Tag: noaa ship gordon gunter

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Kimberly Gogan: Meet the NOAA Corps: Where Service Meets Science! April 24, 2014

NOAA Teacher at Sea
Kim Gogan
Aboard NOAA Ship Gordon Gunter
 April 7 – May 1, 2014

Mission: AMAPPS & Turtle Abundance Survey, Ecosystem Monitoring
Geographical area of cruise:  North Atlantic Ocean
Date: April 24, 2014

Science and Technology: The NOAA Corps!

While the scientist do their work there is a very important group of folks that take care of getting the ship where it needs to be and ensuring the scientists  have the best opportunity to get their work done.  That group is the NOAA Commissioned Officer Corps. NOAA Corps is one of the seven uniformed services of the United States. NOAA has roots as far back as 1807 as the Survey of the Coast under president Thomas Jefferson, and then a branch called the U.S. Coast and Geodetic Survey during WWI & WWII eras. The current NOAA &  NOAA Corps came into existence in 1970 and has been providing leadership and support necessary for the day to day operations associated with the various NOAA Research Platforms. The NOAA fleet is comprised of 19 ships and 12 aircraft. One of the most important requirements for joining the NOAA Corps is that each officer has to have have a college degree in science, math or engineering. NOAA Officers go through an intense demanding fast paced training that includes formal classroom instruction as well as approximately 5 months of officer candidate school that focuses on officer bearing and leadership development as well as marine and nautical skills training at U.S. Coast Guard Academy. Once they have completed their training, the NOAA Corps Officers will be assigned to a NOAA ship for 2 years of sea duty where they learn how to operate the ship. After the officer’s sea duty they are assigned to a 3 year land assignment where they get to apply their degrees doing more hands on scientific work like working in a fisheries lab, weather service, or doing atmospheric studies.

Meet some of the NOAA Corps Officers that are assigned to NOAA Ship Gordon Gunter.

Ensign (ENS) Roxanne Carter
Ensign (ENS) Roxanne Carter

Meet Ensign, or first officer rank, Roxanne Carter! Roxanne join the NOAA Corps in 2012 because she wanted to learn how to drive a ship, conduct more field work, and legally follow marine mammals. Prior to joining, Roxanne was the director of a small environmental company for 7 years working  in the Marine Endangered Species division. She also worked in fisheries at the NOAA Marine Operations Center – Atlantic or MOC-A as an Operations Manager in Norfolk, VA. where she assisted with all the marine center’s activities.  Roxanne has also done a lot of volunteering with various marine mammal agencies.  She has a Masters Degree in Biology and Marine Ecology. Although Biology was not her favorite subject, she knew that once she got her degree, there would be many cool opportunities in that field. Roxy as she is called on the ship, is in charge of the ship’s store along with her regular ship duties. Just last week Roxy also earned her OOD or Officer of the Deck Qualification Letter, by conducting several practical and oral exercises which she has to successfully pass. Earning her OOD  means her fellow officers feel comfortable with her up on the bridge unsupervised maintaining the operation of the vessel and the safety of the people on board.

Field Opperations Offcier (FOO) Leiutenant Marc Weekley
Operations Officer (OO) Lieutenant Marc Weekley .

Meet Operations Officer Lieutenant Marc Weekley! Marc join the NOAA Corps in 2006. He has been stationed on the Gordon Gunter for one year. Marc’s job as Operations Officer on the ship is to communicate between the crew and officers and the scientist coming on to the ship. He mainly needs to work out any questions or details before the ship gets under way. He also organizes port logistics which means he makes port arrangements in various locations between the ships cruises.  Before Marc was assigned sea duty on the Gordon Gunter he was vessel operations coordinator for the Manta which is a small boat for one of NOAA’ s sanctuary offices. Although his position was similar to this one he also tracked the overall cost of the vessel, making sure that it met safety requirements.  Prior to joining NOAA Marc worked full time at an Environmental Lab, part time at the Florida Aquarium in Tampa and was a Dive Instructor in both the Caribbean and West Coast of Mexico. He decided to join NOAA Corps because he wanted the opportunity to operate research vessels at sea and in the air. He likes the idea that being a NOAA Corps officer incorporates science, math or engineering and ship operations.  Because of his scientific background and training as a ship driver in the NOAA Corps, he is better able to maximize the scientists’ time while on the ship and further facilitate their research efforts.

Meet Lieutenant Jounior Grade (LTJG) Reni Rydlewicz
Meet Lieutenant Junior Grade (LTJG) Reni Rydlewicz

Meet Lieutenant Junior Grade (LTJG) Reni Rydlewicz! After interviewing Reni, I can tell you that Fisheries is her love. Reni Joined the NOAA Corps in 2009. Prior to joining the NOAA Corps, Reni had a variety of jobs working as a seasonal field biologist. She worked with state and federal government programs and contractors including NOAA Fisheries as a Federal Observer, dockside Monitor, Area Coordinator dockside monitor, fisheries observer and coordinator. She also worked with birds deer and fish anywhere from the east Coast, Mid-west to Alaska. Reni became interested in joining the Corps after meeting a retired NOAA captain at the local American Legion who told her “The Corps is perfect for you”. Reni had heard of the Corps years before, but after speaking with the retired captain, she decided to apply as it gave her the flexibility to rotate every few years to new roles but still give a sense of permanency. Since she has been in the Corps, Reni has worked as a Navigation Officer aboard the Miller Freeman and Oscar Dyson. She currently is serving her land tour as Communications and Outreach Coordinator for NOAA Fisheries, West Coast Region. In 2015, Reni expects to be Operations Officer on the Oregon II.

Ensign (ENS) David Wang
Ensign (ENS) David Wang

Meet Ensign (ENS) David Wang! David joined NOAA Corps in 2013. Prior to joining NOAA, Ensign Wang was working  as a real estate agent while looking for career opportunities in the marine science field. Ensign Wang also pursued an opportunity to start a mussel aquaculture company in, RI , as well as worked as a deckhand aboard the lobster fishing vessel. David graduated from Long Island University, Southampton with a undergraduate degree in Marine Science. David completed his Masters in 2010 in Fisheries Biology at California State University, Northridge.  David joined the NOAA Corps after hearing from a friend who joined  about the opportunities to travel all over the world, change jobs every 2-3 years from ship to land, while also still being involved in science. Before David was assigned to the Gordon Gunter, he worked at a NOAA port office in Pascagoula, MI,  at a marine support facility taking care of the needs of 3 ships, the Pisces, Oregon II and Gordon Gunter.

 

Personal Log

The beginning of this week was completely amazing! While in Canadian waters we had warm, sunny, calm seas perfect for seeing lot of mammals.  During the stint of nice weather we had multiple days where we saw many sightings. On the top two days we had 97 and 171 sightings of whales and dolphins! That doesn’t even count the cool birds we saw like my favorite the Puffins. The birders were also lucky enough to see a rare bird called a Petrel, the only one of 4 recent sightings in the U.S and the first recent in Canada. I spent most of those days on the fly bridge from breakfast to sunset trying to take in as much as possible.  Although it is difficult to get good pictures with a regular camera there are several folks that have very nice cameras or are professional photographers who   have taken some great shots. Towards the end of the week the weather turned again and found us in a storm that was predicted to be mild getting bigger and stronger. The NOAA Corps Captain and crew navigated our ship to safely, but the storm did damage to one of the generators forcing us back to Cape Cod Bay for some repairs. I actually spent a few days in my cabin feeling a bit sea sick which was very surprising given my Island upbringing.  Now I am feeling better as we are on anchor and patiently waiting for repairs and notification about what we will do next.

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Kimberly Gogan: Science Spot Light – Marine Mammal Observing, April 12, 2014

NOAA Teacher at Sea
Kim Gogan
Aboard NOAA Ship Gordon Gunter
April 7 – May 1, 2014

Mission: AMAPPS & Turtle Abundance Survey,  Ecosystem Monitoring
Geographical Area of Cruise:  North Atlantic Ocean
Date: April 12, 2014

Weather Data from the Bridge
Air Temp: 10.3 degrees Celsius
Wind Speed: 10.5 knots
Water Temp: 8,2 degrees Celsius
Water Depth: 145.65 meters

 

Jen Gatzke, Chief Scientist of AMAPPS Leg 2 aboard the NOAA Ship Gordon Gunter.
Jen Gatzke, Chief Scientist of AMAPPS Leg 2 aboard the NOAA Ship Gordon Gunter.

Science and Technology Log

In the last blog I talked about all the different scientists who are working on Gordon Gunter. Today I am going to explain why. First, all of the scientists are here working under a program called the  Atlantic Marine Assessment Program for Protected Species, or AMAPPS for short. It is a multi-year project that has a large number of scientists from a variety of organizations whose main goal is “to document the relationship between the distribution and abundance of cetaceans, sea turtles and sea birds with the study area relative to their physical and biological environment.” The scientists are here working under the AMAPPS because of several government acts: the Marine Mammal Protection Act and the Endangered Species Act require scientists to do periodic checks of the populations of the protected species and the ecosystems they live in to make sure there have been no major human activities that have affected these species.

The National Environmental Policy Act also requires scientists to evaluate human impacts and come up with new plans to help the protected and endangered species. Finally the Migratory Bird Treaty requires that counties work together to monitor and protect migratory birds.  The project has a variety of activities that need to be conducted which is why all the different scientists are needed from the different groups like NOAA, Fish and Wildlife, Bureau of Ocean Energy Management (BOEM), Navy, and NOAA Northeast  and Southeast Fisheries Science Centers.  The variety of activities that are being done over multiple years under the AMAPPS include: aerial surveys, shipboard surveys, tag data, acoustic data, ecological and habitat data,  developing population size and distribution estimates, development of technology tools and modes, as well as development of a database that can provide all the collected data to different users. The AMAPPS project is also collecting  in depth data at a couple of areas of  special interest to NOAA & BOEM where there are proposed Offshore Wind Farms  to be built in the ocean.

 

Two of the Observer Team working their shifts on the Fly Bridge in on the "
Two of the Observer Team members working their shifts on the Fly Bridge in on the “Big Eyes”

Science Spot Light

Let me introduce the Chief Scientist, Jen Gatzke and the Marine Mammal Observer Team. Chief Scientist Jen works with the Protected Species Branch at the Northeast Fisheries Science Center (NEFSC). She primarily studies right whales.

Her main job here on the ship is to coordinate the teams of scientists so that each team is able to accomplish what it needs most efficiently while meeting the goals of the research mission. In this case the goal is to survey a large number of transect lines in a variety of marine habitats, both inshore and offshore.

She started sailing on NOAA ships 24 years ago in Pascagoula, Mississippi! Even thought Jen oversees all the science going on here on the Gordon Gunter, she is also part of the Marine Mammal Observer Team that does a rotating watch for mammals. The observer team starts its day at 7AM and works until 7PM except  for the 1 hour break at lunch when the daytime Oceanography team can conduct some of their sampling.

When they start their day observing it is called “on effort.” This means that the observer team and NOAA Corps are all ready to conduct the shipboard surveys the way they have determined would be best. This means a group of scientists that are all at their stations are ready to go and the NOAA Corps makes sure the ship stays on a particular designated course for a particular amount of time. When the team is “on effort” they have 4 rotating stations. There are two on the very upper deck, called the fly deck that watches with 2 very large (25×150) binoculars they call the “big eyes” on each side, port (left) and starboard (right) of the ship  Then there is another station on the lower starboard (right)  side deck that also use the “big eyes”  to scan for marine mammals as well. The last  station is the recorder who is located on the Bridge, or wheelhouse, where the NOAA Corps man the ship. The recorder is entering valuable data into a computer program designed specifically for this activity. Not only is the recorder keeping track of the different mammals that are spotted on the “big eyes,” they are also keeping track of important information about the weather, glare of the sun, and conditions of the ocean.

I learned the teams use some cool nautical terms during their observations and recordings. The first one is  the Beaufort Scale for sea state, or basically how calm or rough the seas are. Beaufort is measured by a numerical system with 0 being very calm and with no ripples to a 5 which is lots of white caps with foamy spray. Beaufort numbers go higher but it is very difficult to spot any sort of mammal evidence in seas that are rougher than a Beaufort 5. The team also measures the distance of the sighting using another measurement tool called a Reticle. The reticle is a mark on the inside of the “big”eye” binoculars. Its scale goes from 0 -20 and the 0 is always lined up with the horizon and allows the observer to give a quick reference number that can be used in a hurry to provide distance with a simple geometry equation.

The head shot of' "Thorny" the Right a whale taken by observer Todd Pusser on the Gordon Gunter AMAPPS Leg 2.
The head shot of’ “Thorny” the Right Whale taken by observer Todd Pusser on the Gordon Gunter AMAPPS Leg 2.

Although there are several other pieces of information the observers are looking for and giving to the recorder, the positive identification of the particular species of mammal is the most important. There are some species like the North Atlantic Right Whale, that is of particular interest to the team because they are the most endangered large whale in the North Atlantic Ocean. Not only is it exciting for the team and the rest of the ship as well to see sightings of them, their detected presence in particular areas could mean the implementation of tighter rules, like speed limits for ships that might be in the areas these animals are seen frequently. When the teams sights one of these whales, the ship is allowed to go “off effort” and follow the swim direction of the whales in order to get pictures with very large cameras that will allow the scientist to positively identify the particular whale.  Some of the other species seen frequently are humpback whales, fin whales, sei whales, minke whales, pilot whales, striped dolphins, common dolphins, Risso’s dolphins, gray seals, harbor seals, loggerhead sea turtles, sharks and ocean sunfish.

Me on the Fly Bridge watching for whales and seals.
Me on the Fly Bridge watching for whales and seals.

Personal Log

So far for the first leg of the trip we have taken one very rough trip offshore and because of the weather we have been doing a string of transect lines that are close to the shore off Martha’s Vineyard, which is one of the areas of special interest to NOAA due to the projected offshore wind farm.

The day before yesterday, at just about dusk, the Chief Scientist Jen was the first to spot one of the North Atlantic Right Whales. I was in the lab at the time that Jen came running through yelling “we have right whales!”

She very quickly came back with a huge case which held the team’s camera used for close-ups of the whales. By the time I was on deck, so were many of the off duty scientists and the ship’s crew. Everyone was very excited and joined the frenzy of following, tracking and getting some good shots of the group of right whales. There ended up being 4 whales in all, which mean that there are enough to trigger a Dynamic Management Area (DMA), a management zone designed to provide two weeks of protection to three or more right whales from ship collisions. Ships larger than 65 ft are requested to proceed through the designated area at no more than 10 knots of speed.

One of the observers, Todd Pusser also had a large camera and was able to get a good head shot of one of the whales to send back to the lab. Allison Henry, another right whale biologist at NEFSC, was able to positively identify the whale as an adult male known as “Thorny”, aka EGNO (Eubalaena glacialis number) 1032, who has been seen only in the northeast since the 1980s! (click on “Thorny” to see the New England Aquarium Right Whale Catalog which houses and handles the identifications for all North Atlantic right whales.) It’s pretty cool that I actually got to see him too. Even thought it’s not the warmest job, it makes it all worth it just to see something as amazing as that!

Genevieve & I up on the Fly Bridge on the "Big Eyes!"
Genevieve & I up on the Fly Bridge on the “Big Eyes!”

Did you know?

Did you know you can listen to Right Whale sounds and see where Right Whales are on the East Coast? Check out this page!  Click on this link for The Right Whale Listening Network.  NEFSC even has an Apple APP for seeing where the Right Whales are on the east coast and explains how to avoid them 🙂 Go to the app store – its free!

Me all dressed up in the "Mustang' suit helping the team keeping an eye out for whales.
Me all dressed up in the “Mustang” suit helping the team keep an eye out for whales.
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Robert Lovely, April 10, 2008

NOAA Teacher at Sea
Robert Lovely
Onboard NOAA Ship Gordon Gunter
March 31 – April 12, 2008

Mission: Reef Fish Ecological Survey
Geographical area of cruise: Pulley Ridge and the West Florida Shelf, Gulf of Mexico
Date: April 10, 2008

A bank sea bass (Centropristis ocyurus) tucked in under one of the rock outcrops along the West Florida Shelf.
A bank sea bass (Centropristis ocyurus) tucked in under one of the rock outcrops along the West Florida Shelf.

Weather Data from the Bridge 
Visibility:  12 miles
Wind Direction:  120 degrees
Wind Speed:  16 knots
Sea Wave Height:  2-3 foot
Swell Wave Height:  3-4 foot
Seawater Temp.: 22.1 degrees C.
Present Weather:  Partly Cloudy

Science and Technology Log 

Today we made three ROV dives on the West Florida Shelf, roughly 100 miles off the west coast of Florida. After making our usual CTD profile (see Ship’s Log, April 4, 2008) at about 0730, we lowered the ROV to a depth of 262 feet and followed a transect bearing southwest.  The object was to conduct a fish survey with respect to species presence and abundance as a function of bottom habitat types. Essentially, we were looking for good hard-bottom fish habitats within an area being proposed to the Gulf of Mexico Fishery Management Council as a new Marine Protected Area (MPA).

A blue angelfish (Holacanthus bermudensis).
A blue angelfish (Holacanthus bermudensis).

Each of the video transects revealed a mix of sand and hard bottom, with fish most abundant in areas having some topographic relief. Numerous hard rock outcrops offered attractive habitat for a wide variety of reef fish, such as scamp (Mycteroperca phenax), red porgy (Pagrus pagrus), red snapper (Lutjanus campechanus), almaco jack (Seriola rivoliana) greater amberjack (Seriola dumerili), short bigeye (Pristigenys alta), bank butterflyfish (Chaetodon aya), great barracuda (Sphyraena barracuda), red grouper (Epinephelus morio), blue angelfish (Holacanthus bermudensis), creolefish (Paranthias furcifer) saddle bass (Serranus notospilus) bank sea bass (Centropristis ocyurus) and many others. The sand flats in between ridges and reef outcroppings provided a stark contrast in terms of fish abundance.  Over these areas the ROV would glide for minutes at a time without revealing many fish.  But even in these less productive bottom habitats we would see the occasional fish dart into its hole as we passed over.

A school of jackknife fish (Equetus lanceolatus) captured by the ROV over the West Florida Shelf.
A school of jackknife fish captured by the ROV over the West Florida Shelf.
A sea star (Class: Asteroidea) on the sand flats between reef outcroppings.
A sea star (Class: Asteroidea) on the sand
flats between reef outcroppings.

Personal Log 

The quality and abundance of food on the GORDON GUNTER is remarkable, and I find it impossible to resist (especially the deserts).  I’d rather not return home ten pounds heavier than when I left, so I’ve been trying to visit the weight room whenever I can find the time.  During my first few sessions on the treadmill I had to hang on for dear life due to the rocking motion of the ship. It was pretty comical.  Now, though, I am getting fairly good at going no-handed while compensating for the ship’s motion.  It requires some dexterity, but it’s great practice for getting your sea legs. We also saw other common sea creatures, such as gorgonians, wire coral, basket stars, sea stars, feather sea pens, sea urchins, sponges and snails.

A short bigeye (Pristigenys alta) ready to dart into his hole on the sand flats.
A short bigeye (Pristigenys alta) ready to dart into his hole on the sand flats.
Basket stars (Order: Phrynophiurida) spread their plankton nets near the top of a gorgonian.
Basket stars (Order: Phrynophiurida) spread their plankton nets near the top of a gorgonian.
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Robert Lovely, April 5, 2008

NOAA Teacher at Sea
Robert Lovely
Onboard NOAA Ship Gordon Gunter
March 31 – April 12, 2008

Mission: Reef Fish Ecological Survey
Geographical area of cruise: Pulley Ridge and the West Florida Shelf, Gulf of Mexico
Date: April 5, 2008

This sea anemone was part of a remarkably diverse community found on Pulley Ridge at a depth of about 212 feet.
This sea anemone was part of a remarkably diverse community on Pulley Ridge at about 212 feet.

Weather Data from the Bridge 
Visibility: 7-8 miles
Wind Direction:  140 degrees (SE)
Wind Speed:  13 knots
Sea Wave Height:  1-2 feet
Swell Wave Height:  2-3 feet
Seawater Temp.: 24.7 degrees C.
Present Weather:  Clear

Science and Technology Log 

Today we made three two-hour ROV dives on Pulley Ridge.  We documented an impressive amount of biodiversity along three transects at depths that ranged from about 190 to 225 feet. Downward still images of the bottom were taken at regular four minute intervals; forward facing still shots were taken whenever something of interest presented itself; and a continuous forward-looking video recording was made of the entire transect.

Agaricia sp., a hermatypic (reef-building) coral we found at about 215 feet.
Agaricia sp., reef-building coral we found at 215 feet.

The ideal cruising speed for the ROV video recording is a very slow one-half knot, which presents significant challenges for the people on the bridge. In fact the Commanding Officer, LCDR Brian Parker, remarked on how good a training exercise this cruise is for his team.  Upon our return to port, and for weeks afterwards, fishery biologist Stacey Harter will analyze the video to derive density estimates for the fishes observed.  She will determine the area covered by each video transect and count individuals of each species that intercepted our transect line.  Abundance estimates then can be extrapolated per unit area.  Others will use similar techniques to determine the aerial extent of living corals.  These data, in turn, will be useful to authorities responsible for managing the fisheries. Pulley Ridge is a drowned barrier island system that formed about 14,000 years ago, when sea levels were lower because a larger portion of the Earth’s water was locked up in glacial ice. While the presence of photosynthetic corals, such as Agaricia spp. was patchy on our dives, we did encounter large fields of green algae in relatively high densities.

The green algae, Anadyomene menziesii, dominated large areas in the southern portion of Pulley Ridge.
The green algae, Anadyomene menziesii, dominated large areas in the southern portion of Pulley Ridge.

This species no doubt is the Anadyomene menziesii described by Robert Halley and his group at the USGS. These striking seascapes resembled large fields of lettuce.  At the southern end of Pulley Ridge this green algae dominated the seabed.  As we moved northward from station to station, however, it occurred in much lower densities, and we began to see higher proportions of the calcareous green algae Halimeda spp. Various species of red coralline algae were also common on Pulley Ridge. Apart from the abundance of Anadyomene menziesii, the other striking observation one makes on this deep coral reef is the presence of conical-shaped mounds and pits.  These structures are almost certainly constructed by fish, such as the sand tilefish (Malacanthus plumieri) and red grouper (Epinephelus morio). Sand tilefish in particular burrow into the coral rubble and pile it up for cover. Red grouper are also industrious excavators.

A red grouper (Epinephelus morio) at rest in a small pit on Pulley Ridge.

A red grouper at rest in a small pit on Pulley Ridge.

The mounds and pits introduce an element of topographic relief into an otherwise flat seascape along the top of Pulley Ridge.  Because so many other species of fish are attracted to these structures, I would suggest that (at least among the fish) sand tilefish and red grouper represent keystone species in this unique ecosystem.  The removal of these two species would have a significant impact on the rest of the community. Other fauna we observed today were typical of what one might encounter on a shallow-water reef, including sponges, tunicates, lobsters, bryozoans, amberjacks, angelfish, reef butterflyfish, snapper, barracuda, and a loggerhead turtle.

Personal Log 

My favorite place on the ship is the boatswain’s chair way up on the bow. No one else seems to know about it, for I have yet to find it occupied when I want to use it.  It is the quietest, most scenic spot on the ship.  Whenever I get a chance, I sneak up there to watch the flying fish. They are flushed by the ship, and some of them can remain in flight for long periods, perhaps 20 seconds or more. If I am especially lucky, I also get to watch dolphins riding our bow. This is a real treat because they seem so playful.

Our ROV disturbs the nap of a loggerhead turtle (Caretta caretta).
Our ROV disturbs the nap of a loggerhead turtle (Caretta caretta).
A pod of dolphins bow-riding the GORDON GUNTER.
A pod of dolphins bow-riding the ship. 
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Robert Lovely, April 4, 2008

NOAA Teacher at Sea
Robert Lovely
Onboard NOAA Ship Gordon Gunter
March 31 – April 12, 2008

Mission: Reef Fish Ecological Survey
Geographical area of cruise: Pulley Ridge and the West Florida Shelf, Gulf of Mexico
Date: April 4, 2008

A “rosette” is used to hold the instrumentation for the CTD. Here we see the rosette being lowered down into the water column by way of a crane mounted on the GORDON GUNTER.
A “rosette” is used to hold the instrumentation for the CTD. Here it is lowered down into the water by way of a crane.

Weather Data from the Bridge 
Visibility:  12 miles
Wind Direction:  150° (SE)
Wind Speed:  18 knots
Sea Wave Height:  2-3 foot
Swell Wave Height:  1-2 foot
Seawater Temp: 24.4 degrees C.
Present Weather:  Clear

Science and Technology Log 

We begin and end each day by making a CTD profile of the water column at our sampling site.  CTD refers to conductivity, temperature, and depth, but other parameters, such as dissolved oxygen (DO), also may be measured.  Conductivity is an expression of salinity, which at our location on Pulley Ridge is pretty uniform throughout the water column.  As we see from the graph below, however, both DO and water temperature do vary with depth. Temperature is uniform in the top layer of water and then begins to drop steadily with increasing depth from about 20 meters down.  This portion of the water column, where temperature declines rapidly with depth, is called the thermocline.  The temperature profile on our graph shows that a subtle thermocline extends nearly to the bottom at Pulley Ridge. This may help explain why certain shallow-water organisms are able to survive in this relatively deep water. In other locations the same depth may be well below the thermocline and therefore in water too cold for shallow-water species to live.

Above is a graph of the CTD profiles generated at Pulley Ridge on April 4, 2008. Software linked to the CTD instrumentation on the rosette generates salinity, temperature, depth and oxygen profiles of the water column. Note that the double lines on the graph result from the roundtrip made by the rosette down to the bottom and back.
Graph of the CTD profiles from Pulley Ridge. Software linked to the CTD instrumentation on the rosette generates salinity, temperature, depth and oxygen profiles of the water. The double lines on the graph result from the roundtrip down to the bottom and back.

Dissolved oxygen is normally high at the surface due to the mixing effect of wave action. But oxygen concentrations can be high in the deeper thermocline as well simply because cold water can hold more oxygen than warm water.  Our graph above illustrates this relationship by exhibiting an increase in dissolved oxygen concentrations at depths between 20-45 meters.

This remotely operated vehicle (ROV) carries both a video camera and a still camera. The yellow umbilical shown in the foreground supplies power and control signals from the GORDON GUNTER.
This remotely operated vehicle (ROV) carries both a video camera and a still camera. The yellow umbilical shown in the foreground supplies power and control signals

Marine scientists employ different types of underwater vehicles to collect data on deep coral reefs, and the different vehicle types may seem a bit confusing at first.  Three important underwater vehicles are Submersibles, AUVs, and ROVs.  Submersibles typically refer to human-occupied vehicles, where a pilot climbs inside and drives the vehicle around like a small submarine.  The most famous example is Alvin, a submarine operated by the Woods Hole Oceanographic Institution. AUVs, in contrast, are Autonomous Underwater Vehicles that are programmed to perform specific functions, such as bathymetric mapping.  AUVs are robotic— they are completely independent, having no wires to the surface.  Finally, ROVs are Remotely Operated Vehicles, which are tethered to the ship by means of a cable and umbilical.  The ROV captures video and still images, and is driven by a pilot from a control room onboard the ship.  While utilizing bathymetric charts created during earlier cruises, our mission on Pulley Ridge and the West Florida Shelf employs only the ROV.

Rob finds out that it’s interesting, but difficult, driving the ROV.
Rob finds out that it’s interesting, but difficult, driving the ROV.

Today we made three video transects (dives) with the ROV, each lasting about two hours.  Each dive followed a predetermined course, as we began working our way north along Pulley Ridge.  The depth of our dives normally ranged between 200-230 feet, with the ROV gliding about three feet above the reef. The ship towed the ROV at speeds that typically ranged from .5 to 1.3 knots.  However, because of the slack in the tether, the ROV itself had a remarkable range of speeds. In fact, skilled pilots can bring the ROV to a dead stop (while the ship continues to move) in order to pause for nice steady close-up shots of bottom organisms.  I was very impressed by this flexibility of motion and the freedom it offered the pilot to search around the reef for organisms hiding in nooks and crannies.

Personal Log 

I was given the opportunity to take the helm of the ROV during one of our video transects. I found this experience to be fun and somewhat akin to playing a video game.  However, I also found driving the ROV to be much more difficult than it looks.  It gave me a greater appreciation for the skill of our veteran pilots, Lance Horn and Glenn Taylor.