Kimberly Lewis, July 13, 2010

NOAA Teacher at Sea Kimberly Lewis
NOAA Ship: Oregon II
July 1 -July  16 2010

Mission: SEAMAP Summer Groundfish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: Sunday, July 13, 2010

Ecosystem Conservation and some of the people who monitor it

Me holding a skate.
Me holding a skate.

Weather Data from the Bridge 
Time: 1130 (11:30 AM)
Position: Latitude = 28.57.59 N;
Longitude = 94.49.73 W
Present Weather: Clear
Visibility: 8-10 nautical miles
Wind Speed: 14.97 knots
Wave Height: 4 feet
Sea Water Temp: 29.1 C
Air Temperature: Dry bulb = 31.4 C; Wet bulb = 27.0 C
Barometric Pressure: 1013.77 mb

Science and Technology Log

“IT’S ALL CONNECTED.” Everything in an ecosystem is connected to everything else. This is a guiding principle of studying and managing ecosystems. This past spring in one of my online communities we were discussing whole ecosystem monitoring for conservation rather than the traditional ‘save one species at a time”.

I’m seeing it now in the Gulf of Mexico. Obviously, the ocean environment is connected to human activities – the BP-Deepwater Horizon oil spill makes that abundantly clear. But there are also countless natural connections, and much less obvious human impacts, that must be understood and assessed if the Gulf ecosystem is to be protected. Commercial fish and shrimp stocks can only be sustained through a careful understanding of the human impact and natural connections in the Gulf.

That’s why we identify and count every organism we bring up in a trawl. Sometimes we get 50 or more different species in one catch, and we don’t just count the commercially important ones like red snapper and shrimp. We count the catfish, eel, sea stars, sea squirts and even jellyfish we haul in. Why? Because even though these organisms might seem “unimportant” to us, they might be important to the red snapper and shrimp. They also might be important to the organisms the red snapper and shrimp depend on. And even if they’re not directly important, studying them might tell us important things about the health of the Gulf.

Brittany
Brittany on the deck

Bruce and I are learning a lot about this from the incredibly knowledgeable marine biologists in the science party. Brittany Palm is a Research Fishery Biologist from NOAA’s Southeast Fishery Science Center (SEFSC) in Pascagoula, MS, and leader of the day watch on this leg of the Oregon II’s Summer Groundfish Survey. Brittany is working on her M.S. on a fish called croaker, Micropogonias undulatus, studying its stomach contents to better understand its position in the food web. Croaker is not an economically important species, but it lives in the same shallow sea floor habitat as shrimp so shrimpers end up hauling in a huge amount of croaker as bycatch. So, when the shrimping industry declined in 2003-2004, the croaker population exploded. Since croaker are closely associated with shrimp habitat and the shrimp fishery, we might gain important insights by studying croaker population and understanding what they eat, and what eats them.

Alonzo
Alonzo helping to dissect a fish

Alonzo Hamilton is another NOAA Fishery Biologist from the SEFSC. Alonzo explained that there’s a lot to be learned by looking at the whole ecosystem, not just the 23 commercial species that are managed in the Gulf. For example, many of the crabs we commonly catch in our trawls are in the genus Portunas, known as “swimming crabs.”

Portunas spinicarpus
Portunas spinicarpus

Portunas species normally live on the sea floor, but when severe hypoxia sets in, Portunas crabs can be found at the surface, trying to escape the more severe oxygen depletion that typically takes place at the bottom of the water column.

Sean
Sean on the deck
Geoff on the deck
Geoff on the deck

Sean Lucey and Geoff Schook are Research Fishery Biologists from NOAA’s Northeast Fishery Science Center in Woods Hole, Massachusetts. They are working on the Oregon II right now to support the SEFSC because of huge manpower effort demanded by the oil spill. The NEFSC has been conducting their groundfish survey annually since 1963, making it the longest-running study of its kind. Originally the survey only looked at groundfish population, but as our understanding of ecosystem dynamics increased over time, more and more factors were analyzed. Now NEFSC looks at sex, age, stomach contents and many other species besides groundfish to obtain a more complete picture of the food web and the abiotic factors that affect groundfish. NEFSC even measures primary production in the marine ecosystem as one tool to estimate the potential biomass of groundfish and other species at higher trophic levels.

Fisheries biologist Andre DeBose
Andre DeBose is a NOAA Fishery Biologist from the SEFSC and the Field Party Chief for the Summer Groundfish Survey. In addition to leading the science team on the Oregon II, Andre is conducting research on Rough Scad, Trachurus lathami, an important food species for red snapper and important bait fish for red snapper fisherman. By gaining a better understanding of the relationship between Red Snapper and its prey we can better understand, and better manage, the ecosystem as a whole.

There’s a lot of information to be learned beyond just counting fish. By taking a wide look at the marine environment we can better understand how the whole ecosystem functions. This enables us not only to be more informed in setting sustainable catch levels, but also enables us to identify and respond to things that contribute to hypoxia and other problems that degrade habitat and reduce populations. It’s all connected.

Personal Log

Everyone in the scientific party has been working very hard to gather data. A 12 hour shift can be long at times, and other times fly by. Today Andre told us we will start cleaning up Thursday morning. It doesn’t seem possible that my 17 days with the Oregon II will soon be over. Part of me is excited to get back home to see my family and sleep in a bed that isn’t affected by the Gulf waves. The other part of me is sad due to the fact I will not longer be working with some remarkable people and worked with ongoing scientific research. It is very hard work, but very exciting to see what goes on at sea. I am sure I will call on some of them in the future for collaboration.

Chef Walter made some great meals over the past few days. Crab cakes, roasted buffalo, chicken curry, and quail, not to mention those great breakfasts. Based on my first two days of sea not able to keep anything down and not wanting to eat, I thought for sure I would go back to Ohio 15 pounds lighter. But the sea sickness wore off and I am enjoying food and adjusting to boat life.

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.