Award: OCE-1129668

The marine environment is structured in several fundamentally different ways than the terrestrial environment. On land we are immersed in a thin fluid of atmospheric gases that is relatively light, free-flowing and transparent compared to the sea with its denser medium of seawater that resists the motion of small organisms and absorbs light more rapidly. The photosynthetic plants on land tend to be larger and more slowly growing than those in the sea, which are mainly microscopic, single cells and may only live for a few days before being eaten by tiny grazers, the micro-zooplankton. A single cupfull (or mouthful) of seawater contains million of bacteria and viruses, hundreds of thousands of tiny algal cells and thousands of small animals that feed on these algae and bacteria. We know surprisingly little about these tiny creatures that make up the base of marine food webs. How do they sense their environment? How do they find their food? How do they avoid being eaten themselves? We think of these tiny creatures, such as single-celled protozoa, as being primative, but they have been evolving for billions of years (longer than life on land) and they possess some surprisingly sophiticated adaptations for life in the sea. One of the main challenges to studying the behavior and ecological adaptations of these numerous and diverse micro-zooplankton in the sea is their small size and resistance to being grown under laboratory conditions. During this project we brought many diverse species of micro-zoplankton into culture in the laboratory and used sophisticated optical methods to study how these organisms swim, feed and avoid predators, including the use of high speed video (up to 2000 frames per second), particle image velocimetry (PIV) and digital holography. We developed new methods for observing how water flows around these microscopic organisms as they swim, so we can better understand the environmentala factors that control how they find and capture their food and avoid being eaten by other organisms. This information will improve our ability to understand and predict how the effects of climate change, ocean acidification and other factors will affect the base of the marine food web, and in turn impact the larger organisms that human populations rely on as a major source of food from the sea. This project also helped train several graduate students and post-doctoral students in marine science, and the use of sophisticated optical methods for studying the creatures that form the base of the complex web of life in the sea. Last Modified: 11/24/2015 Submitted by: Edward J Buskey