giant pacific octopus – NOAA Teacher at Sea Blog

August 5, 2019

Erica Marlaine: You Never Know Where a Good Book Will Take You, July 15, 2019

NOAA Teacher at Sea

Erica Marlaine

Aboard NOAA Ship Oscar Dyson

June 22 – July 15, 2019

Mission: Pollock Acoustic-Trawl Survey

Geographic Area of Cruise: Gulf of Alaska

Date: July 15 , 2019

Weather Data from the Bridge:

Latitude: 57º 0.79 N

Longitude: 152º40.72 W

Air Temperature: 16º Celsius

Interview with the Chief Scientist

When Sarah Stienessen was a little girl, she got a book about dolphins, and fell in love. She read the book over and over, dreaming about meeting a real-live dolphin one day. The problem was she grew up in Wisconsin, not a place with a lot of dolphins. However, as Sarah says “If you have an interest, don’t let location deter you from your dreams.”

When she grew up, Sarah studied zoology at the University of Wisconsin, Madison, but her burning fascination with the ocean led her to graduate school at Texas A&M where she finally got to study DOLPHINS (more specifically, the vocal behavior of dolphins). Her research there included using a hydrophone to listen to dolphins. She later moved to Seattle and began working for NOAA conducting acoustic surveys on walleye pollock in Alaska. On this leg of the Oscar Dyson, Sarah acted as the Field Party Chief (or Chief Scientist). Sarah pointed out that while her use of acoustics with dolphins was passive (placing a hydrophone in the water and listening to the dolphins) she is now using acoustics actively by sending an audible PING into the water and reading the echos that the fish send back.

Sarah was part of the amazing NOAA science team onboard the NOAA Ship Oscar Dyson, which included, Denise McKelvey, Kresimir Williams, and Taina Honkalehto.

Scientists — Back row: Sarah and Kresimir Front row: Denise and Taina

Denise was on the day shift, so I mostly saw her during shift changes and on those rare mornings when I was still awake at 7 a.m. and came down for breakfast (okay, bacon). However, early in the trip, she took the time to explain the fish lab procedure to me, even drawing pictures and a flow chart. (Thanks!)

While the duties of the science team often overlap, Kresimir is definitely the “techie” who enjoys inventing and creating new underwater cameras and other devices. Do you remember the TV show MacGyver? MacGyver was a secret agent who was beyond resourceful and had an encyclopedic knowledge of science. Every episode, he would solve the problem at hand in a matter of minutes using a combination of ordinary objects such as duct tape, household cleanser, a Q-tip, and some matches. Kresimir reminded me of MacGyver. If something broke, he would enter the room, grab tools and items that just might work in place of the broken piece, and sure enough, within minutes, the device would be up and running again!

Taina was always in the chem lab during drop camera time, her eyes riveted on the screen. I was excited whenever the camera spotted something, but I loved that Taina seemed equally excited to see what marine species the camera would uncover each night. One of the most exciting, and clearly the biggest, was the Giant Pacific Octopus!

Science and Technology Log

The Giant Pacific Octopus (or Octopus dofleini) is often rumored to weigh more than 600 pounds, but most adult octopuses are much smaller. An adult female might weigh up to 55 pounds while an adult male can weight up to 88 pounds. According to NOAA, the plural of octopus is octopuses, NOT octopi as some people say. Because it doesn’t have bones, a giant octopus can squeeze through a hole the size of a quarter! The body of an octopus is shaped like a bag and it has 8 long arms (or tentacles) covered in suction cups.

A mature octopus can have as many as 280 suction cups on each arm. That’s 2,240 suction cups! The Giant Pacific Octopus loves to eat crabs, but it will also eat snails, oysters, abalone, clams, mussels, and small fish. The octopus’ mouth or jaw is shaped like a parrot’s beak. It is the only hard part of an octopus, and it’s more-or-less indigestible. That means that if a sperm whale eats an octopus, and the contents of the whale’s stomach are later studied, you will see the octopus beak even if you find no other sign that he ate an octopus.

In order to avoid whales and other predators, an octopus will camouflage, or change its color and skin texture to match its surroundings! When he feels threatened, he releases a cloud of purple-black ink to confuse his enemy.

Octopus Elementary Math Time

(Remember, an octopus has 8 arms.)

If an octopus has 2 suction cups on each arm, how many does he have all together? _______
If an octopus has 5 suction cups on each arm, how many does he have all together? _______
If an octopus has 10 suction cups on each arm, how many does he have all together? ______
If an octopus has 2 suction cups on 4 of his arms, and 3 suction cups on his other 4 arms, how many does he have all together? _____________
If an octopus has 4 suction cups on 7 of his arms, but half as many on his 8^th arm, how much does he all together? _____________
If an octopus has 259 suction cups and his octopus friend has 751 suction cups, how many do they have all together?

July 12, 2019July 19, 2019

Erica Marlaine: SAY CHEESE, July 7, 2019

NOAA Teacher at Sea

Erica Marlaine

Aboard NOAA Ship Oscar Dyson

June 22 – July 15, 2019

Mission: Pollock Acoustic-Trawl Survey

Geographic Area of Cruise: Gulf of Alaska

Date: July 7, 2019

Weather Data from the Bridge:

Latitude: 55º 24.63N
Longitude:155 º 18.86 W
Wind Speed: 10 knots
Wind Direction: 210º
Air Temperature: 11º Celsius
Barometric Pressure: 1097 mb

Science and Technology Log

Fishing nets like the ones used on the NOAA Ship Oscar Dyson or on commercial fishing boats can be very expensive. If one plans on doing a bottom trawl (fishing with a net that goes down to the sea floor) one wants to make sure that there are not rocks or other things that can snag or tear the net. If there are too many rocks or boulders or uneven topography, the area is considered “untrawlable”. While computer imagery can provide some guidance with regard to what lies deep beneath the surface, scientists onboard the NOAA Ship Oscar Dyson are hoping that video images taken with an underwater camera can provide a more complete picture and be the basis for a more precise computer model of what areas are in fact untrawlable.

Why is this important? Scientists onboard the NOAA Ship Oscar Dyson are surveying the fish that live in the middle of the water column. However, groundfish surveys need to account for all the fish living on the ocean floor. If the groundfish program can’t trawl in certain areas, then they don’t know what is there. For example, rockfish often live in untrawlable areas. If a groundfish survey can’t put a net in areas where rockfish live, then they won’t really “count” the correct numbers of rockfish in their survey. Data obtained using an underwater camera can help determine what species of rockfish are being underrepresented by the groundfish program.

One of the many perks of being on the 4 p.m. to 4 a.m. shift is that I get to watch the drop camera in action! The camera (with its attached light) is slowly lowered to the sea floor.

I have seen the camera take 4 minutes to reach the bottom or as long as 8 minutes depending upon the depth of the water being surveyed. The camera is then “driven” along the bottom (or right above it) for 15 minutes via a control box on the boat (similar to a tiny joystick). I even got to drive it a few times!

The images are recorded and also seen in real time on several computer screens on the boat. We have seen rocks, of course, but also jellyfish, sea whips, crabs, anemones, octopuses, sea stars, and a wide variety of fish. One night, there were thousands of sand dollars. It looked like we had come across a buried treasure! It is fascinating to see what is happening deep beneath the boat. It’s kind of like virtual scuba diving!

Drop Camera Elementary School Math Fun

If the stereo drop camera takes 8 minutes to reach the bottom when the water is 200 meters deep, how long might it take to reach the bottom if it was:

100 meters deep? ____________

50 meters deep? ______________

300 meters deep? _____________

Personal Log

It’s time to come clean and admit that I suffer from Pareidola. Don’t worry, it’s not contagious, or even dangerous. In fact, I think it’s a lot of fun. You see, Pareidola is a psychological phenomenon where you see patterns. Quite often, people with Pareidola will see faces in objects where there really isn’t one, like on an electrical outlet.

Electrical outlets… do you think they look like faces?

My Pareidola has reached a new level on the NOAA Ship Oscar Dyson as I am seeing not just faces but ROBOTS like these:

Robot!
Robot!

Let me know if you see any robots at your house, and I am on the lookout for more here!

July 15, 2011April 28, 2021

Kathleen Harrison: Finding Fish, July 12, 2011

NOAA Teacher at Sea
Kathleen Harrison
Aboard NOAA Ship Oscar Dyson
July 4 — 22, 2011

Location: Gulf of Alaska
Mission: Walleye Pollock Survey
Date: July 12, 2011

Weather Data from the Bridge
Air Temperature: 10.15° C, Sea Water Temperature: 7.6° C
True Wind Speed: 12.26 knots, True Wind Direction: 191.38°
Very foggy, visibility < 1/4 mile
Door open on bridge to hear other fog horns
Latitude: 56.07° N, Longitude: 158.08° W
Ship Heading: 24°, Ship Speed: 11.7 knots

Science and Technology Log: Finding Fish

In a previous log, I talked about using nautical charts and trawling as 2 methods used in calculating the biomass of Walleye Pollock in the Gulf of Alaska. Finding the fish to catch is tricky business in the ocean, they don’t usually come up to the surface and say hi. The NOAA scientists working on the Walleye Pollock Survey spend a lot of time looking for fish, so that their trawling efforts won’t be wasted (that is the general idea, anyway). How do you look for fish in the ocean? With acoustics, of course, another method used in calculating biomass.

Acoustics is the use of sound, which will travel through the water, and bounce off of objects that it hits. There is Simrad ER60 echosounder that operates 5 transducers mounted on the center board under the ship, and it continuously sends out sound waves.

multibeam sonar mapping the ocean floor — The Simrad ER60 echosounder sends sound directly under the ship, finding fish anywhere in the water column.

In the Acoustics Lab of the Oscar Dyson, the data from the multi-beam echosounder is being studied all of the time. The sound waves leave the device, travel down, hit the swim bladder in a fish (the fish doesn’t even know), and reflect back to the ship. The time it takes for the sound to return is used to calculate the distance down, and a computer generated picture called an echogram is produced.

echogram shows surface, fish, and bottom — The echogram shows plankton at the surface in blue/green, fish near the bottom as red/brown spots, and the ocean floor as a red/brown line.

The echogram tells the scientists several things. The surface of the water is shown, with surface dwelling organisms such as krill, phytoplankton, zooplankton, and juvenile fish. The fish that are mid-water are shown as well, showing up as red or blue dashes or blobs. This is where the Pollock usually are. Some fish are bottom feeders, and the red and blue dashes on the bottom represent those. The ocean floor is also shown, which is very important when choosing which type of trawl to use. If the bottom is flat, the Poly Nor’Easter could be used to capture to fish on the bottom. The Aleutian Wing Trawl might be used in mid water if the bottom is rocky and irregular.

Now, looking at the fish from the surface is nice, but wouldn’t it be better to see them close up? Of course! The scientists have another tool at their disposal, and no, it isn’t me diving down to the fish (brrr). This tool is called a Drop Target Strength, or DTS.

echosounder can be dropped into water — The Drop Target Strength (DTS) can be lowered into the water, and get closer to the fish. The information is fed into the computer by a water proof cable.

About once a day, or every other day, the DTS is lowered over the side, and it starts sending out sound waves (3 pings/second), just like the echosounder mounted on the ship. The advantage with the DTS, though, is that it is closer to the fish, giving a more detailed and accurate picture. Individual fish can be sighted. Taking a picture of a fish is kind of like taking a picture of a toddler, they don’t hold still very well. So, a count of the fish on the echogram might not be exact. Also, they might change the angle of their body, making the sound wave reflect off their swim bladder at a different angle. The colors on the echogram are significant: brown and red mean a strong signal, yellow is medium, and green and blue indicate a weak signal.

echogram shows individual fish — Studying the echogram from the DTS gives scientists a better picture of where the fish are. Each individual wavy line is probably a separate fish.

The scientists will study the echograms to determine where the fish are, and make a decision to fish or not. Once fishing begins, they will move from the acoustics lab to the bridge, and study the echograms there. An estimate of how many fish are in the net is made, and then the scientists will ask the crew to “haul back” the net. (I am learning a whole new language!) Then, things get very busy as we head to the fish lab to process the fish.

scientists at their desks in the acoustics lab — Here are the NOAA scientists that I am privileged to work with on the Oscar Dyson: (left to right) Darin Jones, Fish Biologist, Denise McKelvey, Fish Biologist, Neal Williamson, Chief Scientist.

New species seen:

Giant Pacific Octopus (juvenile, 1 cm)

Opalescent Squid

Chinook (King) Salmon

Egg yolk jelly fish

Sculpin (juvenile)

North Pacific sea nettle

Spud sponge

tiny squid, only 2 cm long — These are juvenile squid, about 2 cm long. They are nearly transparent.

giant pacific octopus, juvenile, only 1 cm — This is a juvenile Giant Pacific Octopus, only 1 cm wide, complete with 2 huge eyes, and 8 perfect legs.

Personal Log

My days have developed a routine now: wake at 3:30 am (ugh), start my shift in the acoustics lab about 4:00, breakfast at 7:30, lunch at 11:30, end my shift at 4:00 pm, dinner at 5:30, shower, in bed by 8:00.

my window and life boats — See the orange life saving ring? My window is just to the right of the ring. The 3 white canisters on the back wall hold life rafts that inflate upon release of the canister.

In between these times, I work on my Teacher at Sea log, post pictures on Facebook, read and answer e-mail, visit the bridge and ask lots of questions, and of course, process fish whenever there is a trawl (very fun). Today marks the halfway point of our cruise! The ship is quieter than I thought, even though there are 35 people on board, the most that I ever see might be 10 during mealtimes. There is constant background noise of the ship’s engines, waves hitting the bow of the ship, creaks and groans of the furniture as the ship rolls, but I am used to it now, and hardly notice it. I am thankful for the calm weather that we have had so far.