0:00:00.0 John Sheehan: Last fall in 2023, scientists at NOAA’s Northeast Fisheries Science Center conducted their fall survey of the East coast called the Northeast Bottom Trawl. A survey that began 60 years ago.

0:00:12.4 Phil Politis: It started in 1963, the fall of 1963. It is a broad scale long running time series of fishery independent survey data from Cape Hatteras North Carolina, all the way up to the Scotian Shelf in the Canadian waters.

0:00:29.1 JS: It's conducted twice a year, during spring and fall for 60 days at a time. And it's rather unassuming name. It doesn't really get at the survey's importance, an importance that is derived largely from that anniversary I just mentioned, 60 years, meaning scientists and managers have this incredible resource of decades of standardized data on fisheries and ocean conditions to help inform their decisions and actions. This is Dive In with NOAA Fisheries. I'm John Sheehan. And today we'll hear about the Northeast Bottom Trawl Survey and how it combines seafaring science with hands-on lab work and sophisticated technology all squeezed into the NOAA vessel, The Henry B Bigelow, named for the 20th century oceanographer.

0:01:16.5 PP: He was one of the pioneer fisheries researchers out of Woods Hole, Massachusetts, just exploring the ocean and getting information about the biology, what are the different species that you could encounter?

0:01:27.6 JS: This is my guest, Phil Politis, a supervisory fishery biologist and the Bottom Trawl Survey program lead at the Northeast Fisheries Science Center. As we'll hear, every aspect of the survey from catching to processing to recording data has all been fine-tuned to both maximize efficiency of their time at sea, and to preserve their meticulously collected time series.

0:01:52.6 PP: When the catch comes on deck, it's put into what we call a checker or a hopper, and then that is run through conveyor belts, where it is sorted by the scientific staff that are on board. It's sorted by species. Some species are further sub-sorted by sex. And then we are processing them individually by species for length, weight, age, sex, the maturity, what stage they are in, sexual development and reproductive stage. And then also, we take age samples as well for based on their length distribution, and then also we sample their stomach contents. That's the baseline information we take. And then each season, and over time these have changed, but we are also taking other biological samples based on a lot of different research studies that are happening across the region, both internally to the Northeast Fisheries Science Center and externally. We also collect samples for other universities and agencies that request it.

0:02:53.0 JS: And there's sort of, to put it lightly, there's a lot of science kind of happening on the boat. Just judging from pictures from sort of blog entries that are covering it, you described these conveyor belts that are sort of bringing on catch, where it's being sorted. There's laboratories where people are taking samples, biological samples. There's a lot kind of happening, a lot of bustling activity on this boat.

0:03:17.3 PP: Sure. There's the catch processing, the scientific sampling of the catch. That is a pretty specialized fish processing system for our needs specific to the Henry B Bigelow and that ship. And the whole idea is to make it as efficient as possible to sort through these catches. So catch does come across a conveyor belt. It's sorted from both sides. We have people on either side of the belt sorting at any given time. Each then individual species is then sent further into the fish lab where it's weighed at a, what we call the watch chief station. They are sort of pacing that operation throughout, so they can control the speed of the belts, they can communicate with the other scientists that are on the watch, how quickly things are coming across. We can stop it if we needed to, if we get too many fish coming over at one time. Those species are then individually sent back to three separate workstations where teams of two will then process those by individual species.

0:04:18.7 JS: And that sounds like really industrial. It reminds me of like the Aisle of Lucy scene of the chocolates coming down the conveyor belt. Is it always like that busy? Is it kind of this constant fish coming in, fish coming in, gotta move the fish? What are we talking about in terms of species and materials? Like what's coming down this conveyor belt?

0:04:38.0 PP: Well, so it depends on where we are. We head down south, we're seeing in the fall, we're seeing especially inshore, a lot of different species that include squid, butterfish, larger fish like spiny dogfish, a lot of different skates that we see come over the belt. What we try to do is position people at the front of the belt to start to sort the large things to get it out of the way, so that as that catch continues down the belt, it's clearer for the rest of the people to sort through to the smaller fish, small scup, butterfish. As we move north, the species compositions tend to change, so we head out onto Georges Bank, typically around that second leg, we'll start to see more haddock, more flatfish, yellowtail flounder, winter flounder, again, skates. And then we move into the Gulf of Maine and Canada and we start to see a lot of the lobsters.

0:05:27.8 JS: And let's talk a little bit about kind of the mechanics of this. So as people are sorting, are people calling out like, we got three skates, this, this, this and it's like someone else's recording? Is this somehow being like typed into a database really quickly, are people there with clipboards?

0:05:48.4 PP: Nope. We're very close to a hundred percent paper-free at sea currently. So this is a fully electronic data entry system that we call FSCS 2.0. FSCS is the Fisheries Scientific Computing System. So it's a software, NOAA developed software that takes in all of the vessel sensor data into one easily accessible place. So we have electronic scales, motion compensated scales for weighing fish. We have electronic fish measuring boards that are enter... The data are entered, but from a magnet. Everything is put directly into an Oracle database, and that allows us to do a lot of cool things, primarily, quality assurance checks in real time at sea. So if for example, there was an accidental magnet press on the measuring board and that rang in as a hundred centimeters but really you have a species that you never expect to see at a hundred centimeters, that will flag us and it helps to alleviate a lot of different errors that you wouldn't have otherwise caught if you did this on paper and then entered it later on.

0:06:54.8 JS: Yeah, that's very sophisticated.

0:06:56.2 PP: One other thing. So we are tracking each individual species throughout that whole process. Fish in baskets, buckets or other containers are moved from the conveyor system, they're sorted. Then they're weighed in. At each weigh-in, we have each basket or container is barcoded. So now you have a weight associated with that specific basket that is moved to the workstation where the teams of two will work through that. They then re-scan that barcode. So we are also checking through what's known as a weight-length relationship, an expected total weight based on each length that's taken for each fish. So if those are off by a certain percentage, we can also verify that in real time at sea before all the fish are gone.

0:07:42.5 JS: And the trawl itself is also pretty sophisticated. How does that work?

0:07:46.4 PP: So this sampling gear is similar to a commercial trawl net with some fairly specific changes. This survey is fully standardized. We want to be able to make comparisons for what we catch say in fall of 2023, all the way back through fall of 1963, and all years and over all areas that are covered. That's really what the term time series gets to. We have three full-time net loss staff that are fishing gear experts that we have full-time on staff here working in our group. They maintain that gear to very specific construction standards and maintenance standards. We do what we call mensurate that gear. We have acoustic net mensuration sensors that are on that net that are measuring spread. So how far open is that net width-wise, how far open is that net height-wise? What depth that net is at, and what distance it is from the bottom. So we can get a very clear measure of when that net touches bottom to start the standard time tow duration, and when that net lifts off to end the standard tow duration, and then also a measure of what is known in as area swept, a good measure of what the area swept was for each individual tow.

0:09:04.8 JS: Wow. So you know what the net itself is doing kind of throughout the whole process?

0:09:10.9 PP: Oh, yes. It's being watched in several places on the ship, both by the winch operator, and then also by scientists that are on the main deck that we have this stuff graphed out. We can look at this in real time. It's not like a video image, but we do see graphically the performance of that trawl in real time and we can make a decision, okay, this isn't working right, let's haul it back, save the time and then repeat it. Or like most times, this is working very well and continue on.

0:09:37.6 JS: That also just sort of paints a picture of how complicated, and again it sounds so industrial. You've got... The scientists on the winch, you've got the scientists down below who are sorting and sampling these fish. And everything is just sort of working in concert very, very quickly as you said, to sort of maximize and efficiently use your time. And it's all happening on this sort of self-contained boat.

0:10:00.8 PP: The whole idea is standardization, and consistently through time to be able to maintain that continuity of the time series for comparability of these data throughout the years. That is the strength of what this survey is.

0:10:14.2 JS: And that really gets to why we're celebrating this 60th anniversary. It's not just a year, it's symbolizing this huge dataset that you've collected over 60 years.

0:10:26.5 PP: I mean, that's really the big benefit of a long running time series. At its core, what we're doing is collecting the baseline fishery independent information that's going into the regional fish stock assessments. And what we're able to do is not just look at the population abundance and distributions for any one given season or year. We're able to look at that across a very long timeframe. This is a time series that can look at, alright, what did these populations look like in 1970s? Well, look what they look like now. What's the ocean temperatures looking like? Is that a factor? Is that driving fish north? And the only way to do that is to look at these things over a long time.

0:11:06.6 JS: Has the survey itself evolved over the decades? I mean, technologically, certainly it has, but are you collecting things now for the future that say you weren't before?

0:11:20.5 PP: Absolutely. If you go back to the 1960s, the actual trawl net was much different. That was the technology at the time, although some people may mention that even at that time that was what's known as a Yankee 36 survey fishing trawl. It may even have been outdated for the 1960s. And that time period, if you look back, was an enormous period of improvements in fishing gear. The industry was growing and exploding in its technological abilities. It actually was one of the main drivers to actually implementing this survey. We didn't have a good handle on what were these population sizes back then? The harvesting activity was really ramping up. There was actually a Russian industrial fishing fleet that was in our areas. The United States had no real baseline to make any inferences or decisions about, well, how much fish should we be harvesting from the oceans?

0:12:13.2 PP: And give credit to the founders of the survey, they implemented this, they began this time series. So yeah, over the years, the vessel has changed. We've been lucky to use two primary survey vessels over its history. The Albatross 4 was the primary survey vessel from 1963 all the way through 2008. And then we moved to the NOAA Ship Henry B Bigelow in 2009. With that change of a ship, it gave us an opportunity to update the sampling gear. We moved to a more modern ship. We moved to a more modern trawl net. But in order to maintain that consistency through the time series, we had to go through a very rigorous, what we call a calibration experiment to get information, to get estimates of what the catchability differences are between the old gear and the old vessel combination, and the new gear and new vessel combination.

0:13:07.3 JS: And let's talk a little bit about the Henry B Bigelow, the ship named after the oceanographer Henry B Bigelow. Can you give me a rundown of like how many people, houses and just sort of like a sort of sense of the scale of the thing?

0:13:21.2 PP: Sure. So the boat is big. It's a 206 foot fisheries survey vessel. It was designed primarily with this survey in mind, although it does do some other projects throughout the year, some oceanographic projects and other things. But we do have 120 sea days per year on this ship. We have a fairly big back deck area that makes it nice for us to work on. The fishing gear gives us a lot of area to process the catch and work with the catch. At any given time, I believe there's about 24 crew and then we take 15 scientists. So you have various groups. You have the NOAA Corps that are driving the ship, and you have a group of engineers that are making sure that everything's running, the engines are working and any other issues that arise, they can address. You have a full-time galley staff that can feed these people three meals a day.

0:14:10.9 PP: We have survey technicians that can assist with a lot of the electronics and also an electronics engineer that can... 'Cause there is a lot of sensors on this ship that go beyond just what we're using for standardized fishery sampling. This ship is collecting a lot of temperature information, weather information, wind speed, wind direction and a whole host of other oceanographic things around the clock. So, there are people on that ship that are maintaining that sensors and maintaining that whole data collection system to ensure that it's functioning properly. And then there's also a deck crew that are handling everything from setting and hauling the fishing gear to helping to process that catch. And then also some other just deck related operational aspects of any ship.

0:14:56.6 JS: And the survey staff is working in 12 hour shifts, right, on and off?

0:15:02.2 PP: Yeah, so we do 12 hour shifts. We'll take one, what we call a chief scientist and then we'll have two watches that are broken down into groups of seven. And each one of those watches will have a watch chief, someone that's sort of overseeing each individual hall sampling, and then six additional staff that help to process through our catch biologically. And we do, we work in 12 hour shifts. So the survey is run around the clock 24 hours a day for the time period that we're at sea. We break those watches down into noon to midnight and then midnight to noon. It allows people to see some daylight, some on each watch. And then it also works well for the standard meal times on the ship, the breakup of the watches.

0:15:46.9 JS: How do people pass their off hours?

0:15:49.8 PP: It is, when we do these legs, it can be quite tiring. People do sleep quite a bit during those off hours. So when you're on a ship at any given time, somebody is sleeping. So you have to be cognizant of that so that you're not waking people up and running up and down halls and banging on doors. In their off hours, there's an area for people to watch TV, there's computers, there's a lot of reading that's done at sea. People as individuals, I think, tend to have their own ways of getting through 20 days at sea. There's a lot of card games that'll happen, some chess, some other types of just group game activities in-between on off watches and then also in-between down times when you're on watch.

0:16:32.5 JS: I read about one game called Flounder Flash.

0:16:38.3 PP: Yeah. So it's a game but it's really not what's important is that we maintain our skillsets at identifying these species. And the flounder complex can be quite complex, so there's a lot of different flatfish that we see, and there's a lot of different flatfish that we don't see often, or some people may see more often than others. So Flounder Flash is actually flashcards. It's a way for the scientific staff to really stay up to speed on the various different fish that we encounter so that when we're sorting fish, we're sorting properly. And fish that looks similar, if you just see it very quickly may not be similar.

0:17:18.0 JS: Yeah. And it's nice that despite the sort of very sophisticated equipment on board, it's still human eyeballs that kind of have to do the real work.

0:17:26.1 PP: Sure, yeah, it is. And beyond that, it's we're sampling these fish as well, so humans are actually cutting into these fish, taking hard parts, biological samples. So it's a skillset that like I said, hard to train on land. Something really has to be done at sea.

0:17:42.7 JS: Phil Politis, thanks so much for talking to me.

0:17:46.2 PP: Yeah, I appreciate it. I think this was great. It's good to always get this information out there and have people better understand what we're doing.

0:17:53.0 JS: Phil Politis is a supervisory fishery biologist and the Bottom Trawl Survey Program lead at NOAA’s Northeast Fisheries Science Center. I recommend checking out some of the blog posts from the survey. They give you a sense of what life is like on the Henry B Bigelow, and if like me, you are landlocked and can only daydream about ocean adventuring, it's pretty cool to see. That's at fisheries.noaa.gov. I'm John Sheehan, and this has been Dive In with NOAA Fisheries.