Erica Marlaine: Onboard the City That Never Sleeps, June 28, 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: June 28, 2018

Weather Data from the Bridge:

Latitude: 58º 28.54 N
Longitude: 154º 46.05 W
Wind Speed: 16.8 knots
Wind Direction: 190º
Air Temperature:  11º Celsius
Barometric Pressure: 102


Science and Technology Log

Scientists aboard NOAA Ship Oscar Dyson are estimating the numbers and biomass of walleye pollock in the Gulf of Alaska.  They use acoustics (sound data)  to help them do this.

acoustic readout
Acoustic representation of fish in the area


Acoustic representation of fish in an area

Echo sounders send an acoustic signal (ping) into the water.  The sound bounces off objects that have a different density than the surrounding water (such as the swim bladder in a fish) and returns back to the echo sounder.  Using the speed of sound, this technology can determine how deep the fish are in the water column. 

How much sound each object reflects is known as the target strength.  The target strength is dependent upon the type of fish and the size of the fish.  A bigger fish will give off more of an echo than a small fish will.  A fish’s swim bladder is primarily what reflects the sound.  Smelt and krill do not have swim bladders. As a result, they do not reflect as much sound as a pollack would. Even though a big fish gives off more sound energy than a small fish of the same species, it is possible that a return echo could indicate either one big fish or several smaller fish clumped together. A big fish of one species could also give off similar sound energy to a big fish of a different species. For that reason, actual fish are collected several times a day in the nets described in a previous blog.

From a net sample, scientists determine the number of each species in the catch as well as the length and weight of individuals of each species. 

Measuring pollock
Measuring pollock

Additionally, scientists also determine the sex and age of the pollock.  The catch data is used to scale the acoustic data, which in turn allows scientists to estimate how many pollock there are of various size and age groups in a given area. These numbers help scientists  determine the sustainability of the pollock population, which in turn allows the North Pacific Fishery Management Council to set catch quotas. 

Counting krill
Counting krill


Krill Fun Facts:

Krill (aka euphausiids) are small crustaceans (a couple of millimeters long) of the order Euphausiacea.  The word “krill” is a Norwegian word meaning “a small fry of fish.” Krill are found in every ocean and are a major food source. They are eaten by fish, whales, seals, penguins, and squid, to name a few.  In Japan, the Phillipines, and Russia, krill are also eaten by humans.  In Japan, they are called okiami.  In the Phillipines and Russia, they are known as camarones. In the Phillipines, krill are also used to make a salty paste called bagoong. Krill are a major source of protein and omega-3 fatty acids.

krill on spoon
There are many kinds of krill. Thus far, in the Gulf of Alaska, we have been seeing mostly Thysanoessa enermis, which measure approximately 1/2 inch in length.

Personal Log  

People often refer to New York as the city that never sleeps. The same can be said for the NOAA Ship Oscar Dyson. Life onboard the Oscar Dyson carries on 24 hours a day, 7 days a week.  There is never a time that the ship is not bustling with activity.  Everyone on the boat works 12-hour shifts, so someone is always working while others are sleeping (or doing laundry, exercising, or watching a movie in the lounge before they go to sleep.) Most people on the boat work either the noon to midnight shift or the midnight to noon shift.  However, the science team works 4 a.m. to 4 p.m., or 4 p.m. to 4 a.m. I am in the latter group.  It was easier to get accustomed to than I had imagined, although it is sometimes confusing when you look at your clock and wonder whether it is 5 a.m. or 5 p.m. since the sun is shining for most of the day.  Kodiak has only 4-5 hours of darkness now, and the sun sets at approximately midnight.  Therefore, it does not really feel like nighttime for much of my shift.

View
The view from NOAA Ship Oscar Dyson
Sunset
Views (and sunsets) like these make it easy to work the night shift!

Patricia Schromen, August 22, 2009

NOAA Teacher at Sea
Patricia Schromen
Onboard NOAA Ship Miller Freeman
August 19-24, 2009 

Mission: Hake Survey
Geographical Area: Northwest Pacific Coast
Date: Thursday, August 22, 2009

Bringing in the nets requires attention, strength and teamwork.

Bringing in the nets requires attention and teamwork.

Weather Data from the Bridge 
SW wind 10 knots
Wind waves 1 or 2 feet
17 degrees Celsius

Science and Technology Log 

In Science we learn that a system consists of many parts working together. This ship is a small integrated system-many teams working together. Each team is accountable for their part of the hake survey. Like any good science investigation there are independent, dependent and controlled variables. There are so many variables involved just to determine where and when to take a fish sample.

Matt directs the crane to move to the right. Looks like some extra squid ink in this haul.

Matt directs the crane to move to the right. Looks like some extra squid ink in this haul.

The acoustic scientists constantly monitor sonar images in the acoustics lab. There are ten screens displaying different information in that one room. The skilled scientists decide when it is time to fish by analyzing the data.  Different species have different acoustical signatures. Some screens show echograms of marine organisms detected in the water column by the echo sounders. With these echograms, the scientists have become very accurate in predicting what will likely be caught in the net. The OOD (Officer of the Deck) is responsible for driving the ship and observes different data from the bridge. Some of the variables they monitor are weather related; for example: wind speed and direction or swell height and period. Other variables are observed on radar like the other ships in the area. The topography of the ocean floor is also critical when nets are lowered to collect bottom fish. There are numerous sophisticated instruments on the bridge collecting information twenty four hours a day. Well trained officers analyze this data constantly to keep the ship on a safe course.

Here come the hake!

Here come the hake!

When the decision to fish has been made more variables are involved. One person must watch for marine mammals for at least 10 minutes prior to fishing. If marine mammals are present in this area then they cannot be disturbed and the scientists will have to delay fishing until the marine mammals leave or find another location to fish. When the nets are deployed the speed of the boat, the tension on the winch, the amount of weight attached will determine how fast the nets reach their target fishing depth.  In the small trawl house facing the stern of the ship where the trawl nets are deployed, a variety of net monitoring instruments and the echo sounder are watched. The ship personnel are communicating with the bridge; the deck crew are controlling the winches and net reels and the acoustic scientist is determining exactly how deep and the duration of the trawl. Data is constantly being recorded. There are many decisions that must be made quickly involving numerous variables.

Working together to sort the squid from the hake.

Working together to sort the squid from the hake.

The Hake Survey began in 1977 collecting every three years and then in 2001 it became a biannual survey. Like all experiments there are protocols that must be followed to ensure data quality. Protocols define survey operations from sunrise to sunset. Survey transect line design is also included in the protocols. The US portion of the Hake survey is from approximately 60 nautical miles south of Monterey, California to the US-Canada Border. The exact location of the fishing samples changes based on fish detected in the echograms although the distance between transects is fished at 10 nautical miles. Covering depths of 50-1500 m throughout the survey. Sampling one species to determine the health of fish populations and ocean trends is very dynamic.

Weighing and measuring the hake is easier with automated scales and length boards.

Weighing and measuring the hake.

Personal Log 

Science requires team work and accountability. Every crew member has an integral part in making this survey accurate.  A willing positive attitude and ability to perform your best is consistently evident on the Miller Freeman. In the past few days, I’ve had the amazing opportunity to assist in collecting the data of most of the parts of this survey, even launching the CTD at night from the “Hero Platform” an extended grate from the quarter deck.

Stomach samples need to be accurately labeled and handled carefully.

Stomach samples need to be accurately labeled and handled carefully.

Before fishing, I’ve been on the bridge looking for marine mammals.  When the fish nets have been recovered and dumped on the sorting table, I’ve sorted, weighed and measured fish. For my first experience in the wet lab, I was pleased to be asked to scan numbers (a relatively clean task) and put otoliths (ear bones) into vials of alcohol. I used forceps instead of a scalpel. Ten stomachs are dissected, placed in cloth bags and preserved in formaldehyde. A label goes into each cloth bag so that the specimen can be cross referenced with the otoliths, weight, length and sex of that hake. With all the high tech equipment it’s surprising that a lowly pencil is the necessary tool but the paper is high tech since it looks regular but is water proof.  It was special to record the 100th catch of the survey.

Removing the otolith (ear bone) with one exact incision. An otolith reminds me of a squash seed or a little silver feather in jewelry.

Removing the otolith (ear bone) with one exact incision. An otolith reminds me of a squash seed or a little silver feather in jewelry.

Each barcoded vial is scanned so the otolith number is linked to the weight, length and sex data of the individual hake.

Each barcoded vial is scanned so the otolith number is linked to the weight, length and sex data of the individual hake.

Questions for the Day 

How is a fish ear bone (otolith) similar to a tree trunk? (They both have rings that can be counted as a way to determine the age of the fish or the tree.)

The CTD (conductivity, temperature and depth) unit drops 60 meters per minute and the ocean is 425 meters deep at this location; how many minutes will it take the CTD to reach the 420 meter depth?

Think About This: The survey team directs the crane operator to stop the CTD drop within 5 meters of the bottom of the ocean.  Can you think of reasons why the delicate machinery is never dropped exactly to the ocean floor?  Some possible reasons are:

  • The swell in the ocean could make the ship higher at that moment;
  • An object that is not detected on the sonar could be on the ocean floor;
  • The rosetta or carousel holding the measurement tools might not be level.

Launching the CTD is a cooperative effort. The boom operator works from the deck above in visual contact. Everyone is in radio contact with the bridge since the ship slows down for this data collection.

Retrieving the CTD

Retrieving the CTD

Jennifer Fry, July 18, 2009

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship Miller Freeman (tracker)
July 14 – 29, 2009 

Mission: 2009 United States/Canada Pacific Hake Acoustic Survey
Geographical area of cruise: North Pacific Ocean from Monterey, CA to British Columbia, CA.
Date: July 18, 2009

Weather Data from the Bridge 
Wind speed: 40 knots
Wind direction: 350°from the north
Visibility: foggy Temperature: 12.9°C (dry bulb); 12.0°C (wet bulb)
Wave height: 8-10 feet

Science and Technology Log 

Lisa Bonacci, chief scientist and Melanie Johnson, fishery biologist in the Freeman’s acoustics lab

Lisa Bonacci, chief scientist and Melanie Johnson, fishery biologist in the Freeman’s acoustics lab

Acoustics: Lisa Bonacci, chief scientist, and Melanie Johnson, fishery biologist, are in the acoustics lab onboard the Miller Freeman as it travels along a transect line. NOAA scientists can detect a variety of marine life under the sea. They use sonar—sound waves bouncing off an object—to detect the animals. There is an onboard sonar system that puts out four different frequencies of sound waves.  Each type of fish will give off a different signal depending on its size, shape, and anatomy.  The fish are then identified on the sonar computer readout.  The strength of the sonar signal will determine the number of hake and the way that they are swimming.  As soon as it appears on the sonar as if hake are present, Ms. Bonacci then calls the bridge to request that we trawl for fish.

This is the sonar readout as it’s seen on the computer screen.

This is the sonar readout as it’s seen on the computer screen.

Personal Log 

The boat was rocking in all directions with 40 knot winds and 8-10 foot waves. The fishing trawl brought up scores of fish including a lot of hake. The sonar signals worked really well to locate them. We dissected and measured many fish, but not before we sat in a giant vat of hake (see photo.)  It was a great learning day.

Animals Seen Today 
Hake,spiny dogfish, Humbolt squid, Myctophidae, and Birds.

Here we are in a giant vat of hake!

Here we are in a giant vat of hake!

Discovery from the Briny 
As the trawl net was raised from the depths
The sun broke through the clouds revealing a sparkling azure sky.
Scores of seagulls circled the stern
In the hopes of a bountiful offering
Tasty morsels from the deep
Soon to be thrown overboard.

American fishery biologist, Melanie Johnson, and Canadian fishery biologist, Chris Grandin, take biological samples.

American fishery biologist, Melanie Johnson, and Canadian fishery biologist, Chris Grandin, take biological samples.

Megan Woodward, July 16, 2009

NOAA Teacher at Sea
Megan Woodward 
Onboard NOAA Ship Oscar Dyson
July 1 – 18, 2009

Mission: Bering Sea Acoustic Trawl Survey
Geographical Area: Bering Sea/Dutch Harbor
Date: Tuesday, July 16, 2009

All bony fish have otoliths (ear bones) that can be used for calculating the age of the fish.

All bony fish have otoliths (ear bones) that can be used for calculating the age of the fish.

Weather and Location 
Position: N 58 13.617; W 171 25.832
Air Temp: 7.2 (deg C)
Water Temp: 6.54 (deg C)
Wind Speed: 15 knots
Weather: Overcast

Science and Technology Log 

One of the most interesting things I’ve learned while participating in the pollock survey is the importance of otoliths. Otoliths are small bony structures situated in the head of all bony fish, and are often referred to as “ear stones.”  For each haul we brought on board, 50 otoliths were taken from large fish (3+ years) and/or 5 from small fish (younger than 3 years old).  The otolith holds the key to accurately calculating the age of a fish (scales and vertebrates can also be used, but are not as reliable).  The average age of fish from the samples collected in the survey helps scientists estimate the strength of a year-class and size of the stock in the future.

Back in the lab, otolith samples are carefully catalogued.

Back in the lab, otolith samples are carefully catalogued.

The first step in taking an otolith is pictured above. An incision is made on the back of the pollock’s head, and an otolith is removed using tweezers.  Once the otolith is removed, it is rinsed with water and placed in a glass vial containing a small amount of 50% ethanol solution for preservation purposes.

The otoliths are taken back to NOAA’s aging lab where ages are determined by reading rings similar to those on a tree trunk. A crosscut is made through each otolith revealing a pattern of rings. Scientists then count the rings to determine the age of the fish.  Lightly burning or staining the otoliths makes the rings more visible.

Cod and sole otoliths

Cod and sole otoliths

New material is deposited on the surface of the otolith creating the rings as the fish grows. The translucent/light zones indicate the main growth that takes place in the summer months.  The opaque/darker rings appear during the winter months when growth is slower. Because of the slower growth rate, new material is deposited on top of the old layers resulting in the dark ring. Each pair of light and dark zones marks one year. In fish younger than one year of age, rings can be identified for each day of life!

woodward_log6bPersonal Log 

I was surprised to discover otoliths have been used for aging fish since the early 1900’s.  While working in the fish lab I observed the scientist removing otoliths, however I did not remove any myself. The cracking sound heard when cutting the head open was like fingernails on a chalkboard to me.  I spent most of my time in sorting and measuring fish, as well as assisting with the stomach collection project.

For the next two days we will be heading back to Dutch Harbor, and the likelihood of trawling for more fish is minimal.  Our remaining work assignment is to give the fish lab a thorough cleaning. Everything in the lab is waterproof, so we’ll put on our Grunden’s (orange rubber coveralls) and boots and spray down the entire space. Working and living at sea for nearly 3 weeks has been an eye opening experience. My time aboard the Oscar Dyson has flown by. I have learned so much about fisheries research and life at sea. Dry land, however, will be warmly welcomed when we get back to Dutch Harbor.  Would I do it again? Absolutely.

Animal Sightings 

The whales have an incredible way of showing up when I don’t have my camera.  Yesterday I spotted two orcas, but did not get a photograph. The seabirds continue to circle. I like the murres most.  They look like small, flying penguins.

New Vocabulary 

Otoliths- Small bony structures situated in the head of all bony fish. Often referred to as “ear stones.”

Stock- Refers to the number of fish available, supply.

*** Much of the information used for this log entry was found on the Centre for Environment, Fisheries & Aquaculture Science (Cefas) web site.

Jennifer Fry, July 15, 2009

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship Miller Freeman (tracker)
July 14 – 29, 2009 

Mission: 2009 United States/Canada Pacific Hake Acoustic Survey
Geographical area of cruise: North Pacific Ocean from Monterey, CA to British Columbia, CA.
Date: July 15, 2009

Weather Data from the Bridge 
Wind Speed: 19 kts.
Wind direction: 355° north
Temperature: 15.4°C (dry bulb); 13.2°C (wet bulb)

Science and Technology Log 

This picture shows the Miller Freeman in Alaskan waters.  On our cruise, it’s working off the coast of California.

This picture shows the Miller Freeman in Alaskan waters. On our cruise, it’s working off the coast of California.

Our cruise was delayed for a day due to poor weather conditions and heavy seas. We began with a meeting of the scientific team which consists of 8 members all with their specific scientific knowledge and expertise. We will be conducting several types of oceanographic sampling during our cruise:  2-3 hake tows per day, weather permitting, an open net tow where fish are viewed through a camera, XBTs: Expendable Bathythermograph, HABS: Harmful Algal Bloom Sampling, and CTD: Conductivity, Temperature, and Density. The ship conducted Man Overboard and Fire drills.

The research vessel Miller Freeman set sail from Eureka, California on Wednesday, July 15th at approximately 12:30. Each person aboard is assigned a specific job and place to report on the Miller Freeman during such an event. Our assignments are posted on our stateroom door. During a Fire/Emergency Drill the signal is a 10 second blast of the general alarm and/or ship’s whistle. I am to report or muster to the Chemical Lab.

In the event of an Abandon Ship Drill, I am assigned to life raft #2 and muster on the O-1 deck, port (left) side. The Abandon Ship signal is more than 6 short blasts followed by one long blast of the general alarm and/or ship’s whistle. If a Man Overboard Drill is called, we will hear 3 prolonged blasts of the general alarm and/or ship’s whistle.  The muster station is the Chemical Lab. If we personally see a person go overboard the ship there are three things to do immediately: Throw a life ring overboard, call the bridge, and keep your eyes on the person. 

These things all need to be done as simultaneously as possible to assure the safety and recovery of the person who is in the sea. It is important to conduct these emergency drills so that everyone is ready and prepared in the case of an emergency event.

Personal Log 

I am sharing a stateroom with Julia Clemons, an oceanographer on board the Miller Freeman. She works for NOAA Fisheries in Newport, Oregon.  Her educational background includes a Bachelors’ degree in Oceanography and a masters’ degree in Geology. The scientists and crew on board are so professional and willing to teach and tell about their job.  They are an amazing group of people.

New Term/Phrase/Word 
Domoic acid

Questions of the Day? 
What does a hake look like in person?

Animals Seen Today 
5 Egrets
1 great blue heron
Numerous gulls

Jennifer Fry, July 14, 2009

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship Miller Freeman (tracker)
July 14 – 29, 2009 

Mission: 2009 United States/Canada Pacific Hake Acoustic Survey
Geographical area of cruise: North Pacific Ocean from Monterey, CA to British Columbia, CA.
Date: July 14, 2009

NOAA Ship Miller Freeman

NOAA Ship Miller Freeman

Weather Data from the Bridge 
No data (In port)

 Science Log 

After arriving at the Eureka airport I found my way to the Miller Freeman thanks to many friendly Eurekan locals. What a lovely town with many interesting sights including the dock area, downtown with its renewed turn of the century architecture.   Upon arriving at the Miller Freeman I was greeted by Ensign Heather Moe who graciously gave me a tour of the ship.

There were four decks or levels to the ship which include:

  • Flying Bridge Deck: observations take place as well as storage
  • Bridge Deck: Navigation can take place from the bridge or the trawl house.  The trawl house faces toward the stern of the ship and is used to control the ship during “fishing.”
  • Boat Deck: Officers’ & Chief Scientist’s staterooms.  A stateroom is where you would sleep on a boat or ship. Your bed is called a “rack.”  Most staterooms on the Miller Freeman have bunk beds. The boat deck is where the small launches/rescue boats are stored.
  • There is: a FRB, Fast Rescue Boat, and a small launch.
  • Quarterdeck/ Main Deck:  Ship’s store, survey officers’ staterooms and the back deck, used for fishing. *The term quarterdeck was originally, in the early 17th century, used for a smaller deck, covering about a quarter of the vessel. It is usually reserved for officers, guests, passengers. It is also an entry point for personnel. Lower/ Galley Deck: Crew’s and scientists’ staterooms, library, two lounges, galley, where everyone eats their meals.
  • Hold: Gym for exercising and engineer’s storage area.

Question of the Day 
Where did the word quarterdeck* originate? (see answer above)

Animals Seen Today
Egrets Blue Heron Gulls

Megan Woodward, July 12, 2009

NOAA Teacher at Sea
Megan Woodward 
Onboard NOAA Ship Oscar Dyson
July 1 – 18, 2009

Mission: Bering Sea Acoustic Trawl Survey
Geographical Area: Bering Sea/Dutch Harbor
Date: Tuesday, July 12, 2009

Any bycatch in a haul has to be measured and weighed if there are more than 25 of the same species caught.

Any bycatch in a haul has to be measured and weighed if there are more than 25 of the same species.

Weather/Location 
Position: N 60.35.172; W 174.08.187
Air Temp: 6.1 (deg C)
Water Temp: 5.24 (deg C)
Wind Speed: 25 knots
Weather: Overcast, rain

Science and Technology Log 

How is all the data collected from a trawl and acoustic lab used?  By collecting data about weight and length from a sample, scientists are able to connect the size of fish caught to the amount of return seen in the acoustic lab. The return is assigned a name (PK1, PK2, etc.) and all schools showing a similar acoustic pattern are given the same name.  In the end, scientists can estimate the number of fish and their size for a given area based on the acoustic and fish lab data collected.  This is repeated throughout the survey resulting in an estimate for the total number of fish in the survey area.  

Both during and after the survey estimates of abundance in the same location over the past several years are compared.  Scientists evaluate the data and determine if the pollock population in the survey area is increasing, declining or stable.  Their conclusions are used to make a recommendation about pollock fishing limits for the upcoming year. In the past few years the pollock population has been lower than in previous years.  Due to the decline, the fishing quota has been reduced.  However, the 2006 year-class is proving to be strong. At 4 years of age pollock are considered mature and fishable.  Therefore, the fishing quota is predicted to rise in the next year or two.

Screen shot 2013-03-24 at 11.32.34 PM

Personal Log 

While discussing the acoustic survey project with the scientists on board, I was quite surprised to hear the pollock survey had been going since 1979.  Acoustic technology has changed and improved, but in essence the project has remained the same. Modern computer technology has allowed collection and analysis of enormous data sets and greatly reduced the amount of paper work needed for the project’s success.

The concept of strong vs. weak year-class is also quite interesting.  There doesn’t seem to be a direct connection between a year-class’ success and environmental factors.  Environmental factors that are potentially influential are water temperature, available zooplankton, ice cover, storms and predators.  The fish currently being caught by commercial fisherman are 5-7 years old. Can you figure out which year classes those fish are from?

We continue to spot plenty of seabirds and a few more minke whale pods.  I was able to watch a group of Dall’s porpoises play in the wake of the bow for half an hour yesterday.  There haven’t been any new animal sightings during the past few days.

We continue to spot plenty of seabirds and a few more minke whale pods. I was able to watch a group of Dall’s porpoises play in the wake of the bow for half an hour yesterday. There haven’t been any new animal sightings during the past few days.

Although we are out here working in the best interest of pollock, I have found it difficult to watch thousands of pollock come through the fish lab.  I have to remind myself that sampling the fish is truly for the good of the order. In addition, after being measured the fish are sent back into the ocean where they become food for other organisms such as crab or birds. One of their natural predators is having a good meal, something that was likely to happen anyway.

Animal Sightings 

  • Seabirds
  • Dall’s porpoises

New Vocabulary 

Bycatch  – Anytime something is caught during a trawl other than pollock it is labeled bycatch.  Jellyfish has been the most common form of bycatch.

Year-class – All the fish born in a given year are members of that year-class.  We have caught a lot fish from the 2008 year-class (1 year old fish).