and reduced cost of computer technology. Prior to this, the Mechanical Bathythermograph (MBT) was the norm Advantages and limitations The advantage of CTD casts is the acquisition of high-resolution data. The limitation of CTD sampling is that only a point in space (the sampling site) can be sampled at one time, and many casts, which are costly and time-consuming, are needed to acquire a broad picture of the marine environment of interest. From the information gathered during CTD casts, however, scientists can investigate how physical parameters are related, for example, to the observed distribution and variation of organisms that live in the ocean, thus deepening our understanding of the processes that govern ocean life. Gallery References Sources Baker D. J. 1981 "Ocean instruments and experiment design" Chapter 14 pp 416–418 Pickard George L. and William J. Emery "Descriptive Physical Oceanography, An introduction" 5th ed., Butterworth-Heineman (Elsevier Science): 1990 Modern oceanographic CTD systems History of the development of CTD systems Footnotes Oceanographic instrumentation Water and the environment Limnology Hydrography