Estimating the abundance of organisms in the ocean is a challenging endeavor. Regardless of whether you’re studying copepods or cod, you’re faced with trying to count creatures that live in three dimensions, in habitats that are often shifting and difficult to identify, and in conditions that frequently make sampling impossible. Further, the sea is big, really big, and most research is limited to just a snippet of time on a small patch of water, and at great expense. Large research vessels cost more than $20,000 a day just to operate!
Despite these daunting obstacles, ocean scientists are driven by an unceasing curiosity about the lives of ocean creatures. They are therefore always inventing new methods and technologies to better understand the distribution, abundance and behavior of these organisms. In these pages you will discover some the newest instruments used to observe and count life in the water, such as the Laser-Optical Plankton Counter (LOPC), which can be towed at speeds up to 15 knots, and can automatically detect, size and count particles as small as 100 microns; and the use of acoustics, such as the Acoustic Doppler-based Profilers, which can simultaneously detect and quantify plankton or fish across the entire water column. Also, you will learn how one of the oldest, most basic oceanographic tools, the net, has been modified in a variety of ways to target specific animals, or particular habitats. For example, the Multiple Opening/Closing Nets and Environmental Sampling System (MOCNESS) , a widely-used system with multiple nets, each of which can be opened and closed at specific depths. This tells scientists not only who is in the water, but also where they are in the water column.
These pages are full of information, images and diagrams about ocean research technology. For those of you interested in further exploration, there are also thorough references listed at the end of each section. We’d like to thank Senior Scientist Dr. Kenneth Foote, and Research Assistant Marjorie Parmenter, from the Applied Ocean Physics and Engineering Department at Woods Hole Oceanographic Institution for contributing this section to our website.