David Madden: Engines, Dolphins, and Sharksuckers, July 24, 2019

NOAA Teacher at Sea

David Madden

Aboard NOAA Ship Pisces

July 15-29, 2019


Mission: South East Fishery-Independent Survey (SEFIS)

Geographic Area of Cruise: Atlantic Ocean, SE US continental shelf ranging from Cape Hatteras, NC (35°30’ N, 75°19’W) to St. Lucie Inlet, FL (27°00’N, 75°59’W)

On board off the coast of South Carolina – about 50 miles east of Charleston (32°50’ N, 78°55’ W) – after a slight change of plans last night due to the approaching tropical depression.

Date: July 24, 2019

Weather Data from the Bridge:
Latitude: 32°50’ N
Longitude: 78°55’ W
Wave Height: 3-4 feet
Wind Speed: 15 knots
Wind Direction: Out of the North
Visibility: 10 nm
Air Temperature: 24.6°C 
Barometric Pressure: 1011.8 mb
Sky: Cloudy

Sunset over the Atlantic Ocean
Sunset over the Atlantic Ocean
NOAA Pisces Full Track 7-20-19
This is a map from the other day outlining the path of the ship. The convoluted pattern is the product of dropping off and picking up 24 (6 x 4) fish traps per day, along with the challenges of navigating a 209 foot ship in concert with gulf stream currents and winds.



Science and Technology Log

Life and science continue aboard NOAA Ship Pisces.  It seems like the crew and engineers and scientists are in the groove.  I am now used to life at sea and the cycles and oddities it entails.  Today we had our first rain along with thunderstorms in the distance.  For a while we seemed to float in between four storms, one on the east, west, north, and south – rain and lightning in each direction, yet we remained dry.  This good thing did indeed come to an end as the distant curtains of rain closed in around us.  The storm didn’t last long, and soon gathering the fish traps resumed. 

Dave with red grouper
Processing fish: measuring length and weight of a red grouper, Epinephelus morio.
Fish Count for July 23, 2019
Yesterday’s fish count. Compare to other day’s catches: Tons of vermillion snapper, tomtate, and black sea bass. And one shark sucker (read on for more). Thank you, Zeb, for tallying them up for me. 


The highlight of yesterday (and tied for 1st place in “cool things so far”) was a tour of the engine room lead by First Assistant Engineer, Steve Clement.  This tour was amazing and mind-blowing.  We descended into the bowels of the ship to explore the engine rooms and its inner workings.  I think it rivals the Large Hadron Collider in complexity. 

I kept thinking, if Steve left me down here I would surely get lost and never be found.  Steve’s knowledge is uncanny – it reminded me of the study where the brains of London cab drivers were scanned and shown to have increased the size of their hippocampus.  (An increase to their memory center apparently allows them to better deal with the complexities of London’s tangled streets.)  And you’re probably thinking, well, running a massive ship with all its pipes and wires and hatches and inter-related, hopefully-always-functioning, machinery is even harder.  And you’re probably right!  This is why I was so astounded by Steve’s knowledge and command of this ship.  The tour was close-quartered, exceptionally loud, and very hot.  Steve stopped at times to give us an explanation of the part or area we were in; four diesel engines that power electric generators that in turn power the propeller and the entire ship.  The propeller shaft alone is probably 18 inches in diameter and can spin up to 130 rpm. (I think most of the time two engines is enough juice for the operation).  Within the maze of complexity below ship is a smooth running operation that allows the crew, scientists, and NOAA Corps officers to conduct their work in a most efficient manner. 

Dave and Steve and engines
First Assistant Engineer Steve Clement and TAS Dave Madden in the Engine Room

I know you’ve all been wondering about units in the marine world.  Turns out, students, units are your friend even out here on the high seas!  Here’s proof from the bridge, where you can find two or three posted unit conversion sheets.  Makes me happy.  So if you think that you can forget conversions and dimensional analysis after you’re finished with high school, guess again!

conversions
Posted unit conversion sheets

Speaking of conversions, let’s talk about knots.  Most likely the least-understood-most-commonly-used unit on earth.  And why is that?  I have no idea, but believe me, if I were world president, my first official action would be to move everyone and everything to the Metric System (SI). Immediately. Moving on. 

Back to knots, a unit used by folks in water and air.  A knot is a unit of speed defined as 1 nautical mile/hour.  So basically the same exact thing as mph or km/hr, except using an ever-so-slightly-different distance – nautical miles.  Nautical miles make sense, at least in their origin – the distance of one minute of longitude on a map (the distance between two latitude lines, also 1/60 of a degree).  This works well, seeing as the horizontal lines (latitude) are mostly the same distance apart.  I say mostly because it turns out the earth is not a perfect sphere and therefore not all lines are equidistant.  And you can’t use the distance between longitude lines because they are widest at the equator and taper to a point at the north and south pole.  One nautical mile = 1852 meters.  This is equal to 1.15 miles and therefore one knot = 1.15 miles/hour. 

This next part could double as a neato fact: the reason why this unit is called a “knot” is indeed fascinating.  Old-time mariners and sailors used to measure their speed by dropping a big old piece of wood off the back of the boat.  This wood was attached to some rope with knots in it, and the rope was spun around a big spool.  Once in the water the wood would act kind of like a water parachute, holding position while the rope was let out.  The measuring person could then count how many evenly spaced knots passed by in a given amount of time, thus calculating the vessel’s speed. 



Personal Log

The scientists on board have been incredibly helpful and patient.  Zeb is in charge of the cruise and this leg of the SEFIS expedition.  Brad, who handles the gear (see morning crew last post), is the fishiest guy I’ve ever met.  He seriously knows everything about fish!  Identification, behavior, habitats, and most importantly, how extract their otoliths.  He’s taught me a ton about the process and processing.  Both Zeb and Brad have spent a ton of time patiently and thoroughly answering my questions about fish, evolution, ecology, you name it.  Additionally, NOAA scientist Todd, who seeks to be heroic in all pictures (also a morning crew guy), is the expert on fish ecology.  He has been exceptionally patient and kind and helpful. 

The fish we’re primarily working with are in the perches: Perciformes.  These fish include most of your classic-looking fish.  Zeb says, “your fish-looking fish.”  Gotcha!  This includes pretty much all the fish we’re catching except sharks, eels, and other rare fish. 

For more on fish evolution here are two resources I use in class.  Fish knowledge and evolution: from Berkeley, A Fisheye View of the Tree of Life.

Fish Tree of Life Berkeley
Fish Tree of Life, from University of California-Berkeley

And check out Neil Shuban’s Your Inner Fish series.


General Updates:

  1. Plenty of exciting animals lately.  Here’s a picture of those spotted dolphins from the other day.
  2. The weather has been great, apart from yesterday’s storm.  Sunrises and sunsets have been glorious and the stars have been abundant. 
  3. We found a common octopus in the fish trap the other day.  The photo is from crew member Nick Tirikos.      
  4. I’m missing home and family. I can’t wait to see my wife and son. 
  5. That tropical depression fizzed out, thankfully. 
spotted dolphins
Spotted Dolphins
common octopus
Common Octopus (Photo by crewmember Nick Tirikos)


Neato Facts =

Yesterday we caught a shark sucker in the fish trap.  I was excited to see and feel their dorsal attachment sucker on top of their head. 

Hold on.  I just read more about these guys and turns out that sucking disc is their highly modified dorsal fin!  That is the most neato fact so far.  What better way to experience the power of this evolutionarily distinct fish than to stick it to your arm?!  The attachment mechanism felt like a rubber car tire that moved and sealed against my skin. (Brad calls them sneakerheads).

Shark sucker
Shark Sucker on Dave’s Arm

Consider all the possible biomimicry innovations for the shark sucker’s ability to clasp onto sharks and fish and turtles while underwater.  This grasp and release adaptation surely has many cool possible applications.  Here are a few: Inspiring New Adhesives.  Robotic Sticky Tech.   Shark Sucker biomimicry

I’d love to hear your questions and comments!

Kimberly Scantlebury: The Night Shift, May 10, 2017

NOAA Teacher at Sea

Kimberly Scantlebury

Aboard NOAA Ship Pisces

May 1-May 12, 2017

Mission: SEAMAP Reef Fish Survey

Geographic Area of Cruise: Gulf of Mexico

Date: May 10, 2017

Weather Data from the Bridge

Time: 15:36

Latitude: 2804.2177  N, Longitude: 9042.0070 W

Wind Speed: 10.2 knots, Barometric Pressure: 1016.8 hPa

Air Temperature: 26.1 C, Water Temperature: 24.89 C

Salinity: 36.49 PSU, Conditions: Some cloud, light wind, 2-4 foot waves

Science and Technology Log

Research vessels do not just work during the day. It is a 24/7 operation. Tonight I checked in with the night shift to learn more about the sonar mapping that has been done in the dark ever since I boarded NOAA Ship Pisces.

IMG_3081

Algebra I level math in action!

The first thing I noticed entering the dry lab was a pad of paper with math all over it. Todd, the survey technician I interviewed earlier, had noticed the the picture the ship’s sonar was producing had a curved mustache-like error in the image. Details like temperature need to be taken into account because water has different properties in different conditions that affect how sound waves and light waves move through it. He used the SOH-CAH-TOA law to find the speed of sound where the face of the transducer head was orientated. He found a six meter difference between the laser angle and what the computer was calculating. Simple trigonometry on a pad of paper was able to check what an advanced computer system was not.

NOAA Ship Pisces is also equipped with an advanced multibeam sonar. (Sonar stands for SOund NAvigation and Ranging.) In fact, there are only eight like it in the world. One of Todd’s goals before he retires from NOAA is to tweak it and write about it so other people know more about operating it. Since they are so few and you need to go to them, there are fewer publications about it.

Another mapping device is the side scan sonar. It is towed behind the vessel and creates a 300 meter picture with a 50 meter blind spot in the center, which is what is underneath the device. Hydrographic vessels have more sonars to compensate for this blind spot. The purpose of the mapping is to identify new habitat areas, therefore expanding the sampling universe of the SEAMAP Reef Fish Surveys.

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Up on the bridge looks much different. The lights are off and monitors are covered with red film to not ruin the crew’s night vision. Everything is black or red, with a little green coming from the radar displays. This is to see boats trying to cross too close in front of NOAA Ship Pisces or boats with their lights off. Lieutenant Noblitt and Ensign Brendel are manning the ship.

Ensign Brendel noted to me that, “We have all of this fancy equipment, but the most important equipment are these here binoculars.” They are always keeping a lookout. The technology on board is built for redundancy. There are two of most everything and the ship’s location is also marked on paper charts in case the modern equipment has problems.

There are international rules on the water, just like the rules of the road. The difference is there are no signs out here and it is even less likely you know who is following them. Each boat or ship has a series of lights that color codes who they are or what they are doing. Since NOAA Ship Pisces is restricted in maneuverability at night due to mapping, they have the right of way in most cases. It is also true that it takes longer for larger vessels to get out of the way of a smaller vessel, especially in those instances that the smaller one tries to pass a little too close. This did happen the night before. It reminds me of lifeguarding. It is mostly watching, punctuated with moments of serious activity where training on how to remain calm, collected, and smart is key.

Personal Log

It has been a privilege seeing and touching many species I have not witnessed before. Adding to the list of caught species is bonito (Sarda sarda) and red porgy (Pagrus pagrus). I always think it is funny when the genus and species is the same name. We have also seen Atlantic spotted dolphins (Stenella frontalis) jumping around. There are 21 species of marine mammals indigenous to the Gulf of Mexico, most in deep water off of the continental shelf. I also learned that there are no seals down here.

One of the neatest experiences this trip was interacting with a sharksucker (Echeneis naucrates). It has a pad that looks like a shoe’s sole that grips to create a suction that sticks them to their species of choice. The one we caught prefers hosts like sharks, turtles…and sometimes science teachers.

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Did You Know?

Fishing boats use colored lights to indicate what kind of fishing they are doing, as the old proverb goes red over white fishing at night, green over white trawling tonight. Vessels also use international maritime signal flags for communication during the day.

Kristy Weaver: The Sea is All I See, May 23, 2012

NOAA Teacher at Sea
Kristy Weaver
Aboard R/V Savannah
May 22, 2012-June 1, 2012

Mission: Reef Fish Survey
Geographical Location: Atlantic Ocean, off the coast of Savannah, GA
Date: May 23, 2012

Current Weather: 85 and Sunny

Hello from the Atlantic Ocean!  Right now we are about 75 miles off the coast of Savannah, GA.  and there is water all around me!  The last time we saw land was about an hour after we left the dock yesterday.

Sunset on our first night at sea

Before I left many of you asked that I be careful while I am out here.  I wanted to tell you that I am safe and that safety seems to be a very important part of being a scientist, especially when you are on a ship.  I took photographs of a lot of the safety equipment and information throughout the ship.  We even had a safety meeting before we went out to sea.  The first mate (he does a lot of work on the ship) showed us how to put on a survival suit, which is something you wear that covers your whole body and has a hood.  This suit will keep you warm and floating if something happens and you need to go into the water.

After the meeting we had a fire drill just like we have at school, except we didn’t leave the boat.  The captain (he is the leader of the ship) sounded the alarm and we all put on life vests and met on the deck.  The deck is the back of the ship–the part that is outside.  A life vest is also called a life jacket or life preserver.  A life vest is put on like a jacket, but it doesn’t have any sleeves.   It’s bright orange and gets buckled and tied around you so that you can float if you go in the water.  You can see a picture of me in my life vest in the safety video that I made.

Many children asked what type of marine life is in the water here.  Here is a list and pictures of the animals I have seen so far.

Scamp Grouper

Scamp

Black Sea Bass

Black Sea Bass

Red Porgy

Red Porgy

After we empty the traps we sort the fish by family. Jennifer (a scientist) and I are sorting Red Porgy in this picture.

After we empty the traps we sort the fish by family. Jennifer (a scientist) and I are sorting Red Porgy in this picture.

The Red Snapper is the large pink fish. The black fish is a Shark Sucker.

If you look closely you can see that the Shark Sucker has a flat head with deep pockets on it that work like suction cups.

Spotted Dolphin

Spotted Dolphin

Gray Trigger Fish

One of the fishermen caught a shark with a fishing pole.  We had to get a picture of it quickly so that we could get it back into the water as soon as possible!

AND…to answer the #1 question that I have received…(drumroll please) YES!  Someone did catch a small shark today!

Did you know that you do things in science class that I have seen real scientists do  on this ship?  What things do you think you do that make you like a real scientist?  Check my next blog to find out how you already are a student scientist!