Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (in port, Kodiak Island): 57o 47.0200′ N, 152o 25.5543′ W
Date: June 22, 2023
TAS Laura Guertin shows off her Teacher at Sea beanie aboard NOAA Ship OscarDyson
As we return to Kodiak, Alaska, for Leg 1 to wrap up and Leg 2 to begin of the 2023 Summer Survey, it’s exciting to know that even during our shortened expedition time at sea, we’ve collected data that is going to inform Alaska walleye pollock stock assessment models and catch allocation. Any/all data are good data to have! I have thoroughly enjoyed my time on Oscar Dyson and met some incredibly smart, passionate, kind, creative, and innovative people. The NOAA community is filled with amazing individuals that are not only dedicated to the NOAA science mission but then sharing that new knowledge with others. I’ve played a small part in this NOAA community during the expedition (while wearing my NOAA hat!), but I hope my future teaching and outreach efforts will shine an even brighter spotlight on the essential work carried out by NOAA Fisheries and the agency as a whole.
Prior to joining the ship, this past academic year was filled with some highs and lows in teaching and student learning. There’s one topic that I’m not quite sure how to classify – and that’s the emergence of Chat GPT, and how AI is being used in higher education. I was joking with the Instructional Designer at my campus (Penn State Brandywine) that I was going to write a sea shanty about this expedition. Turns out, he was able to get AI (Bing, specifically) to write one for me! So as I wrap up my time as a Teacher At Sea Alumna, I leave you with these versus to sing to your favorite shanty rhythm.
A Song of Pollock and Trawls
Oh we are the surveyors of the Gulf so vast and wide We sail the seas with acoustic gear to find the pollock hide We use sound waves to scan the depths and mark what we have found We measure their abundance and their biomass by the pound
(Chorus)
Yo ho ho as we sing this song On Leg 2 we’ll bring the DriX along Yo ho ho as we sing this song We love our job and we love our fish We love our job and we love our fish
We work in shifts around the clock to cover all the grounds We set the course and speed and time to trawl a certain length We haul the net and sort the catch and check their age and health We record all the data and we share it with the world
(Chorus)
We do this work for science and for management as well We help to keep the fishery sustainable and well We study the pollock’s life history, ecology, and stock We are proud to be part of this crew and this important work
(Chorus)
Oh we are the surveyors of the Gulf so vast and wide We sail the seas with acoustic gear to find the pollock hide We love our job and we love our fish We love our job and we love our fish
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (10:45AM (Alaska Time), June 21): 55o 29.7525′ N, 156o 44.7276′ W
Data from 10:45AM (Alaska Time), June 21, 2023 Air Temperature: 8.4 oC Water Temperature (mid-hull): 8.2oC Wind Speed: 8 knots Wind Direction: 20 degrees Course Over Ground (COG): 76 degrees Speed Over Ground (SOG): 11 knots
Date: June 21, 2023
Once the echo sounder has shown us the position of an aggregation of Alaska walleye pollock (we hope they are pollock and not some other fish species), we lower the trawl net and see what we can catch. This is where the trawl sonar and CamTrawl (see previous blog post) come in handy to give us an idea of what is going into the net. It’s an amazing coordination of effort between the acoustics lab (who decides where to trawl), the bridge for navigation, and the deck crew for setting/retrieving the haul.
We aim for trawling at the mid-water level, where the pollock are typically found. Pacific Ocean perch (POP, or rockfish) can also be found in the mid-water level in the Gulf of Alaska, especially just off the shelf break. Bottom trawls can yield pollock and other fish (e.g., POP and other rockfish species, various species of flatfish).
Once the trawl net has been brought back on board, the catch is emptied into a bin called a table. There is a door on the side of the table that opens into the fish lab. Once the table door opens, the fish spill into the laboratory where they travel down a conveyor belt for the initial sorting. Our target species is the pollock. We weigh everything that ends up onto the sorting table, either in bulk (by species) or individually.
Pollock moving along the sorting belt
Pile of Pacific Ocean perch (rockfish) after being hauled on the ship
Small squid that fell out of the trawl net on deck.
A subset of around 250 pollock are set aside to collect length data. The length of these of each individual pollock are measured on an Ichthystick. This is another invention by Rick Towler and Kresimir Williams (remember the CamTrawl? (see previous blog post)). As described in their article An inexpensive millimeter-accuracy electronic length measuring board, these NOAA scientists describe using magnetic measuring technology that, to millimeter resolution, takes a measurement when you placed a magnet on a sensor that runs the length of the board. For our pollock measurements, we were looking to record the fork length, and a quick placement of the red magnet along the fish tail sends the data to a computer program called CLAMS (Catch Logger for Acoustic Midwater Surveys).
Bins of pollock waiting to be measured on the Ichthystick
Ichthystick logo with a pollock sketch
Computer end of Ichthystick, which digitally shows the value of fish length and is written to CLAMS
Sketch showing what is measured for the fork length of a fish. From Corvallis Forestry Research Community.
Pollock lying on Ichthystick getting its fork length being measured
Two scientists measuring pollock fork length on Ichthystick
Another subset of approximately 50 pollock are set aside for additional data collection on individual specimens – length, weight, sex, maturity, and age. Otoliths (e.g., ear bones) are removed, and sometimes organs are removed and measured (ovaries for maturity development analyses, liver).
Otolith pairs (two per individual fish) from an assortment of Bering Sea fish species. Walleye pollock is located in the top left. Note: otolith sizes are not on a relative scale. Photo: NOAA Fisheries.
What are otoliths, and why remove them? Otoliths are ear stones, or ear bones, found in fish. To give you an idea of why we remove ear bones, let’s start by thinking about trees and corals… trees grow a new ring on their structure each year, and corals have differences in their skeletal density between the seasons (both trees and corals are also used to reconstruct past climate conditions (proxy data for paleoclimatology)). By counting the rings on trees and coral, we can calculate the age of that specimen. It turns out that fish also have a way to record their annual growth – and it occurs in their ear through Fish Otolith Chronologies.
Scientists are very interested in studying otoliths. When otolith data are combined with data on fish size, scientists are able to determine the growth rates of fish, which then combined with the survey work, helps inform annual fish stock assessment reports. We don’t do any of the otolith analyses on the ship, but we do collect the samples with a detailed label and all the corresponding data (fish length, sex, weight, location) that is sent back to the NOAA Fisheries Alaska Fisheries Science Center for analyses and entered into their Fish Otolith Collection Database.
Rockfish otoliths
Zoom of rockfish otoliths
Otoliths still inside a pollock
Placing an otolith cleaned in freshwater into a vial for storage and shipment for analysis
Did you know… More than 30,000 otoliths are read annually by NOAA Fisheries Alaska Fisheries Science Center scientists. So far, the Science Center has collected more than 1.1 million fish otoliths for ageing. (from NOAA Fisheries)
To learn more about the fascinating studies of otoliths and what NOAA Fisheries is doing, check out these websites:
NOAA Fisheries Age and Growth – NOAA Fisheries scientists assess the age and growth rates of fish species and populations to better monitor, assess, and manage stocks. There is also a separate site for Age and Growth Research in Alaska.
NOAA Fisheries Near-Infrared Technology Identifies Fish Species From Otoliths – NOAA Fisheries scientists are developing ways to use near-infrared spectroscopy (NIRS) analysis of otoliths (fish ear stones) to provide accurate information for sustainable fisheries management faster.
If you are really curious to explore some fish otolith data, check out the Alaska Age And Growth Data Map, an interactive map displays collected specimen information from recent age and growth studies from Alaska Fisheries Science Center.
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (2PM (Alaska Time), June 19): 55o 30.9384′ N, 159o 47.6478′ W
Data from 2PM (Alaska Time), June 19, 2023 Air Temperature: 8.2 oC Water Temperature (mid-hull): 6.8oC Wind Speed: 18 knots Wind Direction: 62 degrees Course Over Ground (COG): 30 degrees Speed Over Ground (SOG): 11 knots
Date: June 20, 2023
To conduct a fisheries survey or any oceanographic research expedition, there’s an enormous checklist of items you need on a ship. Jokingly, those on board will tell you that food and internet access are at the top of the list. But there’s no doubt that technology and its function, application, durability, etc., are critical during the time at sea. For example, see NOAA’s explainers for Ocean Exploration Technology: How Robots Are Uncovering the Mysteries of the Deep and Collecting and Visualizing Deep-Sea Data. For a broader look at the technologies NOAA uses to explore the ocean (vessels and submersibles, observing systems and sensors, communication technologies, and diving technologies), see Exploration Tools.
Leg 2 of this Summer Survey will be bringing on board the DriX, an uncrewed surface vehicle (USV), to see if this technology can improve the efficiency of collecting acoustic and biological data to estimate pollock abundance when working alongside Oscar Dyson. To read more/see a video, check out NOAA’s article, Uncrewed Surface Vehicles Complement NOAA Vessels for More Efficient Fisheries Surveys.
Trawl Sonar
The Simrad FS70 on the back deck of Oscar Dyson (June 2023)
Trawl sonar units are used to provide a rough estimate of how many fish are going into the trawl net. The device (which we’ve been using on our expedition, a Simrad FS70 nicknamed “the turtle”) is a third wire system that in real time establishes communication between the submerged sonar head and the bridge. On this cruise, the trawl sonar unit is placed on the headrope of the trawl net (i.e., on the top of the mouth of the net). It communicates its depth back to the ship. It also scans the mouth of the net and relays any acoustic images of things going into the net back to the ship. These data allow the scientists and crew to adjust the depth of the net and length of time the trawl net remains in the water to collect samples. Our goal is to collect enough fish (approximately one ton) to have a representative sample of the various species and lengths of fishes in the water column.
Screenshot of the display returned by the FS70 during a trawl. The pink/yellow/blue line in the left column is where you see the bottom of the net. This is also represented in the middle column by the multi-colored horizontal line you see in the third circle from the center. (Screenshot from Leg 1 provided by Rick Towler).
One fascinating piece of technology we’re using on this pollock survey is the CamTrawl. This article I found will give you everything you would want to know about CamTrawl in a non-technical summary:
Introduced in 2012, the CamTrawl is a stereo camera system when attached to a trawl net, can provide data about fish without ever touching a fish. This 3D imagery records fish passing by the camera towards the codend (the closed end of the trawl net), which provides species and size composition data as well as how fish behave in the trawl net to be collected from within a midwater survey trawl. CamTrawl is used to verify the trawl catch and specimen data, and in some cases, can be used to determine where in the water column the species entered the net. These data help inform ecosystem-based fisheries management.
The CamTrawl on Oscar Dyson for 2023 Summer Survey. The orange balls are flotation devices, the two “eyes” in the middle are the stereo camera and computer system, with the battery power across/under the eyes. The four round devices in the corner are lights used during the image recording.
Top-down view of the CamTrawl. The front of the camera set-up is the wider side of the trapezoidal frame (top of image) which is then attached to the trawl net.
Figure 1 from Williams et al. (2016). CamTrawl system description.
CamTrawl attached to trawl net about to be set off the back of Oscar Dyson.
The CamTrawl has uses and applications beyond our walleye pollock survey. It can go to depths of the ocean where it is not possible to lower a trawl net and capture data on other fish species like the bottom-dwelling rockfish. CamTrawl can explore and map deep-sea corals, and there is potential for collaborative research with the fishing industry.
Some CamTrawl footage from Leg 1 of 2023 Summer Survey.
The CamTrawl was developed by NOAA scientists Kresimir Williams and Rick Towler (both of whom I’m sailing with on Oscar Dyson for Leg 1). I feel incredibly fortunate to have sailed with these two scientists and to hear how NOAA encourages their researchers to be creative and experiment with developing technologies to advance NOAA’s overall mission and expedition objectives.
CamTrawl being detached from a trawl net after a mid-water trawl (June 16, 2023, on Oscar Dyson)
Curious to see more? Check out this Salmon shark caught on CamTrawl underwater camera.Below is a picture of a salmon shark from the Shumagin Islands, Alaska area in February 2017 (photo provided by Sarah Stienessen).
Boldt et al. (2018). Development of stereo camera methodologies to improve pelagic fish biomass estimates and inform ecosystem management in marine waters. Fisheries Research, 198. https://doi.org/10.1016/j.fishres.2017.10.013
Williams et al. (2018). A method for computing volumetric fish density using stereo cameras. Journal of Experimental Marine Biology and Ecology, 508. https://doi.org/10.1016/j.jembe.2018.08.001
Williams et al. (2016). Automated measurements of fish within a trawl using stereo images from a Camera-Trawl device (CamTrawl). Methods in Oceanography, 17. https://doi.org/10.1016/j.mio.2016.09.008
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (2PM (Alaska Time), June 18): 55o 15.3391′ N, 160o 17.8682′ W
Data from 2PM (Alaska Time), June 18, 2023 Air Temperature: 8.9 oC Water Temperature (mid-hull): 7.7oC Wind Speed: 4 knots Wind Direction: 182 degrees Course Over Ground (COG): 356 degrees Speed Over Ground (SOG): 12 knots
Date: June 19, 2023
Acoustic fisheries surveys seek to estimate the abundance and distribution of fish in a particular area of the ocean. In my case, this Summer Survey is looking at walleye pollock in the Gulf of Alaska. How is this accomplished? Well, it’s not through this method:
The Alaska walleye pollock is widely distributed in the North Pacific Ocean with the largest concentrations in the eastern Bering Sea. For this expedition, Oscar Dyson is traveling to specific regions in the Gulf of Alaska and running transects perpendicular to the bathymetry/contours (which are not always perpendicular to the shore) to take measurements using acoustics and targeted trawling to determine the abundance and distribution of walleye pollock which informs stock assessment and management models. For this blog post, let’s focus on how and why we can use acoustics to locate fish.
Walleye pollock (Gadus chalcogrammus) are distributed broadly in the North Pacific Ocean and eastern and western Bering Sea. In the Gulf of Alaska, pollock are considered as a single stock separate from those in the Bering Sea and Aleutian Islands. Image from Alaska Department of Fish and Game.An snapshot of a nautical chart with transects plotted. The first transect was run during Leg 1 on June 14 at the furthest location to the west, then the ship worked its way back east with approximately 40 nautical miles between transects. Once Oscar Dyson reached the Shumagin Islands, survey work shifted into this area..
Our story starts with the fish itself. Alaska walleye pollock have a swim bladder. The swim bladder is an internal organ filled with gas that allows a fish to maintain its buoyancy and stability at depth.
One interesting effect of the swim bladder is that it also functions as a resonating chamber that can produce and receive sound through sonar technology. This connection was first discovered in the 1970s, when low-frequency sound waves in the ocean come in contact with swim bladders and they resonated much like a tuning fork and return a strong echo (see WHOI’s Listening for Telltale Echoes from Fish).
Internal anatomy of a boney fish. From Wikipedia (CC BY-SA 3.0).
The sound pulses travel down into the water column, illustrated by the white cones here, and bounce back when encountering resistance.(from NOAA Fisheries)
NOAA Fisheries uses echo sounding, which works by emitting vertical pulses of sound (often referred to as pings), and measuring the return strength and recording the time for the signal to leave and then return. Anything having a different density from the surrounding water (in our case – fish, plankton, air bubbles, the seafloor) can return a signal, or “echo”.
The strength or loudness of the echo is affected by how strongly different ocean elements reflect sound and how far away the source of the element is. The seafloor usually makes the strongest echo because it is composed of rock which has a density different than the density of water. In fish, the swim bladder provides a contrast from the water. In addition, each fish species has a unique target strength or amount of sound reflected to the receiver. The size and shape of the swim bladder influence the target strength. There is a different target strength to length relationship for each species of fish – the larger the fish, the greater the strength of the returning echo.
It’s important to note that echo sounders cannot identify fish species, directly or indirectly. The only way we know which fish species is causing a signal is based on trawl catch composition. There is nothing within the acoustic data that lets us identify fish species, even with the catch data. This is a subtle, but important, distinction. Acoustic data, particularly calibrated acoustic data, in tandem with the information from the trawl, definitely allows us to count fish.
Where is the echo sounder on Oscar Dyson? Look at the figure in the next section of this post – it’s a sketch of NOAA Ship Rainier, but the placement of the echo sounder is the same for Dyson. You can see a rectangular “board” that is extended down from the center of the ship. This is called – what else – the center board! Attached to the bottom of the center board are the echo sounders. When lowered, the echo sounders sit at 9 meters below the level of the sea (~4 meters below the bottom hull of the ship).
Did you know… Southern Resident killer whales use their own echolocation clicks to recognize the size and orientation of a Chinook’s swim bladder? Researchers report that the echo structure of the swim bladders from similar length but different species of salmon were different and probably recognizable by foraging killer whales. (reported in Au et al., 2010)
It starts with a calibration
Typical setup of the standard target and weight beneath the echo sounder.(from NOAA Fisheries)
Before we can begin collecting data, we need to calibrate the echo sounder. The calibration involves a standard target (a tungsten carbide sphere) with a known target strength. The calibration needs to be completed in waters that are calm and without significant marine life for the best results.
The sphere is suspended below the ship’s hull using monofilament lines fed through downriggers attached to ship railings. One downrigger is in line with the echo sounder on the starboard side, and the other two on the port side. This creates a triangle that suspends the sphere in the center of the echo sounder’s sound beam. By tightening and loosening the lines, the sphere can be positioned under the center of the sound beam and can also be moved throughout the beam. By doing an equipment calibration at the beginning and end of a survey, we can ensure the accuracy of our data.
One of the port side downriggers
A weight that goes at the bottom of the filament to ensure the calibration sphere remains below the echo sounder
The tungsten carbide sphere attached to the line, being lowered over the side
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, Western Gulf of Alaska Location (2PM (Alaska Time), June 15): 53o 38.9534′ N, 166o 10.9927′ W
Data from 2PM (Alaska Time), June 15, 2023 Air Temperature: 8.74 oC Water Temperature (mid-hull): 6.2oC Wind Speed: 3.55 knots Wind Direction: 310.61 degrees Course Over Ground (COG): 64.09 degrees Speed Over Ground (SOG): 11.61 knots
And now, it’s time for some science and surveying! Before I dive into the specifics of the methods we are carrying out on Oscar Dyson, I’m sharing this incredibly helpful NOAA Fisheries page that summarizes their Research Surveys, where “Our scientists and partners collect data on the water, from aircrafts, and from shore to understand the abundance, distribution, and health of marine life and habitats. That data forms the scientific foundation for our management and conservation work.”
There is also an informative podcast episode, Learn About NOAA Fisheries Surveys (transcript available at link). This podcast covers the need for sustainable fisheries, the 2013-2016 North Pacific Blob, how surveys were done historically, how surveys are using new technology, the impact of the pandemic, and the concept of being in a “stationary” versus “non-stationary” world. Such a fascinating listen!
First episode of “Dive In with NOAA Fisheries,” titled Learn About NOAA Fisheries Surveys
There is another podcast episode from the same series that is an excellent follow-on from the episode available above. Surveying Alaska’s Waters (transcript available at link) shares how surveys are a tools that allow NOAA to reach its mission, whether those measurement techniques come from satellites, autonomous vehicles, buoys, ships, drones, etc. Although these tools assist NOAA scientists in collecting data, climate change is playing an even bigger role in making ecosystem management a moving target. Again – worth a listen!
Third episode of “Dive In with NOAA Fisheries,” titled Surveying Alaska’s Waters
Surveys in the Gulf of Alaska
Trawl surveys have been conducted by Alaska Fisheries Science Center (AFSC) beginning in 1984 to assess the abundance of groundfish in the Gulf of Alaska (2021 Stock Assessment Report, p. 9). Starting in 2001, the survey frequency was increased from once every three years to once every two years on odd-numbered years. This is a flyer that describes the biennial bottom trawl survey in the Gulf of Alaska 2023.
The strategy of combining trawl and acoustic surveys was developed by AFSC and the University of Washington. They published a paper in the Canadian Journal of Fisheries and Aquatic Sciences (Kotwicki et al., 2018) that discusses the need to perform acoustic-trawl (AT) and bottom-trawl (BT) surveys to accurately estimate the abundance of fish populations along with their spatial distribution. I’ve provided below part of a news release from the University of Washington describing the content of the publication:
Many species of fish spend some of the time on the ocean bottom, and some of their time far off the bottom, which makes them hard to survey. Acoustic surveys (that bounce sound off fish schools), can estimate the midwater component of so-called “semipelagic” fish, while trawl surveys can measure the portion on the bottom. Now a new method has been developed that combines data from both types of surveys into a single estimate using information about the environment (bottom light, temperature, sand type, and fish size). The new method has been used to assess the status of walleye pollock, which sustains the largest fishery in the United States.
This image from Kotwicki et al., 2018, does an excellent job of showing the two types of survey methods, acoustic and bottom trawling.
Fig. 1. Illustration of conceptual model of walleye pollock sampling by an echo sounder and a bottom trawl. Note that acoustic data are collected directly under the survey vessel, while the bottom trawl catches walleye pollock some distance behind the vessel. Diving occurs in the time between the vessel passing over the school of walleye pollock and the trawl catching the same school. Source: Kotwicki et al. 2018.
What is different for my current expedition is that we are not doing any bottom trawling. We are doing the acoustic piece of the survey and trawling off the bottom. Separate surveys and ships are collecting the bottom data, and then will be combined with our data to provide a more accurate snapshot for the water column for the annual Stock Assessment Report for Walleye Pollock. AT and BT surveys get NOAA to their research objective: informing fish stock assessment models and catch allocation. NOAA publishes an annual 100+page Assessment of the Walleye Pollock Stock in the Gulf of Alaska from the surveys conducted each year (see reports from 2019, 2020, 2021).
To prepare to sail on Leg 1 of the Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska, I did a lot of reading and preparation so I could better understand what I would be learning, and how I could then connect the material with my students and additional audiences I see post-expedition. These two books in the image below helped give me a much better picture of not only walleye pollock but the fisheries industry, policy, and practices over time and space.
Each of these books provides some fascinating insight into the history, thought, and even debates, about the nature of ocean resources.
The title of Chapter 4 in Kurlansky’s book gives a hint for how to respond to my questions: “Being The Myth of Nature’s Bounty And How Scientists Got It Wrong For Many Years.” Early in the chapter, Kurlansky states:
“In the 1800s, when the study of fish and oceans was a relatively new science, it was the fishermen who were afraid that fish populations could be destroyed by catching too many fish, especially small fish. Scientists at the time believed that it was impossible to catch too many fish because fish produced so many eggs.” — World Without Fish, p. 53
One of the causes of concern for fishermen was the new technology developing – specifically, engine power, that allowed for even more fish to be caught.
“I believe that it may be affirmed with confidence that, in relation to our present modes of fishing, a number of the most important sea fisheries… are inexhaustible… and probably all the great sea-fisheries, are inexhaustible; that is to say that nothing we do seriously affects the number of fish. And any attempt to regulate these fisheries seems consequently… to be useless.” (*feel free to dive into Huxley’s speech to see his reasoning – the multitudes of fish available, and the destruction is minimal)
Then Lankester gave the final summary speech of the Exhibition – a rebuttal to Huxley. Lankester made the point that the fish in the sea are not unlimited, and captured fish are not readily replaced by others that exist further offshore from the fishing location. He raised the concern that the removal of the parents by fishing was going to impact the production of the young.
Although at the time many gave Huxley the victory in this debate, Huxley did not take into account the new development that I mentioned above – the modern trawl and the steam trawler to pull it, resulting in larger nets and catches. It’s interesting to note that eventually, Huxley studied the impact from engine-driven net draggers and changed his story. Huxley eventually agreed that overfishing was not only possible, but that it was happening.
Now to circle back to why we survey fisheries… it ultimately comes down to ecosystem management. As described in the two audio files at the top of this blog post and in my other posts, as well as the title to Chapter 8 in Kurlansky’s book, “The Best Solution To Overfishing: Sustainable Fishing.” And to engage in sustainable fishing, you need the data to make that happen – hence, fisheries surveys!
