9022227&HistoricalAwards=false
• 关键词: Calcification; Photosynthesis; Measurements; JGOFS; Equatorial

This project will measure the rates of carbon uptake through the process of calcification and photosynthesis during one of the JGOFS cruises in the equatorial Pacific. The overwhelming contribution of calcite to the sediments of the eastern equatorial Pacific has long been realized (70-90% of the total sediment mass is calcite, and less than 1% is organic). Moreover, half of this calcite is produced from the calcified plates of coccolithophorid phytoplankters which are called coccoliths. Using published data on accumulation rates in the equatorial pacific region and conservative assumptions about the ratio of biologically fixed calcite which is ultimately buried, it can be argued that calcification is at least of equal magnitude to new production in the eastern tropical Pacific. In terms of the carbon which is ultimately buried on a yearly time scale, calcite dominated the carbon flux while most of the organic material is re-oxidized to carbon dioxide (CO2) within the water column. This project will document the magnitude of the surface calcification signal along with the standard photosynthesis measurements. Simulated-in-situ measurements will be performed of both calcification and photosynthesis. The data will be compared with the sediment trap data as a cross-check of the sediment- trap-derived accumulation rates; in a region such as the equatorial Pacific, which is known for its large current shears, this verification is essential. The data will also represent some of the first direct measurements of surface calcification in the equatorial Pacific and will be of significant interest and use to both biologists and geologists.

该项目将测量 JGOFS 在赤道太平洋航行期间钙化和光合作用过程中的碳吸收率。 方解石对赤道东太平洋沉积物的压倒性贡献早已被认识到（总沉积物质量的70-90%是方解石，不到1%是有机物）。此外，一半的方解石是由一颗颗石藻类浮游植物的钙化板产生的，这些浮游植物被称为颗石石。 利用已发表的关于赤道太平洋地区积累率的数据以及对最终被掩埋的生物固定方解石比例的保守假设，可以认为钙化至少与东热带太平洋的新产量具有相同的程度。就年时间尺度上最终埋藏的碳而言，方解石在碳通量中占主导地位，而大多数有机物质在水柱内被重新氧化为二氧化碳（CO2）。 该项目将记录表面钙化信号的强度以及标准光合作用测量值。将对钙化和光合作用进行模拟原位测量。 该数据将与沉积物捕集器数据进行比较，作为沉积物捕集器衍生的积累率的交叉检查；在像赤道太平洋这样以海流切变大而闻名的地区，这种核查至关重要。 这些数据还将代表赤道太平洋表面钙化的一些首次直接测量，并且将引起生物学家和地质学家的极大兴趣和使用。