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!

Amanda Peretich: A Community Afloat, June 30, 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: June 30, 2012

Location Data
Latitude: 54ºN
Longitude: 166ºW
Ship speed: 11.5 knots (13.2 mph)

Weather Data from the Bridge
Air temperature: 6.5ºC (43.7ºF)
Surface water temperature: 6.9ºC (44.42ºF)
Wind speed: 7 knots (8.05 mph)
Wind direction: 265ºT
Barometric pressure: 1011 millibar (0.998 atm, 758 mmHg)

Science and Technology Log
Not much science to discuss yet since we just left port at 0900 and I won’t be working in the fish lab until my 0400-1600 shift tomorrow (that’s 4am-4pm for anyone unfamiliar with military time). More to come on the pollock survey in a later post.

However, I did have the opportunity to spend a few hours up in the bridge today and I learned A TON thanks to NOAA Corps Officers ENS (ensign) Libby Chase and LT (lieutenant) Matt Davis! The chemistry teacher in me was amazed by all of the conversions used. Just a few of the things I learned today on the bridge:

Bridge

Main control panel on the bridge

* During the majority of transiting time, the Beier Radio Dynamic Positioning System is used. This is like an auto-pilot that controls the rudder to keep the Oscar Dyson on course using a gyro compass. They have nicknamed her “Betty” because she talks to you in a female voice, kinda like Siri on the new iPhone.

* A gyro compass is different from the magnetic compass that I am more familiar with using. The wind direction is measured in degrees true, which is based on true north being at 0º. Magnetic compasses have about a 9º variation, but things on the ship can also influence the deviation in the magnetic compass reading, so it is much better to use the gyro compass.

* You can drive the ship from multiple locations on the bridge. The main location looks to the bow/forward (front) of the ship. The starboard (right) location is used when the CTD is deployed (more on this later) and also whenever the boat is docked. The aft/stern (back of the ship) location is used when setting and recovering nets during a trawl. And the port (left) location is a ghost town that is rarely used.

* I learned the distance equation used in determining something called DR, or dead reckoning. This allows you to notice any set and drift while going along your course and tells where the current may or may not be pushing you to allow you to correct the course. The equation is as follows:

D = S x T
D is distance (in nautical miles)
S is speed (in knots)
T is time (in hours)

For example, if we were traveling at 11.35 knots, after 30 mins (or 0.5 hours), we should travel a distance of 5.7 nautical miles (D = 11.35 x 0.5). The bridge officers will plot this and see after half an hour if the ship has stayed on course based on the DR and the new coordinates after 30 minutes. Also, in case you didn’t know, 1 nautical mile = 1.15 miles.

* There is no common set of units for any given measurement, so everyone has to be familiar with how to do conversions. For example, when determining barometric pressure, you can use millibar, atmospheres, millimeters of mercury, torr, etc. (1 atm = 1013.25 mbar = 760 mmHg = 760 torr). For speed, you can use knots or miles per hour (1 knot = 1.15 mph).

Personal Log
What an adventure this has already been. Long story short, it took an extra day to get to Dutch Harbor due to weather conditions, giving me an overnight stay in Anchorage. I have come to discover that this is not an uncommon occurrence. It did give me a chance to meet plenty of people from the ship at the airport before we even arrived since we were all sitting around the terminal waiting on standby for flights. But I finally made it, had an exit row seat (see photo) and all of my luggage arrived with me!

Exit Row

On my second flight to Dutch Harbor, lucky enough to get in off standby AND get an exit row seat!

I had the entire day yesterday in Dutch Harbor to explore, so I ran the 3ish miles back to town, checked out the Museum of the Aleutians (history lesson!), did some shopping, and headed back to the Oscar Dyson.

DYK? (Did You Know?): Dutch Harbor was bombed by Japanese naval aircraft on June 3 & 4, 1942 during WWII (about six months after the attack on Pearl Harbor).

I was fortunate to be in the right place at the right time eating a late lunch when the opportunity to kayak in Captains Bay came up. Four of us unloaded the ocean kayaks from the ship into the water, made our way down to the kayaks, and enjoyed breathtaking views while paddling against the current (doing it this way made our return trip much easier). This was a once-in-a-lifetime experience for me and the people I was with were amazing. I plan to introduce everyone on board in a later blog so you can get to know them a little as well. I can also now say that I have swum in the freezing Alaskan waters because at the end three of us jumped in!

Kayaking in Captains Bay

Kayaking in Captains Bay in Dutch Harbor, Alaska

I was able to watch as we left port from the flying bridge (the highest bridge on the ship). Since there isn’t much to do until we are farther out to sea, today I have just done a lot of exploring and talking to people. Basically this is a little community afloat for the next 17 days. There are two things you really need to successfully live on board in such close quarters: you need to be flexible and able to work with others and you need to do your part around the ship, both on and off your shift. Our staterooms are nice (the mattress is actually extremely comfy), the bathrooms are good, we can keep our clothes clean in the laundry room, read books in the library/conference room, watch movies in the theater/lounge (we already have the Hunger Games and other new movies), the galley (where we have food access 24/7 but meals are served at 0700, 1100, and 1700) is amazing thanks to our incredible chief steward, and there are two gym areas on board to work off all the delicious calories! Check out the photos of these areas below:

Ship Spaces

Ship spaces (clockwise from top left): stateroom, bathroom, conference room, laundry room

Ship Spaces

Ship spaces (clockwise from top left): theater, galley, gym 1, gym 2

Animal Love
Before I arrived in Alaska, I thought of the bald eagle as a majestic creature that you rarely see in the wild and mostly see in zoos. Here, they have been fondly called “sky rats” by some people – they are EVERYWHERE: in the sky and on the ship. They are still gorgeous and I can’t help but take multiple photos every time I see them. Make sure to check out the link for the bald eagle and the root of its scientific name; it really makes a lot of sense! I’ve seen more eagles in the past two days than in my entire lifetime.

Bald Eagle

Bald Eagles: the “sky rats” of Dutch Harbor