NOAA Teacher at Sea
Sam Garson
Aboard Henry B. Bigelow
September 6 – 25, 2024
Mission: Leg 1 of Fall Bottom Trawl Survey
Geographic Area of Cruise: Mid-Atlantic Coast
Date: September 13, 2024
Weather Data from the Bridge:
Latitude: 36.93°N
Longitude: 76.3°W
Wind Speed: E 15 G 21 mph
Air Temperature: 22°C (71°F)
Science and Technology Log
NOAA’s Fall Bottom Trawl Survey began in 1963 and holds the distinction of being the longest-running standardized fishery-independent scientific trawl survey in the world. Its primary goal was to monitor the abundance and distribution of fish species in the northwest Atlantic Ocean, particularly on the continental shelf stretching from Cape Hatteras, North Carolina, to the Gulf of Maine. However, over time, the survey’s role has evolved into something far greater.
With over 60 years of continuous data collection, this survey is not only an important resource for understanding fish population dynamics, but it also serves as a data source for marine research across the globe. The data gathered provides unparalleled insights into long-term trends in marine ecosystems, making it a cornerstone of NOAA’s fisheries management program. This consistency allows scientists to assess how various factors—such as fishing pressure, environmental changes, and oceanographic conditions—affect fish populations over time.
By maintaining strict protocols and procedures across the decades, NOAA ensures that the data collected remains comparable year after year. As a result, this long-running trawl survey is a powerful tool for detecting shifts in marine biodiversity, population fluctuations, and changes in habitat use among species. The findings from the survey inform not only U.S. fisheries policy but also global conservation efforts, positioning it as a keystone project for marine resource management. The enduring nature of the Fall Bottom Trawl Survey has provided a reference point for understanding the impact of climate change on marine ecosystems, as rising ocean temperatures and shifting currents are increasingly influencing species distribution.
How Does a Trawl Work?
Members of the Bottom Trawl team work in 12 hour shifts, Midnight to Noon and Noon to Midnight. When it is your turn on watch you will wait for the ship to reach the next “station” or sampling site. Once there the survey team will deploy a CTD and possibly a “Bongo” plankton tow.
Once on station, the ship will deploy and stream the trawling net for between 16 and 20 minutes at a specified depth. Far from a simple task, this operation of the net streaming behind the ship is monitored closely with technology and data. The watch lead has to work closely with the bridge to ensure that the trawl net is running through the water properly. Monitoring the opening, speed and depth throughout the dive. Once all of that is confirmed to be in good working order you’ll hear the call over the PA, “HAUL BACK!”
Haul Back
Once the “haul back” call is given the deck crew springs into action to bring the net back on deck, while the science team moves into position in the sorting room. This process starts in the ready room, where everyone keeps their foul weather gear and gloves.
Once in their foul weather gear, the team will move to their positions along the first of three main conveyor belts. One member of the team will move out to the checker box where all of the trawl contents are first placed. From there the checker will feed the marine life into the first conveyor belt that brings all the specimens up to the main conveyor belt. Here the marine specimens are all sorted into buckets and bins by species, size and sex. The watch leader will tell the team what they are going to “run” that trawl, meaning which species do they leave on the belt to be deposited into bins at the very end. Depending on the goals, catch diversity or needs the watch leader could run everything from squid or crabs to sea robins.
Now that everything is sorted into buckets and bins the real data collection begins! The watch is broken into teams of two. A recorder and cutter work together to process every single marine sample for a variety of data products. These trawls are incredibly productive and have lots of scientists from institutions around the country sending in requests for samples and data. This is where the computer screens are so critical. As buckets of samples move down the last conveyor belt, the cutter scans them into the system and then is prompted by the computer to walk through any number of data collection procedures. The recorder enters them all into the computer, bags the samples, and processes the documentation needed. On this cruise we have been freezing samples, collecting otoliths (unfamiliar? check out this great NOAA resource), collecting stomachs and measuring and weighing hundreds of different species across all of our trawls.
Once that is complete we clean our stations and get ready for the next trawl. Sometimes this could be 30 minutes away, or even an hour, at times. It can be instantly after completing the last trawl. Working in 12 hour shifts, 24 hours a day means that the amount of data we are producing and cataloging is massive, but so is the job of sampling on the scale needed to help scientists answer questions about the ecology, populations, diversity and impacts of climate change along the Eastern Seaboard.
Personal Log
It’s been 10 years since I last sailed and I have been amazed at how quickly I’ve fallen back into the swing of life at sea. The night shift from 12:00 AM – 12:00 PM was a rough adjustment at first, but pretty quickly my body adapted and I settled into the routine.
It has been incredibly interesting to compare my previous time on an ROV based exploration vessel with the reality of a trawl based research mission. The E/V Nautilus was my home for 7 years and walking around the Bigelow definitely brings back some amazing memories, but it also has been a great reminder of how different things are across platforms. The ins and outs of life on Bigelow and the pace of the trawl are worlds different from the 24 hour ops of the ROV missions. I’ll write more on that later, but it has been a really cool comparison to make. It will be interesting to see how the rest of the cruise goes as we are only 3 days into our mission, and lots of cool fish still to come!
Did You Know?
Henry Bigelow was one of the key members of the scientific community who helped found Woods Hole Oceanographic Institute, here is an amazing photo of Henry Bigelow with WHOI’s mascot!
