Collaborative Research: The Effect of Iron-Complexing Ligands on Iron Availability to Phytoplankton in HNLC Waters of the Subarctic Pacific Ocean

缅因州大学和旧金山州立大学的科学家提议在东部(海洋站PAPA)和西部(海洋站结)的高营养、低叶绿素(HNLC)水域进行甲板培养实验，以确定铁供应如何影响浮游植物物种组成。具体地说，这组科学家计划解决以下具体目标：(1)评估不同浮游藻类(蓝藻、硅藻、甲藻、裸藻)之间结合较弱和较强配体的铁的相对有效性如何不同，以及这些差异如何影响HNLC水域富铁后浮游植物群落的演变；(2)确定HNLC水域富铁后产生的新配体是否与周围配体的行为相似，或者它们在长期调节生态系统演变方面是否具有显著不同的作用；以及(3)确定具有不同接近度或铁输入历史的HNLC水域中的浮游植物组合是否对同一组铁配体混合物做出不同的反应，或者条件是否导致它们适应交替吸收能力。此外，还将进行生长率、大量营养素利用率、荧光、细胞大小测定、铁利用效率、铁和碳摄取率的测量以及流式细胞仪分类，以评估特定生物对不同化学形式的铁的反应。

ABSTRACTOCE-0241752OCE-0241385Scientists from the University of Maine and San Francisco State University propose to do deck-board incubation experiments in high nutrient, low chlorophyll (HNLC) waters of the eastern (Ocean Station PAPA) and the western (Ocean Station KNOT) Subarctic Pacific Ocean to determine how Fe supply affects phytoplankton species composition. Specifically, this team of scientists plans to address the following specific objectives: (1) assess how the relative availability of Fe bound to weaker and stronger classes of ligands differs among different phytoplankton groups (cyanobacteria, diatoms, dinoflagellates, prymnesiophytes) and how these differences influence the evolution of the phytoplankton community after Fe enrichment in HNLC waters; (2) ascertain if new ligands produced in response to Fe enrichment of HNLC waters behave similarly to ambient ligands, or if they have significantly different effect on regulating how an ecosystem evolves over the long term; and (3) determine whether phytoplankton assemblages in HNLC waters having different proximity or history of Fe inputs respond differently to the same suite of Fe ligand blends, or whether conditioning has led to their adaptation of alternate uptake capabilities. In addition, measurements of growth rates, macronutrient utilization rates, fluorescence, cell size determinations, Fe use efficiencies, rates of Fe and carbon uptake and flow cytometry sorting will be done to assess how specific organisms will respond to Fe supplied in different chemical forms.