David Walker: Slowly Getting the Hang of Things (Days 3-5), June 29, 2015

NOAA Teacher at Sea
David Walker
Aboard NOAA Ship Oregon II
June 24 – July 9, 2015

Mission: SEAMAP Bottomfish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: Monday, June 29, 2015

Weather Data from the Bridge

Weather Log 6/28/15

NOAA Ship Oregon II Weather Log 6/28/15

Weather remained quite calm through Days 3-5.  I observed a couple minor rain showers during the night shift.  As noted in the above weather log from the bridge, hazy weather (HZ) on multiple occasions during Day 4.  Sky condition on Day 4 went from 1-2 oktas in the morning (FEW), to 5-7 oktas (BKN), to 8 oktas (OVC) by midday.  The sky cleared up by the evening.

Science and Technology Log

Day 3 was incredibly busy.  There were no breaks in the 12 hour shift, as there were many trawl stations, and each catch contained a very large amount of shrimp.

According to many on deck, the shrimp catches on Day 3 would have been deemed successful by commercial shrimping standards.  I got lots of good practice sexing the shrimp from the catch — I sexed over 2000 shrimp on Day 3 alone.  Sexing shrimp is fairly easy, as the gonads are externally exposed.

I also learned how to sex crabs.  This is also a simple process, as there is no cutting involved (see graphic below).  The highlight of the day was the landing of a really large red snapper.  They let me take a picture with it before taking it inside for processing.  I was absolutely exhausted at the end of Day 3 and completely drenched in a mixture of sweat, salt water, and fish guts.

Day 4, in contrast, was very slow.  The trawl net broke on one of the early stations, so the research was delayed for quite awhile.  In fact, in my entire 12 hour shift, we only had to process two catches.  We were able to complete all CTD, bongo, and Neuston stations, however, quite efficiently.  I have gotten to the point where I can serve as the assisting scientist for the CTD, bongo catch, and Neuston catch on my own.  This data also requires two fisherman on hand — one to operate the crane, the other (along with me) to guide the device or net into the water.  The fishermen with whom I most commonly work are Lead Fisherman Chris Nichols, Skilled Fisherman Chuck Godwin, and Fisheries Methods and Equipment Specialist (FMES) Warren Brown (see photo).

On Day 5, I got great practice sexing a wide variety of fish.  An incision is made on the ventral side of the fish, from the anus toward the pectoral fin.  After some digging around inside the fish, you will find the gonads — either ovaries (clear to yellowish appearance with considerable vasculature, round in cross-section often many eggs) or testes (white appearance, triangular in cross-section).  As you might guess, larger fish are much easier to sex than smaller ones, and the ease of sexing is also species dependent.  To make matter even worse, many fish are synchronous hermaphrodites (containing both male and female sex organs), and some are protogynous hermaphrodites (changing from female to male during the course of life).  The ease of sexing is also species dependent.  For instance, I have found the sexing of adult puffer fish and lizardfish to be quite easy (very easily defined organs), however I have experienced considerable difficulty sexing the Atlantic menhaden (too much blood obscuring the organs).

Field Party Chief Andre DeBose provided me with a hypoxia contour chart (see below), representing compiled CTD data from Leg 1 and the beginning of Leg 2.  According to DeBose, these contour charts are generated by the National Coastal Data Development Center (NCDDC) once out of around every 10 stations, and they represent an average of data taken by station near the ocean floor.  A data point is defined as hypoxic if the dissolved oxygen content is below 2 mg/L.  On the below chart, you can see that many hypoxic areas exist along the Texas coast, near the shore.

Bottom Dissolved Oxygen Contours

Dissolved oxygen contours for water at ocean bottom — Plotted data thus far from the SEAMAP Summer Survey (June 9 – 26, 2015)

I could not wrap my head around why this trend exists in the data, as I figured that shallower water would be warmer, allowing for more plant life in greater density, and accordingly more dissolved oxygen in greater density.  Fisheries Biologist Alonzo Hamilton helped me better understand this trend.  The fact that the water is warmer in shallower areas means that more of the dissolved oxygen leaves the surface of water in these areas.  In addition, while plant life is indeed in greater concentration in shallower water, so is the concentration of aerobic microbes.  These organisms use up oxygen through respiration to decompose organic matter.  You can see on the above graphic that the greatest hypoxia is found in areas near major runoff (e.g. Matagorda Bay and Galveston Bay).  Among other things, this runoff feeds nitrates from plant fertilizer into the ocean, which supports growth of more algae (in the form of algal blooms).  Aerobic microbes decompose this excess organic matter once it dies, taking further oxygen from the water. Although it seems counterintuitive, at least to me, the greater heat and greater organism density actually leads to a more hypoxic environment.

I am slowly getting better with the species names of aquatic organisms, but as of now, I am still focusing on common names.  The common names often relate to the fish’s phenotype, and this helps me recall them with more ease.  Common name knowledge, however, is fairly useless when it comes to entering the organisms into the computer during species counts, as the computer only has scientific (Latin) names in its database.  I hope to learn more scientific names as the week progresses.

I am also slowly amassing a really interesting collection of organisms to take back with me to LASA High School.  CJ Duffie taught me how to inject crabs with formaldehyde to preserve them.  Upon return to port, I will spray these crabs with polyurethane, to preserve the outer shell.  I have also been preserving different organisms in jars with 20/80 (v/v) formaldehyde/saltwater.  If you know me, you know I love collecting things, so this process has been particularly enjoyable.  Fisheries Biologists Alonzo Hamilton and Kevin Rademacher have been very supportive in helping me collect good specimens for my classroom.

Personal Log

Life on the ship is very enjoyable.  My bed is comfortable, the work is exciting, the meals are excellent, and the company is gregarious.  However, I have completely lost track of time and date.  My “morning” is actually 11 PM, and my “evening” is actually 1 PM.  Accordingly, my “lunch” is actually breakfast, and my “breakfast” is actually lunch.  I also never have any idea what day of the week it is.  I called my girlfriend yesterday and was surprised to hear that she was not at work (it was a Sunday).

Regarding this blog, I have finally found the optimal time to write and upload photos.  As the satellite internet is shared by all of the ships in the area, it is not possible to access WordPress during the daytime.  Accordingly, I do all of my uploading and most of my writing between 2 and 6 AM.  This works for me, as long as I can find time for the blog between research stations.

I really enjoy the people on the night shift.  Kevin Rademacher, Alonzo Hamilton, and Warren Brown provide such a wealth of knowledge.  These three are absolute experts of their craft, and it is a true honor to work with them.  I am nearing the end of my first week on the ship, and I am still learning just as much as I was on my first day – this is incredibly exciting.

I have found that Alonzo really enjoys the TV show, “Chopped,” as it seems to be on every time I enter the dry lab.  It is pretty interesting to observe him watching the show, as he enthusiastically comments on all of the dishes and regularly predicts the correct winner.

I am also getting well through one of the books I brought – Everything is Illuminated, by Jonathan Safron Foer.  It is a very odd read, but it has been enjoyable so far.

I am looking very forward to every new day.

Did You Know?

The scorpionfish that we are catching are some of the most venomous creatures in the world (see Scorpaenidae) .  These fish have spines that are coated with a venomous mucous, and their sting is incredibly painful – just ask CJ Duffie!  These fish are also incredible masters of camouflage, changing in color and apparent texture to disguise themselves, so as to catch more prey.

Notable Species Seen

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