NOAA Teacher at Sea
Duane Sanders
Onboard Research Vessel Hugh R. Sharp
June 8-19, 2009
Mission: Sea Scallop Survey Geographical Area: New England Coast Date: June 10, 2009
Weather Data from the Bridge
Wind: Speed 19.4 KTS, Direction 86.8 degrees
Barometer: 1013 millibars
Air temperature: 14.2 0C
Seas: 2-3 feet
I’m having fun at the sorting table.
Science and Technology Log
The primary mission of this cruise is to complete the second leg of a three-leg survey of scallop populations along the New England Coast. Other information about the scallop ecosystem is also collected. Scientists evaluate the status of the scallop fishery use data gathered from the survey. Decisions about which areas to allow commercial scalloping and which areas to close to commercial use are based on these surveys. These science-based management decisions help to promote long-term stability of the scallop industry.
Members of the day watch working at measuring stations.
After two complete watches, I think I understand the procedure. Stations to be sampled are determined by a stratified random sampling procedure. Computers, following certain parameters set by NOAA staff, determine which area is to be sampled. It is important to be consistent so that each station from each of the three legs of the cruise can be reliably compared other data from this survey as well as from other years. Once the captain puts the ship on station, an eight-foot wide dredge is lowered to the bottom and dragged for 15 minutes. The captain keeps the ships speed to a constant 3.8 knots. When the dredge is hauled in, its contents are dumped on a large steel sorting table that is bolted onto the to deck. The science team on watch sorts through the contents of the catch and separates all scallops into one basket, all fish into a different bucket and all the rest of the haul into another basket.
We then determine the total weight of the scallops and measure the length of each one. Thankfully we use a computerized system for determining the lengths which automatically record them. All of the fish are sorted by species, and then weighed by species. The length of each fish is recorded using the same system as for the scallops. The total volume of the remaining haul is estimated with each basket being equivalent to 46 liters. The general contents of the basket are characterized by types of shells found, types of substrate material and other organisms present.
Personal Log
A sea mouse (Aphrodite aculeate)
I have been assigned to the night watch. This means we work from midnight to noon. Although I am doing better today, it has been difficult to adjust to sleeping during the day. I am sure that I will continue to adapt. As long as Paul, our cook, keeps preparing his delicious meals I will survive quite nicely!
I have really enjoyed seeing the variety of organisms that come up in the dredge. My favorites are the invertebrates. Some examples include different species of starfish, other mollusks beside scallops, and sea mice. A sea mouse is actually a marine worm in the group known as polychaetes. These strange looking creatures grow long, thin scales that looks like fur. Their bodies have the general shape of a mouse with no tail. There are also many fish species, which I am learning about, but they do not interest me as much as the other organisms.
NOAA Teacher at Sea
Duane Sanders
Onboard Research Vessel Hugh R. Sharp
June 8-19, 2009
Mission: Sea Scallop Survey Geographical Area: New England Coast Date: June 8, 2009
Weather Data from the Bridge
Wind: Speed 16.1 KTS, Direction 50.5 degrees
Barometer: 1014 millibars
Air temperature: 16.8 0C Seas: 1-3 ft.
Science and Technology Log
The Hugh R. Sharp at dock in Delaware
I have been assigned to participate in the annual scallop survey in the New England fisheries area. Our ship, the Hugh R. Sharp, is two years old and designed specifically for ocean research. The Sharp is owned by the University of Delaware and is under contract with NOAA for the scallop survey. It has laboratories, a workshop and specialized equipment for handling large or bulky devices. There is a continuous data stream gathered by the ship’s instruments and posted on monitors on the bridge and in the lab. This includes some parameters related to ocean chemistry as well as the usual weather data. There are several other high-tech sensing systems to assist in a variety of research projects. The ship’s flexible design allows for the science team to install computers, servers and ancillary equipment specific to the research project at hand. Also, modular labs outfitted for specific purposes can be secured to the fantail (rear deck) of the ship.
My favorite piece of technology is the diesel electric drive system. Diesel generators produce electricity that supply power to the drive motors all other electrical needs on the ship. Propulsion is provided by thrusters, which are capable of rotating in any direction as needed. There are two thrusters in the stern and one in the bow. These three acting together can keep the Sharp within six feet of a specified location. The ship’s engineer can monitor all systems from his station on the bridge. This system is very quiet and vibration is kept to a minimum. That means we can sleep much better than with a conventional diesel engine drive. All in all, this vessel seems to me to be an ocean scientist’s dream come true. It is designed for high-tech applications and configurations that change as the need arises.
Here I am practicing donning my emergency immersion suit.
Personal Log
Today is our first day at sea. We spent the morning hours getting acquainted with each other and learning about safety, emergency procedures and shipboard etiquette. For example, the science team was divided into two watches, midnight to noon and noon to midnight. The rule is that people coming on watch need to take everything they want to use during watch hours with them. This allows those coming off watch to get some undisturbed rest. Living in close quarters requires everyone to be considerate and cooperative. We all rely on each other to do their part to help make the cruise a safe and successful one. While there is always room for some fun, everybody takes their responsibilities quite seriously. Life and limb often depend on this careful approach to our work.
“Ships have many pieces of complicated equipment!”
The NOAA Ship THOMAS JEFFERSON awaits a part for the crane that lifts the fast rescue boat, then we set sail
Personal Log
Hello, greetings from Teacher at Sea Candice Autry. I teach science to middle school students at a wonderful school called Sheridan School in Washington, DC. I have been given the great opportunity to sail with the crew on the NOAA Ship THOMAS JEFFERSON. Our cruise has been delayed several days due to unforeseen problems with some of the complex and necessary equipment on the ship. It is important to be flexible with any kind of change, so these past few days have given me the opportunity to explore the ship as we wait for final repairs. The objectives of this particular ship primarily involve hydrographic surveys. Hydrography is the science that has to do with measuring and describing physical characteristics of bodies of water and the shore areas close to land. Thanks to hydrographic surveys, ships, ferries, pleasure boats, and other vessels can safely navigate in busy waters without hitting any obstructions on the bottom of a harbor.
A crane lifts the necessary fast rescue boat aboard.
Hydrographic surveys can also locate submerged wrecks in deep waters; examples include unfortunate events such as shipwrecks out at sea as well as plane crashes over the ocean. These surveys are done by using technology that involves side scan sonar and multi-beam sonar technology. The combination of these two types of technologies can create a clear picture of a barrier on the ocean floor and the depth of the obstruction.
The THOMAS JEFFERSON holds several smaller boats including two launches (one launch is visible in the picture, it is the gray boat) that have this sonar technology located underneath the vessel. The instrument that collects data is often called a “fish.” The data can be seen on a computer screen so that the surveyors can view the data being collected. Once we reach our destination, we will use these launches, one equipped with a fish that uses multi-beam sonar technology and the other with a fish that uses side scan sonar to create a chart of what is on the bottom of a very busy harbor!
Seaman Surveyors Doug Wood and Peter Lewit interpret hydrographic data in the survey roomStaterooms are comfortable and cozy!One of the workrooms aboard the NOAA Ship THOMAS JEFFERSON.A closer look at the navigational equipment on the bridge
Weather Data from Bridge
Visibility: 10 miles to less than 25 miles
Wind direction: 065°
Wind speed: 06 knots
Sea wave height: small
Swell wave height: 4-6 feet
Sea level pressure: 1014.5 millibars
Cloud cover: 3, type: stratocumulus and cumulus
Buoy Technician, Sean Whelan, contacting the Acoustic Releases on WHOTS-2.
Science and Technology Log
Today was very busy because it was the day that WHOTS-2 mooring, which has been sitting out in the ocean for almost a year, was recovered. At around 6:30 a.m., Sean Whelan, the buoy technician, tried to contact the Acoustic Release. (The Acoustic Release is the device that attaches the mooring to the anchor. When it receives the appropriate signal, it disengages from the anchor, freeing the mooring for recovery. There are actually two releases on WHOTS2.) He does this by sending a sound wave at 12 KHz down through the ocean via a transmitter, and when the release “hears” the signal, it returns a frequency at 11 KHz. The attempt failed, so the ship moved closer to the anchor site and the test was repeated. This time it was successful. Based on the amount of time it takes the acoustic signal to return, the transmitter calculates a “slant range” which is the distance from the ship to the anchor. Because the ship is not directly over the anchor, this slant range creates the hypotenuse of a right triangle. Another side of the triangle is the depth of the ocean directly below the ship. Once these two distances are known, the horizontal position of the ship from the anchor can easily be calculated using the Pythagorean theorem.
Recovery of WHOTS-2 buoy aboard the R/V REVELLE.
After breakfast, the buoy recovery began. A small boat was lowered from the ship and driven over to the buoy, as the ship was steamed right near the buoy. A signal was sent down to activate the Acoustic Releases. Ropes were attached from the buoy through a pulley across the A-frame, located on the stern of the ship, to a large winch. With Jeff Lord leading the maneuvering of the 3750-pound buoy, it was disengaged from the mooring and placed safely on deck. This was a bit of a tense moment, but Jeff did a wonderful job of remaining calm and directing each person involved to maneuver their equipment to effectively place the buoy. Once the buoy was recovered and moved to the side of the deck, each instrument on the mooring was recovered. The first to appear was a VMCM, (Vector Measuring Current Meter) located just 10 meters below the buoy.
Jeff Lord, engineering technician, directing the recovery of a Vector Measuring Current Meter (VMCM).
Then two microCATs were pulled up, located 15 and 25 meters below the buoy, followed by a second VMCM. This was followed by a series of eleven microCATs located five or ten meters apart, an RDI ADCP (Acoustic Doppler Current Profiler), and two more microCATs. As each instrument was recovered, the time it was removed from the water was recorded and its serial number was checked against the mooring deployment log. Each instrument was photographed, cleaned off and sent to Jeff Snyder, an electronic technician, for data upload. Each of these instruments has been collecting and storing data at the rate of approximately a reading per minute for a year (this value varies depending on the instrument) and this data now needs to be collected. Jeff placed the instruments in a saltwater bath to simulate the ocean environment and connected each instrument to a computer by way of a USB serial adaptor port. The data from each instrument took approximately three hours to upload. Tomorrow, these instruments will be returned to the ocean alongside a CTD in order to compare their current data collection with that of a calibrated instrument.
Once all of the instruments were recovered, over 4000 feet of wire, nylon rope, and polypropylene rope were drawn up using a winch and a capstan. Polypropylene rope is used near the end of the mooring because it floats to the surface. The last portion of the mooring recovered was the floatation. This consisted of eighty glass balls chained together and individually encased in plastic. The glass balls, filled with air, float the end of the mooring to the surface when the Acoustic Releases disengage from the anchor. It takes them about 40 minutes to reach the surface. Recovering the glass balls was tricky because they are heavy and entangled in one another. Once on deck they were separated and placed in large metal bins. After dinner, a power washer was used to clean the buoy (it is a favorite resting place for seagulls and barnacles) and the cages encasing some of the instruments. The deck was cleaned and organized to prepare for tomorrow.
Recovery of mooring floatation on WHOTS-2, consisting of 80 glass balls encased in plastic.
Personal Log
The theme that keeps going through my mind during this trip and today especially, is how much of a cooperative effort this research requires. It begins with the coordination between Dr. Weller and Dr. Lukas to simultaneously collect atmospheric data using the buoy and subsurface data with the mooring instruments. In addition, Dr. Frank Bradley, an Honorary Fellow at the CSIRO Land and Water in Australia, is on the cruise working to create a manual set of data points for relative humidity using an Assman psychrometer to further check the relative humidity data produced on the buoy. Within the science teams, coordination has to occur at all stages, from the collection of data to its analysis. This was very evident in physical form today with numerous people on deck throughout the day working to retrieve the mooring, fix machinery as it broke down (the winch stopped twice), and clean the instruments. In the labs, others were working to upload data and configure computer programs to coordinate all of the data. In addition to all of this is the quiet presence of the ship’s crew who are going about their duties to be sure that the ship is running smoothly. Several of the crew did take a break today just after the instruments were collected in order to put out fishing lines! They caught numerous tuna and beautiful Mahi Mahi that the cook deliciously prepared for dinner.
Dr. Lukas, aboard the REVELLE collecting water samples from the CTD.
Dr. Roger B. Lukas Professor of Oceanography Dept. of Oceanography and Joint Institute for Marine and Atmospheric Research University of Hawaii at Manoa.
After taking a CTD sample earlier this afternoon, I spoke with Dr. Lukas, the research scientist on this cruise who is leading the recovery and replacement of the mooring components below the WHOTS-3 buoy. The following is a summary of our discussion.
Dr. Lukas encouraged to me to communicate to my students how imperative it is to set up means of continually confirming the accuracy of scientific data. The data from the mooring, for example, is compared with six or seven different profiles in order to verify the accuracy of its data and to determine when an abnormal reading has occurred (i.e. a sensor breaks or fishing lines are caught in an instrument).
Organisms both in the sample and in the surrounding water can shift the conductivity calibration in a CTD (Conductivity Temperature Depth) instrument. Therefore, the calibration of these instruments must be constantly checked and monitored. Throughout the day today at two-hour intervals, Dr. Lukas has been sending down CTD’s that provide a continuous profile of the salinity and temperature of the ocean from the surface to the maximum depth of the cast. There are sampling bottles on the rosette of the CTD that close at a depth of 10 and 200 meters. The water from these samples is brought to the surface and is used to calibrate the conductivity of the CTD. The conductivity readings (which are used to determine salinity measurements) are compared to readings taken from the sampled water via an analytical instrument called an Autosal. The Autosal is located in a lab on the ship near the main science lab. This instrument is contained in a water bath for stabilization and is kept in a temperature-controlled room. Any atmospheric pressure variations that might occur during the Autosal conductivity tests do not have enough of an effect on the conductivity determinations to create inaccuracies in salinity readings. The Autosal itself is calibrated against standard seawater which is quite expensive ($55 for a small vial) but whose salinity is known to the nearest part per million (ppm).
Salinity, or the number of grams of dissolved salts in a kg of seawater, is detected in one part per million (ppm) and is not taken as a direct measurement. Instead, both the temperature of the sample and its conductivity are measured. This is because the conductivity of seawater is affected by three variables: temperature, pressure, and salinity. Temperature affects conductivity ten times more than does salinity. Basically this means that temperature measurements must be extremely accurate in order to obtain precise salinity measurements. If a temperature reading were to be off by 1°C this would produce an error in the salinity determination by a factor of ten. This would render the salinity measurement entirely useless. Salinity measurements are related to a scale known as the Practical Salinity Scale where, for example, a reading of 35 units would be equivalent to the conductivity of 35 grams of salt in 1 kg of water. The scale is practical because the ratio of ionic chemical compounds in the ocean remains relatively constant.
Ultimately, the salinity readings produced by the instruments contained in the MicroCATs in the mooring are being compared to numerous measurements taken off of the ship via the CTD’s profiles. The CTD’s readings are being calibrated against water samples taken by closing bottles on the CTD frame at different depths, which are then measured in the Autosal, which is, in turn, calibrated against standard seawater samples. The multiple checks on the temperature measurements taken at sea are not a stringent as those of the salinity readings because the temperature instruments do not have nearly the same rate of calibration drift. Unless they are broken, they will only drift approximately one millidegree per year.
There are different types of oceanographers who study various parameters of the ocean. Dr. Lukas is a physical oceanographer as opposed to one who studies the biological or chemical aspects of the ocean. Physical oceanographers study such factors as current, waves, wind, heat content, temperature, and salinity. However, there is overlap amongst the different areas of science. A chemical determination, such as salinity, can actually be quite pertinent to the physical study of the ocean. Alterations in salinity correlate with changes in density. Variations in density gradients across the ocean cause flow or ocean currents. Other factors that affect the ocean currents include the depth of the water; wind, which drags water along; and the rotational motion of the earth. For example, if a current is moving northward, the rotation of the earth causes an apparent force to affect the water thus drawing it eastward and changing the direction of the current. Additional smaller factors that affect the current include turbulence in both the air and the sea. Turbulence is chaotic eddying motions that cause mixing amongst masses of water at different temperatures and salinities.
Dr. Lukas has a Bachelor’s degree in Mathematics, and a Master’s and PhD in oceanography. The work that he has done in earning his PhD gives him the ability to lead a research project, such as the Hawaii Ocean Time-series (www.soest.hawaii.edu/HOT_WOCE). However, Dr. Lukas noted that one does not need a PhD to be a vital part of a research team. We have people working as part of the science team on this cruise who are at the Master’s, Bachelor’s and Associate’s degree levels.
When asked about what he likes about his work, Dr. Lukas told me that he enjoys several aspects of his job. He enjoys going to sea and the fact that his work leads him to discover new things. He also values the freedom that his occupation affords him. If he is successful in obtaining funding for a proposal, he has the freedom to carry out a project of his own design. His work has taken him to a variety of places including Papua New Guinea, the Philippines and the Bay of Bengal!
It became very evident in talking with Dr. Lukas that he is devoted to this work that he so enjoys. He puts many hours into his profession. As he stated, he and Dr. Weller have continual “time and a half” jobs. His occupation involves many different aspects including being at sea, gathering data and preparing for such science cruises. He spends large chunks of time working with his research group of eight members. This work involves managing and training the members of the group as well as dealing with various personnel issues. Approximately 20% of his time is spent teaching at the graduate level. This is a smaller percentage than many of his colleagues. Dr. Lukas spends time developing projects and proposals and a significant amount of time completing the science for those that are funded. This science includes analyzing data, writing papers, attending meetings, etc. Finally, another large aspect of his job is of a more global, community nature. Like many of his colleagues, he reviews the work of other scientists. He is a member of various committees including those that make recommendations to funding agencies. He has numerous meetings each year, some of which require extensive travel. He travels to Washington D.C. several times a year, and has worked to raise awareness in congress concerning global issues relating to the ocean and our environment.
Finally, I asked Dr. Lukas if he had any advice for students interested in oceanography. He replied that, “There is no such thing as too much math or science!” One of his team members was nearby and commented that although math might seem boring in high school it becomes so important later on. Dr. Lukas confirmed that it is a tool that allows scientists to accomplish a lot. This is clearly evidenced by the work that he is able to complete.
