haul back

September 13, 2024September 13, 2024

Sam Garson: Everybody’s Trawling for the Weekend, September 12, 2024

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.

NOAA Ship Henry B. Bigelow. Photo Credit: Sam Garson

a diagram of NOAA Ship Henry B Bigelow showing the plankton net, trawl net, and sonar capabilities. title: State of the Art Research Vessel Henry B. Bigelow. box labels identify the following features: (1) Navy designed "quiet" hull does not disturb marine life. (2) Advanced 3-D sonar gives researchers a bigger picture of fish and their marine habitat. (3) Plankton net gives an accurate survey of fish food supply. (4) Fish net can help gauge abundance of fish stocks. — Illustration credit: James Warren / Cape Cod Times, Information source: NOAA

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.

two crewmembers wearing hard hats, life vests, and gloves stand on the deck of the ship near a large piece of scientific equipment. the conductivity, temperature, and depth probe, along with one water sample bottle, is mounted inside a cylindrical metal frame attached to a cable. — Crewmembers ready to deploy the CTD.

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!”

photo of a computer screen showing a plot. on the x-axis is time. the y-axis shows depth and "TE Height," and there are three plot lines. — Trawl net monitoring. Photo Credit: Sam Garson

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.

view of a collection of orange rain coats, orange overalls, and large rubber boots spilling out of a closet-type area on one side of a room — Ready Room. Photo Credit: Sam Garson

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.

view inside the wet lab. there are rows of stations, each comprised of a metal table with a measuring board, a drainage sink, a work surface, a computer monitor. — Cutting Station. Photo Credit: Sam Garson

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.

trawl nets spread out on deck - they are large, green, with orange buoys attached. one net is attached to the A-frame at the aft of the ship's deck. — Trawl net on deck

empty conveyor belt in the sorting room. one purple-gloved hand reaches in front the right side of the image and rests on the rim of the conveyor belt. — Trawl net on deck

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!

a scanned black and white photograph. A man, dressed in a 3 piece suit and white hat, stands on the deck of a ship - the shoreline is visible at the horizon. he braces himself, his left foot positioned back, because a goat standing it on its hind legs is pushing against his chest with its forelegs. the man holds something with both hands, up toward the goat's face - maybe food. — Henry Bigelow and Buck the WHOI Mascot (1904). Photo Credit: NEFSC NOAA

September 24, 2013August 20, 2021

Louise Todd, Haul Back, September 23, 2013

NOAA Teacher at Sea
Louise Todd
Aboard NOAA Ship Oregon II
September 13 – 29, 2013

Mission: Shark and Red Snapper Bottom Longline Survey
Geographical Area of Cruise: Gulf of Mexico
Date: September 23, 2013

Weather Data from the Bridge:
Barometric Pressure: 1009.89mb
Sea Temperature: 28˚C
Air Temperature: 28.2˚C
Wind speed: 8.29knots

Science and Technology Log:

The haul back is definitely the most exciting part of each station. Bringing the line back in gives you the chance to see what you caught! Usually there is at least something on the line but my shift has had two totally empty lines which can be pretty disappointing. An empty line is called a water haul since all you are hauling back is water!

After the line has been in the water for one hour, everyone on the shift assembles on the bow to help with the haul back. One crew member operates the large winch used to wind the main line back up so it can be reused.

Line on the winch — Winch holding the main line

The crew member operating the winch unhooks each gangion from the main line and hands it to another crew member. That crew member passes it to a member of our shift who unhooks the number from the gangion. The gangions are carefully placed back in the barrels so they are ready for the next station. When something is on the line, the person handling the gangions will say “Fish on”.

Everyone gets ready to work when we hear that call. Every fish that comes on board is measured. Usually fish are measured on their sides as that makes it easy to read the markings on the measuring board.

Measuring Grouper — Measuring a Yellowedge Grouper (Photo credit Christine Seither)

Measuring a Sandbar — Christine and Nick measuring a Sandbar Shark

Each shark is examined to determine its gender.

Sexing a shark — Determining the sex of a sharpnose shark (Photo credit Deb Zimmerman)

Male sharks have claspers, modified pelvic fins that are used during reproduction. Female sharks do not have claspers.

Fin clips, small pieces of the fin, are taken from all species of sharks. The fin clips are used to examine the genetics of the sharks for confirmation of identification and population structure, both of which are important for management decisions.

Shark Fin Clip — That’s me in the blue hardhat taking a fin clip from a Sandbar Shark(Photo credit Lisa Jones)

Skin biopsies are taken from any dogfish sharks in order to differentiate between the species. Tags are applied to all sharks. Tags are useful in tracing the movement of sharks. When a shark, or any fish with a tag, is recaptured there is a phone number on the tag to call and report the location where the shark was recaptured.

Some sharks are small and relatively easy to handle.

Small Cuban Dogfish (Photo credit Christine Seither)

Other sharks are large and need to be hauled out of the water using the cradle. The cradle enables the larger sharks to be processed quickly and then returned to the water. A scale on the cradle provides a weight on the shark. Today was the first time my shift caught anything big enough to need the cradle. We used the cradle today for one Sandbar and two Silky Sharks. Everyone on deck has to put a hardhat on when the cradle is used since the cradle is operated using a crane.

Silky Shark — Silky shark coming up in the cradle

Personal Log:

I continue to have such a good time on the Oregon II. My shift has had some successful stations which is always exciting. We have had less downtime in between our stations than we did the first few days so we are usually able to do more than one station in our shifts. The weather in the Gulf forced us to make a few small detours and gave us some rain yesterday but otherwise the seas have been calm and the weather has been beautiful. It is hard to believe my first week is already over. I am hopeful that we will continue our good luck with the stations this week! The rocking of the boat makes it very easy for me to sleep at night when my shift is over. I sleep very soundly! The food in the galley is delicious and there are plenty of options at each meal. I feel right at home on the Oregon II!

Did You Know?

Flying fish are active around the boat, especially when the spotlights are on during a haul back at night. Flying fish are able to “fly” using their modified pectoral fins that they spread out. This flying fish flew right onto the boat!

August 23, 2013August 20, 2021

Liz Harrington: The Temporary Lull in the Action, August 21, 2013

NOAA Teacher At Sea
Liz Harrington
Aboard NOAA Ship Oregon II
August 10 – 25, 2013

Mission : Shark/Red Snapper Bottom Longline
Geographical area of cruise: Western Atlantic Ocean and Gulf of Mexico
Date: August 21, 2013

Weather: current conditions from the bridge:
Partly cloudy
Lat. 29.18 °N Lon. 84.06 °W
Temp. 75 °F (24 ° C)
Wind speed 10-15 mph
Barometer 30.04 in ( 1017.3 mb)
Visibility 10 mi

Science and Technology Log:

It has been just over a week now since I’ve been aboard the Oregon II. The catch has not been as abundant as it was the first couple of days of fishing, but that tells the scientist something as well. So far I’ve experienced three water hauls – not one fish on any of the 100 hooks! Even though we are not catching many fish (for now), the fishing will continue until it is time to return to port. Don’t get me wrong, we are still catching fish, just not as many as we had been. Occasionally we pull up something other than fish, like eels, skates, crabs or sea stars. This is called the bycatch. In the previous blog I explained how the line was set. In this one I’ll explain about the catch.

OLYMPUS DIGITAL CAMERA — “Fish On”. A Sandbar Shark is brought alongside the ship to be cradled.

crab as bycatch — This crab, part of the bycatch, wouldn’t let go of the bait.

preparing for haul back — Lead Fisherman Chris Nichols (right) and Fisherman Buddy Gould prepare to retrieve the high flyer.

Hauling in the line is similar to setting it out. The fisherman handle the line and the science team process the fish. Our team includes a person manning the computer to keep track of the hook numbers and the condition of any remaining bait; a person “racking” (carefully but quickly returning the gangions into the storage barrels); and a “data” person to write down information about each fish, and the rest of the team will be “wranglers” (those who handle the catch). We all rotate through the jobs. I like to be a wrangler, but the racker and computer folks get a nice view of the fish being brought on board. Everything we catch is brought on board, weighed and measured.

tagging Tiger Shark — The Day Team tagging a Tiger Shark

Many species of sharks are tagged and a fin clip is taken to obtain its DNA. They are given an injection of a chemical which will help to age the shark if it is caught again. The entire process only takes a few minutes because they are trying to get the sharks back into the water as soon as possible. The scientists and crew are all very conscientious about doing what is best for the marine life. What’s really nice is that we all take turns tagging the sharks. It is just so exciting to be up close to them, especially the big ones. You can feel the strength and power beneath that sandy skin.

weighing a shark — Sometimes sharks are too heavy for the handheld scale, so they are hoisted up to be weighed. Notice the scientist to the right to get sense of its weight.

processing fish — Kristin and Cliff find otoliths at the end of the rainbow.

The boney fish that are caught are also weighed and measured. After the haul back (when the line is in, gangions are stored, high flyers returned and deck hosed down), they are brought to the back of the ship to have otoliths removed and tissue samples taken. The otoliths are boney structures in the fish’s inner ear which are sensitive to gravity and acceleration. As the fish grows, each year a new layer is added to the otoliths – similar to tree rings. By examining the otoliths under a microscope its age can be determined. I was taught how to remove the otoliths, so now (given enough time – I need plenty) I can help process the fish. Learn more about the procedure here.

Personal Log

It has been easy for me to acclimate to life aboard the ship because all of the people are so friendly and interesting. The ship is always rocking but I don’t even notice it any more. It actually lulls me to sleep at night, along with the constant sound of the engine and particularly the gurgling sound of the water moving along the hull (frame of ship). I was a little worried that I might get seasick in the beginning of the cruise, but I didn’t. The only problem I had was that reading or working on the computer made me queasy, but that only lasted for a couple of days. Quarters are tight, but they make good use of all of the space. Most of the bedrooms (called staterooms) sleep two people. We all eat in a room called the galley. It only holds twelve people at a time, so when we are done eating we leave to make room for someone else. The food on board is delicious and abundant. The chief steward, Walter Coghlan, does a great job providing a variety of choices. There is literally something for everyone. If we have free time, there is a lounge area with a huge selection of movies.

I like to spend my free time out on the decks, if I can find a place in the shade and the breeze. I love to look out over the water. And the sky stretches from horizon to horizon in all directions, something I don’t see in the mountains of Vermont. The cumulus clouds develop during the day and I can usually see a thunderstorm somewhere by late afternoon. It’s a beautiful view. Yesterday we were visited briefly by a small group of dolphins. Their acrobatics were very entertaining. They were here and then gone. That seems to be the continuing theme here; you never know what you are going to see.

Dolphin visit — A small group of dolphins swim along side the ship.

Did you know? The ship makes it own fresh water from the sea water. There is a reverse osmosis desalination system located down in the engine room. The fresh water is stored in large tanks, so it is always available.

volunteers await a haul — Volunteers Micayla, Daniel, David and Cliff waiting to do some wrangling.

New Term

Foul Hook – when a fish is hooked in a place other than its mouth (ie -fin or body)

More examples of bycatch.