Cristina Veresan, Lights, Camera, Ocean! August 13, 2015

NOAA Teacher at Sea
Cristina Veresan
Aboard NOAA Ship Oscar Dyson
July 28 – August 16, 2015 

Mission: Walleye Pollock Acoustic-Trawl survey
Geographical area of cruise: Gulf of Alaska
Date: Wednesday, August 13, 2015

Data from the Bridge:
Latitude: 59° 18.31’N
Longitude: 141° 36.22’W
Sky: Overcast
Visibility: 10 miles
Wind Direction: 358
Wind speed: 8 knots
Sea Wave Height: < 1 feet
Swell Wave: 2-3 feet
Sea Water Temperature: 16.2°C
Dry Temperature: 15°C

Science and Technology Log

When my shift begins at 4am, I often get to participate in a few “camera drops” before the sun comes up and we begin sailing our transect lines looking for fish. We are conducting the “camera drops” on a grid of 5 km squares provided by the Alaska Fisheries Science Center bottom trawl survey that shows whether the seafloor across the Gulf of Alaska is “trawlable” or “untrawlable” based on several criteria to that survey. The DropCam footage, used in conjunction with a multi-beam echosounder, helps verify the “trawlability” designation and also helps identify and measure fish seen with the echosounder.

The Drop Camera being deployed

The DropCam is made up of strobe lights and two cameras, one color and one black and white, contained in a steel frame. The cameras shoot in stereo, calibrated so scientists can get measurements from rocks, fish, and anything else on the images. When the ship is stopped, the DropCam can be deployed on a hydrowire by the deck crew and Survey Tech. In the Chem Lab, the wire can be moved up and down by a joystick connected to a winch on deck while the DropCam images are being viewed on a computer monitor. The ship drifts with  the current so the camera moves over the seafloor at about a knot, but you still have to “drive” with the joystick to move it up and down, keeping close to the bottom while avoiding obstacles. The bottom time is 15 minutes for each drop. It’s fun to watch the footage in real-time, and often we see really cool creatures as we explore the ocean floor! The images from the DropCam are later analyzed to identify and length fish species, count number of individual fish, and classify substrate type.

Emily “drives” the camera from the Chem Lab as the sun begins to rise
DropCam images (clockwise from top left) a skate, brittle stars, a cruising halibut, two rockfish in rocky habitat

Technology enables scientists to collect physical oceanographic data as well. The Expendable Bathythermograph (XBT) is a probe that is dropped from a ship and measures the temperature as it falls through the water column. The depth is calculated by a known fall rate. A very thin copper wire transmits the data to the ship where it is recorded in real-time for later analysis. You launch the probe from a hand-held plastic launcher tube; after pulling out the pin, the probe slides out the tube. We also use a Conductivity Temperature Depth (CTD) aboard the Oscar Dyson; a CTD is an electronic device used by oceanographers to measure salinity through conductivity, as well as temperature and pressure. The CTD’s sensors are mounted on a steel frame and can also include sensors for oxygen, fluorescence and collecting bottles for water samples. However, to deploy a CTD, the ship must be stopped and the heavy CTD carousel lowered on a hydrowire. The hand-held XBT does not require the ship to slow down or otherwise interfere with normal operations. We launch XBT’s twice a day on our survey to monitor water temperatures for use with the multi beam echosounder.

Cristina launching the XBT probe Photo by Alyssa Pourmonir
Survey Tech Alyssa servicing the CTD carousel














Shipmate Spotlight: An Interview with Ensign Benjamin Kaiser

Ensign Benjamin Kaiser, NOAA Corps

Tell me a little more about the NOAA Corps?
We facilitate NOAA scientific operations aboard NOAA vessels like hydrographic work making charts, fisheries data collection, and oceanographic research.

What do you do up on the bridge?
I am a Junior Officer of the Deck (JOOD), so when I am on the bridge driving the ship, I am accompanied by an Officer of the Deck (OOD). I am on my way to becoming an OOD. For that you need 120 days at sea, a detailed workbook completed, and the Commanding Officer’s approval.

What education or training is required for your position?
I have an undergraduate degree in Marine Science from Boston University. My training for NOAA Corps was 19 weeks at the Coast Guard Academy in New London, Connecticut– essentially going through Coast Guard Officer Candidate School.

What motivated you to join the NOAA Corps?
A friend of mine was an observer on a fisheries boat, and she told me about the NOAA Corps. When I was in high school and college, I didn’t know it was an option. We’re a small service, so recruiting is limited; there’s approximately 320 officers in the NOAA Corps.

What do you enjoy the most about your work?
I love not being in an office all the time. In the NOAA Corps, the expectation is two years at sea and then a land assignment. The flexibility appeals to me because I don’t want to be pigeonholed into one thing. There are so many opportunities to learn new skills. Like, this year I got advanced dive training for Nitrox and dry suit. I don’t have any regrets about this career path.

What is the most challenging part of your work?
There’s a steep learning curve. At this stage, I have to be like a sponge and take everything in and there’s so much to learn. That, and just getting used to shipboard life. It is difficult to find time to work out and the days are long.

What are your duties aboard the Oscar Dyson?
I am on duty 12pm to midnight, rotating between working on the bridge and other duties. I am the ship’s Safety Officer, so I help make sure the vessel is safely operating and coordinate drills with the Commanding Officer. I am also the Training Officer, so I have to arrange the officers’ and crew members’ training schedules. I am also in charge of morale/wellness, ship’s store, keys, radios, and inspections, to name a few.

When did you know you wanted to pursue a marine career?
I grew up in Rhode Island and was an ocean kid. I loved sailing and swimming, and I always knew I would have an ocean-related career.

How would a student who wanted to join the NOAA Corps need to prepare?

Students would need an undergraduate degree from a college or university, preferably in a STEM field. Students could also graduate from a Maritime Academy. When they go to Officer Candidate School, they need to be prepared for a tough first week with people yelling at them. Then there’s long days of working out, nautical science class, drill work, homework, and lights out by 10pm!

What are your hobbies?
I enjoy rock climbing, competitive swimming, hiking, and sailing.

What do you miss most while working at sea?
There’s no rock climbing!

What is your favorite marine creature?
Sailfish because they are fast and cool.

Inside the Oscar Dyson: The Chem Lab


This lab is called the Chem Lab (short for Chemical). For our survey, we don’t have that many chemicals, but it is a dry lab with counters for workspace when needed. This room is adjacent to the wet lab through a watertight door, so in between trawls, Emily and I spend a lot of time here.  In the Chem Lab, we charge batteries for the CamTrawl and the DropCam. There are also two computer stations for downloading data, AutoLength analysis, and any other work (like blogging!). There is a window port to the Hero Deck, where the CTD and DropCam are deployed from. In the fume hood, we store Methot net samples in bottles of formalin. There is a microscope for viewing samples. Note the rolling chairs have their wheels removed and there are tie-downs on cases so they are safer at sea. Major cribbage tournaments are also played in this room!

Personal Log

It has been so calm on this cruise, but I have to say that I was looking forward to some bigger waves! Well, Sunday night to yesterday afternoon we experienced some rain and rough seas due to a nearby storm. For a while the ship would do big rolling motions and then a quick lurchy crash. Sea waves were about 2 feet in height, but the swell waves were over 5 feet at times. When I was moving about the ship, I’d have to keep a hand on a rail or something else secured. In the wet lab while I was working, I would lean against the counter and keep my feet spread apart for better balance.

Seas picked up and the ship was rocking and rolling!

Remember the Methot net? It is the smaller net used to catch macroplankton. We deployed one this week and once it came out of the water, it was rinsed and the codend was unscrewed. When we got the codend into the wet lab, we realized it was exclusively krill!

The Methot net is deployed by the Survey Tech and deck crew members

Krill are  small crustaceans that are found in all the world’s oceans. Krill eat plant plankton (phytoplankton), so they are near the bottom of many marine food chains and fed on by creatures varying from fish like pollock to baleen whales like humpbacks. They are not so small that you need a microscope to see them, but they are tiny. We took a subsample and preserved it and then another subsample to count individuals…there were over 800 krill in just that one scoop! Luckily, we had them spread out on a board and made piles of ten so we did not lose count. It was tedious work moving individual krill with the forceps! I much prefer counting big things.

I love it when there is diversity among the catch from the AWT trawls. And, we caught some very memorable and unique fish this week.  First was a beautiful Shortraker Rockfish (Sebastes borealis). Remember, like the Pacific Ocean Perch, its eyes bulge when its brought up from depth. The Shortraker Rockfish is an open-water, demersal species and can be one of the longest lived of all fish. There have  been huge individuals caught in Alaskan waters that are over 100 years old. This fish was not particularly big for a Shortraker, but I was impressed at its size. It was probably my age.

Holding a Shortraker Rockfish. Photo by Emily Collins
Smooth Lumpsucker fish: so ugly it’s cute?! Photo by Mackenzie Wilson

We also caught a Smooth Lumpsucker (Aptocyclus ventricosus). It was inflated because it was brought up from depth, a form of barotrauma. This scaleless fish got its name for being shaped like a “lump” and having an adhesive disc-shaped “sucker.” The “sucker,” modified pelvic fins, are located ventrally and used to adhere to substrate. These pelagic fish are exclusively found in cold waters of the Arctic, North Atlantic, and North Pacific. The lumpsucker fish, and its roe (eggs) are considered delicacies in Iceland and some other countries.

You can see the “sucker” on the bottom of its body. Photo by Mackenzie Wilson

Pollock are pretty slimy and they have tiny scales, so when we process them, everything gets covered with a kind of speckled grey ooze. However, when we trawled the other day and got a haul that was almost entirely Pacific herring (Clupea pallasii), I was amazed at their scales. For small fish, the herring had scales that were quite large and glistened like silvery sequins. The herring’s backs are an iridescent greenish-blue, and they have silver sides and bellies. The silver color comes from embedded guanine crystals, leading to an effective camouflage phenomenon in open water.

As this last week comes to a close, I am not ready to say goodbye…

Herring scales are nature’s sequins

Julia Harvey: Working on the Night Shift (During Shark Week), August 5, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013     

Mission:  Walleye Pollock Survey
Geographical Area of Cruise:  Gulf of Alaska
Date:  8/5/13 

Weather Data from the Bridge (as of 17:00 Alaska Time):
Wind Speed:  9.54 knots
Temperature:  15.7 C
Humidity: 83 %
Barometric Pressure:  1017.9 mb

Current Weather: The winds have decreased and we are not moving as much.  The weather report calls for an increase to the winds with 7 ft swells on Wednesday.  But maybe it will die down before it reaches us.

August 6th sunset
August 6th sunset

Science and Technology Log:

We only will fish during daylight hours.  The sun is now setting before 10:00 pm and rising around 5:30 am.  And even though we are not fishing between sunset and sunrise, science continues.  At nightfall, we break transect and Jodi begins her data collection.

The Sustainable Fisheries Act mandates an assessment of essential fish habitat.  This is in conjunction with stock assessments of groundfish.   Jodi’s research involves integrating multibeam accoustic technology to characterize trawlable and untrawlable seafloor types and habitat for managed species.

Species that are part of the groundfish survey.
Species that are part of the groundfish survey.
Photo courtesy of Chris Rooper (Alaska Fisheries Science Center) from the Snakehead Bank multi-beam survey

A bottom trawl survey is conducted every other year in the Gulf of Alaska.  The goal is to better identify seafloor types using multibeam acoustics.  This would help improve groundfish assessment, and limit damage to habitat and trawling gear.

The Gulf of Alaska survey area is divided into square grids.

Trawlable or Untrawlable?
Trawlable or Untrawlable?

On this cruise we are conducting multibeam mapping in trawlable and untrawlable grid cells.  A grid cell is divided into 3 equidistant transects for a multibeam survey.  Jodi directs the ship to follow these smaller transect lines.  While the ship is following the transects lines, the multibeam sonar is active and data is collected.

Multibeam sonar
Multibeam sonar
Photo courtesy of Tom Weber (University of New Hampshire)
Jodi monitors the screen during ME70 activity.
Jodi monitors the screen during ME70 activity.

The SIMRAD ME70 is the multibeam sonar that Jodi is using for her research.  There are 6 transducers on the ship that will send out a fan of 31beams of varying frequencies.  The strength of their return (backscatter) can be analyzed for sea floor type.  Looking at the diagram below, you can see the differences in backscatter clearly in the range of 30 to 50 degrees (away from straight down).

Illustration of the multi-beams generated. photo courtesy of
Illustration of the multi-beams generated.
photo courtesy of

Silts will have a very weak backscatter and rock will have a strong backscatter.

Substrate differences when looking at 30 - 50 degrees. Courtesy of Jodi Pirtle
Substrate differences when looking at 30 – 50 degrees.
Courtesy of Jodi Pirtle

After the transects are completed,  Jodi and Darin complete 1 – 3 camera drops to record visually how the seafloor appears.  This camera below will be lowered to the ocean floor and video footage will stream to the computer for 10 minutes.  Then the camera is brought up.

Drop Camera
Drop Camera

An example of an untrawlable area. Photo courtesy of Jodi Pirtle
An example of an untrawlable area.
Photo courtesy of Jodi Pirtle.

Last night, Darin gave me the opportunity to operate the camera drop.  After a bit of instruction, it was showtime.  I am very grateful for the chance to explore the seafloor.

I operated the drop camera.   Photo by Darin Jones
I operated the drop camera.
Photo by Darin Jones

Here is what I saw at 190 meters.

Fish and rocks on the seafloor.
Fish and rocks on the seafloor.
I saw a flatfish right in front of the camera.
I saw a flatfish right in front of the camera.

For more photos of my drop camera experience, see the end of this blog.

CTD (conductivity, temperature, depth) drops are conducted in the grid as well.  Data that are gathered are used to correct for the speed of sound under varying conditions of the ocean.

CTD drop to record physical oceanographic data
CTD drop to record physical oceanographic data

The next day, Jodi processes the data from the ME70.  The bottom detection algorithm (a series of calculations) removes backscatter from the water column (from fish).

Each frame product represents 5 minutes of seafloor.  The following are outcomes from the algorithm and represent angle dependent data.  The images below, show backscatter on the left and bathymetry on the right.

This represents a homogenous sea floor.
This represents a homogenous sea floor.
This represents a heterogenous sea floor.
This represents a heterogenous sea floor.

Then Jodi takes into account a number of factors such as results from the CTD, motion of the boat (offset, attitude, pitch, roll), and tides.  These uncertainties are applied.

Uncertainties Photo courtesy of NOAA
Photo courtesy of NOAA

Then she mosaics the data.

Result from Jodi's data.
Photo courtesy of Tom Weber

The color image above represents the depth and the bottom image provides information on seafloor substrate.

The footage from the camera drops is also reviewed for more evidence of the seafloor substrate and to look for objects that would snag trawl nets.

I really appreciate Jodi taking the time to educate me on her research.  Her passion for her work is evident.  I look forward to seeing where her research leads.

Personal Log:

So who actually works the night shift (4pm to 4 am) in the “cave”.   Jodi Pirtle, Paul Walline and Darin Jones are the three scientists I have been lucky to work with during my cruise.

I  discussed Jodi’s work on the ship in the science section.  She has an extensive educational background.  She earned a BS in Biology from Western Washington University in Bellingham and then a MS in Environmental Science from Washington State University in Vancouver.  Then she earned a Ph.D in Fisheries from the University of Alaska at Fairbanks.  Her thesis was on ground fish habitat on rocky banks along the US west coast.  And her dissertation was based on red king crab nursery habitat.  She just finished her postdoc at the University of New Hampshire Center for Coastal and Ocean Mapping where her work applied multibeam acoustics to study trawlable and untrawlable seafloor types and groundfish habitat in the Gulf of Alaska.  She is now working on groundfish habitat suitability modeling after she was selected to be a National Research Council NOAA postdoc at the Alaska Fisheries Science Center Auke Bay Lab in Juneau.  Jodi continues to integrate multibeam acoustics in her research at ABL.

Jodi was born and raised in Cordova, Alaska which we came near when we were in Prince William Sound.  I have enjoyed listening to her speak of growing up in Alaska.  There are no roads out of Cordova, so imagine traveling with a sports team in high school?  I will not forget how she described the Exxon Valdez oil spill to me from the eyes of herself at 11 years old.

I have greatly appreciated her knowledge of the creatures we bring up in the nets.  She has an eye for finding the hidden gems like the chaetognath (arrow worm).

Jodi with a lumpsucker fish
Jodi with a lumpsucker fish

Jodi enjoys cross country skiing, snow boarding, berry picking, hiking and yoga.  She introduced me to beautiful ripe salmon berries back on Kodiak.

Delicate Salmonberries
Delicate salmon berries

Darin is a MACE (Midwater Assessment & Conservation Engineering) scientist who earned his BS in Marine Biology from the University of North Carolina at Wilmington and then his MS in Fisheries Resources form the University of Idaho at Moscow.  His master’s work involved disease resistance in bull trout.  He spent 5 years collecting fishing data as an observer aboard commercial fishing boats in Alaska.  He also tagged cod on George’s Bank and worked at several conservation fish hatcheries before moving to Seattle to work for MACE.  Darin is part of the team to assess the biomass of the walleye pollock in the Gulf of Alaska.

Darin filets some of the fish caught.
Darin filets some of the fish caught.

I have heard that Darin played in a band with some MACE colleagues but they broke up because one of them moved.  Maybe there will be a reunion tour.

Darin measuring a spiny dogfish
Darin measuring a spiny dogfish

He is a surfer and has surfed on Kodiak but his favorite surf spot so far was in Costa Rica. Darin is an easy-going guy who I often call Scott because he reminds me so much of a colleague at school.  Darin has patiently explained my tasks to me and helped me learn what I am really doing.  And he supported me as I did my first camera drop.

Darin watching me control drop camera. Photo by Jodi Pirtle
Darin watching me control drop camera.
Photo by Jodi Pirtle

Paul is a native of Washington state and completed his academics there as well.  He earned a BS in Oceanography and a Ph.D in Fisheries Oceanography from the University of Washington.  For 20 years he worked at the Israel Limnological and Oceanographic Institute.  He was involved in managing the water quality in Lake Kinneret.  His role was to estimate the number of fish to determine their affect on water quality.  Paul accomplished this by developing acoustics surveys of fish stocks in Israel.  Lake Kinneret, also known as the Sea of Galilee, provides Israel with 40% of its drinking water.

Lake Kinneret Courtesy of GoogleEarth
Lake Kinneret
Courtesy of GoogleEarth

In 2000, Paul moved back to Seattle and is working as a fisheries biologist for MACE.

Paul reading echograms and deciding to fish
Paul reading echograms and deciding to fish

I have been fortunate to see photographs that Paul has taken both on this trip and elsewhere.  He has an incredible talent for finding beauty.

Paul Walline
Paul Walline

I am writing this as we are tossing and turning in ten foot swells.  According to Paul, it doesn’t matter if the swells get any  bigger because the effect is the same. His calmness, knowledge and expertise remind me a lot of my dad.

As you can see, I worked with amazing, brilliant individuals.  The night shift rules.  We had awesome teamwork when a haul needed to be processed.

Jodi weighs and measures the pollock.  Darin removes otoliths and I packaged them up
Jodi weighs and measures the pollock. Darin removes otoliths and I packaged them up

And then we slept through the fog and awoke to beautiful sunsets (on some days).

Sunset by Yakutat Bay
Sunset by Yakutat Bay

Did You Know?

Glacial runoff changes the color of the ocean.  Compare the two photos.  The one at the bottom is near a glacier.


The ocean with no glacial runoff.
The ocean with no glacial runoff.
The ocean with glacial runoff.
The ocean with glacial runoff.

Animals Seen Today:

The bottom trawl that was brought up right when I began work, contained three types of sharks.  The smaller ones were spiny dogfish and spotted spiny dogfish.  The big one was a salmon shark.  Check out the video.

To read more about salmon sharks and to monitor their migration pattern, check out the content on Tagging of Pacific Predators website.  Click here: TOPP

My Drop Camera Experience

Checking out the bottom with the drop camera. Photo by Jodi Pirtle
Checking out the bottom with the drop camera.
Photo by Jodi Pirtle
Jodi and I monitoring the drop cam. Photo by Darin Jones
Jodi and I monitoring the drop cam.
Photo by Darin Jones
Julia bringing drop camera aboard. Photo by Darin Jones
Julia bringing drop camera aboard.
Photo by Darin Jones
Sea urchin in color.
Sea urchin in color.
Fish hiding on the left.
Fish hiding on the left.
Another sea urchin
Another sea urchin