Trawling for Booty in the Briny Sea

by Angela Szesciorka, Vertebrate Ecology Lab

Classes at Moss Landing Marine Labs involve a lot of field trips, and this semester is no exception. On November 7, 2011 the marine ecology students ventured seaward to explore the ocean benthos.

Photo by MLML/UNOLS

The students waited with anticipation, saying goodbye to the familiar Moss Landing Harbor as the 135-foot Point Sur pulled slowly out into the open ocean.

Some slept while others sightsaw, their keen eyes watching for fluking humpbacks. An hour and a half into the voyage, the crew dropped the first beam trawl—taking 25 minutes to reach 805 meters.

The boat dragged the trawl along the ocean floor, usurping the denizens of the deep. Finally, a large bag of unknown animals was hauled up. Excited students crowded around the mysterious contents as they were dumped into a large bin.

Among the catch, a Pacific red octopus (Octopus rubescens), a brown cat shark, a Righteye flounder, and lots and lots of red sea urchins …

… which we had to count (thanks, Catherine!). There were 1,353 if you were interested.

The hagfish got a lot of attention — all slime and squirm, as did the octopus, who promptly inked in his bucket so we couldn’t ogle him.

Jon Geller’s invertebrate zoology lab took tissue samples of most of the organisms so they could create a DNA catalogue.

The next beam trawl brought up even more organisms — sea stars, sea cucumbers, coral, sponges, anemone, chitons, worms, crabs, and snails.

The final trawl of the day was a plankton tow, also known as a Tucker Trawl. The net was much finer to collect zoo- and phytoplankton.  We pulled up buckets of cloudy water and a giant Pacific sea nettle!

The students, basters and spoons in hand, began rooting through the soupy mess.

And found really cool deep see organisms. Most of them transparent. This adaptation for mesopelagic fishes allows them to avoid detection by predators or prey.

Seven hours later, the students returned home, bringing with them the newest member of Moss Landing, the octopus. You can read more about him here and if you are lucky, you’ll get to meet him (or her) at the next open house in April 2012.

Until the next adventure!