Suzanne Acord: Round the Clock Fun (and Learning) at Sea, March 21, 2014

NOAA Teacher at Sea
Suzanne Acord
Aboard NOAA Ship Oscar Elton Sette
March 17 – 28, 2014

Mission: Kona Area Integrated Ecosystems Assessment Project
Geographical area of cruise: Hawaiian Islands
Date: March 21, 2014

Weather Data from the Bridge at 14:00
Wind: 6 knots
Visibility: 10 nautical miles
Weather: Hazy
Depth in fathoms: 2,275
Depth in feet: 13,650
Temperature: 25.1˚ Celsius

Science and Technology Log

The Bridge

Learning how to use the dividers for navigational purposes

Learning how to use the dividers for navigational purposes

The Sette crew frequently encourages me to explore the many operations that take place around the clock on the ship. I continue to meet new people who complete countless tasks that allow the Sette to operate smoothly and safely.

XO Haner explains how the radar functions

XO Haner explains how the radar functions on the bridge

NOAA Corps officers operate the bridge. The bridge is the central command station for the ship. NOAA Corps officers consistently ensure that everyone and everything on board is safe. Officers alternate shifts to monitor all radios and radar twenty-four hours a day.

They use numerous instruments to determine the ship’s location. A magnetic compass, maps, dividers, triangles, radar, a steering wheel, and visual observation are just a few of the resources used to guarantee we are on course. According to the NOAA Corps officers, the traditional magnetic compass continues to serve as one of the most reliable tools for navigation.

Location and weather data are officially recorded in the deck log on an hourly basis. However, officers are keeping an eye on the radar, compasses, and weather conditions every moment of the day. On top of that, they are monitoring nearby marine life, boats, and potential hazards.

Teamwork: NOAA Corps officers on the bridge

Teamwork: NOAA Corps officers on the bridge

Personal Log

Marine Mammal Observation Off the Kona Coast

Ali Bayless, Our Marine Mammal Observation (MMO) Lead, has thus far organized three MMO trips out on one of the small boats. Dropping a small boat from the Sette is a task that involves excellent and efficient communication among at least a dozen crew members. The small boat is carefully dropped into the water. Boat operators and scientists then climb down a ladder in their hard hats and lifejackets to embark on their day trip. Today, I was fortunate to take part in one of these MMO expeditions. Two scientists, two boat operators, and I ventured away from the Sette for three hours in hopes of spotting and hearing marine mammals. Excitingly, we did indeed spot up to one hundred spotted dolphins and spinner dolphins.

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If you look closely at the photos, you can see round spots on the dolphins. Our MMO lead believes these are cookie cutter shark bite marks. This is an indication that cookie cutter sharks live in this vicinity. Two of our scientists from the Monterey Bay Aquarium are hoping to return to the Monterey Bay Aquarium with live cookie cutter sharks for the aquarium’s educational exhibits. There is a good possibility that we will find these sharks in our trawl lines that will be dropped later this week.

Listening to whales using the hydrophone during small boat operations.

Listening to whales using the hydrophone during small boat operations

Science Party Interview with Jessica Chen

University of Hawaii PhD student, Jessica Chen, is working the night shift in acoustics from 16:00 to 01:00 during this IEA cruise. She displays patience and a high level of knowledge when I stopped by to pester her around 20:00. During our conversation, Jessica stated that she is from Colorado and came to Hawaii for her graduate studies. She will complete her PhD in 2015. She is interested in learning more about marine mammal behavior through acoustic monitoring and analysis.

Jessica points to the line of micronekton during a late night conversation

Jessica points to the line of micronekton during a night shift conversation

This is Jessica’s second IEA cruise. Jessica, Aimee, and Adrienne monitor our acoustic screens 24/7. In the photo above, Jessica points out the slanted line (slanting up) that represents the diel (daily) vertical migration of the micronekton. The micronekton migrate daily from around 400-500 meters up to approximately 100 meters from the surface. Many even migrate all the way to the surface. When the sun goes down, they come up. When the sun comes up, they start their journey back down to their 400-500 meter starting point. Micronekton consist of potentially billions of small organisms including larval fish, crustaceans, and jellyfish. Their behavior is not completely understood at this point, but they may be migrating at these very specific times to avoid predators.

When asked what Jessica’s long term goals are, she shares that she would like to increase personal and public knowledge of the animals in the ocean. This will allow us to better manage the ocean and protect the ocean. It is clear that Jessica truly enjoys her work and studies. She states that she especially appreciates the opportunities to see wildlife such as dolphins and whales.

Did You Know?

Cookie cutter sharks have extremely sharp teeth. Their round bite is quick and leaves a mark that resembles one that could have been made with a cookie cutter. Hence the name, cookie cutter shark.

Johanna Mendillo: Hello pollock…. can you hear me now? August 7, 2012

NOAA Teacher at Sea
Johanna Mendillo
Aboard NOAA ship Oscar Dyson
 July 23 – August 10

Mission: Pollock research cruise
Geographical area of the cruise: Bering Sea
Date: Tuesday, August 7, 2012

Location Data from the Bridge:
Latitude: 59 52 ’ N
Longitude: 177 17’ W
Ship speed:   8.0 knots ( 9.2 mph)

Weather Data from the Bridge:
Air temperature: 7.3C (45.1ºF)
Surface water temperature: 8.4C (47.1ºF)
Wind speed:  4 knots ( 4.6 mph)
Wind direction: 75T
Barometric pressure:  1018 millibar (1 atm)

Science and Technology Log:

We are wrapping up our final few sampling transects.  Now that you are practically fisheries biologists yourselves from reading this blog, students, we must return to the fundamental question— how do we FIND the pollock out here in the vast Bering Sea?  The answer, in one word, is through ACOUSTICS!

Look at all of these birds off the stern!  Why do you think they are following us?  Are we about to haul up a catch, perhaps?

Look at all of these birds off the stern! Why do you think they are following us? Are we about to haul up a catch, perhaps?

Hydroacoustics is the study of and application of sound in water.  Scientists on the Oscar Dyson use hydroacoustics to detect, assess, and monitor pollock populations in the Bering Sea.

Now, you may have heard of SONAR before and wonder how it connects to the field of hydroacoustics.  Well, SONAR (SOund Navigation and Ranging) is an acoustic technique in which scientists send out sound waves and measure the “echo characteristics” of targets in the water when the sound waves bounce back— in this case, the targets are, of course, the pollock!  It was originally developed in WWI to help locate enemy submarines!  It has been used for scientific research for over 60 years.

(PLEASE NOTE: The words sonar, fishfinders, and echosounders can all be used interchangeably.)

The transducer sends out a signal and waits for the return echo...

The transducer sends out a signal and waits for the return echo once it bounces off the fish’s swim bladder… (Source: http://www.dosits.org)

On the Dyson, there is, not one, but a collection of five transducers on our echosounder, and they are set at five different frequencies.  It is lowered beneath the ship’s hull on a retractable centerboard.  The transducers are the actual part of the echosounder that act like antennae, both transmitting and receiving return signals.

The transducers transmit (send out) a “pulse” down through the water, at five different speeds ranging from 18-200kHz, which equals 18,000-200,000 sound waves a second!

When the pulse strikes the swim bladders inside the pollock, it gets reflected (bounced back) to the transducer and translated into an image.

First of all, what is a swim bladder?  It is simply an organ in fish that helps them stay buoyant, and, in some cases, is important for their hearing.

Swim Bladder (Source: www.education.com)

Swim Bladder (Source: http://www.education.com)

Now, why do the pulses bounce off the swim bladders, you ask?  Well, they are filled mostly with air and thus act as a great medium for the sound waves to register and bounce back.

Think of it this way: water and air are two very different types of materials, and they have very different densities.  The speed of sound always depends on the material through which the sound waves are traveling through.  Because water and air have very different densities, there is a significant difference in the speed of sound through each material, and that difference in speed is what is easy for the sonar to pick up as a signal!

It is the same idea when sound waves are used to hit the bottom of the ocean to measure its depth- it is easy to read that signal because the change in material, from water to solid ground, produces a large change in the speed of the sound waves!

Here is a sonar system measuring the depth of the ocean...

Here is a sonar system measuring the depth of the ocean… (Source: http://www.dosits.org)

Interestingly, different types of fish have different shaped and sized swim bladders, and scientists have learned that they give off different return echos from sonar signals!  These show up as slightly different shapes on the computer screen, and are called a fish’s “echo signature”.  We know, however, that we will not encounter many fish other than pollock in this area of the Bering Sea, so we do not spend significant time studying the echo signatures on this cruise.

So, what happens when these signals return to the Dyson?  They are then processed and transmitted onto the computer screens in the hydroacoutsics lab on board.  This place is affectionately known as “the cave” because it has no windows, and it is, in fact, the place where I spend the majority of my time when I am not processing fish!  Here it is:

Here is Anatoli observing potential fish for us to go catch!

Here is Anatoli observing potential fish for us to go catch!

We spend a lot of time monitoring those computer screens, and when we see lots of “specks” on the screen, we know we have encountered large numbers of pollock!

Here we are approaching a LARGE group of pollock!

Here we are approaching a LARGE group of pollock!

When the scientists have discussed and confirmed the presence of pollock, they then call up to the Bridge and announce we are “ready to go fishing” at a certain location and a certain depth range!  Then, the scientists will head upstairs to the Bridge to work with the officers and deck crew to supervise the release, trawling, and retrieval of the net.

Now, in addition to the SONAR under the ship, there are sensors attached to the top of the net itself, transmitting back data.  All of the return echos get transmitted to different screens on the bridge, so not only can you watch the fish in the water before they are caught, you can also “see” them on a different screen when they are in the net!  As I told you in the last post, we will trawl for anywhere from 5-60 minutes, depending on how many fish are in the area!

Left: Echosounder at work/  Right: The "return signature" is visible on the computer!

Left: Echosounder at work/ Right: The “return signature” is visible on the computer!  (Source: http://www.dosits.org)

A full catch- success!  Without acoustics, it would be much harder for NOAA to monitor and study fish populations.

A full catch- success! Without acoustics, it would be much harder for NOAA to monitor and study fish populations.

Personal Log:

In these last few days, we have crossed back and forth from the Russian Exclusive Economic Zone (EEZ) and the U.S. several times.  There were some nice views of Eastern Russia before the clouds and fog rolled in!

I can see Russia from my ship!

I can see Russia from my ship! (Photo Credit: Allan Phipps)

In addition, we crossed over the International Date Line!  It turns out that everyone on board gets a special certificate called the “Domain of the Golden Dragon” to mark this event.  This is just one of a set of unofficial certificates that began with the U.S. Navy!  If you spend enough time at sea, you can amass quite a collection- there are also certificates for crossing the Equator, Antarctic Circle, Arctic Circle, transiting the Panama Canal, going around the world, and more…

I will award a prize to the first person who writes back to tell me what does it mean when one goes from a “pollywog” to a “shellback”, in Navy-speak!

Here is a picture of me with the largest pollock I have seen so far- 70cm!

If I am 5' 4", how many 70cm pollock would it take to equal my height?

If I am 5′ 4″, how many 70cm pollock would it take to equal my height?

Lastly, on to some, perhaps, cuter and more cuddly creatures than pollock- pets!  Here in the hydroacoustics lab, there is a wall dedicated to pictures of pets owned by the officers, crew, and scientists:

Those are some pretty cute pets left ashore...

Those are some pretty cute pets left ashore…

Clearly, this is a dog crowd!   I did learn, however, that our Chief Scientist, Taina, has her cat (Luna) up there!  Students, do you remember the name of my cat and, what do you think, should I leave a picture of her up here at sea?

Amanda Peretich: Awesome Acoustics, July 13, 2012

NOAA Teacher at Sea
Amanda Peretich
Aboard Oscar Dyson
June 30, 2012 – July 18 2012

Mission: Pollock Survey
Geographical area of cruise:
Bering Sea
Date:
July 13, 2012

Location Data
Latitude: 59ºN
Longitude: 174ºW
Ship speed: 11.7 knots (13.5 mph)

Weather Data from the Bridge
Air temperature: 7.3ºC (45.1ºF)
Surface water temperature: 7.6ºC (45.7ºF)
Wind speed: 4.3 knots (4.9 mph)
Wind direction: 12ºT
Barometric pressure: 1010 millibar (1.0 atm, 757.5 mmHg)

Science and Technology Log

How sonar works: energy (sound) waves are pulsed through the water. When it strikes an object, it bounces back to the receiver. (from http://www.dosits.org/)

How sonar works: energy (sound) waves are pulsed through the water. When it strikes an object, it bounces back to the receiver. (from http://www.dosits.org/)

Before stepping onto the Oscar Dyson, I wasn’t quite sure about much of the science going on. Did they just put the nets in the water every so often and hope to catch some fish? Carefully lean over the side of the ship saying “here fishy fishy” with the hope that the pollock would find their way into the net? Neither of these scenarios is correct (good thing I’m not actually a fisherman!). So today’s lesson is going to be all about what the chief scientist actually uses to find fish: hydroacoustics (hydro meaning water and acoustics meaning sound). This also involves SONAR, which is short for SOund Navigation And Ranging.

Fishfinding Basics

Fishfinding basics.

If you’ve ever been on a smaller boat, yacht, fishing vessel, or the like, you may have seen something called a fishfinder. The basic concepts are the same as what is happening on the Oscar Dyson. An echosounder sends a pulse of energy waves (sound) through the water. When the pulse strikes an object (such as the swim bladder in fish), it is reflected (bounced) back to the transducer. This signal is then processed and sent to some sort of visual display.

Swim Bladder

Swim bladder in a fish.
(from https://www.meted.ucar.edu/)

The Oscar Dyson uses acoustic quieting technology where the scientists can monitor fish populations without altering their behavior. The Scientific Sonar System and various oceanographic hydrophones (underwater microphones) are raised and lowered through the water column beneath the ship on a retractable centerboard. This is important so that the transducers can be lowered away from the flow noise generated by the hull, which in turn will improve the quality of data collected. In addition, there is a multibeam sonar system located on the forward hull. Ultimately the hydroacoustic data is all used as one piece to the puzzle of measuring the biomass of fish in the survey area.

OD acoustics

The different sonar signal transmitter/receivers (transducers) used on this leg of the pollock survey and their location on the ship.

Neal at work

Chief scientist Neal working away in the Acoustics lab. The second screen from the left on the upper row is showing the information from the ME70 multibeam.

So how does this all work when we are looking for fish? The chief scientist (Neal on the 0400-1600 watch) or another scientist (Denise on the 1600-0400 watch) will spend a lot of time analyzing the various computer screens in the acoustics lab, which has been affectionately termed the “cave” (no windows). They are looking at the information being relayed from both the multibeam and the EK60.

What is a multibeam? The Oscar Dyson has the Simrad ME70 scientific multibeam echosounder. It is located on the hull (underside) of the ship on the front half and sends 31 sonar beams per second down to the bottom of the sea floor.

Multibeam

Multibeam echosounder.
(from http://www.simrad.com/)

Aft of the multibeam (on the centerboard) are the five Simrad transducers. It may seem confusing, but hopefully I can walk you through a teensy little bit of how it works when we are looking to trawl for fish.

EK60 Transducer

Information from the EK60 transducer at 18kHz (top) and 38kHz (bottom).

Information from the EK60 echosounder is displayed on the far left screen in the acoustics lab while information for the ME70 multibeam is displayed on the next screen. The darker patches are showing that there are fish in that area. When the scientist first starts to see a good amount of fish, they will “mark” it and keep watching. If the screen fills up with fish (as in the EK60 image), the scientist will call upstairs to the bridge and tell them where to head back to on the transect line to start trawling. Depending on the location of the fish in the water column, it may be a bottom trawl (83-112 net), a midwater trawl (AWT net), or a methot trawl. Side note: the 83-112 midwater comparison trawl that I’ve mentioned before is done almost immediately after an AWT midwater trawl to compare the fish caught in a common area.

ME70 Multibeam

Information from the ME70 multibeam. You can determine the sea floor depth and there are five narrow beam slices from the mid-section of the multibeam (of the 31 different beams that span 120 degrees) displayed on screen.

Neal on bridge

Chief scientist Neal up on the bridge.

Then the scientist will head upstairs as the deck crew is preparing the net. One of the many sensors attached to the net is called the FS70 fishsounder or “the turtle”, and it is only used during trawls (because it is attached to the headrope). The scientist can “watch” the fish swimming under the ship using the EK60 information combined with the information from the fishsounder. The yellow “turtle” on the right in the image shows how the FS70 is flying in the water. You want minimal pitch and roll and for the front of it to be facing the back of the ship. This way, we can “see” the fish as they are going through the net. The officer of the deck and lead fisherman or head boatswain can adjust various things to keep the turtle in the right orientation. The middle image below is constantly changing on the screen in the bridge as the sonar is sweeping back and forth, so you can almost watch the individual fish enter the net. It was interesting to watch the delay between when you would see the fish from the EK60 (on the left) and when you saw them with the FS70 (middle).

Trawl Fishsounder

Display screens on the bridge used during a trawl.

Once the scientist is satisfied that enough fish have been caught for a sufficient sample size, the net will be hauled back and the acoustics work is done for just a little bit (giving Neal some time to grab some well-deserved coffee and the rest of us time to get our rain gear on to process the fish).

So some of the questions I had asked (that don’t really fit nicely in the information above):

Why do we use different frequencies in the acoustic studies?

Frequency Wavelength

Relationship between frequency and wavelength. (from http://emap-int.com)

This ties right back in to chemistry (and other sciences) with an equation and the relationship between frequency and wavelength (yay!). Basically there is an inverse relationship which means that at a high frequency there is a smaller or shorter wavelength (wavelength is the distance for peak to peak of a wave). At a low frequency, there is a higher or longer wavelength.

At a low frequency, you will see only see things that are larger, like pollock, whereas you will see very small things like krill and zooplankton at higher frequencies. Having information from both types of frequencies is necessary to complete the scientific research on the Oscar Dyson.

Single Fish

Traveling at 1 knot, showing single fish from EK60 sonar.

Is it possible to see a single fish?
Yes! From sunset to sunrise, the Oscar Dyson doesn’t actually travel the transect lines. This is because the pollock behave differently during darkness than during the day. So instead of traveling between 11 and 12 knots (which is what happens between trawls), it’s almost like the boat is just sitting around for a couple of hours. But during this time, since the boat isn’t moving along quickly, it’s possibly to see individual fish on the sonar as shown in the image.

Hydroacoustics

Hydroacoustic surveys can involve any number of different types and locations of the transducers. (from http://btechgurus.blogspot.com/2012/06/sonar.html)

Personal Log
Today is Friday the 13th but it was far from unlucky – I finally saw something out in the water other than fog: a boat! Again, all good sightings seem to come from up on the bridge, so I’m thankful for Lieutenant Matt for allowing me to ask a billion questions while I’m up there and teaching me more than I ever thought my brain could hold. He has all of the qualities of a great teacher, which is nice to see.

Ship

The ship we saw up on the bridge this morning from about 5 nautical miles away (left), on the sonar (middle), and through the binoculars (right).

Dancing in the fish lab on the Oscar Dyson

Neal and I dancing while waiting for the fish!

Highlight from the other day? Chief scientist Neal finally dressed out in his Grundens (rain gear) and came to help process a catch in the fish lab! While waiting, he even took a quick second to dance in the doorway (we were “Dougie”-ing) to my music that was playing over the speaker system.

References
NOAA Oscar Dyson flier
NOAA Oscar Dyson Ship Electronics Suite
HTI Sonar
Wikipedia: Sonar
Simrad

Marilyn Frydrych, September 25, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters
Date: September 25, 2008

Weather Data from the Bridge 
41.27 degrees N, 70.19 degrees W
Partly Cloudy with wind out of the W at 19 knots
Dry Bulb Temperature: 26.0 degrees Celsius
Wet Bulb Temperature:  20.9 degrees Celsius
Waves: 2 feet Visibility:  10 miles
Sea Surface Temperature:  21.6 degrees Celsius

Science and Technology Log 

We received a call from the Coast Guard yesterday telling us to seek shelter because of the impending interaction of Hurricane Kyle with a strong cold front approaching us. We cut our cruise a day short and headed for Woods Hole. As we headed back in I had time to reflect on my experiences over the last couple weeks. I particularly appreciated all the positive energy of the scientific crew. They were always very helpful and thoughtful as well as efficient. I learned a lot from them.  Each morning I found myself looking forward to what might unfold as we worked together.  I totally enjoyed my four or five hours of free time each day. Often I would spend this time on the bow or the fantail taking in the rhythm of the sea.  It was a very soothing experience much like watching a camp fire. The sunsets, too, brought a sense of awe and peace.

Each of the crew was a master of multiple tasks.  Jon Rockwell was not only an expert cook, but a medic as were three others aboard.  As part of their initial training with the NOAA Corps the four officers had entered a room fully in flames and totally filled with smoke.  If they had to, they could navigate by the stars. Two of the officers were NOAA trained SCUBA divers.  The engineers could fix anything whether it had to do with distilling water, leaking hydraulic pipes, stuck drawers, broken toilets, cracked welds, or the various diesel engines.  They were experts in the “green” rules governing disposal of waste.  The ET specialist could fix both hardware and software.  The scientists knew their software programs backwards and forwards.  All very impressive.

Each day brought a new, wondrous sunset.

Each day brought a new, wondrous sunset.

Marilyn Frydrych, September 24, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters
Date: September 24, 2008

Weather Data from the Bridge 
41.27 degrees N, 70.19 degrees W
Partly Cloudy with winds out of the W at 19 knots
Dry Bulb Temperature: 26.0 degrees Celsius
Wet Bulb Temperature:  20.9 degrees Celsius
Waves: 2 feet
Visibility:  10 miles
Sea Surface Temperature:  21.6 degrees Celsius

Science and Technology Log 

Marie Martin, the bird watcher, came rushing down from her perch on the flying bridge in the early afternoon announcing that she had just spotted a humpback whale close by.  We all rushed here and there to get a view. I went up to the bow and looked for about 10 minutes.  As I came back through the bridge LT(jg) Mark Frydrych, the OOD (Officer of the Deck), and Marie were talking about a right whale entangled in a net.  Mark called the captain seeking his advice.  Whenever a situation like this is observed the captain is expected to report it.  The captain told Mark to report it and let the trained people steam out to try to find it.  I interjected that I never did spot the pilot whale. Everyone said, “What pilot whale?”  Mark said he saw a right whale. Marie piped up that she had said it was a humpback whale.  Then I remembered that indeed she had said humpback whale.  At that point the whole thing was moot because the humpbacks are not endangered. Then we asked Mike, the chief scientist, what would happen if a right whale got caught in his net. He said he didn’t want to think about it.  When a sturgeon got caught he said he had two weeks of doing nothing but filling out forms.  If a right whale got caught he would probably have 2 months of paperwork.

Marilyn Frydrych, September 23, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters
Date: September 23, 2008

Weather Data from the Bridge 
42.42 degrees N, 67.39 degrees W
Cloudy with wind out of the N at 32 knots
Dry Bulb Temperature: 15.5 degrees Celsius
Wet Bulb Temperature:  11.6 degrees Celsius
Waves: 6 feet
Visibility:  10 miles

Science and Technology Log 

Yesterday we were fairly busy doing CTD casts and trawls. Today we woke to find the night crew just starting to record the lengths and weights of their large catch. We grabbed some cereal and took over from them at 5:45 a.m. They had collected and sorted all the fish. Jacquie and I took about two hours measuring, weighing, and examining the innards of the half basket of herring they left us. Our chief scientist, Dr. Mike Jech, summarized his findings so far in a short report to everyone including those back at Woods Hole: “Trawl catches in the deeper water near Georges Bank have been nearly 100% herring with some silver hake.  Trawl catches in shallow water (<75 m) have occasionally caught herring, but mostly small silver hake, redfish, butterfish, and red hake.

A night haul of herring.  Notice the brilliant blue stripe on the top of the herring. The camera’s flash is spotlighted in the reflective tape on the life vests.

A night haul of herring. Notice the brilliant blue stripe on the top of the herring. The camera’s flash is spotlighted in the reflective tape on the life vests.

Small being less than 5-6 cm in length.  We caught one haddock this entire trip.  Trawl catches north of Georges Bank have been a mix of redfish and silver hake, with a few herring mixed in.” This afternoon the Officer of the Deck, LT(jg) Mark Frydrych, gave me a run down of many of the instruments on the bridge.  I spotted a white blob on the northeastern horizon and pointed it out. He showed me where it was on the SIMRAD FS900, a specialized radar.  The SIMRAD FS900is often able to identify a ship and its name.  This time it couldn’t.  Looking through binoculars we could see it was a large container vessel.  Then we looked at a different radar and saw both the ship’s absolute trajectory and its trajectory relative to the Delaware 2.  It was on a path parallel to the Delaware2 so Mark didn’t worry about it intersecting our path.  We also noticed another ship off to the west and north of us on the radar, but we couldn’t yet see it on the horizon. It too was projected on a path parallel to us.

Then Mark pointed out an area on the SIMRAD FS900 outlined in red. It’s an area where ships can voluntarily slow to 10 knots in an effort to avoid collisions with whales. It seems that sleeping right whales don’t respond to approaching noises made by ships.  There are only about 350 to 500 of them left and they are often killed by passing ships. The Delaware 2 was steaming at about 7 knots because in the 6 ft waves it couldn’t go any faster. However the container ship was steaming at 15.5 knots.  Few ships slow down in the red zone.

Mark showed me how to fill out the weather report for that hour.   I typed in all my info into a program on a monitor which assembled all my weather data into the format the weather service uses. I first recorded our position from an instrument displaying the latitude and longitude right there above the plotting table.  I read the pressure, the wet bulb temperature and the dry bulb temperature from an instrument which had a readout in a room off to the starboard of the bridge.  The ship has two anemometers so I averaged these to get the wind speed and direction.  We looked at the waves and tried to imagine standing in the trough of one and looking up.  I figured the wave would be over my head and so estimated about 6 feet.  We also looked at the white foam from a breaking wave and counted the seconds from when it appeared until it rode the next wave. The period of the wave we watched was four seconds.  Next we looked out the window to search out any clouds. It was clear in front of us but quite cloudy all behind us.  I estimated the height of the clouds. I typed all this information into the appropriate boxes on the monitor.  It was all so much easier than my college days when we had to gather the information manually then switch it by hand into the code appropriate for the weather service.  The OOD sent this information to NOAA Weather Service on the hour, every hour operations permitting.

Personal Log 

Though my son was instrumental in persuading me to apply for the Teacher-at-Sea position I haven’t seen much of him thus far.  He’s standing the 1 to 4 shift both afternoon and night.  When I’m free he seems to be sleeping.  We don’t even eat meals together.  That’s why I made a special trip to the bridge today to meet up with him during his watch.