Selective feeding by mucous-net filter feeders on the ocean&#39;s smallest organisms

GSTDTAP

项目编号	1537201
	Selective feeding by mucous-net filter feeders on the ocean's smallest organisms
	Kelly Sutherland
主持机构	University of Oregon Eugene
项目开始年	2015
	2015-08-01
项目结束日期	2018-07-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	239488(USD)
国家	美国
语种	英语
英文摘要	The surface of the ocean is dominated by microscopic plants and animals called picoplankton, which are at the base of the marine food web. Jelly-like animals called appendicularians specialize in feeding on these miniature organisms by filtering large quantities of water using nets made out of mucus. In the past, it was thought that appendicularians eat anything that passes through the mucous net, but new work shows that feeding may be selective. The most abundant group of microorganisms in the ocean, called SAR 11, seems to evade the appendicularian, while similar-sized photosynthetic microbes are captured. In this study, a series of lab and field experiments will be conducted in Oregon, USA, and Villefranche-sur-mer, France, to uncover the mechanisms for selectivity. The research will test the effect of particle shape (e.g. spherical vs. ellipsoidal), adhesion properties of particles to mucous meshes, and the role of hydrodynamics. It will focus on the cosmopolitan appendicularian Oikopleura dioica, an important grazer of picoplankton. Results will be important for understanding the role of mucous-net filter feeders in shaping the structure of the ocean's microbial community as well as biogeochemical cycling. The project will support an early-career faculty member, will provide training and mentoring for one PhD student and two undergraduates, involves collaboration with scientists in France and Israel, and will engage the public through exhibits and images to be displayed at the Hatfield Marine Science Visitor Center and Charleston Marine Life Center. Picoplankton occur at densities of up to a million per mL and numerically dominate the upper ocean prey field. Since appendicularians influence pico- and nano-particle flux through their high filtration rates and the production of mucous aggregates, selective grazing will have important ramifications for microbial loop dynamics and vertical flux. Therefore, this work will provide insights into the mechanisms governing bacterioplankton community structure in the upper ocean and increase understanding of microbial-metazoan food web interactions in both neritic and oceanic ecosystems. The specific goals of the project are to a) determine the role of flow morphology in regulating particle capture within the houses of free-swimming appendicularians using micro-Particle Image Velocimetry, b) determine the effect of particle shape on retention efficiencies by appendicularians, and compare this effect between synthetic and biological particles, and c) quantify particle adhesion to the mucous filtration apparatus in order to determine if picoplankton cell surface properties influence retention efficiencies by mucous-net filter-feeders.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68352
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Kelly Sutherland.Selective feeding by mucous-net filter feeders on the ocean's smallest organisms.2015.