Development of Plankton Sampling

Early plankton samplers were set out one at a time. Here Dean Bumpus launches a small Clarke-Bumpus sampler from the Atlantis, during a 1941 research trip to the Georges Banks off Massachusetts. (Woods Hole Oceanographic Institution)

By 1965 most plankton nets were still deployed singly, like this one that Jack Laird readied aboard the Atlantis II (Woods Hole Oceanographic Institution)

Plankton nets are easy to use: lower overboard and tow slowly behind the ship. Plankton, and anything else larger than the mesh, collect in a sampling jar at the tapered end of the net. (Woods Hole Oceanographic Institution)

The MOCNESS uses up to 20 nets on a single tow, and lets scientists open and close the nets at desired depths or water conditions. Here, the multiple net-ends are visible in the water as Debbie Steininberg hauls the MOCNESS aboard. (courtesy Ken Buesseler, WHOI)

Water enters the MOCNESS nets through a sturdy rectangular frame that is one of four standard sizes, allowing scientists to calculate plankton density in the water. Sensors mounted on the frame report water conditions to the ship during towing. Taken aboard the R/V Roger Revelle in the northwest Pacific, 2005. (courtesy Ken Buesseler, WHOI)

A shipboard computer monitors readouts from instruments on the MOCNESS frame. Scientists use the data to decide when to open or close nets. This monitor is on the R/V Kilo Moana off Hawaii, 2004. (courtesy Ken Buesseler)

Regardless how sophisticated a net system is - single net or MOCNESS - the final sampling step is the same: open the container at the tail of the net, and look inside. (Woods Hole Oceanographic Institution)