Experimental investigations of the giant colonies of Phaeocystis globosa in China

College Of William & Mary Virginia Institute Of Marine Science, Gloucester Point VA

Investigators

Abstract

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.