This course is a study of the phytoplankton and zooplankton in marine and brackish environments. Qualitative and quantitative comparisons will be made between the planktonic population of various types of habitats in relation to primary and secondary productivity. This course is periodically offered at the Marine Science field station at Wallops Island, Va., only during a summer session. Since this course also is offered for graduate credit, a differentiation of requirements will be made.