Amy Orchard: Day 7 & 8 – ROV, Multibeam, New Scientists, More Dolphins, September 22, 2014

NOAA Teacher At Sea
Amy Orchard
Aboard NOAA Ship Nancy Foster
September 14 – 27, 2014

Mission: Deep Habitat Classification
Geographical area of cruise: Tortugas Ecological Reserve and surrounding non-reserve area
Date: September 21 & 22, 2014

Weather: September 22, 2014 20:00 hours
Latitude 24° 25.90 N Longitude 83° 80.0 W
Few clouds, clear
Wind speed 10 knots
Air Temperature: 28.5° Celsius (83.3° Fahrenheit)
Sea Water Temperature: 29.9° Celsius (86° Fahrenheit)

CLICK ON THE SMALL PHOTOS TO MAKE THEM LARGER

SATURDAY:

The ROV

All week we have had the privilege of using the Remotely Operated Vehicle.  This model is the Mohawk 18.  It has two cameras, one that provides still photographs and the other takes high-definition video.  Both are geo-referenced so we know exactly which latitude and longitude we are working.

It has an amazing maneuverability and gets around, over and under things quite quickly.  The footage is sent back up aboard in real time via a long fiber optic umbilical cord.

This amazing piece of equipment has allowed us to see down to depths that the divers would not have been able to reach.  It has also allowed us lengthy bottom times that the divers would not have been able to sustain.  Most of the divers have been trained to dive with double air supply tanks, which affords them more bottom time, but the ROV can stay down for hours and hours at a time.  The only limitation is the stress it puts on the pilots. Jason and Lance, our pilots, said that a four hour dive is about all they can run at a time without getting extremely crossed-eyed and need a break!  However, they are troopers and we have been doing multiple ROV dives each day, some lasting up to 4 hours.

Here are some fun things we have seen.

The last ROV dive of our day (& this cruise) was to a 56’ shrimp boat wreck which was down 47 meters (154 ft) just along the boundary of the North Reserve.  We saw nine Goliath Groupers (Epinephelus itajara) all at once.  Groups of these fish are often seen on wrecks, but the scientists were a bit surprised about the high density on such a small boat.  Due to over fishing of the Goliath Grouper, about twenty years ago, a moratorium was placed on fishing them and they were being considered for Endangered Status.  After just 10 years, a significant increase in population size was observed.  It’s still illegal to bring them over board but they are not on the Endangered Species list.  Juveniles live in the mangroves but adults live in deeper waters where our scientists were able to observe them with the ROV.

During the last 6 days we spent 14 hours and 20 minutes underwater with the ROV.  The entire time was recorded in SD and the scientists recorded the most significant events in HD.  They also sat at the monitors the entire time snapping still shots as often as they saw things they wanted photos of.  957 digital stills were taken.  The longest dive was 4 hours and 10 minutes.  Our deepest dive was 128 meters (420 feet!)

The screen on the left shows the map of the area the ROV is surveying.

These maps were created by the Multibeam Echo Sounder (MBES) The ROV depends on the MBES as do the fish scientists.  Without these maps, the ROV would not know where to dive and the fish scientists would not know where to conduct their research.  The MBES gives the fish scientists a wider view of the terrain than they can get on their own by SCUBA diving in smaller areas.

Multibeam Sonar

The Multibeam Echo Sounder (MBES) uses SOund NAvigation and Ranging (Sonar) to create high-definition maps of the sea floor and it’s contours (as well as other objects such as shipwrecks) by shooting sound waves (from 512 sonic beams) down to the seabed and then listening as they reflect back up to the ship.

cartoon of MBES

On the Nancy Foster, the Multibeam Echo Sounder sends down 512 sonic beams and listens as they return. Image courtesy of NOAA

This is very similar to the way a topographic (topo) map represents the three-dimensional features (mountain and valleys) of the land above water.  Instead of using contour lines to show variations in relief, MBS uses color to depict the bathymetry (submarine topography)  Red shows the shallowest areas, purple the deepest.

Another important element of the MBES for the fish researchers is called backscatter.  This byproduct of the sonar action wasn’t always collected.  Not until advances in technology allowed for an understanding of how to gather useful information from the backscatter did technicians realized how valuable it can be.  Backscatter is the amount of acoustic energy being received by the sonar after it is done interacting with the seafloor.  It is now recognized that the information from backscatter can determine substrate type.  Different types of substrate will “scatter” the sound energy differently. For example, a softer bottom such as mud will return a weaker signal than a harder bottom, like rock.

Layering together the multibeam data (which provides seafloor depth information and is computed by measuring the time that it takes for the signal to return to the sonar) with the backscatter, provides information which is especially helpful to fish researchers as it can assist them in classifying habitat type.  This allows them to know where they might find the species of fish they are looking to study.

Engine Room

Tim Olsen, Chief Engineer, toured Camy and I through the engine room.  It was overwhelming how many wires, cranks, moving parts and metal pieces there were.  Tim and the other engineers are brilliant.  I can not fathom what it takes to keep this 187 foot ship going with it’s multiple cranes, winches, engines, thrusters, small boats, air conditioners, toilets, kitchen appliances, etc.

I was most interested in the water systems.  The ship makes all its own drinking water since salt water is non-potable and it would take a lot of storage space to carry fresh water (space its tight on a ship!)  They have two systems.  One is a reverse osmosis system which, using lots of pressure, moves sea water through a membrane to remove the salts.  This system produces 1500 gallons of potable water a day. The second one is a flash distiller.  In this system, seawater is heated by the engine and then pumped into a vacuum chamber where it is “flashes” into water vapor which is condensed and collected.  The distilling system makes 1800 gallons a day aboard the Nancy Foster.  Distillers, in some form, have been used on ships since the 1770s.

The other thing that caught my attention was the sewage treatment system.  Earth Campers, this one is a bit smaller than the one we toured!

 

sewage treatment "plant"

sewage treatment “plant”

Of course, I also took a ride out in one of the small boats to assist the divers.  Sometimes all I do is fill out the dive log and pull the buoys back into the boat but I really enjoy being out in the open ocean, feeling the sea spray in my face and watching the light move across the top of the water.

Amy on boat

I always am happy to get out on the little boats!

Mexican Train

This week Tim has been coming around every now and then wearing his Domino King’s crown and cape, reminding us all to come challenge him to a game of Mexican Train (a fun dominos game).

Mexican Train

Mexican Train is played by building runs on each others dominoes. There has been some fun and some definite sassy times.

 

Tim has won every tournament game on the Nancy Foster in the last three months and has the bling to show for it! Then tonight, to the surprise of all, one of the scientists, Mike, dethroned the king!  This was the first time ever that a member of the science team has won the championship game.

SUNDAY:

Today was a fairly quiet day.  Not too much science was done except setting out a few more fish traps.

The big news was that we steamed back to Key West and made a science crew change.  We said goodbye to Jason, Lance & the ROV as well as Sean, Brett, Linh, Alejandro, Ariel, Ben and Camy.  They will all be missed.  Be sure you see Camy’s Miami Herald news articles–the first: (http://www.miamiherald.com/news/local/community/florida-keys/article2113805.html); and second: (http://www.miamiherald.com/news/local/community/florida-keys/article2500074.html)

New Scientists

We welcomed aboard NOAA’s Mary Tagilareni, Deputy Superintendent for Operations & Education and Beth Dieveney, Deputy Superintendent for Science & Policy as well as Lonny Anderson, our new dive master.  From the FWC, Bill Sympson, Biological Scientist, as well as our conch biologists Bob Glazer, Associate Research Scientist and Einat Sandbank, Biological Scientist.

Ship Propeller 

Also while in port, a few of the crew dived under the ship to check for any calcium carbonate secreting critters that may be growing on the transducer.  While down there, they found some lobster pot line that had caught on the propeller.

Sam dives under ship

Samantha Martin, Senior Survey Technician, is seen here diving to remove the lobster pot line. Again and again I was incredibly impressed with the NOAA crew. Their skill set was so vast. Sam not only runs the multibeam system but also dives, loads the small boats on & off the ship, drives the small boats and just about anything that needs done. This was the same for all the crew members. Photo taken by Sam’s diving buddy, the Commanding Officer, LCDR Jeff Shoup.

More Dolphins

To end the evening, a pod of dolphins can by again and Ensign Conor Maginn caught this video.

WORD OF THE DAY:  Extirpated

BONUS QUESTION:  Tell me about any Sonoran Desert species which were once being listed as Threatened or Endangered (or were being considered to be listed) and then had their populations recover.

Answer to the quiz from the last blog:  Lion Fish are INVASIVE.

IMG_7087

Allan Phipps: Shhh! Be very, very quiet! We’re hunting pollock! August 7, 2012

NOAA Teacher at Sea
Allan Phipps
Aboard NOAA Ship Oscar Dyson
July 23 – August 11, 2012

Fun with Blue King Crab (Paralithodes platypus)!

Mission: Alaskan Pollock Midwater Acoustic Trawl Survey
Geographical Area: Bering Sea
Date: August 7, 2012

Location Data
Latitude: 60°25’90” N
Longitude: 177°28’76” W
Ship speed:  3 knots (3.45 mph)

Weather Data from the Bridge
Wind Speed:  5 knots (5.75 mph)
Wind Direction: 45°
Wave Height:   2-4 ft with a  2 ft swell
Surface Water Temperature: 8.6°C (47.5 °F)
Air Temperature: 8°C (46.4 °F)
Barometric Pressure: 1019 millibars (1 atm)

Science and Technology  Log:

In my last blog, we learned about how the scientists onboard the Oscar Dyson use some very sophisticated echo-location SONAR equipment to survey the Walleye pollock population.

Can the Walleye pollock hear the “pings” from the SONAR?

No.  Unlike in the movies like “The Hunt for Red October” where submarines are using sound within the human audible range to “ping” their targets, the SONAR onboard the Oscar Dyson operates at frequencies higher than both the human and fish range of hearing.  The frequency used for most data collection is 38 kHz.  Human hearing ranges from 20 Hz to 20 kHz.  Walleye pollock can hear up to 900 Hz.  So, the pollock cannot hear the SONAR used to locate them…

Can the Walleye pollock hear the ship coming?

Normally, YES!  Fish easily hear the low frequency noises emitted from ships.

A comparison of hearing ranges for various organisms showing the anthropogenic source noise overlap (courtesy of oceannavigator.com).

If you are operating a research vessel trying to get an accurate estimate on how many fish are in a population, and those fish are avoiding you because they hear you coming, you will end up with artificially low populations estimates!  The International Council for the Exploration of the Seas (ICES) established noise limits for research vessels that must be met in order to monitor fish populations without affecting their behavior.  Fish normally react to a threat by diving, and that reduces their reflectivity or target strength, which reduces the total amount of backscatter and results in lower population estimates (see my last blog).

A comparison of two ships and fish reaction to the noise produced by each.  The Oscar Dyson has a diesel electric propulsion system as one of its noise reduction strategies.  Notice the smaller noise signature (in blue) and fewer fish avoiding (diving) when the ship approaches (www.uib.no).

That is why NOAA has invested in noise-reducing technology for their fish survey fleet.  The Oscar Dyson was the first of five ships build with noise-reducing technology.  These high-tech ships have numerous strategies for reducing noise in the range that fish might hear.

There are two main sources of engine noise onboard a ship:  machinery noise and propeller noise.

The two main sources of ship noise. (www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf)

The best acoustic ship designs are going to address the following:

1)   Address hydrodynamics with unique hull and propeller design.

2)   Use inherently quiet equipment and choose rotating rather than reciprocating equipment.

3)   Use dynamically stiff foundations for all equipment (vibration isolation).

4)   Place noisier equipment toward the centerline of the ship.

5)   Use double-hulls or place tanks (ballast and fuel tanks) outboard of the engine room to help isolate engine noise.

6)   Use diesel electric motors (diesel motors operate as generators while electric motors run the driveshaft.

Propeller Design:

The U.S. Navy designed the Oscar Dyson’s hull and propeller for noise quieting.  This propeller is designed to eliminate cavitation at or above the 11 knot survey speed.  Not only does cavitation create noise, it can damage the propeller blades.

Photo of cavitation caused by a propeller. These air bubbles that form along the edge of the blades can cause damage to the propeller and cause excess noise. (www.thehulltruth.com/boating-forum/173520-prop-cavitation-burn-marks.html)

Hull Design:

The Oscar Dyson’s hull has three distinguishing characteristics which increase its hydrodynamics and reduce noise by eliminating bubble sweep-down along the hull.  The Oscar Dyson has no bulbous bow, has a raked keel line that descends bow to stern, and has streamlined hydrodynamic flow to the propeller.

An artist rendition of the NOAA FRV-40 Class ships. Notice the unique hull design. (http://www.noaanews.noaa.gov/stories2004/images/bigelow2.jpg)

Vibration Isolation:

To reduce a ship’s noise in the water, it is absolutely crucial to control vibration.  The Oscar Dyson has four Caterpillar diesel gensets installed on double-stage vibration isolation systems.  In fact, any reciprocating equipment onboard the Oscar Dyson is installed on a double-stage vibration isolation system using elastomeric marine-grade mounts.

A picture of one of the Caterpillar diesel generators before installation in the Oscar Dyson. Notice the double vibration isolation sleds to reduce noise (www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf).

Since the diesel engines are mounted on vibration isolation stages, it is necessary to also incorporate flexible couplings for all pipes and hoses connecting to these engines.

A look at one of the four diesel generators onboard the Oscar Dyson. Notice the black flexible hose couplings in place to allow vibration isolation in the white pipes.

Any equipment with rotating parts is isolated with a single-stage vibration system.  This includes equipment like the HVAC, the electric generators for the hydraulic pumps, and the fuel centrifuges that remove any water and/or particles from the fuel before the fuel is pumped to the diesel generators.

A close-up of the single sled vibration isolation system supporting the hydraulic pumps that run the deck winches.

 

Low Noise Equipment:

The only equipment that does not use vibration isolation stages are the two Italian-made ASIRobicon electric motors that are mounted in line with the prop shaft.  Both are hard-mounted directly to the ship because they are inherently low-noise motors.  This is one of the benefits of using a diesel-electric hybrid system.  The diesel motors can be isolated in the center of the ship, near the centerline and away from the stern.  The electric motors can be located wherever they are needed since they are low noise.

Even the propeller shaft bearings are special water-lubricated bearings chosen because they have a low coefficient of friction and superior hydrodynamic performance at lower shaft speeds resulting in very quiet operation.  They use water as a lubricant instead of oil so there is a zero risk of any oil pollution from the stern tube.

Acoustic Insulation and Damping Tiles:

The Oscar Dyson uses an acoustic insulation on the perimeter of the engine room and other noisy spaces.  This insulation has a base material of either fiberglass or mineral wool.  The middle layer is made of a high transmission loss material of limp mass such as leaded vinyl.

The Oscar Dyson also has 16 tons of damping tiles applied to the hull and bulkheads to reduce noise.

The Results:

All of these noise-reducing efforts results in a fully ICES compliant research vessel able to survey fish and marine mammal populations with minimal disturbance.  This will help set new baselines for population estimates nationally and internationally.

A comparison of the Oscar Dyson and the Miller Freeman. Notice that the Oscar Dyson is at or below the standards set by ICES (http://icesjms.oxfordjournals.org/content/65/4/623.full).

As you can see from the graph above, The Oscar Dyson is much quieter than the Miller Freeman, the ship that it is replacing.  You can see the differences in the hull design from the picture below.

The quieter Oscar Dyson (on right) replaced the noisy Miller Freeman (on left) http://www.afsc.noaa.gov.

Next blog, I will write about new, cutting edge technology that might reduce the need for biological trawling to verify species.

Sources:

Special thanks to Chief Marine Engineer Brent Jones for the tour of the engineering deck and engine room, and for the conversations explaining some of the technology that keeps the Oscar Dyson going.

http://marine.cat.com/cda/files/1056683/7/VRS_Commercial+Vessel+3512B%26+Commercial+Vessel+3508B+Workboat+(6-2005).pdf

www.maritimejournal.com/features101/power-and-propulsion/no_noise_for_noaa

www.publicaffairs.noaa.gov/nr/pdf/aug2002.pdf

www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf

http://icesjms.oxfordjournals.org/content/65/4/623.full

Personal Log:

I found out drills aboard ships are serious business!  Unlike a fire drill at school where students meander across the street and wait for an “all clear” bell to send them meandering back to class, fire drills on a ship are carefully executed scenarios where all crew members perform very specific tasks.  When out at sea, you cannot call the fire department to rescue you and put out a fire.  The crew must be self-reliant and trained to address any emergency that arises.  When we had a fire drill, I received permission from Commanding Officer Boland to leave my post (after I checked in) and watch as the crew moved through the ship to locate and isolate the fire.  They even used a canister of simulated smoke to reduce visibility in the halls similar to what would be experienced in a real fire!

Robert and Libby suit up during a fire drill!

Late last night, we finished running our transects!  Our last trawl on transect was a bottom trawl which brought up some crazy creatures!  Here are a couple of photos of some of the critters we found.

From left to right, Blue King Crab (Paralithodes platypus), Alaska Plaice (Pleuronectes quadrituberculatus), Red Irish Lord eating herring on the sorting table (Hemilepidotus hemilepidotus), and Skate (unidentified).

Next blog will probably be my last from Alaska.  T-T

Mary Patterson, June 29, 2009

NOAA Teacher at Sea
Mary Patterson
Onboard NOAA Vessel Rainier 
June 15 – July 2, 2009 

Mission: Hydrographic Survey
Geographical area of cruise: Pavlov Islands, AK
Date: June 29, 2009

Weather Data from the Bridge 
Broken clouds
Wind 6 kts
10 mi visibility
Pressure 1023.9 mb
Dry Bulb Temp 7.8 ˚C, 46˚ f Wet bulb 6.7˚C, 44˚ f
Seas 0-1 ft.
Water temp 7.2˚C

Small “bite” on the propeller

Small “bite” on the propeller

Science and Technology Log 

During one of the launch missions of the day, one boat ran aground on an uncharted rock. Immediately, they radioed in and announced that all were safe and they were attempting to back off the rock. Another launch in the vicinity radioed in that they were available to help if needed. Safety is always a priority! The launch was able to get past the rock safely and came back to the ship to be checked out. After the boat was picked up by the gravity davits, the damages were checked out. A few bites out of the propeller and some scrapes across the keel were the extent of the damages. I discovered that extra parts such as a propeller are often kept on board for emergencies such as this. The crew switched launches and went back out to continue surveying.

Gravity Davits

Gravity Davits

After all launches return, there is a daily survey meeting where each HIC (Hydrographer in charge) reports what they accomplished that day and any problems they had with weather, computers, hardware, software or boat issues. Many times, this turns into a great discussion and problem-solving opportunity. This is a true community of scientists communicating and sharing ideas. The group tries to understand a problem so that it is not repeated. Especially after today, I can truly understand the importance of the work this ship and its crew does every day. We saw a tug towing a barge and several fishing boats in the area today. I can only imagine what could happen if they were to run aground. The survey work being done in this area is essential for mariners. Other work done aboard the ship today included taking bottom samples from the seafloor as we moved to another anchorage. This task required communication from the bridge to the fantail (back of the boat) and the fantail to the plot room and the plot room to the bridge.  For the first shift, I worked in the plot room.  I used the Hypack software that shows an electronic navigation chart to tell the bridge where we wanted the next sample to take place.

Collecting seafloor samples

Collecting seafloor samples

The bridge navigated to that location and gave the fantail permission to sample the seafloor. The scientists on the fantail operated a claw-like device to collect the seafloor samples. As they lowered the claw, they radioed to the plot room to tell us how far down it was in 25 m increments. When it reached bottom, I marked that spot on the computer. Then, the fantail radioed as the claw came back up to the surface and finally, what was in the sample. The scientists on the fantail used a chart to identify the size and type of particles found. I made notes as to what was found in the sample on the electronic navigation chart. My partner used Caris Notebook to enter the attributes of the seafloor surface. Then, it was my job to show the bridge, via the electronic navigation chart, where the next target was located. Most of the seafloor we sampled was identified as green, sticky, mud. However, one sample held worms and another held some fine gravel and some broken shells. My next shift was down on the fantail, collecting the samples. This was a great time to dig in the mud! My final shift was back in the plot room logging in the samples.

Personal Log 

Collecting seafloor samples

Collecting seafloor samples

I was initiated into the bottom sample crew with a swath of mud smeared on my face. Later, I realized what a great sea mud mask I could have and wished I’d kept a bucket full of that mud! As we completed our transit to our next anchorage, I spent some time on the bridge. As the conning officer called out instructions, the helmsman and the EOT (Engine Order Telegraph) officer repeated the instruction and ended with “Aye.” I asked if they really had to say “Aye” and ENS Reed explained to me that “Aye” is a confirmation that they have understood the direction given. For example, If the direction was engines full ahead, and you did not say “Aye,” it would mean that the engines were already at full ahead.

Another interesting thing I found on the bridge was the words “left” and “right” on plaques attached beside the front windows on the bridge. I thought for sure that these incredibly smart mariners would know their right from their left without a visual reminder. Again, I was told that it has to do with safety and communication. Think about the times you were driving and you told someone to take a right and they went left by accident. On the ship, the order is given to go right and the helmsman looks at the plaque and turns correctly. This is crucial for stressful situations such as a whale crossing your path or narrow passages etc.

Did You Know? 

The EOT (Engine Order telegraph) term dates back to when a pilot wanting to change speed would “ring” the telegraph on the bridge, moving the handle to a different position on the dial. This would ring a bell in the engine room and move their pointer to the position on the dial selected by the bridge. The engineers would move their handle to the same position to signal their acknowledgment of the order, and adjust the engine speed accordingly. This term is still used today even though the bridge can control the engines from their control panel. The same is true of the phrase, “steam ahead.” Even though few modern ships are steam powered, it is a phrase that has come into common usage.

Hydrographer in Charge, Ian Colvert, and me with my “initiation” mud mask!

Hydrographer in Charge, Ian Colvert, and my “initiation” mud mask!