Melissa George – NOAA Teacher at Sea Blog

August 8, 2013August 20, 2021

Melissa George: Scraping the Bottom-Dwellers, August 6, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22 – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: Tuesday, August 6, 2013

Current Data From Today’s Cruise (9 am Alaska Daylight Time)

Weather Data from the Bridge
Sky Condition: Partly Cloudy
Temperature: 15° C
Wind Speed: 7 knots
Barometric Pressure: 1019.6 mb
Humidity: 90%

August 6, 2013: Partly Cloudy or Partly Mountainy?

Sun and Moon Data
Sunrise: 5:15 am
Sunset: 9:33 pm
Moonrise: 5:33 am
Moonset: 8:45 pm

Geographic Coordinates ( 9 am Alaska Daylight Time)

Latitude: 59 ° 20.4 N Longitude: 141° 16.6 W
The ship’s position now can be found by clicking: Oscar Dyson’s Geographical Position

Science and Technology Log

Besides the mid-water trawling, information about the pollock population is gathered in other ways on the Oscar Dyson research vessel. One of these ways is direct, monitoring the pollock by trawling in other parts of the water column; the other way is indirect, evaluating the prey that the pollock feeds on.

Bottom Trawling

Scientists use acoustics to locate the signal for the fish. Sometimes this signal is noticed near the ocean floor. In this case, the PolyNor’eastern (PNE) Bottom Trawl Net is used to trawl for fish. This net is a large net equipped with rubber bobbins that allow it to get close to the benthic region of the ocean without dragging.

During this research expedition, we used the PNE net six times to survey pollock. Often times these trawls brought up other interesting sea life, that were quickly assessed (identified, measured, and recorded) and returned to the ocean. The majority of invertebrate sea animals such as poriferans (sponges), cnidarians (sea anemones), annelids (segmented worms), mollusks (barnacles), arthropods (hermit crabs hiding in mollusk shells), and echinoderms (sea urchins and starfish) were brought up in these hauls. In addition, some interesting species of fish (see this blog’s Trawling Zoology segment below) were gathered in bottom trawls.

Miscellaneous Invertebrates from Bottom Trawl

Using the Methot Trawl

We use the Methot trawling net to sample krill, a type of zooplankton that pollock feeds on. On this voyage, the Methot was used 6 times as well. The Methot is a single net with a large square opening or mouth. The net is deployed from the stern and towed behind the vessel. Inside the Methot is a small removable codend where much of the catch is deposited.

The krill is measured and counted as well. First, the water is drained out, then it is weighed, and a small sample is weighed and counted.

Bottom trawls and Methot trawls are both important aspects of the pollock survey.

Personal Log

Accomplishment

Continuing with Maslow’s hierarchy of needs, I will discuss the top part of the pyramid, how self-actualization, or being involved in creative endeavors to expand one’s full potential, are met on the Oscar Dyson.

A Version of Maslow's Hierarchy of Needs — A Version of Maslow’s Hierarchy of Needs

Since I am an honorary member of the am science team, I am privy to many discussions between the scientists on the team regarding a variety of topics. For example, one side project on the mission is to gather information regarding the abundance and distribution of euphausiids (krill) in the Gulf of Alaska. This research project involves the use of a smaller “critter camera,” engineered and built by two of the MACE (Midwater Assessment and Conservation Engineering) group members, to take pictures of krill at various ocean depths and (ideally) reconcile its distribution with acoustic and Methot trawl data. The goal of the project is to provide insight into the feeding conditions of pollock. The discussions between group members involve postulating, speculating, testing, theorizing, analyzing, teaching, and questioning; clearly this meaty dialog indicates that the process of science is an intellectually stimulating and creative endeavor.

Scientist Team Members--- Abigail, Patrick, and Kirsten---Engaged in a Stimulating Discussion — Scientist Team Members— Abigail, Patrick, and Kirsten—Engaged in a Stimulating Discussion

Did You Know?

One of the people who views my blogs before they are posted is the Executive Officer (2nd in Charge) of the crew on the Oscar Dyson. His name is Chris and on this mission he is “augmenting” or filling in for another employee. Chris administers the day-to-day operations of the crew including logistics, payroll, and travel. Chris is a member of the NOAA Corps; he has both a BS in Marine Biology and an MS in Management Information Systems from Auburn University located in Auburn, Alabama. He grew up in various places in the Midwest (his dad was in the U.S. Airforce) and has worked in several fields including information technology and zookeeping. He applied to the NOAA Corps because he wanted to live and work near the ocean.

Chris, the Executive Officer of the Oscar Dyson — Chris, the Executive Officer of the *Oscar Dyson*

Something to Think About:

In previous posts, we have explored invertebrates encountered on this mission. Today we will look at a group of vertebrates from the class Osteichthyes, a word that comes from the Greek osteon meaning “bone” and ichthus meaning “fish.” We will focus on some of the other fish besides pollock found in bottom trawls. These bottom-dwellers are quite interesting creatures.

One of the most frequently found fish, other than pollock, is a type of rockfish called the Pacific Ocean Perch (POP); the species name is Sebastes alutus (Greek: Sebastes “August, venerable”, alutus “grow, nourish”). This fish actually was seen in many trawls, both mid-water and bottom. As the picture below indicates, the body and fins of the POP are light red; however, there are dark olivaceous areas on back under soft dorsal fin and on the caudal peducle. The maximum length of the fish is 55 cm and it is commonly found at a depth between 100-350 m.

Pacific Ocean Perch (a type of Rockfish)

A fish that belongs to the same genus as the POP is the Tiger Rockfish, Sebastes nigrocinctus ( Latin: niger, “black” and cinctus, “belt”). We found this fish once in a bottom trawl. The bottom of the tiger rockfish is light red to orange with several broad, vertical black-red bands on body. It grows to a maximum length of 61 cm and is commonly found at a depth between 55 to 274 m. Notice how similar it looks to the POP.

Tiger Rockfish, notice the similarities to the Pacific Ocean Perch

One of the most colorful fish that was found in a bottom trawl was the kelp greenling, Hexagrammos decagrammus (Greek: hexa, “six”; grammus, “letter, signal”, deca, “ten”), a fish that generally hangs out in rocky reefs and kelp beds in relatively shallow waters (up to 46 m). The fish is olive brown to bluish grey, speckled with irregular blue spots if male and reddish brown to gold spots if female (those we caught were most likely female). The fish reach a maximum length of 53 cm.

August 6, 2013August 20, 2021

Melissa George: Would You Like Fries with That? August 5, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22 – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: August 5, 2013

Current Data From Today’s Cruise (2 pm Alaska Daylight Time)

Weather Data from the Bridge
Sky Condition: Partly Cloudy
Temperature: 15.8 ° C
Wind Speed: Light Wind
Barometric Pressure: 1018.7 mb
Humidity: 84%

August 5, 2013 is a Cloudy Day on the Oscar Dyson

Sun and Moon Data
Sunrise: 5:13 am
Sunset: 9:35 pm
Moonrise: 4:22 am
Moonset: 8:27 pm

Geographic Coordinates ( 2pm Alaska Daylight Time)

Latitude: 59 ° 09.7 N Longitude: 141° 27.6 W
The ship’s position now can be found by clicking: Oscar Dyson’s Geographical Position

Science and Technology Log

Processing the Catch
My last blog post focused on mid-water trawling; this blog will focus on processing the catch. When we process the catch, we are processing it in a scientific way, not a food production way. The goal of any fish survey is to try to determine how many fish (in this case pollock) are in the sea in order to establish sustainable fishing limits. Ideally, trawling allows scientists to randomly select a sample of pollock to measure a good representation of the pollock population. The survey is undertaken in an ecologically friendly way with a focus to preserve as many fish as possible by releasing them alive back into the ocean. I will go through the steps of this process.

Step 1: Sorting and Measuring

Usually, fish brought in with the trawl net are placed directly on the table. If the catch is especially large, it may be weighed first by attaching a scale to a crane, and then attaching the load to the scale. The entire catch is weighed so the scientists can use the length and gender data taken from the sample to extrapolate for the entire catch. Then a sample (ideally 300 pollock) are kept to process and the rest are released. This data is combined with the acoustics data to estimate the size of the entire stock.

Delivering Fish From Trawling Net to Table

Fish are emptied out of the net and onto the table outside of the fish lab. The number of fish that land on the conveyor belt can be controlled by raising the table and opening the door. The fish on the conveyor belt are separated by species. Although in the catch there are often many types of species of sea animals present, the focus of this blog will be the pollock that are caught.

An Interested Observer Checks out the Pollock on the Conveyor Belt

In the video clip, the vast majority of the fish are adult pollock, but sometimes there are a variety of age stages; Age 0, Age 1, and Adult are what we have seen. Pollock are sorted by age, gathered into baskets, and weighed. Age 0 and Age 1 pollock are weighed and then measured with the icthystick, a magnetic fish measuring board, from the head to the fork in the tail. The icthystick is connected to a computer that automatically records the data. (The icthystick below shows how the length of capelin, a prey of pollock, are measured and recorded; the method is the same pollock).

Step 2: Sexing

Each age group has a somewhat different protocol for processing. Counts and measurements of weight and length are taken for the smaller pollock (and capelin). The larger pollock are grouped by sex. To do this, the abdomen is sliced open with a scalpel, the innards are pushed aside, and ovaries or testes are identified. After determining the sex of the fish, its length is measured with the icthystick. Finally, a subsample of fish are set aside for otolith removal. As we process a catch, samples of fish and other species are collected for various off-board scientists. For example, Age 0 pollock are kept for one scientist; ovaries from mature pollock for another.

Sometimes it is difficult to tell the testes from the ovaries. Generally, both are paired organs that lie along the vertebrae under the guts (stomach, liver, intestines). The ovaries tend to be fuller and more brightly colored; the testes, stringier and paler. However, these organs can vary somewhat depending on the maturity of the fish. Below are examples of the organs from fish that have not yet spawned (photos courtesy of Story Miller, TAS 2010).

These are the testes of a pre-spawning male — Testes of a Pre-Spawning Male Pollock (bottom right)

These are ovaries in the pre-spawning stage — Ovaries of a Pre-Spawning Female Pollock (center)

Step 3: Removing Otoliths

Otoliths are made of calcium carbonate and are located directly behind the brain of bony fishes. They are involved in the detection of sound and the process of hearing. The age of the fish can be established by counting the annuli (small ridges on the otoliths) much like one does when counting tree rings. This age data allows scientists to estimate growth rates, age at maturity, and exposure to various environmental conditions.

The otoliths are brought to Seattle for more detailed analysis, so after extracting them from the pollock, they are placed in jars with a preservative called glycerol thymol. The jars have bar codes on the side so that the otoliths are linked to the fish’ weight, length and sex. These results will be used to correspond length to age in the stock assessment report.

Personal Log Accomplishment

Continuing with Maslow’s hierarchy of needs, I will discuss some of the ways that the need of feelings of accomplishment are met on the Oscar Dyson.


A Version of Maslow’s Hierarchy of Needs

The goal of the Oscar Dyson crew is to safely and successfully navigate the ship through the Gulf of Alaska transects collecting and processing pollock. As of Saturday, August 3 on this mission, we have traveled almost 3000 nautical miles, traversed through 33 transects and completed 26 Aleutian Wing Trawls, 6 Poly Nor’eastern Bottom Trawls, and 6 Methots. We have measured and recorded data for 4,387 fish; 2,696 of these were pollock. We have also collected 334 otoliths. These numbers give the team a sense of accomplishment, knowing that they have contributed to the data and information processing to promote sustainable fishing practices. Check out this link, the NOAA FishWatch webpage that provides information on sustainable fishing practices.

Did You Know?

Married couples can work together aboard the Oscar Dyson. Kristin and Vince met in graduate school at the University of Florida where they were working on Master’s Degrees in Fisheries and Aquatic Science. They were collaborating on a project that focused on river systems in Florida. After getting married and working in labs at both the University of Maryland and Oregon State, they applied for Survey Technician positions with NOAA. Kristen and Vince work opposite shifts on the Oscar Dyson; Kristen works mornings and Vince works evenings. As survey technicians they are responsible for the calibration and deployment of various data acquisition systems such as the Scientific Computer System (SCS) that is constantly monitoring information such as air temperature, sea temperature, salinity, chlorophyll levels and weather. Kristen and Vince work as liaisons between the science team and the NOAA Corps.

Vince and Kristen, Oscar Dyson Survey Technicians

Something to Think About:

So far we have discussed the following invertebrate animal phyla: Porifera and Cnideria. Today’s episode of Trawling Zoology features other interesting representatives of the invertebrate animal kingdom: Annelida, Mollusca, Arthropoda, and Echinodermata that have turned up in our catches.

Phylum Annelida-from the Latin word anulus meaning “little ring”

Annelids are segmented worms that have a linear series of external segments divided by septa (walls between segments) that house serially repeated nervous, muscle, and excretory systems. Their anterior segments contain jaws, eyes, and cirri (small feelers that help with feeding). Filter-feeding marine annelids capture bacteria and feed selectively on sediment particles within tubes buried in sand or mud.

Polychaete from the Phylum Annelida (found in a bottom trawl)

Phylum Mollusca-from the Latin word mollis meaning “soft”

Mollusca is one of the most diverse groups of animals on the planet, with at least 50,000 living species (and more likely around 200,000). It includes such familiar organisms as sea snails, octopuses, squid, clams, and chitons, all of which we have seen on this mission. They all have soft bodies which typically have a “head” and a “foot” region. Often their bodies are covered by a hard exoskeleton, as in the shells of snails and clams or the plates of chitons. Squid and octopuses have small internal shells.

Members of the Squid Family, Gonotopsis borealis, the Armhook Squid

Hermit Crabs (Arthropods) Inhabiting the Shells of Mollusks

Phylum Arthropoda-from the combination of Greek words arthron meaning “jointed” and pous meaning “feet”

The Phylum Arthropoda includes organisms such as insects, spiders, and crustaceans (crabs and shrimp). The vast majority of sea dwelling arthropods are crustaceans. For example, the hermit crabs emerging from the mollusk shells in the picture above are members of the most abundant family on Earth, the arthropods. Arthropods have an exoskeleton of a tough compound called chitin that forms a rigid armor with joints in between. This outer shell provides the structure against which arthropod muscles pull, reduces water loss, and protects them from environmental dangers. Below are other examples of arthropods found frequently in trawls.

Isopods (The Cockroaches of the Sea) among Krill, another type of Arthropod

Phylum Echinodermata-from the combination of Greek words echinos meaning “spiny” and derma meaning “skin”

The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as starfish, sea urchins, sand dollars, and sea cucumbers. Echinoderms are found at every ocean depth and contains about 7000 living species. Echinoderms are also the largest phylum that has no freshwater or terrestrial (land-based) representatives. Two unique characteristics of this phylum are the ability to regenerate tissues and their ossified limestone exoskeletons.

Various Starfish found in a Bottom Trawl

August 1, 2013August 20, 2021

Melissa George: Catch Me if You Can, July 31, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22 – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: July 31, 2013

Current Data From Today’s Cruise

Weather Data from the Bridge (12 noon Alaska Daylight Time)
Sky Condition: Cloudy
Temperature: 12.8 ° C
Wind Speed: 14 knots
Barometric Pressure: 1024.7 mb
Humidity: 89%

Clouds Seen from Bow of Oscar Dyson on July 31, 2013

Sun and Moon Data
Sunrise: 6:03 am
Sunset: 10:28 pm

Moonrise: 1:06 am
Moonset: 5:58 pm

Geographic Coordinates at 12 noon (Alaska Daylight Time)

Latitude: 59° 39.3′ N
Longitude: 157° 51.2′ W

The ship’s position now can be found by clicking: Oscar Dyson’s Geographical Position

Science and Technology Log

The main goal of Leg 3 of this mission is to survey the mid-water portion of the pollock population using acoustics and trawls. Pollock usually inhabit the middle of the water column down to the seafloor. This mid-water survey is typically carried out once every two years. Another NOAA Fisheries survey observes the pollock that live close to the seafloor using bottom trawls.

Trawling

The Oscar Dyson carries three different types of trawling nets for capturing fish as part of the mid-water survey: the Aleutian Wing Trawl (AWT), a mid-water trawl net called the Poly Nor’Eastern bottom trawl, a net with special rubber bumpers so it can bounce along the ocean floor; and the Methot, a small encased net that gathers very small ocean creatures such as krill. I will be discussing trawling with the AWT in this blog.

leg 3 — Leg 3 of the Mid-Water Survey Began East of Kodiak and Will End Near Yakutat

First, I will describe the AWT net, then I will explain how it works. The AWT net is HUGE: the mouth is about 25 m high and 35 m wide while the net itself is over 150 m long (this is not counting the trawling wires that it is attached to!). To give you an idea of how big this is, let’s think in school buses. If we estimate a school bus to be about 10 m long, then this net would be 15 school buses long, and its mouth would be 3 school buses wide and 2 school buses (end to end) tall. The picture below also gives perspective in dimensions (keep in mind that the Blue Whale is only used to give relative dimensions, they are never caught in NOAA’s nets!)

Relative Dimensions of AWT Net (courtesy of Kresimir Williams)

I am going to describe how the net goes into the water, step by step. Then you can watch a short sped-up video that my fellow Teacher at Sea mate, Julia Harvey, created. She works the night shift (4 pm to 4 am) on the same cruise that I am on.

So here it goes…

Step 1: The Codend

When the net is deployed from the ship, the first part of the net to hit the water is called the codend (see the far right of the diagram above). This is where most of the fish end up after the trawl. The mesh size of the net is smallest at the codend (about 1 cm) and gets larger as it approaches the doors (about 1 m).

Labeled Scale Model of the Aleutian Wing Trawl (AWT) Net (courtesy of NOAA Scientist Kresimir Williams)

Step 2: The Trawl Camera

A trawl camera is the next major part that hits the water. This is a pair of cameras that help scientists identify and measure the fish that are caught in the net. This technology can also be used to help scientists validate their biomass estimate from trawling sampling counts. This piece of equipment has to be clipped into the side of the net each time the crew is instructed to deploy the AWT.

Step 3: The Kite

The next piece of the net to hit the water is the kite which is secured to the head rope. Attached to the kite is a series of sensors that help the scientists gather data about the condition of the net including depth, size, and shape underwater. The major acoustic sensor, affectionately termed the turtle, can tell the scientists if the fish are actually going into the net.

Close-up view of the AWT scale model to highlight the kite and the turtle that ride at the top of the net. The third wire holds the electrical wires that send data from the turtle to the bridge.

Step 4: Deployment from A-Frame

Once the kite is deployed, a pair of tom weights (each weighing 250 lbs), are attached to the bridal cables to help separate the head rope from the foot rope and ensure the mouth of the net will open. Then, after a good length of cable is let out, the crew transfers the net from the net reel to the two tuna towers and attaches the doors. The doors act as hydrofoils and create drag to ensure the net mouth opens wide.

The scientists use acoustic data to determine at what depth they should fish, then the OOD (Officer on Deck) uses a scope table to determine how much cable to let out in order to reach our target depth. Adjustments to the depth of the head rope can be made by adjusting speed and/or adjusting the length of cable released.

The scientists use more acoustic data sent from the turtle to determine when enough fish are caught to have a scientifically viable sample size, then the entire net is hauled in. Once on board, the crew uses a crane to lift the codend over to the lift-table. The lift-table then dumps the catch into the fish lab where the fish get sorted on a conveyor belt. Click on Julia’s video below to see the entire process (sped up to retain the your interest!)

Personal Log:

Belongingness

Continuing with Maslow’s hierarchy of needs, I will discuss some of the ways that the need of belongingness is met on the Oscar Dyson. There are several different ways that comaraderie is fostered on the ship: teamwork, common areas, meal time, and celebrations.

Teamwork

Remember the main goal of Leg 3 of this mission is to survey by acoustic-trawl the mid-water portion of the pollock population. To ensure that the goal of the mission is accomplished, several crews are necessary: engineering, officer, deck, and science crews. People assigned to a crew work together, and there is cross-talk between crews. For example, on the bridge where the officers work, there are two to four people navigating the ship and instructing the deck crew. The deck crew works together to put out and pull in the trawling nets, and the engineering crew works together to make sure the ship is operating properly. Similarly, the scientist crew members consult with each other while: reading the acoustics on the computer screens; deciding when, where, and how long to trawl; determining the best way to process the trawl; and reconciling the “catch” with the acoustical data. The collaboration within and between the four crews mimics a sports team that has offensive and defensive strings working together to maintain their positions to accomplish a common goal.

Common Areas

The ship is like a house with many rooms. Most of the staterooms (bedroom/bath) are shared. In terms of “living space” there is one dining area (called the galley), a conference room with books where people meet for drills or quiet work, a movie room, a laundry room, and an extra rest room. Because all these areas are shared, “ship etiquette” is followed, meaning that every individual keeps his or her space neat and also keeps the other common areas clean and organized. Sometimes, reminders are placed in areas where ship etiquette needs polishing.

Reminder of Ship Etiquette in Common Restroom

Meal Times
Meals on the Oscar Dyson are during one hour windows three times a day. Breakfast is served from 7 to 8 am, lunch 11am to noon, and dinner 5 to 6 pm. Unless people are sleeping or actively involved in trawling or processing, they eat at these times. Therefore, mealtime is a time to chat, joke, ask questions, and tell stories.

Galley Reminder


Celebrations
We have had three celebrations. Two of these were for birthdays celebrated on the ship. The stewards made a cake for dessert in one instance and hosted an ice cream social in the second. Another celebration was when we were in Prince William Sound to pick up net repair supplies. Because we were near land for the first time in many days and the sun was shining, many people came on deck at the same time to take pictures. Some spotted porpoises which added to the excitement. Fellow Teacher at Sea, Julia Harvey, captured a wonderful video of this event.

Did You Know?

The ship stewards are the people who plan and prepare the meals for those on board. Adam (below) is the second cook on the Oscar Dyson. He worked in various restaurants in Portland before coming to NOAA as a General Vessel Assistant (GVA) helping with the different crews on various ships as needed. When the spot as a steward opened on the Oscar Dyson, Adam got the job. He has taken various NOAA training courses for stewardship and is on the ship nine months out of the year as it surveys both in the Bering Sea and the Gulf of Alaska.

Something to Think About:

Today’s episode of Trawling Zoology features the animal family, Cnidaria. Cnidaria is a word that originates from the Greek word cnidos which means “stinging nettle.” Although the cnidarians are a very diverse family, all the members contain nematocysts (combination of Greek words nema meaning “thread” and kystis meaning “bladder”), basically barbed threads tipped with poison. If you have ever been stung by a jellyfish, you have felt this stinging sensation.

There are four very diverse groups of cnidarians: Anthozoa which includes true corals, anemones, and sea pens; Cubozoa, the amazing box jellies with complex eyes and potent toxins; Hydrozoa, the most diverse group with siphonophores, hydroids, fire corals, and many medusae; and Scyphozoa, the true jellyfish. We have brought up several members of these groups in our trawling.

Anthozoa: We have brought on deck both sea pens and sea anenomes. In both groups there was only one species represented.

Sea Anenomes (hermit crabs in front are not anthozoans)

Schyphozoa: We brought up a couple of different species of jellyfish; we used a classification field guide to help us identify them.

Jellyfish from the Invertebrate Field Guide for Alaskan Waters

Many Jellies (members of the Aequorea genus) Found in the Methot Trawl

To learn more about the Cnidaria Family, click the Cnidaria on the picture below, and stay tuned for further exploration of this animal Tree of Life.

Can you spot the Cnidarian on the Tree of Life? Click on it to learn more.

July 28, 2013August 20, 2021

Melissa George: Do You Hear What I Hear? July 28, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22 – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: Sunday, July 28, 2013

Current Data From Today’s Cruise

Weather Data from the Bridge
Sky Condition: Cloudy
Temperature: 14° C
Wind Speed: 4 knots
Barometric Pressure: 1025.1 mb
Humidity: 90%

Sun and Moon Data
Sunrise: 5:57 am
Sunset: 10:34 pm

Moonrise: 11:52 pm (July 27, 2013)
Moonset: 2:35 pm

Geographic Coordinates at

Latitude: 59° 53.3′ N
Longitude: 149° 00.0′ W

The ship’s position now can be found by clicking: Oscar Dyson’s Geographical Position

False Point on Kenai Peninsula (viewed this morning through the fog)

Science and Technology Log

How do scientists use acoustics to locate Pollock (and serendipitously other ocean creatures)?

Scientists aboard the NOAA Research Vessel Oscar Dyson use acoustic, specifically hydroacoustic data, to locate schools of fish before trawling. The trawl data provide a sample from each school and allow the NOAA scientists to take a closer look by age, gender and species distribution. Basically, the trawl data verify and validate the acoustics data. The acoustics data, collected in the Gulf of Alaska in systematic paths called transects, combined with the validating biological data from the numerous individual trawls, give scientists a very good estimate for the entire Walleye pollock population in this location.

This screen is showing the echogram from the EK 60 echosounder during a trawl at 83.13 meters. The red line in the middle of the screen is the ocean floor. The colorful spikes above the red line indicate “backscatter” that is characteristic of capelin, a small fish that pollock feed on.

Hydroacoustics (from Greek words: hydro meaning “water” and acoustics meaning “sound”) is the study of sound in water. Sound is a form of energy that travels in pressure waves. In water, sound can travel great distances without losing strength and can travel fast, roughly 4.3 times faster in water than in air (depending on temperature and salinity of the water).

Click on this picture to see how sound travels from various ocean creatures through water. (Photo from sciencelearn.org)

The Oscar Dyson has powerful, extremely sensitive, carefully calibrated, scientific acoustic instruments or “fish finders” including the five SIMRAD EK60 transducers located on the bottom of the centerboard, the SIMRAD ME70 multibeam transducer located on the hull, and a pair of SIMRAD ITI transducers on the trailing edge of the centerboard.

Image of acoustic instruments on the Oscar Dyson. (Photo courtesy of NOAA Teacher at Sea Program)

This “fish-finder” technology works when transducers emit a sound wave at a particular frequency and detect the sound wave bouncing back (the echo) at the same frequency. When the sound waves return from a school of fish, the strength of the returning echo helps determine how many fish are at that particular site.

The green ship’s transducer is sending out sound waves towards the fish. The waves bounce back echoes towards the ship that are received by the transducer. (Photo courtesy of Oracle Thinkquest)

Sound waves bounce or reflect off of fish and other creatures in the sea differently. Most fish reflect sound energy sent from the transducers because of their swim bladders, organs that fish use to stay buoyant in the water column. Since a swim bladder is filled with air, it reflects sound very well. When the sound energy goes from one medium to another, there is a stronger reflection of that sound energy. In most cases, the bigger the fish, the bigger the swim bladder; the bigger the swim bladder, the more sound is reflected and received by the transducer. The characteristic reflection of sound is called target strength and can be used to detect the size of the fish. This is why fish that have air-filled swim bladders show up nicely on hydroacoustic data, while fish that lack swim bladders (like sharks) or that have oil or wax filled swim bladders (like Orange Roughy), have weak signals.

The above picture shows the location of the swim bladder. (Photo courtesy of greatneck.k12.ny.us)

These reflections of sound (echoes) are sent to computers which display the information in echograms. The reflections showing up on the computer screen are called backscatter. The backscatter is how we determine how dense the fish are in a particular school. Scientists take the backscatter that we measure from the transducers and divide that by the target strength for an individual and that gives the number of individuals that must be there to produce that amount of backscatter. For example, a hundred fish produce 100x more echoes than a single fish. This information can be used to estimate the pollock population in the Gulf of Alaska.

The above picture shows a computer screen with dense red “backscatter” characteristic of large amount of fish. The yellow lines above and below the backscatter show the location of the trawl lines. — The above picture shows a computer screen with dense red “backscatter” characteristic of large amount of fish, most likely pollock. The yellow lines above and below the backscatter show the location of the trawl lines.

Personal Log:

Safety

Continuing with Maslow’s hierarchy of needs, I will continue up the pyramid (see below) and discuss some ways that the basic need of safety is met on the ship. The safety and security of all staff (as well as sea animals we encounter) are top priority on the Oscar Dyson. There are constant reminders of this priority during ship life.

: A Version of Maslow’s Hierarchy of Needs

Safety Drills

On the first day of our travel, before the Oscar Dyson was far from port at Kodiak, we had three drills. The fire drill and man overboard drill required me to report to the conference room and meet up with the rest of the science team. Patrick, the lead scientist, then reported that we (the scientist team) were all accounted for. The crew had more complex tasks of deploying a small boat and retrieving “the man overboard”.

The other drill was the abandon ship drill. On the ship, every person is assigned to a life boat (mine is Lifeboat 1). When the drill commenced, I reported to my muster, the portside of the trawl deck, with survival gear: jacket, hat, survival suit and life preserver. We will have drills weekly at anytime.

Safety Gear

When working in the lab, the scientists wear orange slickers, boots, and gloves, not only to keep clean, but to protect us from anything that might be dangerous (fish spines, jellyfish tentacles, and so on). When on deck, we must wear hardhats (to protect from falling objects from the crane or trawl) and life preservers like the rest of the crew.

Water Tight Doors

Watertight doors are special types of doors found on the ship which prevent the flow of water from one compartment to other during flooding or accidents. These doors are used onboard in areas, such as the engine room compartment, science and acoustics labs, and control bridge, where chances of flooding are high.

These are just a few examples of how safety is emphasized on the ship. There are reminders in one’s line of vision constantly.

Safety, Everyone's Responsibility — Safety, Everyone’s Responsibility

Did You Know?

There are various seafarer or crew positions on the Oscar Dyson. A ship’s crew can generally be divided into three main categories: the deck department, the engineering department, and the steward department. Rob and Greg are members of the deck department; both men hold Merchant Mariner Credentials as “Able Bodied Seamen” or ABS. Rob is from Boston, Massachusetts and went to school for seamanship in Fairhaven, MA. He considers his NOAA position as a good job with a good income, but his main profession is lobstering which he does on the open sea when he is not working for NOAA. Rob says, “The ocean is in my blood” and always wanted to work on it. Greg, on the other hand, chose to be a Merchant Mariner after a voyage at sea. He moved to Texas from Louisiana in his 20’s, went fishing for the first time, and got seasick. He considered battling seasickness a challenge, and thus pursing seamanship as a career. In his free time he is a free-lance photographer and journalist. Below are some pictures of Greg and Rob on the job. Notice they are always wearing their safety gear.

Greg and Rob Bringing in the Trawling Net

Greg and Rob, Preparing for a Camera Drop

Something to Think About:

Since I will begin teaching Zoology later in August, I have decided to highlight some of the animals that the scientist team has found in our trawls. Today’s feature will be one of the simplest multicellular animal families, the Porifera. Porifera is a word formed from combining the Latin words porus which means “passage-way” and fera meaning “bearing.” Porifera, commonly referred to as sponges, have tiny pores in their outer walls that filter water to get nutrients.

Various Porifera (Sponges) from a Bottom Trawl

Teacher (me) Demonstrating How Water Flows out the Osculum (opening) of a Poriferan

To learn more about the Porifera Family, click the Porifera on the picture below, and stay tuned for further exploration of this animal Tree of Life.

Tree of Life: Can you spot the Poriferan?

July 26, 2013August 20, 2021

Melissa George: Crossing the Line, July 25, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22 – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: Thursday, July 25, 2013

Current Data From Today’s Cruise

Weather Data from the Bridge (at 6:00 am Alaska Daylight Time)
Sky Condition: Fog
Temperature: 12° C
Wind Speed: 11 knots
Barometric Pressure: 1017.5 mb
Humidity: 87%

Sun and Moon Data
Sunrise: 5:51 am
Sunset: 10:40 pm

Moonrise: 10:57 pm (July 24, 2013)
Moonset: 10:37 am

Geographic Coordinates (at 6:00 am Alaska Daylight Time)

Latitude: 58° 30.5′ N
Longitude: 148° 47.7′ W

The ship’s position now can be found by clicking:

Oscar Dyson’s Geographical Position

Science and Technology Log

How can you determine the population size of species? You could count every member of the population. This would be the most accurate method, but what if the individuals in the population move around a lot? What if the population is enormous and requires too much time to count each individual? For example, krill is a small crustacean (usually between 1 and 6 cm long) that accounts for 400-500 million metric tons of biomass in the world’s oceans. Would you want to count all of the krill in the Gulf of Alaska?

Often, ocean populations of animals are just too large to count. Sampling, or collecting a manageable subset of the population and using the information gathered from it to make inferences about the entire population, is a technique that ocean scientists use. There are a variety of ways to sample.

One method is called mark and recapture. In this method, one catches individuals from the population, tags them, and releases them in a certain area. After a set amount of time, an attempt is made to recapture individuals. Data are compiled from the recaptures and the population is mathematically calculated. Tuna populations in some areas are monitored this way; fishermen are required to report any fish that are recaptured. (Photo courtesy of Western Fishboat Owners’ Association)

Another method is quadrat sampling. The organisms in a subset area (quadrat) are counted and then the overall population in the entire area is calculated. For example, in the picture below, one quadrat would be randomly selected and the organisms counted. From this count the overall population would be extrapolated. (Photo courtesy of BBC Bitesize Biology)

The sampling method used on the Oscar Dyson employs the use of a transect line. The picture below illustrates the use of a transect line. On various increments along the transect line, samples of populations are taken. Imagine the Oscar Dyson’s path on the sea as the measuring tape and the trawl net is the sampling square. (Photo courtesy of Census of Marine Life Organization)

The overall survey area of the pollock study this summer is the northern Gulf of Alaska between the shore and the continental break. Within this area transect lines were established. These are pathways that the Oscar Dyson will travel along and periodically take samples of the fish.

The current set of transects are 25 nautical miles apart and are parallel, but transects in other areas may be 2 or 5 nautical miles apart. One nautical mile is equal to 1/60 of a degree (or 1 minute ) of latitude. Transects that we are following now are located on the shelf and are perpendicular to the coastline. Transects in inlets and bays may run differently, perhaps even zigzag.

Screen Shot of Oscar Dyson Transect Line Travel

If fish are located through acoustics monitoring off the transect line, the ship might break transect (a mark is made on the map), circle around to the desirable position, and collect a sample by trawling. The population of pollock can then be mathematically calculated from counting the sample. After trawling, the ship will return to the break and continue along the transect line.

Most days, scientists hope that the Oscar Dyson will finish a transect line by nightfall and then the ship can be at the next transect by sunrise. This maximizes the time for detecting fish acoustically and trawling to collect samples.

Personal Log:

In his 1943 paper “A Theory of Human Motivation,” Abraham Maslow, a developmental psychologist, proposed a hierarchy of needs which focus on describing the stages of growth in humans. The largest, most fundamental needs are at the bottom, and as those are satisfied, individuals are able to progress up the pyramid. So, I am going to use this diagram (somewhat tongue-in-cheek) to discuss how basic needs are met on the ship. In today’s blog, I will begin the discussion at the bottom level (where else?).

The bottom layer includes the most basic physiological needs one requires for survival: food, water, warmth, and rest. (We might also include exercise in this level). So, let us begin at the beginning.

Food

Food is available in the galley. It is planned for and shopped for before the mission. Chief Steward, Ava, and Second Cook, Adam, do an excellent job preparing and executing delicious, healthy meals at set times during the day (Breakfast: 7 to 8 am, Lunch 11 am to noon, Dinner 5 to 6 pm). Since the staff on the ship are working around the clock, there is always food available (salad bar, cereal, yogurt, peanut butter and jelly sandwiches) if meal time is missed for sleeping. Below is a photo of the galley. (What are those neon yellow things on the bottom of the chair legs for, do you think?)

Water

Water is needed for in several capacities on the ship. The staff on the ship needs potable water to drink and to cook with. Additionally, water is needed for washing dishes, bathing, flushing toilets and doing laundry.

To get clean drinking water, we pump the salt water from the ocean into a desalination unit (a distiller). The distilled water is then sent to a 10,000 gallon holding tank. When water is needed, it is pressurized so that it will move to the faucets, drinking fountains, showers, and so on.

Water is also needed on the ship in the lab and on the deck to clean up after the catch is hauled in and processed. The water used here is salt water and is pumped onto the boat directly from the ocean.

Rest

Half of the staff on the ship is working around the clock; the other half is resting. For the science staff, there are two shifts, a morning shift (4 am to 4 pm) and an evening shift (4 pm to 4 am). The shifts are staggered at these hours so that the evening shift will be able to share two meals with the rest of the staff (usually lunch and dinner). In most cases, two people share a stateroom: one works days and the other works nights. Because the quarters are close on a ship, this gives each person some time alone in the room to sleep, bathe, and take care of other personal needs. A stateroom consists of a bunk bed, a desk, two lockers, and a bathroom/shower. Below are some photos of the stateroom that I share with my roommate, Abby. (Note: Because rooms are small and space is shared, it is not advisable to bring a large purple suitcase that won’t fit inside one’s locker.)

Exercise

There are two workout areas on the ship. One workout area has a treadmill, an elliptical machine, a bike, and a yoga mat; the other has a treadmill, a rowing machine, and some free weights. There are limited walking spaces on the ship, so these machines provide a way to stretch one’s legs, so to speak.

Did you Know?

With a bachelor’s degree in science, math, or engineering and a 6 month training program at the US Coast Guard Academy in New London, CT, one can serve the United States as a member of the National Oceanic and Atmospheric Administration’s Commissioned Officer Corps (NOAA Corps). Members of the NOAA Corps serve as operational experts, taking researchers to sea and helping to generate environmental intelligence. My roommate, Abby, serves as a member of the NOAA Corps.

This is Abby’s second cruise with the NOAA Corps. She has a bachelor’s degree in chemistry and just completed her NOAA officer basic training. One of her tasks is to be ready to deploy specific measures in case of a fire on board. Below, she is reviewing all of the locations on the Oscar Dyson with fire response equipment. For more information on NOAA Corps, click on the link.

Something to Think About

Knowing geography is essential to various positions on the ships such as scientific exploration and navigation. Many types of maps are seen on board, for example, computer generated bathymetric maps show the contour and depth of the ocean. Equally valuable are the “old school” tools (paper maps, compasses, straight edges, and pencils) used to plot the ship’s course.

Fun Fact

Etymology is the study of the origin of words. Many of the words in science originate from ancient languages such as Greek or Latin. For example, the word etymology comes to us from two Greek words: etymon meaning “the true sense of a word“ combined with logia meaning “doctrine, study.” Combining these two roots gives us “the study of the true sense of words,” which can be said to be the meaning of the word etymology.

Here are some root words I came across today all originating from Greek words:

zoo-from zoion meaning “animal”

phyto-from phyto meaning “plant”

plankton-from planktos meaning “drifting” or “wandering”

vorous-from vorous meaning “eating”

In the blogs thus far, I have discussed two species: walleye pollock and one of their prey, krill. Krill are classified as zooplankton, literally “animals that drift. ” Krill eat phytoplankton, or “animals that drift.” Pollock are considered to be zooplanktivorous, or “drifting animal eaters.” An award winning short video explaining The Secret Life of Plankton can be viewed by clicking on the link.

July 25, 2013August 20, 2021

Melissa George: Yakutat or Bust, July 24, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22, – August 9, 2013

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: Wednesday, July 24, 2013

Current Data From Today’s Cruise

Weather Data from the Bridge (6:00 am Alaska Daylight Time)
Sky Condition: Scattered Clouds
Temperature: 12º C
Wind Speed: 12 knots
Barometric Pressure: 1017.2 mb
Humidity: 93%

Sun and Moon Data
Sunrise: 5:40 am
Sunset: 10:38 pm

Moonrise: 10:36 pm (July 23, 2013)
Moonset: 9:11 am

Geographic Coordinates (6:00 am Alaska Daylight Time)
Latitude: 58º 30.5’ N Longitude: 150º 53.9’ W

The ship’s position now can be found by clicking:

Oscar Dyson’s Geographical Position

Science and Technology Log

This blog is titled Yakutat or Bust because there is a great deal of hope to complete the survey around Yakutat, Alaska in the southeast. On the map below, the green mark is our position in the water near Kodiak Island (the survey actually began a bit west near the islands of Four Mountains) and the red is our final destination of Yakutat Bay. (Photo courtesy of GoogleEarth)

http://www.msc.org/track-a-fishery/fisheries-in-the-program/certified/pacific/gulf-of-alaska-pollock

The purpose of this cruise is to survey the walleye pollock (Theragra chalcogramma) in the Gulf of Alaska. Pollock is a significant fishery in the United States as well as the world. Pollock, a certified sustainable fishery, is processed into fish sticks, fish patties and imitation crab. Last year, about 3 million tons of pollock were caught in the North Pacific. The scientists on board will collect data to determine the pollock biomass and age structure. These data are used with results from other independent surveys to establish the total allowable pollock catch.

According to the Alaska Fisheries Science Center, typically pollock grow to about 50 cm and weigh about .75 kg. They live in the water column and feed on small krill, zooplankton, and small fish as they grow. As they age they will eat other pollocks. Sexual maturity is reached around age 4. Spawning and fertilization occurs in the water column in early spring. The eggs stay in the water column and once hatched are part of the zooplankton until they are free swimming.

The general process used to catch the pollock involves multiple parts. I will break down those steps in a series of blogs. But basically, acoustics are used to locate fish in the water column. Once the scientists have located the fish along the transect (transects are the paths that the ship will travel on so the scientists can collect data), the Oscar Dyson sets out a trawl equipped with a camera. The trawl is brought in and data from the catch is documented. And then the ship continues on.

Bringing in the Aleutian Wing Trawling (AWT) Net

Trawling is usually completed only during daylight hours. Fortunately the sun does not set here in Alaska right now until after 10 pm. When it is dark, work aboard the Oscar Dyson continues. For example, one of the scientists is documenting the sea floor with a drop camera. She is looking at life that is there as well as potential threats to the trawl nets for the bottom trawl surveys.

Questions to Think About:

How do scientists use acoustics to locate pollock?
How are the transects locations determined?
How are pollock and the rest of the catch processed?
What information is retrieved from the trawl camera and other types of sensors?
What is a bottom trawl and how is it different from a mid-water trawl?
What types of careers are available on the Oscar Dyson?

Personal Log:

Before we left Kodiak Island on July 22, I was able to spend a day exploring alone and with some of the members of the science team while the crew prepared the ship. The town of Kodiak is one of seven communities on the island and the central location for all commercial transportation on and off the island either by airplane or ferry boat.

Kodiak is the ancestral land of the Sugpiaq, native Alaskans of the Alutiq Nation, who subsisted by hunting, fishing, farming, and gathering. Russian explorers were the first outsiders to visit the island, and under Grigory Shelikof, established a settlement in 1792 that became the center of Russian fur trading. Following the 1867 Alaska Purchase from Russia, the island and the rest of Alaska became the 49th of the United States in 1959. Russian influence is still apparent on Kodiak: the Shelikof Strait separates Kodiak Island from mainland Alaska and the Holy Resurrection Russian Orthodox Cathedral holds a full house on Sunday mornings.

Holy Resurrection Russian Orthodox Church

Flora and fauna are abundant in this beautiful location. On a short hike, I was able to sample the delicate salmonberries; fear the beautiful, yet invasive and poisonous hogweed; and watch a gorgeous sunset.

Did You Know?

The background of scientists on the Oscar Dyson varies; however, most have a strong affinity for the ocean and spent a lot of time outdoors exploring nature and playing with various critters as children. Kirsten, for example, is a post-doctoral researcher funded by the National Research Council. She has a BS degree in Marine Biology from Roger Williams University in Rhode Island as well as MS and PhD degrees in Oceanography and Coastal Sciences with a concentration in Fishery Science from Louisiana State University in Baton Rouge. She came aboard the ship to develop a time series of krill distribution in the Gulf of Alaska and to relate that to other species of importance such as pollock.

Kirsten's Krill Collection — Kirsten’s Krill Collection

Something to Think About:

STEM (Science, Technology, Engineering, and Math) are not the only important subjects to know to work on the Oscar Dyson. All three crews on the ship (NOAA Corp, Deck/Fishery Crew, and Scientists) use writing every day. Below are pictures of two log books: one records Weather Data by the NOAA Corp and the other Scientists’ notes.

Scientists' Trawling Log — Scientists’ Trawling Log

Fun Fact:

Alaska’s official flag is based on a design by Benny Benson, a thirteen year old boy. It was submitted in a territory-wide contest for schoolchildren sponsored by the American Legion in 1926. Benny Benson chose the background color of the flag to represent both the blue sky and the forget-me-not. The Alaska legislature later named the forget-me-not as Alaska’s official state flower. The flag inspired the state song, the lyrics of which are seen in the picture below. Marie Drake wrote the lyrics, and Elinor Dusenbury composed the song.

July 20, 2013August 20, 2021

Melissa George: Contemplating Kodiak, July 20, 2013

NOAA Teacher at Sea
Melissa George
Aboard NOAA Ship Oscar Dyson
July 22–August 9, 2013

Mission: Alaska Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: July 20, 2013

Introductory Blog

Greetings from Lafayette, Indiana, where I recently moved back after spending two years in Washington, D.C. as an Albert Einstein Distinguished Educator Fellow at the National Science Foundation in the Division of Environmental Biology. In my recent position, I learned of many of the interesting research projects that ecosystem ecologists, population and community ecologists, systematic biologists, and evolutionary biologists are working on in various parts of the world. Beginning this fall, I will be returning to the Lafayette School Corporation to teach Biology and Zoology at Jefferson High School in Lafayette, Indiana. I am excited to integrate aspects of the research I have learned about into my classroom.

Enhancing my understanding will be the authentic research experience in the Gulf of Alaska as a NOAA Teacher at Sea. I will fly to Kodiak Island and board NOAA Ship Oscar Dyson, a support platform to study and monitor various aspects of the ocean: environmental conditions, habitat assessments, and marine mammal, fish, and bird populations.

This particular mission will be surveying the population of a species of fish called Alaskan pollock or scientifically speaking, Theragra chalcogramma. These fish belong to the cod family and are one of the United States’ most valuable fisheries; they are typically sold as fish sticks, fish patties, or imitation crab, scallops, or shrimp. Pollock populations vary from year to year, thus fish surveys, help to enact management practices as well as monitor the effects of climate change.

This adventure is exciting to me for several reasons. First, growing up on the Pacific Coast in Santa Cruz, California I fell in love with the ocean at a young age. I realize the importance of respecting the ocean and the ecosystems within it and around it. Having spent the second half of my life in the Midwest, I have missed its calming effect as well as the wealth of ecological wonders it holds. I escape to the ocean whenever I have the chance. Below is a picture of me resting on the beach at Halawa Bay on the east end of Molokai, one of the Hawaiian Islands.

Second, I hope to incorporate what I learn about how ocean scientists monitor various animal populations into my high school classes. There are so many aspects to this endeavor, I think my students will be excited to learn about many, if not all, of them.

Fun Fact:

I have four traveling companions. They are in the photo below. One of them will be accompanying me on the Teacher at Sea mission. See if you can find pictures of this traveling companion in future posts and please comment when you do!

My Four Traveling Companions: Manny, Molly, Mini Me, and Bust of Einstein