TDR – NOAA Teacher at Sea Blog

June 2, 2014August 21, 2021

Spencer Cody: Science at Sea, June 1, 2014

NOAA Teacher at Sea

Spencer Cody

Aboard NOAA Ship Pisces

May 27 – June 11, 2014

Geographical Area of Cruise: Gulf of Mexico

Mission: SEAMAP Reef Fish Survey

Date: June 1, 2014

Observational Data:

Latitude: 27˚ 50.503 N

Longitude: 93˚ 46.791 W

Air Temp: 26.3˚C (79.3˚F)

Water Temp: 23.3˚C (73.9˚F)

Ocean Depth: 126.8 m (416 ft.)

Relative Humidity: 84%

Wind Speed: 7.8 kts (9.0 mph)

Barometer: 1,009.5 hPa (1,009.5 mbar)

Science and Technology Log:

It was not until the Pisces arrived at its first survey area off the coast of Texas that I was able to appreciate the volume of scientific data collection that this vessel could collect. It took most of the 27^th and all of the 28^th to arrive at our initial survey area. While in transit, the Pisces is constantly collecting data. Data such as air temperature, wind direction, relative humidity, wind speed, and barometric pressure are recorded and periodically reported back to NOAA and the National Weather Service and from other marine vessels to improve data on meteorological events in the Gulf and weather forecasts.

In addition to collecting meteorological data, the Pisces uses a fishery acoustics system called the ER-60 to track depth and various sea floor features. This system can also be used to monitor biomass such as fish, coral, and even plankton. Once we arrived at our initial survey area within the SEAMAP survey grid, the amount of science conducted increased dramatically. In the survey areas, the camera array is dropped to the sea floor to survey fish populations. In most cases we are looking at fish habitat from 50 to 120 m deep. Video and still photos are taken of fish attracted to the bait bag filled with squid. To ensure that sampling is both consistent and unbiased for the survey, pictures and video are pulled at random from all four cameras on the camera array. It is important that the same procedures are carried out throughout the SEAMAP survey gird concerning data collection in order to be able to reliably compare different survey areas and track species development and abundance.

In order to assist the camera array in obtaining accurate information about precisely how deep the camera array is when it is recording fish population data, a Temperature Depth Recorder or TDR is attached to the camera array to compare position in the water column to what the ship’s fishery acoustics system is displaying. This is necessary in case the camera array has fallen off an underwater cliff or is hung up on some other topographic feature.

106_0233 — The Conductivity Temperature and Depth or CTD submersible probe can measure the salinity of the water, temperature, pressure, plankton concentrations, dissolved gases, and water samples at different depths.

The Conductivity Temperature and Depth submersible aids the ship’s acoustic equipment in determining an accurate depth of the ocean bottom. Since sound travels at different velocities in water that has different densities and temperatures, information regarding the salinity and temperature of the water must be fed into the ship’s fishery acoustics system to calibrate the system for it to accurately read the bottom depths. If temperature or salinity are not taken into account, the depth will either be too shallow or too deep compared to the true value.

The Pisces not only has the ER-60 for fishery acoustics, but it also has a state of-the-art multi-beam echo sounder, the ME-70, that has 27 transducers that are aligned in a configuration allowing for scans of wide swaths of the ocean bottom. In fact, the Pisces has engines that are specifically designed to run quietly enough to accommodate such advanced acoustic equipment. The ME-70 is used for mapping various sample areas of the SEAMAP survey.

While the camera array can be used to measure the length of some of the fish viewed, it cannot reliably determine characteristics such as age or sex. Determining age or sex just through appearance can be very tricky in the Gulf and is frequently unreliable. Many species of fish will grow at different rates depending on available forage and other environmental factors. This is an issue that is also commonly encountered among freshwater fish in South Dakota. Complicating fish characteristics even further, many reef fish are one or the other sex at different phases of their lives. They are not strictly male or female but change roles depending on complex physical or environmental factors. With so many factors complicating these characteristics, live catches are necessary to determine the full story of what is going on with reef fish in the Gulf.

For live catches we use bandit reels. Bandit reels are similar in concept to a standard fishing rod and reel except they are built for heavy duty sea fishing. The reel and rod are attached to the side of the ship. One hundred pound test line is used with a five pound sinker weight. Each line for the bandit reels has ten hooks, a small float that keeps the hooks in a vertical column, and a large float that keeps the ten hooks just above the ocean bottom.

Again, in order to guard against bias in the results, we use the bandit reels with a set procedure. For our survey we are using three bandit reels at a time each with ten hooks. The bandit reel stations are in radio communication with the dry lab, where the chief scientist is coordinating the sampling, and the bridge, which is keeping the ship in position for the lines preventing lines from running under the ship. Since we want to be as objective as possible without contributing to any type of bias in the sampling, each line was in the water for exactly five minutes. Even though it may have went against every natural inclination of most fishermen and fisherwomen, we were not allowed to jig our lines or do anything that might attract more fish to our bait. In addition to standardizing the number of hooks and the length of time spent fishing, three different sizes of hooks are used and rotated out from each bandit reel station; consequently, one of each of the three hook sizes is always being used for each survey area.

105_0180 — White, nickel-sized disk-like structures called otoliths can reliably age fish. They are inner ear structures that grow in size as a fish ages allowing calcium carbonate deposits to form over the course of its life. Scientists can read these calcium carbonate deposit rings like rings in a tree to determine the age of the fish. Credit Harriet Nash for the photo.

107_0275 — After all the measurements are taken of the fish and their otoliths and gonads have been sampled, the information must be added to the database for use in the SEAMAP Survey. Credit Adam Pollack for the photo.

After five minutes of fishing, the lines are brought up and fish are tagged one through ten to keep fish identified with a specific hook and depth. The tagged fish are then taken to the wet lab for measurement readings. In the wet lab, fish length, weight, sex, and phase of reproductive development are recorded. Since reproductive development, and sometimes even sex, can be difficult to determine, a sample of each fish’s gonads (ovaries or testes) are removed and placed in a labeled specimen vial for confirmation in the lab back on land. The otoliths (inner ear bones) are removed from the fish, as well, in order to reliably age the fish back in the lab. Once the measurements are recorded, they need to be added to the database to be compiled with the gonad and otolith specimens. This is just a small piece of the monitoring that is occurring in the Gulf through NOAA. The Gulf of Mexico is a remarkably diverse expanse of ocean and requires significant scientific research in order to understand and track fish populations and the habitat and forage that sustain them. Without these types of intensive scientific studies on the ocean, we could not possibly manage or attempt to conserve a natural resource that we would, otherwise, have little to no understanding of.

Personal Log:

Since we had arrived off the coast of Texas a couple of days ago, we have been slowly back tracking to Pascagoula as we go through our survey areas. The weather has been beautiful the last couple of days; however, sea swells do cause the boat to jostle around a bit. Each day we see more species on the surface of the water and through our camera array under the water. Since the science log is rather long for this post, I will talk more about life at sea and the different types of organisms we are encountering in future posts.

Did You Know?

Fish identification can be a tricky business in the Gulf of Mexico. Many species of Gulf fish alter their physical appearance depending on their reproductive development, environmental factors, or phase of physical development. Fish will even appear to have different patterns depending on whether they are viewed under our out of water.

July 9, 2010April 22, 2021

Elizabeth Warren, July 9, 2010

NOAA Teacher At Sea: Elizabeth Warren
Aboard NOAA Ship Pisces

Mission: Reef Fish Surveys
Geographical Area of Cruise: Gulf of Mexico
Date: July, 9 2010

Getting into it!

Weather Data from the Bridge:
Temperature: Water: 30.5℃ Air: 29.6 ℃
Wind: 2 knots
Swell: .3 meters
Location: 27. 51° N, 91.48° W
Weather: Sunny, Humidity 70%, light clouds

Science/Technology Log
Today we began the SEAMAP Reef Fish Survey.
A little background information: The surveying began in 1992 through now with a few years with no data in the middle where there wasn’t enough funding or boat time. The survey is conducted to show what types of species of fish live around the different types of topographical locations on the seafloor, specifically around the continental shelf (think about the sea floor as if it is a continent, there are mountain ranges, plains, banks, ledges, etc). The survey runs from Brownsville, TX to the Dry Tortuga’s, FL. Currently, I am on the second leg of the survey. The first leg was two and half weeks.

The areas that are surveyed are called blocks they are 10 by 10 nautical miles, these sites are selected randomly from previous bathymetric data, this is the mapping that we did yesterday. At each site an aluminum four stereo camera array and a Seabird 911 CTD is dropped, more information about this tomorrow. The camera pod, which NOAA actually makes in their lab, is composed of specially designed housing units that include two black and white still cameras that take pictures like you would blink your eyes, as well as a color mpeg camera that runs continuously.

Attached to the aluminum casing is a Temperature Depth Recorder (TDR), more about this later. At each site the pod is dropped over the side of the ship using a hydraulic side A-frame. The camera is left in the water for 45 minutes, once the camera is at the seafloor it begins to record. Throughout the day the cameras save their data to the 180 GB hard drive, all of the day’s drops are then downloaded onto an 2 TB external hard drive and burned to a blue ray disc during the night. This disc is briefly observed by the chief scientist and then later taken back to the onshore lab to identify and count all species of fish.

Also throughout the day, 4 sites are randomly chosen to drop either a bandit reel or a chevron fish trap. This random selection is done very scientifically. One scientist asks another to pull up a randomly created number table on the computer, the person at the computer wiggles the mouse and closes his eyes and then calls out one of the numbers that corresponds with the site numbers. A chevron fish trap which is a large wire cage is baited with squid, (Yes!) then left at the site to soak for an hour.

A bandit reel is a vertical line with ten evenly spaced hooks baited with mackerel. The line is lowered to the sea floor and soaked in for ten minutes. When these fish are brought on board they are weighed, measured, cataloged, and some are frozen to preserve for further research. On this survey groupers, trigger fish, and snapper are frozen and taken back for baseline testing by National Seafood Inspection Laboratory.

Today we were sampling at Sweet Bank. All together we dropped the camera at 7 different sites throughout this block. Science out at sea is 10 minutes of a lot of excitement followed by an hour of waiting. For the first site I observed from inside the lab, watching as they dropped the camera and brought it back up. The first site was early in the day so when they pulled the camera’s up they found that they couldn’t see anything because the light had not yet penetrated to the ocean floor. At the second site I had my first job, I was to go out after they pulled the camera, turn it off, then turn the other knob to configure then turn the camera back on. I was so nervous that I turned the second knob to configure then back to record! Oops!

We also dropped the first chevron trap of the day. While the trap was soaking we moved to the third site and dropped the camera. We went back to the fish trap to pick it up. When you go out and there are hydraulic A-frames working you have to wear a hard hat and aPDF (Personal Floatation Device).

Bob Carter, the electronics technician lent me his helmet. When Captain Jerry was on deck he took issue with the design on the helmet. Anne-Marie and I got all ready and watched as they pulled up an empty fish trap, something had eaten the bait but they escaped capture. We were all dressed up with no fish to go! When we went back in the labs Kevin explained to us that one of the hardest things to learn as a scientist is that zero is a number. Even though it was disappointing that the trap came up empty it did mean something to the data.

We moved on to pick up the camera at the fourth site. At the fourth site we also did a bandit reel. I have no problem getting a little dirty so I helped bait the bandit reel. You have to put the hook through the bait then turn it and pull the hook through again. I got pretty fishy! We waited with baited breath to see if what we could pull up. The crew pulled up the bandit reel and there were two enormous fish caught on the reel. One was red snapper (Lutjanus campechanus) and the other was a red porgy (Pagruspagrus).

We took the fish into the wet lab and measured them. There are three different ways to measure the fish. First you measure the total length which is to the end of the tail. Then you measure the forked length which is to the fork of the tail. Then you measure the standard length which is to the end of the hyplural plate at the end of the vertebrae. Then, the fish is weighed on a scale. All of this is done using the metric system. ( Ahh hah! There is a reason I teach the metric system of measurement! ) Lastly, Joey Salisbury, the watch leader for the scientist crew, checked to see what the sex of the two fish were. With the porgy he could cut him open and check the sex because he wasn’t being kept for Seafood Inspection, another way to tell the sex on some species that are dimorphic ordichromatic, is to look at the color of their lips . For the red snapper, since it had to be kept for inspection we were not able to tell what the sex was.

After some cajoling Joey also agreed to pull the otoliths (ear bones) of the porgy for me so I could bring them back to my class. You can tell the age of the fish from their ear bones, you stain them and count the rings just like you would for a tree.

While all of this was happening on deck, in the lab the bathymetric mapping was noticing an odd mass, that was eating up everything and leaving behind blank space. Kevin decided to run an oil soaking rag down on the bandit reel to test if the mass was oil. Thankfully, when he pulled the rag back up it was oil free! We decided that the mass on the screen must have been a school of fish.

At each site we were able to do a little bit more of the science. I was able to weigh and measure the second set of fish from the last bandit reel. The fish were so heavy, and they move. I did squeal a little but I’m proud to say I did not scream! The spines on the snapper’s dorsal fin could poke holes in you, so I had to be careful when I picked her up. We could tell she was a female because when we pulled her up the change in pressure blew her air bladder and pushed her ovaries came out. (I know , I know, but remember this is in the realm of science so you all should be saying “how interesting” no ewws out there. )

Personal Log:

Where to start! Yesterday really felt like three days in one. All of the science is so interesting. I keep asking a billion questions and everyone is a hundred percent willing to answer every one. Their patience is greatly appreciated since for every answer they give me I come up with 50 more questions to clarify their answers. They were also extraordinary patient when I made a mistake. I was so embarrassed and worried that I had somehow messed up the video feed! They assured me that I hadn’t messed it up, but for the rest of the day Joey, the watch leader, gave me a hard time about knobs, hatches, and doors. The hatches and doors are incredibly heavy so I have to stop and really pull whenever I go into any hallway, and closing the hatches requires me to have nothing in my hands. At one point during the day I got confused as to which way to turn the hatch, and the crew kept telling me to pull the wrong way.

Everyone jokes constantly and you have to go with the flow and be a quick. Attempting to come up with comebacks is keeping me on my toes. As most of you know I’m willing to get dirty so any job that dealt with touching things I’m all over it. Baiting the bandit reel and the chevron fish trap were gooey and squishy and I was covered in fish guts and squid parts by the end of the day. I couldn’t have been more thrilled to be smelly and gross! It was pretty funny that they put me in the Cowboys helmet, you know cause you know I watch so much football. Captain Jerry threatened to throw it overboard because he is a Saints fan. The first two days we were conserving water while we were in possible oil impacted waters; today we were given the go ahead to take what the captain called “rock star showers”. Boy, was I in need of one today, at the end of the day I even had a streak of grease up my leg!

The crew is hilarious! They are constantly working everywhere you go. I go down one passageway and they are mopping, another they are vacuuming, down the ladder well and I run into someone sweeping. Think about how important it is to keep the ship clean. As we were standing waiting for the bandit reel to come up one of the crew started to fish with a line and a hook right off the side of the boat.

When they threw the fish heads in from the cut up mackerel they caught a bunch of blue runners (Caranx crysos). I even managed to catch one! I was okay trying to kiss the fish..until he tried to kiss back!

At the end of the day, Anne Marie and I went out to the back deck to try and work on our logs but the crew was out their fishing. One of the crew, Ryan, caught a 55 lb greater amberjack (Seriola dumerili) and then turned around and caught another one that was just a little bit smaller! The big one was almost as long as I am tall! The Junior Officer Kurt caught a yellow-edge grouper, which Kevin pulled the otoliths out of for me and Anne-Marie. Every other minute another of the crew would catch another fish. I didn’t get much of my log done I was so distracted by the different fish they kept catching.

I’m leaving so much out, but I’ll include more in my next log.