Free Drifting Icebergs: Influence of Floating Islands on Pelagic Ecosystems in the Weddell Sea.

该项目旨在研究冰山对西北威德尔海的远洋生态系统的重要性。过去十年来，气候变暖与南大洋冰川消退和冰山增多有关。冰山最集中的地方是西北威德尔海，它们沿着南极半岛的轮廓向东北方向顺时针方向漂移，穿过一个被称为“冰山小巷”的区域。人们对自由漂浮的冰山对威德尔海的远洋生态系统或整个南大洋的影响知之甚少。据推测，作为漂流岛，中小型冰山(最大尺寸为10公里)赋予周围水域独特的物理、化学和生物特征。将提出三个一般性问题来回答这一假设：1)根据现场测量与卫星传感器获取的图像的相关性，自由漂流冰山在几天到几个月的时间尺度上的动力学(大约大小、丰度和空间分布)是什么？2)自由漂流冰山的大小与相关远洋群落的结构之间的关系是什么？3)估计西北韦德尔海自由漂流冰山对远洋带生物特征的综合影响是什么？这项跨学科的研究将使用标准的海洋取样，加上从所有类型的传感器和调查方法获得的船上数据的独特方法，以确定作为冰山大小函数的各种生物因素的影响范围。这里提出的探索性研究将提供有关南极半岛地区大气变暖影响的关键数据。最近南大洋自由漂流冰山的盛行，应该会对周围的远洋生态系统产生明显的富集性影响，从而改变群落动态。与这些冰山相关的初级生产力的增加可能会影响全球碳循环，因为南大洋被认为是大气中过量二氧化碳的主要汇。拟议的研究将包括通过海洋探索中心(OEC)的创新教育部分，其重点是提供非科学家和研究人员都能理解的海洋的全面看法，并可直接访问最先进的数据库和选定的网站。OEC将允许用户访问已被分类为四个级别之一的内容：入门(K-6年级)、学生(6-12年级)、学院和研究。这一冰山项目的成果将被纳入OEC南极研究部，提供记录自由漂浮的冰山对周围远洋生态系统影响的数据库。然后，这些数据将被外推，以评估冰山对威德尔海生态系统的影响。研究生、本科生、教师和志愿者是拟议的实地和实验室工作的重要组成部分。

This project seeks to examine the importance of icebergs to the pelagic ecosystem of the North-West Weddell Sea. Atmospheric warming has been associated with retreating glaciers and the increasing prevalence of icebergs in the Southern Ocean over the last decade. The highest concentration of icebergs occurs in the NW Weddell Sea, where they drift in a clockwise pattern to the northeast, following the contours of the Antarctic Peninsula through an area dubbed "Iceberg Alley". Little is known about the impact of free-drifting icebergs on the pelagic ecosystem of the Weddell Sea or on the Southern Ocean as a whole. It is hypothesized that as drifting islands, icebergs of small to intermediate size ( 10 km in largest dimension) impart unique physical, chemical and biological characteristics to the surrounding water. Three general questions will be asked to address this hypothesis: 1) What are the dynamics (approximate size, abundance and spatial distribution) of free-drifting icebergs on temporal scales of days to months, based on correlation of field measurements with imagery derived from satellite sensors? 2) What is the relationship between the size of free-drifting icebergs and the structure of the associated pelagic communities? 3) What is the estimated combined impact of free-drifting icebergs in the NW Weddell Sea on the biological characteristics of the pelagic zone? This interdisciplinary study will use standard oceanographic sampling coupled with unique methodology for staging shipboard data from all types of sensors and survey methods to determine the sphere of influence for a diverse set of biological factors as a function of iceberg size. The exploratory research proposed here will provide critical data on the effects of atmospheric warming in the Antarctic Peninsula region. The recent prevalence of free drifting icebergs in the Southern Ocean should have a pronounced enrichment effect on the surrounding pelagic ecosystem, altering community dynamics. Enhanced primary production associated with these icebergs could influence the global carbon cycle since the Southern Ocean is considered a major sink for excess CO2 from the atmosphere. The proposed research will include an innovative education component through the Ocean Exploration Center (OEC), whose focus is to provide a comprehensive view of the oceans, intelligible to non-scientists and researchers alike, with direct access to state-of-the-art databases and selected websites. The OEC will allow users to access content which has been classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. The results from this iceberg project will be incorporated into the Antarctic Research division of the OEC, providing databases documenting the impact of free-drifting icebergs on the surrounding pelagic ecosystem. These data then will be extrapolated to evaluate the impact of icebergs on the ecosystem of the Weddell Sea. Graduate students, undergraduates, teachers and volunteers are an important part of the proposed field and laboratory work.