Experimental investigations of the giant colonies of Phaeocystis globosa in China

本项目将研究球形棕囊藻在中国沿海沃茨中的生存和生长机制。近年来，广东沿海沿着形成了长期水华，造成养殖网箱中大量鱼类死亡，给当地经济造成了巨大的经济损失。这种水华是相对可预测的，因为它们每年都会在一个地方重复发生。这些中国花的殖民地的一个独特特征是它们的大小：它们的直径可达3厘米，比任何其他已知的植物生长因子大一个数量级。因此，菌落受到不同的物理因素的影响，它们的细胞/菌落生理学和碳营养，营养吸收和生态学方面必须与它们的较小对应物有很大不同。学术成就：这个合作项目将包括与暨南大学的同事一起对这些巨大的棕囊藻群落的生态进行国际调查。研究人员将具体研究，菌落细胞丰度，密度和碳，粘液碳和菌落大小之间的关系，以及菌落大小和细胞密度与营养吸收和光合作用之间的关系;作为菌落大小和生理状态的函数的菌落下沉率;和结肠内液含量，包括pH值，O2，DOC，DMSP以及它如何影响下沉。这项研究将为球形棕囊藻菌落建立一个理论框架，包括湍流，扩散和下沉对碳和氮吸收的影响，并将实验结果作为理论发展的一部分。实验计划将在暨南大学进行，使用在广州附近收集的巨型菌落样本。通过实验和观察相结合的项目，研究人员希望能够对这一种群如何在这些沿海沃茨中繁衍到这样的水平进行初步的预测性了解。巨大的球形藻群体是已知的最大的浮游植物，并且是少数几种能扩展到受湍流运动影响的大小的浮游植物之一;因此，对群体生态学的研究将代表对一种新的适应机制的独特研究：浮游植物的浮游性。更广泛的影响：该项目代表了两个国家和三个机构之间的合作，所有这些都集中在一个单一的，引人注目的科学问题上。美国调查人员将在该项目中开展重要的外联活动，包括：1）培训VIMS研究生和济南客座教授现代藻类技术; 2）参加威廉和玛丽大学题为“亚洲环境问题”的本科课程，并强调中国沿海沃茨有害藻华的作用; 3）在中国两所大学教授球形棕囊藻微型课程（济南和青岛海洋大学），并在VIMS重复课程（免费提供给更广泛领域的所有研究生）; 4.在中国举办一次关于棕囊藻生物学和生态学的国际研讨会，并将会议记录出版成同行评议卷。

This project will investigate the mechanisms by which giant colonies of the haptophyte Phaeocystis globosa survive and grow in Chinese coastal waters. In recent years long-lived blooms along the Guangdong coast have formed and caused substantial fish kills in aquaculture cages, resulting in substantial economic losses to the local economies. The blooms are relatively predictable, in that they repeatedly occur in one location each year. One unique feature of the colonies of these Chinese blooms is their size: they reach up to 3 centimeters in diameter, an order of magnitude larger that any other known phytoplankter. As such, the colonies are subject to different physical factors, and aspects of their cellular/colonial physiology and carbon nutrition, nutrient uptake, and ecology must be much different than their smaller counterparts. Intellectual Merit.This collaborative project will involve an international investigation of the ecology of these giant Phaeocystis colonies in conjunction with colleagues from Jinan University. The investigators will specifically examine, the relationship among colonial cell abundance, density and carbon, mucous carbon, and colony size and the relationships among colony size and cell density with nutrient uptake and photosynthesis; the sinking rates of colonies as a function of colony size and physiological state; and Intracolonial fluid contents, including pH, O2, DOC, DMSP and how it influences sinking. This research will develop a theoretical framework for Phaeocystis globosa colonies that includes the effects of turbulence, diffusion, and sinking on carbon and nitrogen uptake, and use the experimental results as part of the theoretical development. The experimental program will be conducted at Jinan University, using samples of giant colonies collected near Guangzhou. Through the combined experimental and observational programs, the investigators hope to develop the beginnings of a predictive understanding of how this population thrives to such levels in these coastal waters. Giant colonies of P. globosa are the largest phytoplankton known, and represent one of the few planktonic autotrophs that extend into sizes that are influenced by turbulent motion; hence, a study of the colonies' ecology will represent a unique investigation of a novel adaptive mechanism: gigantism in phytoplankton. Broader Impacts.This project represents a collaboration between two countries and three institutions, all focused on a single, compelling scientific question. The US investigators will perform significant outreach activities within this project that include: 1) training a VIMS graduate student and a Jinan Visiting Professor in modern algal techniques; 2) participating in an undergraduate course at William and Mary entitled "Asian Environmental Issues" and highlight the role of harmful algal blooms in coastal Chinese waters; 3) teaching mini-courses on Phaeocystis globosa at two Chinese Universities (Jinan and Ocean University in Qingdao), and repeat the course at VIMS (available to all graduate students in the broader area at no cost); and 4 organizing an international symposium on the biology and ecology of Phaeocystis, to be held in China, with the symposium proceedings to be published in a peer-reviewed volume.