Stacey Jambura: Sargassum, Sargassum, Sargassum! July 15, 2012

Stacey Jambura
July 6 – 17, 2012
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Geographical Area of Cruise: Gulf of Mexico
(You can view the NOAA ShipTracker here: http://shiptracker.noaa.gov/shiptracker.html)
Date: July 15, 2012
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Weather Details from Bridge: (at 18:45 GMT)
Air Temperature:  28.6◦C
Water Temperature: 28.5◦C
Relative Humidity: 73%
Wind Speed: 9.28 kts
Barometric Pressure: 1,017.65 mb
 

Science and Technology Log

The Neuston Net

Nueston Net

Neuston Net

The Neuston net is the first net to be deployed at sampling stations. This net has a wide rectangular opening that skims the surface of the water to collect surface dwelling organisms. Before the net is deployed, a cylindrical cod end is attached to the bottom of the net. The cod end has many holes that are covered by a screen. The screen allows water to flow through, but the organisms to get caught. We usually deploy the neuston net for 10 minutes, but sometimes we only deploy it for 5 minutes, depending on the amount of sargassum that is collected inside the net.

Filefish

Filefish collected from sargassum.

Sargassum is a type of seaweed that floats at the surface of the water, almost like little islands. Sargassum provides an important habitat for many marine animals in the open ocean. We frequently find small filefish, jacks, and flying fish, as well as juvenile puffer fish, crabs, and shrimp. Young sea turtles also use the sargassum as a hiding place from larger predators, though we have not found any during this trip.

Sargassum

Sargassum
(image from www.bigelow.org)

Emptying the Neuston net

Emptying the Neuston net.

When sargassum makes its way into our Neuston net, we collect all of it into large buckets. We have to rinse all of the sargassum off into large buckets to make sure that we collect all of the creatures living inside of it. We do this because we want to get the most accurate sampling of the population of living organisms in the sampling area. Depending on how much sargassum is collected in the Neuston net, the collection process can anywhere from 10 minutes to an hour!

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Rinsing a sample into a sieve.

Rinsing a sample into a sieve.

Once the sample has been rinsed into buckets, the buckets are poured into sieves. The sieves have screens that allow the water to flow through, but not the organisms we want to save. Once the buckets have been poured into the sieves, rinsed, and poured out again (to make sure nothing stuck to the inside of the bucket), we use alcohol to rinse the sieves into funnels that channel the sample into quart-sized jars. Once the entire sample has been rinsed into a jar, we fill the jar with alcohol, place a label inside the jar to record the location the sample came from, stick a similar label on the lid, and place the jar in a box back in our chem lab. The samples are analyzed later at a lab once the survey is over.

 

The Bongo Nets

Bongo Nets

Bongo nets being deployed.

Bongo nets are similar to the neuston net, but there are some differences. The bongo nets have cod ends like the neuston, but they have two cod ends because there are two separate nets, where the neuston has only one. The holes of the bongo cod ends are covered by screens that have smaller openings than the neuston cod ends so that they can collect smaller organisms. The main purpose of the bongo nets is to collect plankton samples. We cannot collect plankton easily using the neuston net because the openings in the screen on the cod end are larger.

Bongo Nets and Cod Ends

Bongo Nets and Cod Ends

Relaying Flow Meter Numbers to the Lab

Relaying Flow Meter Numbers to the Lab

Before the bongo nets are deployed, we have to report the numbers on the flow meters from the left bongo net and the right bongo net. The numbers on the flow meters are used to determine the amount of water that passed through the nets during deployment. Depending on how deep the water is determines how much water passes through the nets. After the nets are deployed, a sensor sends a message back to the lab to determine their depth. The person back in the lab monitors the depth and makes sure that the nets go as far down as possible, but do not make contact with the ocean floor. If the nets were to make contact with the ocean floor there is a good possibility that they could be damaged, which is why it’s so important to closely monitor the depth of the bongo nets. After the nets are brought back up on deck, the numbers are reported back to the lab where they subtract the first number of each flow meter (left bongo net and right bongo net) from the final number from each bongo. The difference is then divided by the length of time the net was deployed in the water.

Flow Meter Numbers

Flow Meter Numbers

Bongo Net Sample

Bongo Net Sample

Personal Log

Day 8 – July 12th

Sunset

Calm waters as the sun sets over the Gulf of Mexico.

Today was a VERY slow day. We only had four sampling stations, and of those only one was a trawl station. I was able to work a bit more on my blogs today, and start working on some cool lesson plans to bring back to school with me this fall. We also managed to watch a couple movies and raid the ice cream freezer during our down time. The seas were exceptionally calm tonight, almost as smooth as glass. It was very calming and serene, almost surreal! I made sure to take several pictures before the sun had set. The waters were smooth for the rest of the night which made for easy sleeping..

Day 9 – July 13th

Trawling was the focus of today. We had 4 trawls plus a couple neuston and bongo net sampling stations, so it was quite the busy day! We saw quite a number of new species that we hadn’t seen in previous trawls so I made sure to photograph those to share with my students later. At one of our sampling stations, we collected almost 6 5-gallon buckets worth of sargassum in our neuston net. It took us quite a bit of time to rinse it all down and collect the samples into preservation jars. It took three, quart-sized jars to hold all of the sample we collected!

Day 10 – July 14th

I found out this was our last day of sampling before we make our way back to Pascagoula. We mostly had trawls today, so we got to examine lots of critters. We had lots of down time because one of our runs to a sampling station was almost four and a half hours long! I spent that time working on my blog, and taking a much needed nap to catch up on my sleep! We had a really pretty sunset right before a thunderstorm that delayed one of our trawls. We worked right up until the next team came onto their shift and took over cleaning up from our trawl.

Day 11 – July 15th

All of our sampling was completed over the night, but I was able to work on the last neuston/bongo sampling when I went onto my shift. After all of the sampling was done, it was time to start scrubbing everything down to get it back into ship shape! The wet lab, dry lab, neuston net, bongo nets, and the stern were all hosed down, power-washed, scrubbed, bleached, and Windex-ed until everything smelled clean again. It took us most of the afternoon, but when it was done, we were done! The rest of our time on the Oregon II was left for unwinding and relaxing. After a lunch of king crab legs and a Thanksgiving-like dinner, my stomach was happy and satisfied (but not until after an ice cream sandwich of course!) Movies filled the remainder of the afternoon and evening, until I was ready for bed.

Andrea Schmuttermair: Tows Away! June 26, 2012

NOAA Teacher at Sea
Andrea Schmuttermair
Aboard NOAA Ship Oregon II
June 22 – July 3

Mission: Groundfish Survey
Geographical area of cruise: Gulf of Mexico
Date: June 26, 2012 

Ship  Data from the Bridge:
Latitude:  2805.26N
Longitude: 9234.19W
Speed:  10mph
Wind Speed:  5.86 knots
Wind Direction:   E/SE
Surface Water Salinity:  35.867 PPT
Air Temperature:  28.8 C
Relative Humidity: 86%
Barometric Pressure:  1010.51 mb
Water Depth:  96.5 m

Science and Technology Log


Sunrise

Sunrise on the Oregon II

Opisthonema oglinum, Lagadon rhomboides, Chloroscombus chrysurus…..yes, I have officially started dreaming about taxonomic names of our fish. It’s day 4 and I now have a much better grasp at identifying the variety of critters we pull up in our trawls. I am always excited to be out on deck when they bring up the trawl to see what interesting critters we catch. Surprises are great!

Do you want to know where the Oregon II is headed?

Check out Ship Tracker at http://shiptracker.noaa.gov/

If you click on the link above, you can see the path that our ship is taking to hit all of our stations for the survey. We often have station after station to hit- meaning as soon as we are done sorting and measuring, we have to bring in the next catch. Because some stations are only 3-5 miles apart, we sometimes have to do “double dips”, where we put in the trawl for 30 minutes, pull it up, and put it right back in again.

It’s been interesting to note the variety of our catches. Croakers, bumperfish, and shrimp have been in high abundance the last 2 days as we were in shallower water. Before that we had a couple of catches that had a high abundance of pinfish. When we take our subsample, we typically enter data for up to 20 of that particular species. We take length measurements on each fish, and on every fifth fish. We will also weigh and sex it (if sexing is possible).

Shrimp in the Gulf

A comparison of the various sizes of shrimp we pull up from our trawls.

Shrimp waiting to be measures

A relatively small catch in comparison to the 200+ we’ve been pulling up recently.

When we were in shallower waters, we had a significant increase in the number of shrimp we brought up. Tuesday morning was the first catch that did not have well over 200 shrimp (this is because we’ve been moving into deeper waters).  For the 3 commercial shrimp, white (farfantepenaeus setiferus), pink (farfantepenaeus duorarum), and brown (farfantepenaeus aztecus), we take 200 samples, as opposed to our high-quantity fish, where we will only take 20 samples. For each of the commercial shrimp we catch, we measure, weigh and sex each shrimp. I’ve gotten very good at identifying the sex of shrimp- some of the fish are much more difficult to tell. The information we get from this survey will determine the amount of shrimp that boats can take during the shrimping season in Louisiana and Mississippi. During the first leg of the groundfish survey, the data collected determined the amount of shrimp that could be caught in Texas. The groundfish survey is crucial for the shrimping industry and for ensuring that shrimp are not overfished.

Students- think of the food chain. What would happen if we overfished and took out too many shrimp? (Hint: Think of predators and prey.)

Sunrise

The trawl net at sunrise

We’ve now started doing 2 different tows  in addition to our trawls. Some of the stations are trawl stations, whereas others are plankton stations.

The trawl on deck

Alex, Alonzo and Reggie unloading the trawl net.

At a trawl station, we lower the trawl from the stern down to the ocean floor. The trawl net is meant for catching larger critters that live at the bottom of the ocean. There is a chain, also known as a “tickler”, which moves lightly across the ocean floor to lure fish to leave their hiding spots and swim into our net. The trawl is down for 30 minutes, after which it is brought back on deck to weigh the total catch, and then brought back into the wet lab for sorting.

Another important mission of the groundfish survey is to collect plankton samples. To do this, we use a Neuston tow and a bongo tow.

neuston tow

The Neuston tow about to pick up a lot of Sargassum- oh no!

The Neuston tow has a large, rectangular frame with a fine mesh net attached to it. At the end of the net is a large cylindrical bucket, called a codend, with a mesh screen meant for catching the organisms. In comparison to the trawl net, which has openings of 41.4mm , the Neuston’s mesh is only 0.947mm. This means the mesh is significantly finer, meant for catching some of the smaller critters and plankton that would otherwise escape the trawl net. The Neuston tow is put on the surface of the water and towed for 10 minutes. Half the tow is in the water while half is out. We end up picking up a lot of Sargassum, or, seaweed, that is found floating at the water’s surface. When we gather a lot of Sargassum, we have to sift through it and spray it to get out any of the organisms that like to hide in their protective paradise.

Bongo tow

The bongo tow on deck waiting to be sent down to about 3m from the ocean floor.

After we’ve completed the Neuston tow, we do the bongo tow.  The bongo’s mesh is even finer than the Neuston tow’s mesh at only 0.333mm. The bongo has 2 parts- a left and a right bongo (and yes they do look a little like bongo drums- hence their name). The top part of the bongo is a large cylinder with an open bottom and top. The net is attached to this cylinder, and again at the bottom of each side is cylindrical tube  called codends meant to catch the plankton. The bongo tow is meant to take a sample from the entire water column. This means that instead of riding on the surface of the water, it gets sent down to about 3 meters from the ocean floor (there is a sensor at the top that is 2m from the bottom of the net)  and brought back up immediately.

Sifting through the sieve

The remnants from our Neuston tow. This is the sieve we use to weed out what we want and don’t want.

bongo leftover

Here are our 2 samples from the bongo tow. The left one is preserved in ethanol and the right is preserved in formaldehyde (10% formalin and sea water)

Neuston tow samples

Here is a sample from the Neuston tow. Carefully camouflaged are thousands of crab megalops, aka juvenille crabs.

For both tows, it is important to rinse the nets to get any lasting organisms we might not see with our own eyes into our sample. Once we’ve done this, we bring the tubes back into the wet lab where we continue to rinse them through a sieve so that only certain items are leftover. In the Neuston, we often find small fish (usually less than 3mm), baby shrimp, crabs and Jessica’s favorite, the Sargassum fish. Most recently a few flying fish got caught in our Neuston tow. Prior to pulling it up, I was enjoying watching them flit across the water- they were about all we could see in the water in the middle of the night. After being rinsed thoroughly through the sieve, we preserve them by placing the sample in a glass jar with either ethanol or formaldehyde solutions. They are preserved in ethanol for DNA work and in formaldehyde for long-term preservation. These samples are then saved to send to a lab in Poland, which is the sorting center for the SEAMAP samples.

Flying fish

Flying fish we pulled up in our Neuston tow at nighttime.

Personal Log

My stateroom

My sleeping quarters (top bunk), also known as a stateroom. My roommate is Kristin, one of the scientists on board.

Well, I think I am finally getting used to the schedule of working the night shift. I am thankful that my bunk is on the bottom floor of the ship- which means it is completely dark- so that I can sleep during the daytime. Yesterday was probably one of the least busy days we’ve had so far, and because we were in deeper waters, our trawls were much smaller. This means I had a little more time to work on my blogs, which at times can be hard to fit in. It amazes me that we have internet access on the ship, and it’s not even as slow as I expected. It goes down from time to time, especially when the waters are rough. We’ve been fortunate to have pretty calm waters, aside from the first day.

You may have heard about Hurricane Debby on the news as it prepared to hit the Gulf. On Sunday, we were heavily debating heading back to Galveston to “bunker down” and ride out the storm. However, the storm that was forming seemed to dissipate and head in a different direction, thank goodness.  I was not thrilled about the possibility of heading back to port!

We had our first drills the day after we set sail. The drills- fire and abandon ship are distinguished by different types of bells, similar to using Morse code. The abandon ship drill was fun. We got to put on our survival suit, which is like a big orange Gumby suit. It not only protects you in cold water, but also makes you highly visible. I remember reading some of the former TAS blogs, and this picture was always in. Of course, I’ve got to add mine as well.

Survival Suit

Here I am in my survival suit. Judd also decided to be in the picture. 🙂

I’ve been having fun exploring different areas of the ship, even though there is only so far you can go on the ship. Yesterday, I went up to the bridge, which is the front of the ship where the captain or the NOAA Corps officers steer the ship from. You can think of it like a control center of an airplane. There are navigation charts (both computerized and paper) and radars that help guide the ship so it knows what obstacles are out there. There is a great view from the bridge that you don’t get anywhere else on the ship. It’s also fun to watch the folks down on deck when they are deploying the CTD or either of the 2 tows.

We’ve caught such an abundance of critters, I thought I’d share some of my favorite catches thus far:

cownose ray

Here I am holding a cownose ray (Rhinoptera bonasus)- my favorite catch yet. He weighed about 25lbs! This one was the highlight of my day as rays are some of my favorite ocean critters!

Atlantic sharpnose shark

One of the 4 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) we’ve caught so far.

Sharksucker
A sharksucker (Echeneis naucrates)- these guys hang onto sharks to catch a ride- he’s still alive so is able to hang onto my arm!

Critter Query Time!

Critter Query #1: What is a fathom (in your own words please)?

Critter Query #2: What are the differences between skates and rays?

Nicolle von der Heyde, June 21, 2010

NOAA Teacher at Sea
Nicolle Vonderheyde
Onboard NOAA Ship Pisces
June 14 – July 2, 2010

Nicolle von der Heyde
NOAA Ship Pisces
Mission: SEAMAP Reef Fish Survey
Geographical Area of Cruise: Gulf of Mexico
Dates: Monday, June 21

Weather Data from the Bridge

Time: 0800 hours (8 am)
Position: Latitude: 28º 09.6 minutes N
Longitude: 094º 18.2 min. W
Visibility: 10 nautical miles
Wind Direction: variable
Water Temperature: 30.6 degrees Celsius
Air Temperature: 27.5 degrees Celsius
Ship’s Speed: 5 knots

Science Technology Log

Atlantic Spotted dolphins are the graceful ballerinas of the sea. They are just incredible! The Gulf of Mexico is one of the habitats of the dolphin because they live in warm tropical waters. The body of a spotted dolphin is covered with spots and as they get older their spots become greater in number.

Atlantic Spotted Dolphins

Atlantic Spotted Dolphins

Atlantic Spotted Dolphins

Atlantic Spotted Dolphins

Atlantic Spotted Dolphin

Atlantic Spotted Dolphin

Here you can see the spots on an older Atlantic Spotted Dolphin. To read more about dolphins go to http://www.dolphindreamteam.com/dolphins/dolphins.html

Because Dolphins are mammals they breathe air through a single blowhole much like whales. Dolphins live together in pods and can grow to be 8 feet long and weigh 200-255 pounds. Like whales, dolphins swim by moving their tails (flukes) up and down. The dolphin’s beak is long and slim and its lips and the tip of its beak are white. They eat a variety of fish and squid found at the surface of the water. Since dolphins like to swim with yellow fin tuna, some dolphins die by getting tangled in the nets of tuna fishermen.

Newborn calves are grey with white bellies. They do not have spots. Calves mature around the age of 6-8 years or when the dolphin reaches a length of 6.5 feet. Calving takes place every two years. Gestation (or pregnancy) lasts for 11 1/2 months and babies are nursed for 11 months.

While watching the dolphins ride the bow wave, Nicolle and I wondered, “How do dolphins sleep and not drown?” Actually, we found that there are two basic methods of sleeping: they float and rest vertically or horizontally at the surface of the water. The other method is sleeping while swimming slowly next to another dolphin. Dolphins shut down half of their brains and close the opposite eye. That lets the other half of the brain stay “awake.” This way they can rest and also watch for predators. After two hours they reverse this process. This pattern of sleep is called “cat-napping.”

Dolphins maintain a deeper sleep at night and usually only sleep for two hours at a time. This method is called “logging” because in this state dolphins look like a log floating in the ocean.

The 1972 Marine Mammal Protection Act (MMPA) prohibits the hunting, capturing, killing or collecting of marine mammals without a proper permit. Permits are granted for the Spotted Dolphins to be taken if it is for scientific research, public display, conservation, or in the case of a dolphin stranding. The maximum ffor violating the MMPA is $20,000 and one year in jail.

Atlantic Spotted Dolphin

Atlantic Spotted Dolphin

Personal Log

The best part of this trip is all the marine life I see in the Gulf. In the past few days, dolphins have been swimming up to the boat and riding the bow wave of the ship. They are so graceful and playful in the water. In addition to the Tiger Shark seen feasting on the dead Sperm Whale, I have seen quite a few sharks swimming in the water near our ship. One, called a Silky Shark, took the bait as some of the crew was fishing from the stern of the boat (shown to the left). It was hauled up so the hook could be taken out and released back into the water. The second was a baby shark swimming near the bow of the ship as I watched the dolphins in the distance. I also saw a shark swimming near the starboard side of our ship while the deckhands were hauling up one of the camera arrays.

The fourth shark was the most exciting. As the crew was working at the stern of the ship to release a line that was caught in the rudder, I looked over the stern to see a large shark very near the surface swimming toward the starboard (right) side of the ship. I hurried to look and to my surprise it was a giant Hammerhead! I never expected to see one of these in its natural habitat. Unfortunately, by the time I got my camera out, the Hammerhead was too far away and too deep to get a clear shot, but what a sight to see!

Hammerhead shark

Hammerhead shark

The photo on the right is from Monterey Bay Aquarium. For more information, go to http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=C53nR+hhcrXgfKW+bt/MWA==

The photo on the right is from Monterey Bay Aquarium. For more information, go to http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=C53nR+hhcrXgfKW+bt/MWA==

The photo on the right is from Monterey Bay Aquarium. For more information, go to http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=C53nR+hhcrXgfKW+bt/MWA==

I often mistake the fish shown on the left for sharks. Actually they are Cobia, also known as Lemonfish. Once in a while thefish approach the boat as we are hauling fishup on the bandit reel. I have also seen bojellyfish in the water as we are working on the starboard side of the ship and I spotted a brief glimpse of an Ocean Sunfish (Mola mola) from the bridge of the ship as I was talking to our Commanding Officer (CO). I wish I could have seen this fish up close. They are the largest bony fish in the oceans and as someone on the ship described, they resemble a giant Chiclet swimming in the water.

The smallest living things I have seen while at sea are the tiny creatures that live in the Sargassum, a type of seaweed that floats freely within and on the surface of the Gulf waters. The Sargassum provides a habitat for tiny creatures that are the foundation of the food web, even providing food for some of the largest animals in the sea like whales. The picture below on the left shows a giant patch of Sargassum, while the picture on the right shows some of the creatures that live within it including tiny shrimp, krill, and very small crabs.

Sargassum

Sargassum

Creatures that live within the sargassum including tiny shrimp, krill, and very small crabs

Creatures that live within the sargassum including tiny shrimp, krill, and very small crabs

Seeing all this life has been reassuring as the oil continues to gush into Gulf waters off the coast of Louisiana, however I can’t help but think what the overall impact of this spill will be for the future of the Gulf. Will we see the negative environmental impact spread to the Eastern Gulf? Are microscopic droplets of oil and chemical dispersants infecting the food chain beyond the area that we visibly see being impacted? These questions will be answered as NOAA scientists continue to collect and analyze the type of data that I am helping gather on this SEAMAP Reef Fish Survey. I feel so fortunate to be a part of this scientific endeavor.

Animals Seen

Silky Shark (Carcharhinus falciformis)

Hammerhead (Sphyrna mokarran)

Cobia (Rachycentron canadum)

Ocean Sunfish (Mola mola)

Krill, Shrimp, Crab (species unidentified)

Dave Grant: The Straits of Florida, March 3, 2012

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: March 3, 2012

Weather Data from the Bridge

Position:30 deg 37 min North Latitude & 79 deg 29 min West Longitude
Windspeed: 30 knots
Wind Direction: North
Air Temperature: 14.1 deg C / 57.4 deg F
Water Temperature: 25.6 deg C / 78.4 deg F
Atm Pressure: 1007.2 mb
Water Depth:740 meters / 2428 feet
Cloud Cover: 85%
Cloud Type: Cumulonimbus and Stratus

Science/Technology Log:

Entering the  Gulf Stream and Straits of Florida

“There is in the world no other such majestic flow of waters.
Its current is more rapid than the Mississippi or the Amazon.
Its waters, as far out from the Gulf as the Carolina coasts, are of an indigo blue.
They are so distinctly marked that their line of junction with the common sea-water
may be traced by the eye.”

Matthew Maury – The Physical Geography of the Sea

 While our cruise could hardly be called leisurely, most sampling has been spread out between sites, sometimes involving day-long periods on station while the CTD and moorings are recovered from great depths (5,000 meters). However, Chief Scientist Dr. Baringer regularly reminds us that west of the Bahamas in the Gulf Stream transect, our stations are in much shallower water (≤800 meters) and close together (The Florida Straits are only about 50 miles wide), so we should anticipate increased activity on deck and in the lab. In addition to the hydrology measurements, we will deploy a specialized net to sample those minute creatures that live at the surface film of the water – the neuston.

The Neuston net is deployed for a 10-minute tow.

The Neuston net is deployed for a 10-minute tow.

Now that we have crossed the Bahama Banks and are on-station, the routine is, as expected, very condensed, and there is little time to rest. What I did not anticipate was the great flow of the Gulf Stream and the challenge to the crew to keep the Brown on our East-West transect line as the current forces us north.  Additionally, as Wordsworth wrote, “with ships the sea was sprinkled far and wide”  and  we had to avoid many other craft, including another research ship sampling in the same area.

Ben Franklin is famous for having produced the first chart of this great Western Boundary Current, but naval officer Matthew Maury – America’s Scientist of the Sea – and author of what is recognized as the first oceanography text, best described it.  Remarkably, in The Physical Geography of the Sea, first published in 1855, he anticipates the significance of this major climate study project and summarizes it in a short and often-quoted paragraph:

“There is a river in the ocean. In the severest of droughts it never fails,
and in the mightiest floods it never overflows.
Its banks and its bottom are of cold water, while its current is of warm.
The Gulf of Mexico is its fountain, and its mouth is the Arctic seas.
It is the Gulf Stream.”

 

Gulf Stream water

CTD data from the Straits of Florida
1. Note that temperature (Red) decreases steadily with depth from about 26-degrees C at the surface,
to less than 10-degrees C at 700 meters. (Most of the ocean’s waters are cool where not warmed by sunlight).
2. Dissolved Oxygen (Green) varies considerably from a maximum at the surface, with a sharp decline at about 100 meters, and a more gradual decline to about 700 meters. (Phytoplankton in surface water produce excess oxygen through photosynthesis during daylight hours. At night and below about 100 meters, respiration predominates and organisms reduce the level of dissolved oxygen.)
3. Salinity (Blue) is related to atmospheric processes (Precipitation and Evaporation) and also varies according to depth, being saltiest at about 150 meters.

***************************
“Ron Brown: Phone Home!”

At Midnight, just within sight of the beam of the Jupiter Inlet Lighthouse (And to the relief of the home-sick sailors on board – “Finally –  after  more than two weeks, we are within the range of cell phone towers!”) we began our studies of the Straits of Florida and the Gulf Stream. Nine stations in rapid order – standing-by for a CTD cast, and then turning into the current to set the neuston net for a ten-minute tow.

The purpose of the net is to sample creatures that live on or visit the interface between air and water, so the mouth of the net is only half submerged. Neuston comes from the Greek for swimming and in warm waters a variety of invertebrates and even some young mesopelagic fishes rise within a few centimeters of the surface at night to filter phytoplankton and bacteria, and feed upon other zooplankton and even drowned terrestrial insects that have been blown out to sea.

On the upper side of this water/atmosphere interface, a smaller variety of floating invertebrates, notably Physalia  and Velella (Portuguese man-of-war and By-the-wind-sailor) use gas-filled buoyancy chambers or surface tension to ride the winds and currents. This much smaller group of seafarers is further classified by oceanographers as Pleuston.

Prior to this cruise, my experience with such a sampling device was limited – Years ago, spending miserable nights sailing in choppy seas off of Sandy Hook, NJ searching  for fishes eggs and larva rising to the surface after dark; and later, much more enjoyable times studying water striders – peculiar insects that spend their lives utilizing surface tension to skate along the surface of Cape Cod ponds.

Our CTD and net casts are complicated by rising winds and chop, but some great samples were retrieved. Once the net is recovered, we rinse it down with the seawater hose, collect everything from the bottle at the cod end, rinse off and separate the great mass of weed (Sargassum) and pickle the neuston in bottles of alcohol for analysis back at the lab.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Since much of the zooplankton community rises closer to the surface at night where phytoplankton is more concentrated and the chances of being preyed upon are slimmer, there are some noticeable differences in the samples taken then and during daylight hours. Unavoidably, both samples contain great quantities of Sargassum but the weed-colored carapaces of the different crustaceans are a clue to which specimens are from the Sargassum community and which are not.

Gulfweed Shrimp - Latreutes

Gulfweed Shrimp – Latreutes

We hit the jackpot early; snaring a variety of invertebrates and fishes, including the extraordinarily well-camouflaged Sargassum fish – a piscatorial phenomenon I’ve hoped to see ever since I was a kid reading William Beebe’s classic The Arcturus Adventure. What a tenuous existence for such a vulnerable and weak swimmer, hugging the Sargassum as it is dashed about in the waves. Even with its weed-like disguise and ability to blend in with the plants, it must lead a challenging life.

A unique member of the otherwise bottom-dwelling frogfishes, the Histrio histrio has smooth skin, and spends its life hitch-hiking along in the gulf-weed forest. Like other members of the family Antennariidae, it is an ambush predator, luring other creatures to their doom by angling with its fleshy fins.

The Sargassum fish (Histrio)

The Sargassum fish (Histrio)

Needlefish and Sargassum fish

Needlefish and Sargassum fish

Another highlight for me is the water striders we found in several samples. These “true bugs” (Hemiptera) are remarkable for several reasons. Most varieties of these “pond-skaters” (Or Jesus Bugs if you are from Texas) are found on calm freshwater lakes and streams, but a few members of this family (Gerridae) are the only true marine insects – representing a tentative Arthropod reinvasion of the sea after their splendid foray onto land hundreds of millions of years ago.

Two great finds: Sygnathus pelagicus– A Sargassum pipefish – a cousin of the sea horse. Halobates – the water strider. An example of the Pleuston community.

Two great finds:
Sygnathus pelagicus– A Sargassum pipefish – a cousin of the sea horse.
Halobates – the water strider. An example of the Pleuston community.

Using surface tension to their advantage, they “skate” along by flicking their middle and hind legs, and can even “communicate” with each other by vibrating the surface of the water with the hair-like setae on their feet. On lakes their prey is other insects like mosquito larvae, confined to the surface. How they manage to find food and communicate at the surface of the raging sea is a mystery, but whatever the means, they are adept at it, and we recovered them in half of the samples.

The ocean's insect: The  remarkable water stride

The ocean’s insect: The remarkable water stride

The scientists who provided the net are generally more interested in ichthyoplankton to monitor fish eggs and larvae to predict population trends, and monitor impacts like oil spills; so this is why samples are preserved to return to the lab in Miami.

Before packing up things after our marathon sampling spree I was able to examine our catch and observed a few things:
1. I am the “High-Hook” on the cruise – catching far more fishes (albeit tiny ones) than the rest of the crew with their fishing poles. (Needlefish, sargassum fish, pipe fish, filefish and several larval species)
2. Depending on the time of day the samples were taken, there is a marked difference in the quantity and composition of organisms that have separated from the Sargassum and settled in the sample jars – (Noticeably more at night than during daylight hours).
3. There appears to be a greater variety of sea grasses present (Turtle grass, etc.) on the eastern (Bahamas side) of the Straits. We observed one seabean – drift seeds and fruits (or disseminules) from terrestrial plants.
4. Plastic bits are present in all samples – particularly plastic ties (Table 1.)

Settled organisms in sample jars.

Settled organisms in sample jars.

Sargassum fauna: Portunid crab – with eggs on her belly.
(Portunus was a Roman god – Protector of harbors and gates,
who supposedly also invented navigation)

Belly view of a Caridean shrimp

Belly view of a Caridean shrimp

A tiny fish egg ready to hatch!

A tiny fish egg ready to hatch!

A larval fish begins its perilous journey in the Gulf Stream.

A larval fish begins its perilous journey in the Gulf Stream.

Site/Local time

Notable Contents*

Biomass Site Depth
8 Day 17:48 Weed, Grasses(3 spp) 3.0 mm 79˚12’ 485 m
7 Day 16:10 Grasses(4 spp) 2.0 mm 79˚17’ 616 m
6 Day 14:30 Grasses(2 spp) Fish eggs and larva Trace 79˚22’ 708 m
5 Day 12:45 Water striders, Grass (1 spp) Trace 79˚30’ 759 m
4 Day 10:13 Crustacean larva, shrimp (large), 7.0 mm 79˚36’ 646 m
3 Dawn 07:53 Crustacean larva, shrimp (large), water striders Trace 79˚41’ 543 m
2 Night 05:10 Crustacean larva, shrimp (small), Pipefish, water striders 7.0 mm 79˚46’ 388 m
1 Night 02:48 Crustacean larva, shrimp, needlefish, Sargassum fish, Herring(?), Portunid crabs, shrimp (large), Copepods 13 mm 79˚51’ 264 m
0 Night 00:37 Crustacean larva, shrimp, Copepods 25 mm 79˚56’ 148 m

*Plastic bits and Sargassum weed and its endemic epibionts are present in all samples.

Table 1.   Contents in sample jars.

There is a marked difference in the quantity and composition of organisms collected at night (Left).

There is a marked difference in the quantity and composition of organisms collected at night (Left).

There is a marked difference in the quantity and composition of organisms collected at night (Left) and during the day (Right).

There is a marked difference in the quantity and composition of organisms collected during the day (Right).

With sampling completed we steer north to ride the Gulf Stream towards the Brown’s home-port,  and turn away from the bright lights of Florida …

“Where the spent lights quiver and gleam;
Where the salt weed sways in the stream;
Where the sea-beasts rang’d all around
Feed in the ooze of their pasture ground:”

Matthew Arnold

"Red sky at morning...sailor take warning!"

“Red sky at morning…sailor take warning!”

Homeward bound:

A storm battering the Midwest will impede our progress back north to Charleston and threatens to bring us the only foul weather of the cruise. Note the location of the cold front over the Florida Straits.

“Now the great winds shoreward blow;
Now the salt tides seaward flow;
Now the wild white horses play,
Champ and chafe and toss the spray.”
Matthew Arnold

As the sailors say: "The sheep are grazing." A gale is brewing and kicking up whitecaps as we sail north to Charleston.

As the sailors say: “The sheep are grazing.”
A gale is brewing and kicking up whitecaps as we sail north to Charleston.

Dave Grant: The “River in the Ocean”, March 2, 2012

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: March 2, 2012

Weather Data from the Bridge

Position: 26 degrees 19 minutes North Latitude & 79 degrees 55 minutes West Longitude
Windspeed: 14 knots
Wind Direction: South
Air Temperature: 25.4 deg C / 77.7 deg F
Water Temperature: 26.1 deg C / 79 deg F
Atm Pressure: 1014.7 mb
Water Depth: 242 m / 794 feet
Cloud Cover: none
Cloud Type: NA

“The moment one gives close attention to anything, even a blade of grass,
it becomes a mysterious, awesome, indescribably magnificent world in itself.”

Henry Miller

My evenings looking through the microscope are a short course in invertebrate zoology. Every drop of water filtered through the plankton net reveals new and mystifying creatures. Perhaps 90% of marine invertebrates, like newly hatched mollusks and crustaceans, spend part of their life in a drifting stage – meroplankton; as opposed to holoplankton – organisms that are planktonic throughout their life cycle.

MOLLUSK LARVAE

Bivalve

Bivalve

 Univalve

Univalve

The lucky individuals that escape being eaten, and are near a suitable substrate at the right moment, settle out into a sedentary life far from their place of origin. For the long distance travelers swept up in the Gulf Stream, the most fortunate waifs of the sea that survive long enough might make it all the way to Bermuda. The only hope for the remainder is to attach to a piece of flotsam or jetsam, or an unnatural and unlikely refuge like the electronic picket fence of moorings the Ron Brown is servicing east of the Bahamas.

“The gaudy, babbling, and remorseful day,
Is crept into the bosom of the sea.”
Shakespeare

A league and a half* of cable, sensors and a ton of anchor chain are wrestled on deck during a day-long operation in the tropical heat. (*A mariner’s league equals three nautical miles or 3041 fathoms [18,246 feet])

It is easy to be humbled by the immensity of the sea and the scope of the mooring project while observing miles of cable and buoys stretched towards the horizon, about to be set in place with a ton of anchor chain gingerly swung off the stern for its half-hour trip to the bosom of the sea.

Thanks to the hard labor and alert eyes of our British and French (“And Irish”) colleagues retrieving and deploying the attached temperature and salinity sensors, I am regularly directed to investigate “something crawling out of the gear” or to photograph bite marks from deep sea denizens on very expensive, but sturdy equipment.

A retrieved sensor with bite marks.

A retrieved sensor with bite marks.

To my surprise, other than teeth marks, very little evidence of marine life is present on the miles of lines and devices strung deeper than about 200 meters. This may be due in part to the materials of which they are constructed and protective coatings to prevent bio-fouling, but sunlight or more precisely, the attenuation of it as one goes deeper, is probably the most important factor.

Fireworm (Drawings and images by Dave Grant - NOAA Ron Brown)

Fireworm
(Drawings and images by Dave Grant – NOAA Ron Brown)

Handle with care! Close-up of worm spines

Handle with care! Close-up of worm spines

The first discovery I was directed to was a striking red bristle worm wiggling out of the crevice in a buoy.  It appears to be one of the reef-dwelling Amphinomids – the aptly-named fireworms that SCUBA divers in the Caribbean avoid because of their venomous spines; so I was cautious when handling it.  This proved to be the deepest-dwelling organism we found, along with some minute growths of stony and soft corals.

Five o’clock shadow” on a buoy – A year’s growth of fouling organisms – only an inch tall.

On shallower buoys and equipment, there are sparse growths of brown and blue-green algae, small numbers of goose barnacles, tiny coiled limey tubes of Serpulid worms like the Spirobis found on the floating gulfweed, some non-descript bivalves (Anomia?) covered with other fouling growth, skeleton shrimp creeping like inch-worms, and of course the ubiquitous Bryozoans. Searching through this depauperate community not as challenging as the plankton samples, but not surprising since our distance from land, reefs or upwelling areas – and especially clear water and lack of seabirds and fishes; are all indicators that this is a nutrient-deficient, less productive part of the ocean.

   

Bio-fouling – “on the half-shell.”                       Skeleton shrimp (Caprellidae)

The Ron Brown is the largest workhorse in the NOAA fleet and its labs and decks are intentionally cleared of equipment between cruises so that visiting scientists can bring aboard their own gear that is best suited to their specific project needs. NOAA’s physical oceanographers from Miami arrived with a truckload of crates holding Niskin water sampling bottles for the CTD and their chemistry equipment for DO (Dissolved Oxygen) and salinity measurements; and in a large shipping container (“Ship-tainer”) from England, the British and French (“and Irish”) scientists transported their own remote sensing gear, buoys, and (quite literally) tons of massive chain and cables to anchor their moorings. (I am surprised to learn from the “Brits” that the heavy chain is shipped all the way from England because it is increasingly hard to acquire. )

In the lab: Scores of sensors serviced and ready for deployment

In the lab: Scores of sensors serviced and ready for deployment

This is how most science is facilitated on the Brown and it requires many months of planning and pre-positioning of materials. I am lucky and can travel light – and with little advanced preparation. I am using simple methods to obtain plankton samples and images via a small portable microscope, digital camera and plankton net which I can cram into my backpack for any trips that involve large bodies of water. The little Swift* scope has three lens (4x, 10x, 40x) with a 10x ocular, and I get great resolution at 40x, and can get decent resolution to 100x. Using tips from Dave Bulloch (Handbook for the Marine Naturalist) I am able to push that somewhat with a simple Nikon Coolpix* point-and-shoot camera – but lose some of the sharpness with digital zoom.  As you might suspect, the ship’s movement and engine vibration can be a challenge when peering through the scope, but is satisfactory for some preliminary identification. (*These are not commercial endorsements, but I can be bought if either company is willing to fund my next cruise!)

PHYTOPLANKTON

Centric diatom - Coscinodiscus

Centric diatom – Coscinodiscus

    

Dinoflagellates –  Different Ceratium species

ZOOPLANKTON

A Plankton précis

Collecting specimens would be much more difficult without the cooperation of the Brown’s crew and visiting scientists, and their assistance is always reliable and appreciated. The least effective method of collection has been by filtering the deep, cold bottom water brought up in the Niskin bottles. As mentioned earlier, no live specimens were recovered; only fragments of diatom and Silicoflagellate skeletons surviving the slow drift to the bottom, which I have been able to identify through deep sea core images posted at the Consortium for Ocean Leadership website.

Needless to say, the most indiscriminate method of collection and the most material collected is through the large neuston net. The greatest biomass observed on the trip is the millions of tons of Sargassum weed, which covers the surface in great slacks around us that are even visible in satellite images.

Although the continuous flow of ocean water pumped into the wet lab and through my plankton net is effective and the most convenient collection method, the most surprising finds are from the saltwater intake screens that the engineer directed me to. This includes bizarre crystal-clear, inch-long, and paper-thin Phylosoma – larvae of tropical lobsters – that I initially mistook for pieces of plastic.

Inch-long Phylosoma larvae on a glass slide. (One of the tropical lobsters.)

Inch-long Phylosoma larvae on a glass slide. (One of the tropical lobsters.)

“All the ingenious men, and all the scientific men, and all the fanciful men in the world …
…could never invent anything so curious and so ridiculous, as a lobster.”

Charles Kingsley -The Water-Babies

Plankton communities are noticeably different between the Gulf Stream, inshore, and offshore in the pelagic waters east of the Bahamas.  Near the coast, either the shallower Bahama Banks or the neritic waters over the continental shelf closer to Charleston, the plankton is larger, more familiar to me and less challenging to sort, including: copepods, mollusk larvae and diatoms. Steaming over the shelf waters at night, the ship’s wake is often phosphorescent, and dinoflagellates, including the “night-light” Noctiluca are common in those samples.

Dinoflagellate - Noctiluca

Dinoflagellate – Noctiluca

 The waters east of the Bahamas along the transect line are notable for their zooplankton, including great numbers and varieties of Foraminifera, and some striking amphipod shrimp. Compared to cooler waters I am familiar with, subtropical waters here have over a dozen species of Forams, and some astonishingly colorful shrimp that come up nightly from deeper water.

It’s not all work and no play on the Ron Brown, and there are entertaining moments like decorating foam cups with school logos to send down with the CTD to document the extreme pressure at the bottom. Brought back to class, these graphically illustrate to younger students the challenges of deep sea research.

Foam cup:  Before-and-after a trip to 5,000 meters

Foam cup: Before-and-after a trip to 5,000 meters

Navigating by Dead-reckoning

On calm days while we are being held on-station by the Brown’s powerful thrusters, I can measure current speeds using Sargassum clumps as Dutchman’s logs as they drift by. Long before modern navigation devices, sailors would have to use dead-reckoning techniques to estimate their progress.  One method used a float attached to a measured spool of knotted line (A log-line), trailing behind the moving vessel. The navigator counted the number of knots that passed through his hands as the line played out behind the ship to estimate the vessel’s speed (in knots). Since nothing is to be tossed off the Brown, I rely on a simpler method by following the progress of the Sargassum as it drifts by stem-to-stern while we are stationary at our sampling site. Since I know the length of the Brown at the waterline (~100-meters), I can estimate current speed by observing drifting Sargassum.

Watching sargassum, I wonder if a swimmer could keep pace with the currents in these waters. When in college
my brothers and would strive to cover a 100-meter race by swimming it in under a minute. Here is the data from east of the Bahamas. See if you can determine the current speed there and if a good swimmer could keep pace.

ESTIMATING CURRENT SPEED

Data on currents:
Average of three measurements of Sargassum drifting  the length of the Ron Brown = 245 seconds.
Length of the Ron Brown – 100-meters.

1. How many meters per second is the current east of the Bahamas?
2. As a swimmer in college – with my best time in the 100-meters freestyle of one minute – could I have kept up with the Ron Brown… or been swept away towards the Bahamas?

For more on currents, visit my site at the college:
http://ux.brookdalecc.edu/staff/sandyhook/Student%20Page%201/TUTS-2-09-1/Index.html

****************************

Other navigational exercises I try to include determining Latitude and Longitude. Latitude is easy as long as you can shoot the sun at midday or find the altitude of Polaris in the night sky; and sailors have done that for centuries. The ship’s navigator will get out the sextant for this, or, since the width of one’s fist is about 10-degrees of sky, I can estimate the height of both of these navigational beacons by counting the number of fists between the star and the horizon.

ESTIMATING LATITUDE

Data:
Night observation (Shooting the North Star) – Number of Fists from the Northern horizon to Polaris = 3
Day observation (Shooting the Sun) – Number of Fists from the Southern horizon to the Sun = 5.5

If the width of a fist is equal to about 10-degrees of horizon, our estimate of Latitude using Polaris is 30-degrees (3 x 10).
Not too bad an estimate on a rocking ship at night, compared to our actual location (See Data from the Bridge at the top.).

Shooting the Sun at its Zenith at 12:30 that day gives us its altitude as 55-degrees – which seems too high unless we consider the earth’s tilt (23.5-degrees). So if we deduct that (55 – 23.5) we get 31.5, which is closer to our actual position. And if we consult an Almanac, we know that the sun is still about six degrees below the Equator on its seasonal trip North; so by deducting that (31.5 – 6) we end up with an estimate of 25.5-degrees. This is an even better estimate of our Latitude.

Here is the dreaded word problem:

By shooting the Sun, our best estimate of Latitude is 25.5 degrees (25 degrees/30 minutes)
The actual Latitude of the ship using GPS is 26-degrees/19 minutes.
If there are 60 minutes to a degree of Latitude – each of those minutes representing a Nautical Mile – how many Nautical Miles off course does our estimate place us on the featureless sea?

**************************

Longitude is much harder to determine if you don’t have an accurate timepiece to compare local time with universal time (The time at Greenwich, England), and an accurate ship’s chronometer wasn’t in use until the mid-1700’s.
To understand the challenge of designing a precise timepiece that reliably will function at sea, I used two crucial clock mechanisms:  a pendulum and a spring. Finding a spring was easy, since “Doc” had a scale at Sick Bay. For the pendulum I fashioned a small weight swinging on a string)

Using the scale to observe the ship’s motion.

Using the scale to observe the ship’s motion.

Standing on the scale and swinging the pendulum even in calm weather quickly demonstrated three things:

First: I have developed my sea legs, and no longer notice the regular motion of the ship.
Second: Even when the sea feels calm, the scale’s spring mechanism swings back and forth under my weight; adding and deducting 20 pounds to my real weight and reflecting the ship’s rocking that I no longer notice.
Three: On rough days, even if I can hold still, the ship’s heaving, pitching and rolling alters my pendulum’s reliable swing – its movements reflecting the ship’s indicator in the lab. Experimenting helps me appreciate clock-maker John Harrison, and his massive, 65-pound No. 1 Ship’s Chronometer  he presented to the Royal Navy in 1728.

Ship movement as recorded by the computer

Ship movement as recorded by the computer

Doc: Always on duty -  Sick Bay on the Ron Brown

Doc: Always on duty – Sick Bay on the Ron Brown

Besides having very well-provisioned Sick Bays, NOAA ships have experienced and very competent medical officers.  Our “Doc” received his training at Yale, and served as a medic during the Gulf War.

Especially alert to anyone who exhibits even the mildest symptoms of sea-sickness, Christian is available 24-hours for emergencies – and in spite of the crew constantly wrestling with heavy equipment on a rocking deck, we’ve only experienced a few minor bumps and bruises. He has regular office hours every day, and is constantly on the move around the ship when not on duty there.

Besides keeping us healthy, he helps keep the ship humming by testing the drinking water supply (The Brown desalinates seawater when underway, but takes on local water while in port); surveys all departments for safety issues; and with the Captain, has the final word if-or-when a cruise is to be terminated if there is a medical emergency.

Since a storm pounding the Midwest will head out to sea and cross our path when we head north to Charleston, he is reminding everyone that remedies for sea sickness are always available at his office door, and thanks to NASA and the space program, if the motion sickness pills don’t work, he has available stronger medicine. So far we have been blessed with relatively calm weather and a resilient crew.

                          The warm  (Red) Gulf Stream waters viewed from a satellite iamge.

The warm (Red) Gulf Stream waters viewed from a satellite image.

 Contact: The edge of the Gulf Stream - Matthew Maury’s  River in the Ocean

Contact: The edge of the Gulf Stream – Matthew Maury’s River in the Ocean

Birdwatching on the Ron Brown

For the time being I take advantage of the calm seas to scrutinize what’s under the microscope, and when on break, look for seabirds. East of the Bahamas, as anticipated after consulting ornithologist Poul Jespersen’s map of Atlantic bird sightings, I only spotted two birds over a two-week stretch at sea (storm petrels). This is very much in contrast to the dozens of species and hundreds of seabirds spotted in the rich waters of the Humboldt Current off of Chile , where I joined the Brown in 2008.
(http://ux.brookdalecc.edu/staff/Web%2012-2-04/seabirds/Brown%20terns%202/Terns%20%20fixed/SEPacific.html)

Passing through Bahamian waters was no more rewarding, but now that we are west and in the Florida Straits there are several species of gulls during the day, and at night more storm petrels startled by the ship’s lights. One windy night a large disoriented bird (Shearwater?) suddenly fluttered out of the dark and brushed my head before bumping a deck light and careening back out into the darkness. Throughout the day a cohort of terns has taken up watch on the forward mast of the Brown and noisily, they juggle for the best positions at the bow – resting until the ship flushes a school of flying fishes, and then swooping down across the water trying and snatch one in mid-air.  Like most fishermen, they are successful only about 10% of the time.

Royal tern "on station" at the jack mast.

Caspian tern “on station” at the jack mast.

Royal tern "on station" at the jack mast.

Royal tern “on station” at the jack mast.

  

*************************************

Despite the dreary forecast from the Captain, Wes and I are enthusiastic about all we have done on the cruise and formulated a list of why NOAA’s Teacher At Sea program is so rewarding.

Top Ten Reasons:
Why be a Teacher At Sea?

10. Fun and excitement exploring the oceans!

9. Meeting dedicated and diligent scientists and crew from around the world!

8. Bragging rights in the Teachers’ Room – and endless anecdotes!

7. Cool NOAA t-shirts, pins and hats from the Ship’s Store!

6. Great meals, three times a day…and FREE laundry!

5. Amazing sunsets, sunrises and star-watches!

4. Reporting on BIG science to students…and in real-time!

3. Outstanding and relevant knowledge brought back to students and colleagues!

2. First-hand experience that relates to your students’ career objectives!

1. Rewarding hours in the lab and fieldremembering why you love science and sharing it with students!

Powerpoint:
Shots from the deck and under the microscope

(Drawings and images by Dave Grant – NOAA Ron Brown)

Dave Grant: Sea State, Sick Bay and Longitude, February 26, 2012

February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 26, 2012

Weather Data from the Bridge

Position: 26.30N Latitude – 71. 55W Longitude
Windspeed:  15 knots
Wind Direction: South (bearing 189 deg)
Air Temperature: 23.2 C / 74 F
Atm Pressure: 1013.9 mb
Water Depth: 17433 feet
Cloud Cover: 30%
Cloud Type: Cumulus

Sea State, Sick Bay and Longitude

“Now would I give a thousand furlongs of sea
for an acre of barren ground.”
Shakespeare – The Tempest.

There is considerable excitement on board since the winds have come up; adding to the work load of the deck crew and scientists struggling to snag the mooring buoy and haul in the miles of cable and sensors that are arrayed below. With swells arriving from two directions and wind chop on top of that, the ship’s motion is unpredictable. So there is no room for error above or below the waterline and the heaving of the ship and spray mean everyone must be alert and ready to respond instantly if anything swings loose.

We are “line-sailing” on this cruise, steaming back-and-forth while maintaining a straight course on Latitude 26.30; deploying and servicing various sampling devices on the electronic “picket fence” dividing the Atlantic. Watching the deck crew cutting heavy wire and even heavier  chain, banging on metal,  wrestling with equipment and sweating under the sun all day as they back-track along the same line doing back-breaking work, I can almost hear them singing an old Mississippi Delta field holler – Line ‘em:

“All I hate ’bout linin’ track
These ol’ bars ’bout to break my back
Moses stood on the Red Sea shore
Smotin’ that water with a two-by-four
If I could I surely would
Stand on the rock where Moses stood”

Line-sailing is also an old technique used when mariners could only accurately determine their latitude North or South of the equator by means of the sun and stars. Simply stated, one would sail North or South to the known latitude of a destination, then sail East or West until it was found.

The Polynesians perfected this – line-sailing the latitude of specific stars that they knew had islands beneath them. On clear nights we go out on the shadowy deck, so far away from the glare of lights on land, and marvel at the great spectacle of stars. The two brightest above us are Arcturus and Sirius – known to the Polynesians as Hōkūleʻa (Star of Joy) and Ka’ulua (Queen of Heaven). Navigators steered under Arcturus to reach Hawaii, and returned to Tahiti by sailing under Sirius.

Tahiti lies under Sirius, and Hawaii under Arcturus, providing navigators with bright sign posts to guide them to those jewels in the vast Pacific. From the deck on the Ron Brown it looks like our zenith star could be Pollux, one of twins in Gemini. This seems appropriate  “By Jiminy”  for good luck,  since early sailors swore an oath to those Twins – the protectors of ships.

Still, Longitude remained a problem because its measure is the time East or West from a fixed point –Greenwich, England and the Prime Meridian. Until accurate ship’s chronometers were perfected, navigators had to rely on repeated estimates of their speed and direction – Dead Reckoning.

Since early clocks relied on a pendulum and inferior materials, and the challenge of perfecting an accurate timepiece became apparent to me while weighing-in at Sick Bay. The roll of the ship has that up-down effect you feel in an elevator, and your weight on the scale fluctuates accordingly. (Mine swings between 165 and 225 pounds, depending on the size of the swells; so I’ll have to wait until we reach port for more accuracy.) Navigators had to wait until 1764 when watchmakers finally perfected sturdy, spring-powered and rust-resistant chronometers accurate enough to satisfy the British Admiralty to guide ships across the featureless ocean waters. Incidentally, William Harrison’s chronometer was hardly portable. It weighed 85 pounds (!).

I am going to try two experiments later. One, fashion a simply pendulum and see how the ship’s rocking affects it, and two, try some dead reckoning to determine current speed.

(Interesting coincidences: My office at work is in the shadow of Sandy Hook Lighthouse, the entrance to NY Harbor. This important beacon is the oldest continuously lit lighthouse in America – and first lighted in 1764 (!). Also, with the perfection of wireless communication;  in 1904, the US Navy established the first radio station to continuously broadcast the time for navigators to set their ship’s chronometers – at Navesink, NJ,  across Sandy Hook bay and within the sight of my office window.)

A Biologist’s Bouillabaisse

With the help of Danny, one of the ship’s engineers, I have struck gold sampling marinelife. He alerted me to the intake screen for sea water that he was removing to clear and I was able to sort through it. It is a bonanza, as you can see in the image.

Although most of the material is Sargassum weed, and some bits of plastic, there is a great assortment of material here to keep me busy for the rest of the day. I will start from the bottom. Besides the sargassum, there is other plant material swept here from shallow water. Sea grasses from around the islands support turtles and a thriving subtidal community. One colleague in Puerto Rico thinks that these meadows are as productive as an ecosystem in the ocean. Not obvious is the Aufwuchs community covering the grass blades, but under the microscope, one piece is enough to keep a class busy for hours identifying the specimens in this “fouling community.”


Bryozoa, worm tubes and coralline algae cover a slender blade of grass.


A tiny drifting animal from the surface, the Cnidarian – By-the-wind Sailor.

Perched on my fingertips, a larval crustacean ready
to drop out of the planktonic community.

A tiny larval crab viewed under the microscope (20 x’s)

An amphipod shrimp.

A Polychaete worm. One of the many annelids in the sample.
Not everyone’s favorite, unless of course, you are a fish.

Dave Grant: Horse Latitudes, February 22, 2012


NOAA Teacher at Sea

Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 22, 2012

Weather Data from the Bridge

Position:26.30 N – 75.42 W
Windspeed: 0
Wind Direction: Calm
Air Temperature: 29 C
Water Temperature: 24 C
Atm Pressure: 1025
Water Depth: 4,410 meters
Cloud Cover: 0
Cloud Type: Slight haze

Science/Technology Log:

We are becalmed and even the veteran sailors onboard are remarking on how flat the sea has become. At about 30 degrees North and South Latitude, moist, low pressure air that was heated and lifted from the surface at the Equator has cooled and is now plunging back down to Earth, forming a line of light winds in a band across the sea. This dry, high pressure air becomes the Trade winds as it is drawn back towards the Equator along the sea surface in what is called a Hadley Cell (After its discoverer). We seem to be on the edge of this meteorological milepost, which was more than a nuisance in the days of sail. If stranded in its pattern too long, food and especially drinking water became an issue, and the first to suffer would be animals being transported from the Old World to the New. Legend has it that subsequent voyagers would come across their carcasses…hence the name Horse Latitudes.

While observing ships returning to port near his home, sixteen year-old future rock star Jim Morrison (The DOORS)  composed what is perhaps his most eerie ballot – Horse Latitudes.

“When the still sea conspires an armor
And her sullen and aborted
Currents breed tiny monsters
True sailing is dead
Awkward instant
And the first animal is jettisoned
Legs furiously pumping”

However, the stable ship makes deck work easier and I am catching up on samples under the microscope, including some of my own tiny “monsters” that the currents have bred.

It is the astonishing variety of life that makes the sea such a fascinating
hunting ground. Get a tow-net, dredge and simple microscope,
and a new world is yours – a world of endless surprises.”

(Sir Alister Hardy)

The chief survey technician set me up  with his  flow-through seawater system and I can leave a net under it to continuously gather plankton. I have noticed some patterns already.
One: Phytoplankton is scarce compared to temperate waters off of New Jersey, and this helps account for the clarity and
brilliant blue color of the water. The absence of large rivers here adding nutrients to the system, and little coastal
upwelling,  means that there is little to fertilize plantlife.
Two: More accumulates in the nets at night, confirming that Zooplankton rises to the surface at in the dark. This diurnal
pattern of the plankton community has been well documented ever since biologists and fishermen went to sea.
Three: Also, there is much more plankton at the surface than in deeper water. This is no surprise since sunlight is the
key ingredient at the surface of this ocean ecosystem.
Four: Creatures from offshore tend to have a more feathery look about them than inshore species. This added surface
area may use the turbulence to help support them near the surface  and increase their buoyancy.

It is said:  “Turn off the sun, and the oceans will starve to death in a week.”  It is assumed that among other stresses on the Biosphere that accompany disastrous impacts of large asteroids, dust and ash from these rare collisions block out enough sunlight to stifle photosynthesis, causing Phytoplankton (The “Pasture of the Sea”) to waste away, and setting the stage for the collapse of the Food Chain and mass extinction events. Fortunately we have plenty of brilliant sunshine here and no celestial catastrophes on the horizon.

Some of the most interesting Zooplankton are the Pteropods, the Sea Butterflies.

   
Empty shell and live pteropod specimen
(Images on the Ron Brown by Dave Grant)

The renowned oceanographer Alister Hardy used them as indicators of different water masses flowing around the British Isles; and New England’s great oceanographer, Alfred Redfield correlated their drifting with the anti-clockwise circulation of water in the Gulf of Maine. Although most are small and less than an inch long, they feed on a variety of creatures and in turn become food for many others. In surface waters they gather phytoplankton, some utilizing cilia and mucus to sweep food to the mouth; but in deeper waters, others are carnivorous.

I am informed by our English colleagues that on Europe’s fishing grounds, they are sometimes fed upon by herring, cod and haddock; which is bad news for British fishermen, whose catch rapidly decays and is not marketable. Such fish are referred to as “black gut” or “stinkers.”

How concentrated are pteropods? Whales and seabirds that we hope to encounter later in the cruise are sustained by them, and in the warmer waters of the Atlantic, at relatively shallow depths and on the tops of submerged peaks at around 2,000 meters, R.S. Wimpenny reports considerable deposits of “pteropod ooze” from their descending shells, covering an estimated 1,500,000 square kilometers of the bottom of the Atlantic (An area the size of the Gulf of Mexico.). Like the Foraminifera, in deeper waters the aragonite in their shells (a more soluble form of calcium carbonate) dissolves, and other sediments like silicates from diatoms accumulate instead. Check out any oceanography text and you are likely to find a picture of this biogenic pteropod mud, as well as other types of deposits.

At least 90% of the animals in the ocean are meroplankton – spending time in this itinerant stage before becoming adults. This phase may vary from a few days to over a year, depending on the creature. (European eels larva are the long distance champions; for over a year, drifting from below us in their Sargasso Sea breeding grounds, all the way to rivers in Britain and France.)

Drifting larvae are cheap insurance for a species, filling the surrounding habitat with individuals of your own kind, settling in new areas and expanding ranges, and particularly, not lingering around their birthplace and competing with the parent stock. However, most individuals simply end up as food for other creatures that are higher on the food chain.

Not surprising, there are copepods, the “cattle of the sea” grazing on smaller organisms.

  
(Images on the Ron Brown by Dave Grant)

Calanus finmarchicus is sometimes called the most abundant animal in the world and is found throughout the oceans, sustaining many types of marinelife; even right whales and basking sharks off the coast of New England.

Other sea soup and children of the sea that author David Bulloch likes to call them, drift by me and swim circuits trapped by surface tension in the water drop under the microscope.

  
Radiolaria are single cell Protozoa that not only ensnare food with mucous, but harbor mutualistic algae
among their spines. (100 x’s)


More live pelagic snails. (Pteropod means winged foot.)

  
An empty shell with  copepod sheltered inside. Other skeletons filled with Paramecia, and a mixed sample of shells
and dust particles.  (Images on the Ron Brown by Dave Grant)

Now that is calm, everyone seems to have their sea legs and are comfortable talking about their bouts of mal de mer.
Here is the worst story about sea sickness I have come across:

 From Dave Grant’s collection of sea stories:
The world’s worst tale of seasickness.
As told by Ulysses S. Grant in his Memoirs

One amusing circumstance occurred while we were lying at anchor in Panama Bay. In the regiment there was a Lieutenant Slaughter who was very liable to seasickness. It almost made him sick to see the wave of a table-cloth when the servants were spreading it. Soon after his graduation [from West Point] Slaughter was ordered to California and took passage by a sailing vessel going around Cape Horn. The vessel was seven months making the voyage, and Slaughter was sick every moment of the time, never more so than while lying at anchor after reaching his place of destination. On landing in California he found orders that had come by way of the Isthmus [Panama], notifying him of a mistake in his assignment; he should have been ordered to the northern lakes. He started back by the Isthmus route and was sick all the way. But when he arrived back East he was again ordered to California, this time definitely, and at this date was making his third trip. He was sick as ever, and had been so for more than a month while lying at anchor in the bay. I remember him well, seated with his elbows on the table in front of him, his chin between his hands, and looking the picture of despair. At last he broke out, “I wish I had taken my father’s advice; he wanted me to go into the navy; if I had done so, I should not have had to go to sea so much.”

Poor Slaughter! It was his last sea voyage. He was killed by Indians in Oregon.