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David Walker: Florida, Speciation, and Learning All Over Again (Days 13-15), July 8, 2015

Posted on by davidwalker2015

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: July 8, 2015

Weather Data from the Bridge

Weather Log 7/7/15

NOAA Ship Oregon II Weather Log 7/7/15

The seas have remained incredibly calm, again with waves normally no higher than 1 ft.  July 7, 2015 was a beautiful day, with few (FEW, 1-2 oktas) clouds in the sky (see above weather log from the bridge).  Visibility from the bridge was 10 nautical miles (nm) throughout the day.

Science and Technology Log

After a run of around 16 hours, we finally arrived on the west coast of Florida to continue the survey.

Wow!  The organisms caught on the west coast of Florida were entirely different from those caught west of the Mississippi.  In our first trawl catch, I almost didn’t recognize a single species.

Fisheries biologist Kevin Rademacher shared with me an article, “Evidence of multiple vicariance in a marine suture-zone in the Gulf of Mexico” (Portnoy and Gold, 2012), that offers a potential explanation  for the many differences observed.  The paper is based on what are called “suture-zones.”  A suture-zone, as defined previously in the literature, is “a band of geographic overlap between major biotic assemblages, including pairs of species or semispecies which hybridize in the zone” (Remington, 1968).  In other words, it is a barrier zone of some kind, allowing for allopatric speciation, yet also containing overlap for species hybridization.  As noted by Hobbes, et al. (2009), such suture-zones are more difficult to detect in marine environments, and accordingly, have received less attention in the literature.  Such zones, however, have been discovered and described in the northern Gulf of Mexico, between Texas and Florida (Dahlberg, 1970; McClure and McEachran, 1992).

Portnoy and Gold note that “at least 15 pairs of fishes and invertebrates described as ‘sister taxa’ (species, subspecies, or genetically distinct populations) meet in this region, with evidence of hybridization occurring between several of the taxa” (Portnoy and Gold, 2012).  The below table delineates these sister taxa.  On this table, I have highlighted species that we have found on this survey.

Sister Taxa

Sister taxa found in the northern Gulf of Mexico. Highlighted are species we have encountered on this survey (Portnoy and Gold, 2012).

The figure below geographically illustrates distribution patterns of two pairs of sister species within the northern Gulf of Mexico.  We have seen all four of these species on this survey, and our observations have been consistent with these distribution patterns.

Distributions of sister taxa within the northern Gulf of Mexico

Distributions of “sister taxa” within the northern Gulf of Mexico (Portnoy and Gold, 2012)

Prior to Portnoy and Gold, hypothesized reasons for the suture-zone and allopatric speciation in the northern Gulf included “(1) a physical barrier, similar to the Florida peninsula, that arose c. 2.5 million years ago (Ma) during the Pliocene (Ginsburg, 1952), (2) an ecological barrier, perhaps a river that drained the Tennessee River basin directly into the Gulf, that existed approximately 2.4 Ma (Simpson, 1900; Ginsburg, 1952), (3) a strong current that flowed from the Gulf to the Atlantic through the Suwanee Straits approximately 1.75 Ma (Bert, 1986), and (4) extended cooling during early Pleistocene glaciations occurring c. 700–135 thousand years ago (ka) (Dahlberg, 1970)” (Portnoy and Gold, 2012).  Another explanation has been offered by Hewitt (1996), involving marine species being forced into different areas of refuge during the glacial events of the Pleistocene, allowing for allopatric speciation.  Following the retreat of the glaciers, according to this hypothesis, these species would have been allowed to come into contact again, allowing for hybridization.

Portnoy and Gold used mitochondrial and microsatellite DNA sequence data from Karlsson et al. (2009) to “determine if estimated divergence times in lane snapper were consistent with the timing of [the above] hypothesized variance events in the suture-zone area, in order to distinguish whether the Gulf suture-zone is characterized by a single or multiple vicariance event(s)” (Portnoy and Gold, 2012).

Their results suggest that the divergence of lane snapper in the northern Gulf occurred much more recently than the hypothesized events described by Ginsberg (1952), Bert (1970), and Dahlberg (1970).  These results also suggest that the explanation offered by Hewitt (1996) is an unlikely explanation for the divergence of lane snapper, for even though the time of multiple glaciations is consistent with the time of lane snapper divergence, water temperatures across the Gulf are estimated to have been within the thermal tolerance of lane snapper during these glaciations.  Evidence also suggests that a shallow shelf existed during these glaciations, representing a habitat in which lane snapper could have lived.

The explanation that Portnoy and Gold favor, in terms of explaining lane snapper divergence, is one suggested by Kennett and Shackleton (1975), as well as by Aharon (2003).  This explanation involves “large pulses of freshwater from the Mississippi River caused by a recession of the Laurentide Ice Sheet between 16 and 9 ka” (Portnoy and Gold, 2012).  This explanation would have also allowed for potential sympatric or parapatric speciation, because it contains multiple lane snapper habitat types (carbonate sediment, as well as mud and silt bottom).

Notably, the fact that the above explanation is favored by Portnoy and Gold for lane snapper divergence does not discount the explanations of Ginsberg (1952), Bert (1970), Dahlberg (1970), and Hewitt (1996), in terms of explaining the many other examples of species divergence exhibited within the northern Gulf.  It is most probable that many geological and ecological causes worked, sometimes in confluence, to create the divergences and hybridizations in species observed today.  A geographical depiction of many of the hypothesized explanations described by Portnoy and Gold is below.

Geographic Depiction

Geographical depiction of hypothesized triggers of species divergence in the northern Gulf of Mexico (Portnoy and Gold, 2012)

In addition to the species divergence observed in our survey, another interesting difference noted in our catches along the western coast of Florida was the emergence of lionfish.  These invasive species are native to the Indian Ocean and southwest Pacific Ocean, and they were most likely introduced by humans into the waters surrounding Florida.  There are two lionfish species that are invasive in Florida, P. miles and P. volitans (Morris, Jr. et al., 2008), and the earliest records of their introduction into Florida’s waters are from 1992 (Morris, Jr. et al., 2008).  Many characteristics have allowed these species to be successful alien invaders in these waters – (1) they are formidable, with venomous spines and an intimidating appearance, (2) they reproduce incredibly quickly, breed year-round, and mature at a young age, (3) they outcompete native predators for food and habitat, (4) they are indiscriminate feeders with voracious appetites, and (5) they take advantage of a sea that is over-fished, in which many of their predators are regularly being eliminated by humans (Witherington, 2012).

Life cycle of the lionfish

Life cycle of the lionfish

This invasion mechanism hauntingly reminds me of that of the Cane Toad, a very famous alien invader which has decimated the flora and fauna of Australia.  One of the main worrisome effects of lionfish around Florida is on coral reefs.  Lionfish “can reduce populations of juvenile and small fish on coral reefs by up to 90 percent…[and] may indirectly affect corals by overconsuming grazing parrotfishes, which normally prevent algae from growing over corals” (Witherington, 2012).

One of the ways in which Floridians are trying to eliminate this problem is through lionfish hunting tournaments.  CJ Duffie, a volunteer on this survey from Florida, has participated in these tournaments and also participates in lionfish research directed by the Florida Fish and Wildlife Commission.  CJ harvested the gonads of the lionfish we caught on Day 13 to take back to the lab for further analysis.  Floridians also actively promote the lionfish as a delicacy, in an attempt to encourage more people to eat the invasive species.  CJ described the fish as the best he has ever tried, so I was very easily intrigued.  A fillet was prepared from the large lionfish caught on Day 13 fish, and Second Cook (2C) Lydell Reed was able to cook it on the spot.  I agree with CJ – white, flakey, slightly sweet, this is the best fish I have ever tasted.

Personal Log

The survey is nearly over, and this will be my last post.  We are in transit back to Pascagoula, Mississippi, the ship’s home port.  I leave by plane from Mobile, Alabama for Austin on Friday, July 10, 2015.  I am eagerly anticipating walking on land, as I’ve heard it’s strange at first after being on a boat for awhile.  Apparently this weird feeling has a semi-formal name — “dock rock”.

This experience has truly been one of the best of my life, especially in terms of the raw amount I have learned every day.  Coming in, the sole knowledge of fish life I had derived from my stints fly fishing with my father, and most of this knowledge concerns freshwater fish.  I now feel as though I have a much more comprehensive knowledge of the biodiversity that exists in the Gulf of Mexico and a much greater appreciation for the diversity of life as a whole.  I have taken over 200 photos to document this biodiversity, accumulated a diverse collection of preserved specimens, and collected a wide variety of resources (textbooks, scientific papers, etc.) on marine life in the Gulf of Mexico.  These resources will surely make the preparation of a project-based activity for my students focused on this research a much easier feat.

Sharksucker (Echeneis naucrates)

Having fun with a sharksucker (Echeneis naucrates) during analysis of the last trawl catch

I have also learned how a large portion of marine field research is conducted.  We have surveyed dissolved oxygen levels in the water, plankton biodiversity, and bottomfish biodiversity throughout the northern Gulf, using established (and quite popular) research methods.  The knowledge I have gained here can be applied to the biodiversity project portion of my geobiology class, in which students conduct biodiversity surveys in local Austin-area parks and preserves.  I anxiously await the comprehensive results of this summer’s NOAA survey – the complete dissolved oxygen contour map, the biodiversity indexes for different regions of the Gulf, and plankton biodiversity data from Poland.  These data will definitely help me come to even more conclusions about the marine life in the Gulf and the factors affecting it.

Through this experience, I have also gained much appreciation for the diversity of careers that exist on board a NOAA research vessel.  I have learned about the great work of the NOAA Corps, a Commissioned Service of the United States.  I have learned from the fisherman, engineers, stewards, and other personnel on the boat, all required for a successful research survey.

First and foremost, I have to thank the science team on the night watch – fisheries biologists Kevin Rademacher and Alonzo Hamilton, FMES Warren Brown, and volunteer CJ Duffie.  These individuals were instrumental in helping me identify organisms, label my photos, and craft my blog posts and photo captions.  Kevin Rademacher provided me with most of the papers which I have referenced in this blog, and with no internet connectivity on the boat for around half of the trip, his library of information was essential.  For the “Notable Species Seen” section of this blog, Kevin also individually went through all of my species photos with me to help me add common and scientific names in the photo captions.  This took a great deal of his time, almost every day, and I am incredibly appreciative.

Night Watch

The rest of the night watch. From left to right — FMES Warren Brown and NOAA Fisheries Biologists Kevin Rademacher and Alonzo Hamilton

I also definitely need to thank Lead Fisherman Chris Nichols and Skilled Fisherman Chuck Godwin for their mentorship with CTD data collection and plankton sampling.  In addition, many thanks to Field Party Chief Andre Debose and Lieutenant Commander Eric Johnson for proofreading my blog entries and ensuring that my experience on the ship was a good one.  I enjoy learning from people much more than I enjoy learning from books, and these have been some of best (and most patient) teachers I have ever had.

Lastly, thanks so much to the NOAA Teacher at Sea staff for your work on this great program.  It truly makes a difference for many teachers and many students.  I have had an amazing time, and I am positive my students will benefit from what I have learned.

Survey Plot

The ship’s path during the survey, thus far. I have been on the boat for Leg 2, drawn in black.

Did You Know?

Lionfish venom is not contained within the tips of the fish’s spines.  Rather, glandular venom-producing tissue is located in two grooves that run the length of  each spine.  When skin is punctured by a spine, this glandular tissue releases the venom (a neurotoxin), which travels up the spine and into the wound by means of the grooves (Witherington, 2012).

Venomous Spines

Anatomy of the lionfish spine

Notable Species Seen

David Walker: Crossing the Mississippi River Delta (Days 10-12), July 5, 2015

Posted on by davidwalker2015

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: July 5, 2015

Weather Data from the Bridge

Weather Log 7/5/15

NOAA Ship Oregon II Weather Log 7/5/15

This has been some of the smoothest water I’ve seen yet on the ocean.  At times, you can’t even see wave motion on the surface of the ocean, and it looks more like a lake.  On July 5, 2015, waves were estimated to be 1 ft. in height, at most (see above weather log from the bridge).  Sky condition on July 5 began as scattered (SCT, 3-4 oktas), moved to broken (BKN, 5-7 oktas) and overcast (OVC, 8 oktas) by the afternoon and evening, and then returned to FEW (1-2 oktas) by 11 PM.  There was rain observed in the vicinity (VC/RA) at 4 PM, and some lightning (LTG) was observed in the late evening.

Science and Technology Log

The survey is still progressing smoothly.  We have just crossed the Mississippi River delta, and I have observed a much greater human presence in the water — many ships, mostly commercial shrimping vessels, and even more oil rigs than usual.

Of particular interest to me, we have caught many new species over the past couple of days.  One notable new catch on Day 11 was a giant hermit crab (Petrochirus diogenes), the largest species in the Gulf of Mexico.  In most cases, hermit crabs need to be removed from their shells in order to be successfully identified.  This process was much more difficult than I had imagined, and I ended up having to use a hammer to crack the shell.  The crab contained within was indeed large – it amazed me that such a large species could occupy such a moderately-sized shell.  After analyzing the crab in the laboratory, we quickly returned it to the ocean, in the hope that it would find another shell in which to occupy and survive.

Another interesting catch on Day 11 was a seabiscuit (Brissopsis alta).  This organism was caught at a station overlying a sandy/muddy bottom, this type of seafloor environment providing a habitat for these unique creatures.  We were able to prep the seabiscuit with bleach in the same manner in which we prepped the sand dollars a couple of days ago.  The product was a purely white – a very delicate, yet quite beautiful specimen for my classroom.  Much thanks to fisheries biologist Kevin Rademacher for his help in preparing these organisms.

On Days 11 and 12, we caught some particularly large individuals, which made for great photo opportunities.  On Day 11, we caught the largest roundel skate (Raja texana) that we’ve seen yet, and on Day 12, we netted a large gulf smoothhound (Mustelus sinusmexicanus), a shark species that interestingly has no teeth.  The rest of the night shift was encouraging me to take a photo with my hand down the shark’s mouth, but I settled for the typical catch photo.  This shark was swiftly returned to the water (head first) after laboratory analysis was conducted, and it survived the catch.

As we have to open up fish in order to sex them, it is a natural investigative temptation to look at the other anatomy inside the fish.  A usual focal point is the stomach, as many times, fish stomachs are very disproportionately bloated.  Many times, enlargement of organisms such as the air bladder, stomach, and eyes of caught fish is due to barotrauma.  When a fish is quickly taken from deep waters to the surface, the pressure rapidly decreases, causing internal gases to expand.  In certain cases, we have discovered very recently eaten fish inside organisms’ stomachs.  One particularly interesting example was the stomach of a threadtail conger (Uroconger syringinus), in which we found a yellow conger (Rhynchoconger flavus) of equal size!

Uroconger Ate Rhyncoconger

We found the yellow conger on the right inside the stomach of the threadtail conger on the left! Photo credit to Kevin Rademacher.

I have started to realize the very subtle differences between some species.  One great example of such subtle variance is found in two similar sole species – the fringed sole (Gymnachirus texae) and the naked sole (Gymnachirus melas).  The naked sole contains a faint secondary stripe in between each of the bold stripes on its back; the fringed sole does not have this stripe.  During our initial sorting of species, I unwittingly threw both of these species into the same basket.  Fortunately, fisheries biologist Kevin Rademacher noticed what I was doing and identified the distinguishing phenotypic difference.  I have adjusted the brightness, contrast, and shadowing of the below photos to make the difference in striping more apparent.

Flatfish, such as the soles above, have a very interesting developmental pattern from juvenile to adult.  Fisheries biologists Kevin Rademacher and Alonzo Hamilton were able to nicely summarize it for me.  As juveniles, they start off with eyes on both sides of their heads and swim in the same manner as normal fish.  However, once they get large enough to swim out of the current, they “settle out” onto the seafloor.  At this time, a very interesting series of morphological changes takes place.  Notably, the eyes of the fish migrate such that they are both on one side of the fish’s body.  This morphological change has clearly been evolutionary favored over generations, as it allows the fish to see with both of its eyes while slithering along the seafloor.  The side of the fish on which the eyes end up depends on the particular species of fish.  Flatfish are accordingly categorically defined as “right-eyed” or “left-eyed,” based on the side of the fish containing the eyes.  The procedure is fairly simple to define a flatfish a right-eyed or left-eyed.

  1. Look down at the side of the fish containing both of the eyes.
  2. Orient the fish such that the eye that migrated from the opposite side is on top.
  3. If the head faces left, the flatfish is defined as left-eyed.
  4. Otherwise, it is defined as right-eyed.

On many occasions, we have been able to keep some of our catch to later eat.  I have had fresh white shrimp, brown shrimp, red snapper, lane snapper, vermillion snapper, hogfish, and even paper scallops.  I have obtained lots of practice heading shrimp and fileting fish, as well as shucking scallops.  It has been very interesting to visualize the entire process, from catch to table.  It is true what they say, incredibly fresh seafood tastes much better.  Most of the credit here goes to Chief Steward (CS) Mike Sapien and Second Cook (2C) Lydell Reed, the chefs on the ship.

Also after my shift, I was able to visit the ship’s bridge for the first time during the day.  The environment at night is quite different on the bridge, as the NOAA Corps Officers driving the ship need to keep their eyes adjusted to the dark.  Accordingly, the only lights used in the bridge at night are red, reminding me of the lights used by the scientists I observed on a recent night trip to the UT McDonald Observatory.  My trip to the bridge during the day allowed me to observe the operation of the ship and many instruments clearly for the first time.  It was honestly quite intimidating — so many instruments, controls, and dials, and I had no clue what any of them did.  I was very scared to touch anything – the only instrument with which I braved to interact was a very nice pair of binoculars.  The ship is always driven by NOAA Corps Commissioned Officers.  During the time of my observation, Ensign (ENS) Laura Dwyer, a Junior Officer, and Lieutenant Junior Grade (LTRG) Larry Thomas, the ship’s Operations Officer, were on the bridge.  The Captain (Commanding Officer) of the ship, Master David Nelson, entered and exited periodically.  ENS Dwyer was very kind to point out to me different instruments on the bridge and discuss the operating of the ship.  Interestingly, the NOAA Ship Oregon II operates on a system similar to that of a car with a manual transmission – while the ship has two engines instead of one, each engine has a clutch.  There is also a controllable pitch system that allows the operator of the ship to change the angle of the propeller.  There are two RADAR devices, as well multiple GPS navigational systems, on which the stations of the survey are plotted.  The are multiples of each of these important ship systems as a safety measure.  Despite the GPS systems, the ship still has a chart table on the bridge, and even a chart room, where routes are plotted out in more detail.  The helm, which controls the rudder, is still a large, prominent wheel, just as it was in the pirate stories I read as a child.  ENS Dwyer told me, however, that helms are much more abbreviated in appearance in more modern ships.  She indicated that many members of the NOAA Corps appreciate the “vintage” feel of the bridge of the NOAA Ship Oregon II — the ship will be 50 years old in 2017!

We have more or less finished the intended stations for Leg 2 of this survey, but as we still have time left before we are due back in port, we have received orders to proceed through to Leg 3 stations.  These stations are entirely across the Gulf of Mexico, along the western coast of Florida.  The traveling time there is over 14 hours by boat, and we will be traveling more or less as the crow flies.  I am really looking forward to these new stations, as I have heard the biodiversity is vastly different.

Survey Locations

Sections of the 2015 SEAMAP Bottomfish Survey

Personal Log

Ever since my shift on Day 11, in which I felt particularly fatigued and engorged, I have been completing cardio workouts daily.  There is quite a bit of workout equipment stored in various places throughout the ship, and I have finally found an enjoyable cardio workout.  I am using a rowing machine that I found on the top deck of the ship, and I set it up to face the direction of the ship’s movement.  In this way, when I row, I feel as though I am actually pushing the boat through the water.  The wave motion and periodic jostling of the ship makes the rowing machine feel even more like the real thing, and I am forced to recall my days rowing at the crack of dawn on Lake Dunmore near Middlebury, Vermont while in college.

Workout Setup

My workout setup on the top deck of the ship

The Fourth of July on the boat was free of any special pomp and circumstance.  It was, more than anything, just another work day.  Fortunately, all of the employees on the boat get paid overtime for working this day, as well as weekend days.  I definitely missed the Zilker fireworks celebration in Austin (TX), but it was meaningful to be on a boat with members of the NOAA Corps, a Commissioned Service of the United States, on this important day for America.

I have made significant progress in Tender is the Night and am almost finished.  I have also spent free time watching the FIFA Women’s World Cup and the Wimbledon Championships on the satellite television upstairs.

Regarding my sleep, I have finally stopped taking Dramamine®.  Lo and behold, I have had no more nightmares, this lending further support to my theory that Dramamine® was the cause.

The days are still very exciting, and I have yet to encounter a day without a great deal of fresh learning.  On to Florida!

Did You Know?

The Navy Motion Picture Service provides encrypted DVDs for use on deployed ships.  In the upstairs lounge, there are well over 700 DVDs, from classics to quite new releases, organized for anyone to watch in their free time.

DVD Binder

On of the many DVD binders on the ship, courtesy of the Navy Motion Picture Service

Notable Species Seen

David Walker: Equilibrium at Sea (Days 6-9), July 3, 2015

Posted on by davidwalker2015

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: July 3, 2015

Weather Data from the Bridge

Weather Log 7/2/15

NOAA Ship Oregon II Weather Log 7/2/15

Weather has fortunately continued to be calm.  The only main deviation from clear skies has been haziness (symbolized “HZ” on the above weather log from 7/2/15).  On 7/2/15, sky condition varied from FEW (3-4 octas) in the very early morning, to SCT (3-4 octas) and BKN (5-7 octas) at midday and afternoon, to SCT (3-4 octas) in the evening and night.  Swell waves have varied throughout the past couple of days, from less that 1 meter to around 3 meters in height.

Science and Technology Log

The past few days honestly blend completely together in my mind.  I feel as though I have reached an equilibrium of sorts on the boat.  The night shift has proceeded normally – station to station, trawl to trawl, CTD data collection at each station, plankton collected periodically throughout the shift.  Certain trawl catches have been exceptionally muddy, which poses a further task, as the organisms must first be separated from all of the mud and cleaned, before they can be identified.

In addition, on Day 6, the trawl net was damaged on a couple of occasions.  I’ve realized that a trawl rig is quite the complicated setup.  The trawling we are doing is formally called “otter trawling”.  Two boards are attached at the top of the rig to aid in spreading out the net underwater.  To allow the net to open underwater, one of the two lead lines of the net contains floats to elevate it in the water column.  A “tickler chain” precedes the lead lines to stir fish from the sea floor and into the net.  The fish collected by the net are funneled into the terminating portion of the net, called the “cod end”.  FMES Warren Brown is an expert when it comes to this entire rig, and he is in charge of fixing problems when they arise.  On Day 6, Warren had to fix breaks in the net twice.  With help from Lead Fisherman Chris Nichols and Skilled Fisherman Chuck Godwin, new brummel hooks were attached to the head rope for one of the door lifting lines, and a new tickler chain was installed.

I also learned a lot more of the specifics involved in the workup of the plankton catch.  The dual bongo contains two collection nets in parallel.  Plankton is removed from the cod ends of these nets, but not combined.  The plankton from the left bongo is transferred to a mixture of formaldehyde (10% v/v) and sea water for preservation.  The plankton from the right bongo is transferred to 95% ethanol.  The reason for this is that different solvent mixtures are needed to best preserve different parts of the plankton in the sample.  The formaldehyde solution is best for fixing tissue, yet it tends to dissolve hard parts (for example, otoliths, discussed below).  The ethanol solution is better for preserving hard parts (bones, cartilage, etc.).  This explains the need for two bongos.  Workup of collected plankton from the Neuston net is similar, except many non-plankton species are often collected, which have to be removed from the sample.  Highlight non-plankton species from the past couple days have been sailfin flyingfish (Parexocoetus brachypterus) and a juvenile billfish (Istiophoridae).  Neuston-collected plankton is transferred to 95% ethanol.  This solvent is the only one needed here, as only DNA analysis and stock assessment are conducted on Neuston-collected plankton.  All plankton is shipped to Poland, where a lab working in collaboration with NOAA will analyze it.  Samples are broken down according to a priority species list sent by NOAA.

The CTD survey is coming along nicely.  Progress through July 1 is shown on the below bottom dissolved oxygen contour.  Similar trends to those commented on in my last blog post continue to be observed, as a further area of hypoxia has been exposed near the coastline.  You can see that our survey is progressing east toward Mississippi (we will finish this leg in Pascagoula, MI, though the survey will continue on to the Florida coast during Leg 3).

A couple of other distinct memories stand out in my mind from the past couple of days:

  • Sexing “ripe” fish. Sometimes, certain species of fish are so fertile over the summer that certain individuals are deemed “ripe”.  Instead of cutting into these fish, they can be more easily sexed by applying pressure toward that anus and looking for the expression of semen or eggs.  One of the species for which this technique is most often applied this time of year is the Atlantic cutlassfish (Trichiurus lepturus).  One must be careful, however, for as I found out, the gametes sometimes emit from the anus with much force, shooting across the room.  It only takes wiping fish semen off of your face once to remember this forever.
  • Flying fish. I saw my first flyingfish (Exocoetidae) during a plankton collection with the neuston net.  The net would scatter the fish, and they would fly for cover, sometimes 10-15 meters in distance.  Amazing.
  • Preparing sand dollars. Interestingly, the sand dollars we caught (Clypeaster ravenelii) looked brown/green when they came out of the ocean.  Sand dollars are naturally brownish, and in the ocean, they are most often covered in algae.  We kept a couple of these organisms to prepare.  To prepare, we first placed the sand dollars in a dilute bleach solution for awhile.  We then removed them and shook out the sand and internal organs.  We then placed them back in the bleach for a little longer, until they looked white, with no blemishes.  The contrast between the sand dollar, as removed from the ocean, and this pure white is quite remarkable.
  • Otoliths.  Fisheries biologist Kevin Rademacher showed me a nifty way to remove the otoliths from fish.  Otoliths, “commonly known as ‘earstones,’ are hard calcium carbonate structures located behind the brain of bony fishes,” which “aid fish in balance and hearing” (Florida Fish and Wildlife Conservation Commission).  When viewed under microscope and refracted light, otoliths show a pattern of dark translucent zones (representing period of quick growth) and white opaque zone (representing periods of slower growth).  By counting the white opaque zones (called “annuli”), fisheries biologists can estimate the age of the fish.  Granted, this process differs for different fish, as different fish species have different otolith size.  Accordingly, a species standard is always prepared (usually a fish raised from spawn, from which the otoliths are taken at a known age) to estimate the growth time associated with one whole annulus for the particular species.  Sample otoliths are compared to the standard to estimate age.  Otolith analysis also allows scientists to estimate “growth rates,…age at maturity, and trends of future generations” (Florida Fish and Wildlife Conservation Commission).  On this survey, we only take otoliths from fish that are wanted for further laboratory analysis, but are too large to store in the freezer.  On some surveys, however, otoliths are removed from all fish caught.  I got to remove the otoliths from a large red snapper (Lutjanus campechanus).  The first step is to make an incision to separate the tongue and throat from the lower jaw.  The hand is then inserted into the hole created, and using a fair bit of force, the throat and gills are ripped away from the head to expose the vertebrae.  The gills are then cut from the base of the vertebrae, to expose the bony bulb containing the sagittal otoliths.  Diagonal cutters are then used to crack open the boney bulb containing the sagittal otoliths, and the otoliths are removed using forceps.

Personal Log

I am still feeling great on the boat.  The work is quite tiring, and I usually go straight to the shower and the bed after my shift ends.  Interestingly, I think I’m actually gaining quite a bit of weight.  The work is hard and the food is excellent, so I’ve been eating a bunch. I’ve been getting 7-8 hours of sleep a night, which is more than I normally get when I am at home, especially during the school year.  One thing I have been noticing ever since the trip started is that I have been having quite nightmarish dreams every night.  This is rare for me, as I usually either don’t have dreams or can’t remember the ones that occur.  I initially thought that this might be due to the rocking of the boat, or maybe to the slight change in my diet, but I think I’ve finally found the culprit – Dramamine®.  Research has indicated that this anti-motion sickness drug can cause “disturbing dreams” (Wood, et al., 1966), and I have been taking this medication since the trip started.  This hypothesis is consistent with the observation that my nightmares lessened when I reduced my daily Dramamine® dose from 2 pills to one. I finished Everything is Illuminated and have begun a new novel (Tender is the Night, by F. Scott Fitzgerald). I am now well into the second week of my trip!

Did You Know?

Earrings can be made from fish otoliths (ear stones).  These seem to be quite popular in many port cities.  Check out this article from the Juneau (Alaska) Empire Newspaper.

Notable Species Seen

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

Posted on by davidwalker2015

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


David Walker: Lots to Do, Lots to Learn (Days 1-2), June 26, 2015

Posted on by davidwalker2015

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: Friday, June 26, 2015

Weather Data from the Bridge

Weather Log 6/26/15

NOAA Ship Oregon II Weather Log 6/26/15

Weather was quite calm on Days 1 and 2.  As noted in the above weather log, the only real disturbance was a small squall (SQ) observed at 7 AM on Day 2.  Sky conditions are estimated in terms of how many eighths of the sky are covered in cloud, ranging from 0 oktas (completely clear sky) through to 8 oktas (completely overcast).  FEW in the above log represents 1-2 oktas of cloud coverage.  SCT represents 3-4 octas, and BKN represents 5-7 oktas.

Science and Technology Log

I have been assigned the night watch, which runs from 12 midnight to 12 noon.  Accordingly, on Day 1, I went to sleep around 2 PM and woke up around 10 PM to prepare for watch. My first day consisted mostly of general groundfish biodiversity survey work, one of the focuses during the summer being on shrimp species.  Data collection points have been randomly plotted throughout the Gulf, and data is collected via trawling the seafloor, which consists of the boat pulling a fishing net behind the boat, along the seafloor, for a predetermined length of time.  To allow for collection along the seafloor, the net has rollers on the bottom.  The net also contains a “tickler chain” to stir up organisms (mainly shrimp) from the seafloor, so that they can be captured with the net. The trawl catch is transferred to the boat, where the following steps are completed:

Tranferring catch to boat

CJ Duffie transferring a trawl catch to the boat.

1. The total catch is weighed.
2. The catch is run along a belt, and the three significant shrimp species (white, brown, and pink) are taken out and saved. In addition, multiple unbiased samples are taken from the catch and saved.  The sample should contain at least one of each species encountered in the catch.
3. The entire taken sample is sorted by species.
4. Individuals within each species are counted.
5. Length, weight, and gender are recorded for shrimp individuals within a significant species (white, brown, and pink).
6. Length measurements are taken for all other species individuals within the sample. Weight and gender are recorded for one individual out of every five within a species, for species other than shrimp.
7. Everything is returned to the ocean.

Sorting by species

Sorting the catch by species along the belt. Left to Right — Volunteer CJ Duffie, Equipment Specialist Warren Brown, me, and Research Fisheries Biologist Kevin Rademacher.

On Day 1, we completed the above process for 4 separate catches.  Aside from my lack of knowledge, the only other mishap was that my middle finger accidentally got pinched by a fairly large Atlantic Blue Crab.  I was amazed at the amount of force of the pinch, as well as the amount of pain caused.  I ended up having to break the crab’s claw off in order to free myself.

Also on Day 1, I got to observe the CTD (Conductivity, Temperature, Depth) sensor in action.  A CTD’s “primary function is to detect how the conductivity and temperature of the water column changes relative to depth” (NOAA).  The salinity of the seawater can be determined from this conductivity and temperature data.  On the Oregon II, the CTD also contains a dissolved oxygen sensor for measuring levels of dissolved oxygen in the seawater.  In addition, the CTD is housed in a larger metal frame (called a “rosette”) with water bottles, allowing for sampling at various depths.  Various data collection points have been randomly plotted throughout the gulf, and data collection consists of sending the CTD (+ dissolved oxygen sensor and water bottles) to and from the ocean floor.  The photo at right shows the data output – the y-axis represents water depth, temperature is recorded in blue (two data points taken at each scan), salinity is recorded in red, and dissolved oxygen is recorded in green (2 data points taken at each scan).  The ocean floor was at a very shallow depth (between 10 and 20 meters) for all sampling done on Day 1.

CTD data output

CTD data output

On Day 2, we completed more shrimp survey work and CTD sampling.  I also got to participate in a plankton survey at the beginning of my shift.  This entailed dropping two fine-mesh nets into the water – a dual-bongo and a neuston – and dragging them through the water to collect plankton.  The dual-bongo is lowered to a predetermined depth, while the neuston remains at the surface.  Obtained plankton is transferred to a jars with salt water and formaldehyde (for preservation) and sent to a lab in Poland (with which NOAA has a partnership) where it is categorized, measured, etc.

Personal Log

I have already met all of the scientific personnel and most of the other core and crew on the ship.  Andre Debose is the Field Party Chief, and he heads up all scientific operations on the ship.  The Executive Officer of the ship is Lieutenant Commander (LCDR) Eric Johnson, a NOAA Corps Officer.  These are the two people who approve of all of my blog posts before I submit them to NOAA. The night watch (12 AM – 12 PM) consists of me, Kevin Rademacher, Warren Brown, and Alfonso Hamilton (watch leader).  The day watch (12 PM – 12 AM) consists of Adam Catasus, Jeffrey Zingre, Joey Salisbury, and Michael Hendon (watch leader).  CJ Duffie completes his watch from 6 AM to 6 PM. Adam, Jeffrey, and CJ are volunteer graduate students from Florida.  This is their first NOAA research cruise, but they have already completed a two-week leg, so they know much more than I do.  Alfonso, Kevin, Warren, Adam, and Joey are all seasoned NOAA veterans, have completed many years of research cruises, and have a wealth of knowledge.

Stateroom

My stateroom

My stateroom is quite nice.  There is sufficient storage space for all of my clothing and equipment, such that I am able to keep most everything off of the floor.  I am rooming with Joey Salisbury (I have top bunk), but as Joey is on the day shift, we do not see too much of each other.  I am quite paranoid about not waking up on-time, so I tethered my cell phone to a pipe on the boat, directly above my head.  This way, the phone alarm blares directly toward my face, and there is no danger of my phone falling off of the bunk.

I have not yet experienced any seasickness, although I am still taking preventative medication every day.  Andre noted before we left that ginger helps with seasickness, so I brought some ginger ale and ginger cookies.

The food served on the ship is amazing, definitely much more than what I was expecting.  There are multiple course options for each meal, and everything I have had so far has been exceptional.  The highlight was the made-to-order omelet that I had for breakfast after 7 hours of sorting and measuring fish.

Notably, I also got to experience two boat safety drills on Day 1 – a fire drill, and an abandon ship drill.  For the abandon ship drill, I got to try on my survival suit.  It is made out of neoprene, so in that regard it reminds me of fly fishing waders.  However it feels quite claustrophobic once you put your arms in it and zip it
halfway up your face.  I needed much assistance in putting it on.

Survival suit

In my survival suit, during an abandon ship drill

Did You Know?

NOAA has a Commissioned Service, one of the seven Uniformed Services of the United States.  The NOAA Corps consists only of Commissioned Officers (i.e. no enlisted personnel or Warrant Officers).  The Corps first became a Commissioned Service in 1917, during World War I, as the United States Coast and Geodetic Survey Corps.  In 1965, this Corps was renamed the Environmental Science Services Administration Commissioned Corps, and in 1970, was again renamed the NOAA Corps (Source — NOAA).

Notable Species Seen

June Teisan, Ichthyo-WHAT? Ichthyoplankton! May 6, 2015

Posted on by juneteisan

NOAA Teacher at Sea
June Teisan
Aboard NOAA Ship Oregon II
May 1 – 15, 2015

Mission: SEAMAP Plankton Study
Geographical area of cruise: Gulf of Mexico
Date: Wednesday, May 6, 2015

Weather Data from the Bridge:
12:00 hours; Partly cloudy skies; Wind 080 (WNW) 9 knots; Air temp 25.8C; Water temp 25.7C; Wave height 3-4 ft.

Science and Technology Log:

From my very first shift the day we left port at Pascagoula, I’ve been out on the ship’s deck deploying nets and processing samples. Samples of what, you ask? Ichthyoplankton! Ichthyo-What? Ichthyoplankton are the eggs and larvae of fish, and are typically found less than 200 meters below the surface, in the “sunlit” zone of the water column. We have 40 testing sites or “stations” ahead during this cruise, as shown below.

SEAMAP_OregonII

The blue area holds the SEAMAP Plankton stations we plan to sample on the first leg of the spring cruise. The other stations will be sampled on the second leg May 17-31.

 

With my noon to midnight teammates Pam Bond and Jonathan Jackson, and the invaluable Oregon II deck crew to operate the winches, I’ve learned to draw samples from the Gulf with specially developed equipment: the Bongo net, Neuston net, MiniBongo net, and S-10 Neutson net, and the CTD sampler.

The Bongo and its smaller cousin the MiniBongo are designed with funnel-shaped nets that collect samples into a cylinder at the end of the net. Once the nets are sprayed down to chase the last of the biomass into the PVC cylinder or “codend”, we take the cylinders to the processing table to sieve the biomass, transfer that to the glass lab jars, and fill with preservative solution.

The name “Bongo” makes sense once you see the shape of the apparatus!
The name “Bongo” makes sense once you see the shape of the apparatus!
The name “Bongo” makes sense once you see the shape of the apparatus!
The name “Bongo” makes sense once you see the shape of the apparatus!
The name “Bongo” makes sense once you see the shape of the apparatus!
The name “Bongo” makes sense once you see the shape of the apparatus!

The Neuston net is affixed to a large metal rectangle and is pulled along the surface of the water for a ten minute time segment. The mesh of the Neuston is not as fine as the Bongo, so smaller plankton slip through and larger organisms are gathered.

 Once the samples are gathered they must be sieved, transferred into lab jars, and preserved. Immediately after collecting the samples, we walk the buckets holding the codend cylinders to the back deck where the processing table holds the equipment and solutions we need for this part of the process.

Personal Log:

I’ve been on board the Oregon II for five days, and I am deeply impressed by many facets of this scientific journey.

  • The level of dedication, professionalism, and passion of the NOAA science team: This work is high caliber data gathering in sometimes grueling conditions, with monotonous waiting periods in close quarters; but the good humor, dedication to best practice field science, and mutual respect and support among the team is always evident.
  • The complexity of running a working research vessel: From the Commanding Officer down the chain, each crew member has their jobs and each person is vital to the success of the excursion.
  • The importance of the work: Our fisheries are a vital food source; to manage the stocks and avoid overfishing we need data to make management decisions that ensure a healthy ecosystem.
  • The beauty and jaw-dropping magnificence of the Gulf: This vast expanse of water – teeming with life, driving weather patterns, supplying us with food and fuel – is a sight beyond words.

Finally, here’s a shout out for Teacher Appreciation Week! Kudos to all my colleagues across the country and especially to the teaching staff at Harper Woods Schools in Harper Woods, Michigan for all you do everyday!

huzzah

And a special hello for the students in Mrs. Wesley’s class all the way from the Gulf of Mexico!

Julia West: Bongos! March 22, 2015

Posted on by jwest425

NOAA Teacher at Sea
Julia West
Aboard NOAA ship Gordon Gunter
March 17 – April 2, 2015

Mission: Winter Plankton Survey
Geographic area of cruise: Gulf of Mexico
Date: March 22, 2015

Weather Data from the Bridge

Time 1700; clouds 100%, stratus; wind 325° (NNW), 9 knots; air temperature 22°C, sea temperature 25°C

Science and Technology Log

Here’s what we have covered as of Sunday evening, 3/22. I’m getting quite the tour of the Gulf! Notice we are going back and forth across the shelf break (the edge of the continental shelf), as that is our area of interest.

Stations covered 3/22

This is what we’ve covered so far. We’re doing well!

Again, thanks to all of you who are reading and asking questions. One recent question had to do with whether we are bringing specimens back. So let me explain what we do with them. Most plankton are so small that you see them best through a microscope. So the “specimens” that we are bringing back are all in jars – thousands of organisms per jar! Every time we collect samples, we get at least three jars – two from the bongo nets and one (or more) from the neuston net. That’s not including the CUFES samples described earlier, which are only big enough for a tiny bottle. Here are some pictures:

Kim labeling a sample

Kim Johnson (scientist) in the wet lab, labeling a sample. Notice the cardboard boxes – they are all full of sample jars, both empty and full.

Bongo sample

This is a nice sample from one of the bongo nets. Lots of little guys in there!

 

 

 

 

 

 

 

 

These samples get brought back to shore for analysis in the NOAA lab. Oddly, many of the samples get sent to Poland to be analyzed! Why Poland, you ask? Well, for a few decades we have had a cooperative agreement with the Polish sorting and identification center. They remove the fish and eggs from all samples, as well as select invertebrates. These specimens and the data get sent back to US for analysis. We double check some of the IDs, and plug the data into models. (If you are a biology student, this is an example of how models get used!) The information then goes to fisheries managers to use to help form fishing regulations. This division of NOAA is called the National Marine Fisheries Service (NMFS), which manages stocks of fish populations.

NOAA has been doing spring and fall plankton sampling for 30 years now. Winter sampling is newer; it started in 2007. SEAMAP (SouthEast Area Monitoring and Assessment Program) is cooperative agreement between the Gulf states, federal (NOAA), and university programs. The samples from the states and universities get sent to Poland with our samples. The the timing of the surveys is to target specific species when they are spawning. This winter survey is targeting grouper, tilefish, and other winter spawning species. The other surveys target bluefin tuna, red drum, red snapper, and mackerels, which spawn at other times of the year. The invertebrate data is used to build an understanding of invertebrate community structure throughout the Gulf.

In science, research is cumulative. We know, from past research, what the mortality rate of some fish species is. So if we get a fish larva or fry that is a certain size, we can estimate the percentage of that size larvae that will reach adulthood, and back calculate to see how much mortality has already happened to get fish of that size. All this allows us to get a peek into the size of adult population.

The first piece of equipment that we use when we get to each station is the bongo nets. You can see how they got their name!

Bongos

The bongo nets just entering the water. They will be lowered to 200m, or near the bottom if it is shallower.

Here are the bongos ready to be deployed:

Bongos ready to deploy

These bongos are ready to go as soon as we get the OK.

Flow meter for bongos

This little whirlybird is the flow meter.

SeaCAT

The SeaCAT

 

 

 

 

 

 

 

The flow meter is inside each bongo net, near the top. We read the numbers on it before the net goes out, and after it comes back. Using this information – the rate of flow, together with the area of the opening, we can calculate the volume of water filtered. The SeaCAT is a nifty unit that measures conductivity (salinity), temperature, and depth. Since we have a much fancier unit to measure these factors, we use this primarily for depth, so we know when we are getting to 200 meters (or the bottom, whichever comes first). We go to 200 meters because that is the lowest effective light penetration. Phytoplankton need light, and zooplankton need phytoplankton! What’s more, larval fish have not yet developed their lateral line (the organ that many fish use to sense vibrations in the water around them), so they feed visually. Even if they want to eat something below the photic zone, they wouldn’t be able to “see” it yet.

I, of course, am full of questions, and knowing that I’m supposed to identify every acronym I write, I asked what SeaCAT stands for. The unit is made by a company called SBE (Sea Bird Enterprises), so is the CAT just a fun name that they came up with? Nobody knew the answer! But everyone was curious, and Tony and Steve (both electronics technicians) did some emailing and got the answer straight from SBE. CAT stands for “Conductivity And Temperature” (seems we could have figured that out). And the Sea? Could be for Seabird, Seattle, or just the plain ol’ sea!

Deploying the bongos

Here I am holding the “codends,” ready to drop them over the side. The crane does all the heavy lifting. Photo by Andy Millett

 

Once we get the nets in the water, the crane operator monitors the speed that it is lowered. Our job is to communicate the “wire angle” constantly to the bridge and the lab. Here’s how this is done:

Measuring wire angle

Measuring the wire angle (angle of the cable) with the inclinometer. Photo by Madalyn Meaker.

The angle of the cable is important because it allows the nets to sweep the desired amount of water as they are pulled up. If the wire angle is too high (above 55°), the crew on the bridge slows the ship down just a bit. The perfect angle is 45°. Many other factors can mess this up, most notably current. The ship has to be facing the right direction, for example, so the current isn’t coming toward the ship (have you ever been fishing and had your line swept under the boat?). It’s tricky business, requiring constant communication between bridge, lab, and deck! Oh, and by the way, the cable is a “smart wire,” meaning it has electrical flow through it, which is how the depth gets communicated to the computers. Fascinating technology, both on the micro and macro scale!

Once we pull in the bongos, we hose them off very thoroughly, to get any of the little plankton that are stuck to the net. They are all funneled into the codend, which is a PVC cylinder. From there, we dump the sample into a sieve, and transfer it into a jar, and get read to do it again in 3 hours or so.

Bongo cod end

This is a close-up of the “cod end” of the bongo, where the plankton get funneled into.

Plankton from the bongo

This is the sample from one of the bongo nets. Can you see why it’s hard to come up with pictures of individual organisms? There are thousands in here!

Did I tell you that sampling goes on 24/7? Perhaps you figured that out when you heard the shift times. It costs a lot to run a ship; operations continue whether it’s night or day.

Personal Log

Now, to keep people happy when they are living in close quarters, far from home, and working strange shifts, what’s the most important thing of all? FOOD! The Gunter is well known among NOAA circles for having fantastic food for people of all diet types and adding ethnic flavor to her meals. The person responsible for our good and abundant food is Margaret, our Chief Steward. She has worked for NOAA for ten years, and says it’s the best job she has ever had. Her husband is now retired from the Coast Guard, so they moved around a lot. Margaret worked for the Coast Guard for four years, then went back to cooking school, and had various other jobs before signing on with NOAA. She has a few years left before she retires, and when she does, what will she do? She wants to do subsistence farming! This is right up my alley – Margaret and I have a lot to talk about! Not to mention the fact that Margaret makes her own juices, some amazing homemade hummus, AND dries her own fruit (dried cherries -yum!).

Margaret, chief steward

Margaret, assembling some spinach lasagna rolls while talking about her life.

Margaret also has a helper, Mike, who was reluctant to have his picture taken. He’s not the usual assistant steward, but sure seems highly capable! It always sounds like a lot of fun is being had in the galley.

Gunter dining room

The dining room, or “mess deck.”

condiment selection

World’s largest selection of condiments, including anchovy sauce and REAL maple syrup!

 

 

 

 

 

 

 

Lunch spread

Decisions….

more food

and more decisions…

 

 

 

 

 

 

 

That’s it for this post – I’m getting hungry. Time to eat!

Challenge Yourself

What executive branch of the U.S. government does NOAA belong to? Is it the same branch that oversees our national parks? How about our national forests?

Did You Know?

There are nearly 4000 active oil and gas platforms in the U.S. Gulf of Mexico (NOAA), and more than 27,000 abandoned oil and gas wells (Assoc. Press, 2010)

Oil and gas platforms in the Gulf

Locations of the active oil and gas platforms in the Gulf of Mexico. From http://oceanexplorer.noaa.gov/