NOAA Teacher at Sea John Clark
Aboard NOAA Ship Henry B. Bigelow
September 23 – October 4, 2013
Mission: Autumn Bottom Trawl Survey
Geographical Area of Cruise: North Atlantic
Date: September 27, 2013
Science and Technology Log
It’s going to be a busy night trawling and processing our catch. Yippee. I like being busy as the time passes more quickly and I learn about more fish. A large number of trawling areas are all clustered together for our shift. For the most part that means the time needed to collect data on one trawl is close to the amount of time needed for the ship to reach the next trawling area. The first trawl was a highlight for me as we collected, for the first time, a few puffer fish and one managed to stay inflated so I had a picture taken with that one.
However, on this night there was more than just puffer fish to be photographed with. On this night we caught the big one that didn’t get away. One trawl brings in an amazing catch of 6 very large striped bass and among them is a new record: The largest striped bass ever hauled in by NOAA Fisheries! The crew let me hold it up. It was very heavy and I kept hoping it would not start flopping around. I could just see myself letting go and watching it slip off the deck and back into the sea. Fortunately, our newly caught prize reacted passively to my photo op. I felt very lucky that the big fish was processed at the station I was working at. When Jakub put the big fish on the scale it was like a game show – special sounds were emitted from our speakers and out came the printed label confirming our prize – “FREEZ – biggest fish ever “-‐-‐the largest Morone Saxatilis (striped bass) ever caught by a NOAA Fisheries research ship. It was four feet long. I kept waiting for the balloons to come down from the ceiling.
Every member of the science team sorts fish but at the data collection tables my role in the fish lab is one of “recorder”. I’m teamed with another scientist who serves as the “cutter”, in this case Jakub. That person collects the information I enter into the computer. The amount of data collected depends on the quantity and type of fish caught in the net. I help record data on length, weight, sex, sexual development, diet, and scales. Sometimes fish specimens or parts of a fish, like the backbone of a goose fish, are preserved. On other occasions, fish, often the small ones are frozen for further study. Not every scientist can make it on to the Bigelow to be directly part of the trip so species data and samples are collected in accordance with their requests.
Collecting data from a fish as large as our striped bass is not easy. It is as big as the processing sink at our data collection station and it takes Jakub’s skill with a hacksaw-‐-‐yes I said hacksaw-‐-‐to open up the back of the head of the striped bass and retrieve the otolith, the two small bones found behind the head that are studied to determine age. When we were done, the fish was bagged and placed in the deep freeze for further study upon our return. On the good side we only froze one of the six striped bass that we caught so we got to enjoy some great seafood for dinner. The team filleted over 18 pounds of striped bass for the chef to cook up.
More Going On:
Processing the trawl is not the only data collection activity taking place on the Bigelow. Before most trawls begin the command comes down to “deploy the bongos”. They are actually a pair of closed end nets similar to nets used to catch butterflies only much longer. The name bongo comes from the deployment apparatus that holds the pair of nets. The top resembles a set of bongo drums with one net attached to each one. Their purpose, once deployed, is to collect plankton samples for further study. Many fish live off plankton until they are themselves eaten by a predator farther up the food chain so the health of plankton is critical to the success of the ecological food chain in the oceans.
Before some other trawls, comes the command to deploy the CTD device. When submerged to a target depth and running in the water as the ship steams forward, this long fire extinguisher sized device measures conductivity and temperature at specified depths of the ocean. It is another tool for measuring the health of the ocean and how current water conditions can impact the health of the marine life and also the food chain in the area.
On a personal note, I filleted a fish for the first time today – a flounder. Tanya, one of the science crew taught me how to do it. I was so excited about the outcome that I did another one!