All Hands On Deck

Picture a scientist in your mind and you probably envision white lab coats in a laboratory. On the Gould, we run with a tougher crowd. Preparation for our month at sea includes wrenches, hard hats, and steel toed boots. Let me explain.

As part of the zooplankton team on the Palmer Long Term Ecological Research (LTER) I must both build our plankton tow nets (there are three in total) and help put them in the water. The frames are huge…and heavy. They are lead weights meant for sinking.

A net consists of a box frame, the largest of which is 2 meters, or the height of a car, and a mesh net that extends several car lengths behind. At the end of the net we catch all the critters in a cylindrical container, the cod-end.


Step one: assemble the frame. We take four lead beams and bolt them together to make a square frame.

Step two: attach the nets. A few basic sewing and knot skills are essential. We thread rope between holes in the frame and the net one side at a time and synch each end with bowline and half hitch knots. Once a novice, I can now proudly tie both knots on command.


Step three: attach the Cod-end. Each net tapers to a small funnel at the end. The opening deposits into the Cod-ends. We secure the nets to the cod-ends with a metal bracket and handy dandy duct tape. Very Scientific. If there is one thing I have learned, it is that duct tape is the most essential tool on the ship.


But the beast of our net collection is the MOCNESS, or Multiple Opening and Closing Net Environment Sampling System. It holds nine nets at once and as the MOCNESS is lowered over the side of the boat a new net is opened at a predetermined depth. As one net closes another opens and when we pair this with the depth we can see how the types and amounts of zooplankton that we catch change over time.


The MOCNESS is a fussy little beast.  The opening and closing mechanism is electrically communicated from scientist to the device via a cable that runs tandem to the tethering wire.  Electrical systems and water never like to play nice, especially when they run on Windows XP. We often pray to the MOCNESS gods before releasing it over the back of the boat but they are fickle deities that like to toy with our tempers.


Assemblage of our gear was a success! Now it’s time for the real scientific work. Wish me luck.


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