food web – Page 3 – NOAA Teacher at Sea Blog

March 22, 2006March 18, 2021

Vince Rosato and Kim Pratt, March 22, 2006

NOAA Teacher at Sea
Vince Rosato & Kim Pratt
Onboard NOAA Ship Ronald H. Brown
March 9 – 28, 2006

Mission: Collect oceanographic and climate modeling data
Geographical Area: Barbados, West Indies
Date: March 22, 2006

Science and Technology Log: The Echo Sounder

For the past few days, we’ve been transiting back and forth picking up (recovering) and launching (deploying) a special kind of buoy called an Inverted Echo Sounder (IES). This buoy is attached to a weight and sinks to the bottom of the ocean. There it sends out a sound pulse to the surface and measures the travel time of that pulse to hit the surface and return to the unit on the bottom of the ocean. Using the travel time of the sound, scientists use it with a historical profile of the water to estimate temperature and salinity of the water. They obtain the historical profile by doing repeated CTD casts and especially the cast before deploying the IES. Sound speed is proportional to salinity/density and scientists use the density and temperature estimations to identify water mass and current movement. Remember, these currents are moving all over the world! The buoy we deployed also had a current sensor as well as a pressure and temperature sensor. When scientists are ready to get the information from the buoy, they travel to the site of the buoy, and park the ship right on top of it, and the buoy sends the information to them.

The buoys stay down in the bottom of the ocean sometimes as long as 6 to 7 years but usually they’re picked up after 5 years. They cost between $25,000 and $45,000 each! When scientists are ready to pick up the buoy, they send a signal that tells the buoy to detach from the weight holding it down and then it floats to the surface attached to a large yellow float. At night, it sends a strobe light flashing across the water so it can be easily found. Also in the past week, all the Styrofoam cups that have been decorated by students at Cabello, Searles Elementary, Key Biscayne Community School, and members of the crew of the RON BROWN were lowered into the ocean at about 5000 meters, or a little more than 3 miles below sea level. The effect of pressure can be as great as 70,500 pounds of pressure! This rids the cups of all the air and shrinks them to 75% of their original size. It’s sort of like when you dive into a swimming pool, and while going down you feel your ears get tight— that is the effect of pressure.

Finally, although we’ve been out to sea for over two weeks, we’ve seen very little wildlife. We’ve seen pilot whales, two or three squid, flying fish and some little fish called Ballyhoo that dance on top of the water with a long snout. They look like mini swordfish. The reason we haven’t seen much wildlife is that there is very little life in the middle of the ocean. In fact, if you look at the middle of the ocean from space, it almost looks purple because there is no phytoplankton, (green plant material that is the base of the food chain). You’ll find life near the coasts or in the North Atlantic because all animals need nutrients to live and you need currents or up welling to move the nutrients around to feed the phytoplankton (plants) which feed the zooplankton (little animals), which feed the fish, which feed the dolphins, which feed the sharks! This is an example of the food chain.

Interview with Chris Churylo – Chief Electronics Technician

An important person on any cruise is the Chief Electronics Technician or Chief ET as they are called. Their main job is to make sure that all the electronics are working – that means sonar, networks, navigation, radio and all the things that keep the ship going to where it needs to go, and people talking to whom they need to talk. On board the RON BROWN, the Chief ET is Chris Churylo. Chris is multi-talented—not only is he a Chief ET, he’s also a Licensed Practical Nurse, an Emergency Medical Technician, a truck driver, a fireman, a pilot, has a real estate license and is a Notary. Chris likes working on the RON BROWN because he works two months on and gets two months off. While he’s at sea and not working, he likes to play chess, learn guitar and work out in the gym. During his off-time he likes to fly his plane, a Cessna 150, explore local places and hang out with his girlfriend of 18 years. Chris, who grew up in Philadelphia now calls a farm in West Virginia his home. During his career he has traveled all over the world, notably to the South Pole and Barrow Alaska during his 20 years of government service. Chris’s attitude on board the RON BROWN is contagious. He is a happy spirit, energetic and genuinely likes what he does.

Assignment: In your logs, illustrate the effect of pressure. Step one – Draw your decorated Styrofoam cup at the surface. Step two – draw it on the CTD in a bag ready to go to the bottom of the ocean. Step three – draw it now 2/3 smaller than when it started.

Personal Log – Kimberly Pratt

Yesterday was a quiet day. We headed back to Marsh Harbor, Bahamas so the science staff had most of the day off with CTD casts in the evening. I got to do some reading about Great White Sharks off the Farallones Islands – outside of San Francisco Bay. One of the main researchers in the book is Peter Pyle, who I sailed with last year on the MCARTHUR II. I’ve really met some great people being a Teacher at Sea. This trip feels like it is winding down with less than a week to go. The weather is still beautiful. Sorry to hear about all the rain and hail back home. Keep writing I love hearing from you all.

Personal Log – Vince Rosato

Sad news came on three fronts today. First, a crewmember heard by ship’s phone of a tragedy in the family and had to be brought to shore to catch a plane back home. If you noticed the ship tracker had us going back and forth from Abaco Island, one of those trips was to bring a crewmate ashore. Second, I heard from my home that a neighbor friend had a stroke and is under observation in the hospital. And third, from my school, a teacher friend is taking the rest of the year off for health reasons. Those things drained my energy. Work doesn’t stop whether we are happy or sad, so I continued becoming proficient at salinity analysis. If counting time, however, I spent most of the day replying to your wonderful emails and working on logs. I got to call out on the radio set the depths to the winch driver, and fire the CTD bottles on the late night cast. That boosted my morale with Dallas, the author, and Mick, the father of Dr. Beal. We have formed a bond with Carlos, our CTD team leader, through our tradition of after-shift snack time in the galley.

August 25, 2005March 18, 2021

Joan Raybourn, August 25, 2005

NOAA Teacher at Sea
Joan Raybourn
Onboard NOAA Ship Albatross IV
August 14 – 25, 2005

Mission: Ecosystem Productivity Survey
Geographical Area: Northeast U.S.
Date: August 25, 2005

Personal Log

Today was the last day of our two-week adventure at sea. At dawn this morning, we paused for a while before entering the north end of the Cape Cod Canal. While we have been within sight of land for a day or two, it was strange to see land on both sides of us. The canal was built in the 1930s, and using it to get back to Woods Hole saves at least half a day’s sailing time. Without it, we would have to sail all the way around the “arm” of Cape Cod. We slipped into the canal and eased our way south, back into civilization. We stood on the bow of the ship and watched fish playing in the water, seabirds hovering hopefully over them. People walked their dogs on the path beside the canal, and sailboats passed silently. All was quiet. When a siren split the air, we knew we were back.

The trip through the canal took about an hour and a half, and we were in Buzzards Bay. We made our way through the islands and back around to Woods Hole, to the pier where our trip began. We cleaned the labs and packed our gear and samples to go ashore. At the pier, a gangplank was attached to the ALBATROSS IV so that we could move “all ashore that was going ashore”. We lugged boxes and crates over it to the NOAA warehouse, the EPA truck, and the NOAA van that would take the samples back to the lab in Rhode Island. It was a strange feeling to be back on land. At the beginning of the trip, my body had to adapt to the motion of the ship, and for the first two days I staggered around until I got my sea legs. Back on land, my body had to adapt again; even though my brain knew I was on solid land, the sensation of motion persisted.

And then it was over. By 2:30, everyone who was leaving was gone, and our shipboard community was dissolved. Since my flight home is not until tomorrow, I will stay one more night aboard the ALBATROSS IV. It’s a little lonely now, with everyone gone and no work to do. But I’ve been up since midnight, when my last watch began, and an early bedtime tonight will be welcome. What an adventure this has been! I will never forget my days out on the wide blue sea, with nothing to see but sky and wind and ocean. Whenever city life hems me in, I’ll be able to go back in my mind’s eye, feeling the wind and the sunshine, and watching the endless play of the sea, all the way to forever.

August 24, 2005March 18, 2021

Joan Raybourn, August 24, 2005

NOAA Teacher at Sea
Joan Raybourn
Onboard NOAA Ship Albatross IV
August 14 – 25, 2005

Mission: Ecosystem Productivity Survey
Geographical Area: Northeast U.S.
Date: August 24, 2005

Weather Data from the Bridge

Latitude: 43°32’ N
Longitude: 69°55 W
Visibility: 8 miles
Air Temperature: 17° C
Wind direction: E (99 degrees)
Wind speed: 5 knots
Sea wave height: 1’
Sea swell height: <1’
Sea water temperature: 18.8°C
Sea level pressure: 1018.0 millibars
Cloud cover: 7/8 Cumulus

Question of the Day: At what degrees on the compass would you find the intermediate directions? (Use information below to help you and look for the answer at the end of today’s log.

Yesterday’s Answer: GMT stands for “Greenwich Mean Time”. GMT is the time at the Prime Meridian, which passes through Greenwich, England. People around the world can use this time as an international reference point for local time. We are on Eastern Daylight Time (EDT), which is four hours behind GMT. At 1:33 a.m. GMT, it was already August 24 in Greenwich, but our local time was 9:33 p.m. EDT, still August 23, so that is the date I used in the log.

Science and Technology Log

Over the last eleven days, the ALBATROSS IV has zigzagged back and forth across southern New England waters, Georges Bank, and the Gulf of Maine. The collection stations were chosen in advance of the trip and plotted on an electronic chart. So how does the crew drive the boat to the next station?

Ship navigation is a combination of automated and manual tasks. Based on the ship’s current position and the latitude and longitude of the next station, the navigator determines what heading to take. That is, he decides in exactly which direction to go using a compass. The ship has an electronic gyroscope as well as a manual compass similar to the ones you may have seen, only larger. It has a magnetic needle that points north, and is divided into 360 degrees. The cardinal directions are these: 0° is north, 90° is east, 180° is south, and 270° is west. The navigator enters the heading into the ship’s navigation computer, and if conditions are normal, he can set the ship on Autopilot. Then the computer will automatically adjust the ship’s direction to keep it on course.

The fact that the ship is running on Autopilot does not mean that the crew can take a break. The crew sets the ship’s speed depending on weather and sea conditions, and on how much other ship traffic there is in the area. In open water, the ALBATROSS IV cruises at about ten to twelve knots, which means we cover about 10 to 12 nautical miles per hour. The crew must constantly monitor to make sure the ship is operating safely and efficiently. They plot the ship’s course on paper, monitor weather conditions, watch for other ships and communicate with them, and adjust the ship’s course and speed. At the collection stations, they are able to put the ship at the exact latitude and longitude called for, and keep it there during water casts and sediment grabs, or moving at just the right speed for plankton tows.

Navigators keep a constant watch out for other ships, using a combination of visual and radar data. They use radar to pinpoint the ships’ locations, and often can be seen scanning the sea with binoculars. Signal lights on ships help with navigation, too. Ships have a red light on the port (left) side and a green light on the starboard (right) side. This helps navigators know which side of a ship is facing them and in which direction it is headed. Of course, radio communication makes it possible for ships’ crews to talk to each other and make sure they are passing safely.

Personal Log

Tonight will be the last night of the cruise. We expect to be back in Woods Hole by midday tomorrow, two days earlier than planned. We’ve been blessed with excellent weather, and have made good time cruising between stations. I was very excited last night to see fireworks in the toilet! Toilets on the ship are flushed with sea water, which often contains some bioluminescent phytoplankton. Sometimes the swirling action of the water will excite them, and we’ll see blue-green sparkles and flashes as the water washes down. (Sewage and waste water are biologically treated on board so that they are safe to release into the ocean.)

I want to thank the crew of the ship, especially the NOAA Corps officers who have welcomed me on the bridge and answered many questions about ship operations. I am particularly grateful to Capt. Jim Illg, who reviewed all of my logs, and Ensign Patrick Murphy, who answered many questions about weather and navigation.

Finally, I want to thank the scientists who willingly shared their knowledge and patiently taught me protocols for their work. Jerry Prezioso, a NOAA oceanographer, served as chief scientist on this cruise. He helped me prepare ahead of time via telephone and email, and has been endlessly helpful to this novice seafarer. His enthusiasm is infectious, and he has a knack for turning any event into a positive experience. Jackie Anderson, a NOAA marine taxonomist, taught me to operate the CTD unit and helped me identify the kinds of zooplankton we captured in the bongo nets. Don Cobb, an EPA marine environmental scientist, helped me understand the kinds of research the EPA is doing to monitor the health of our oceans and estuaries. Thanks to all of them for their work in keeping Planet Earth healthy, and for making this an experience I can take back to my classroom and use to help make science real for my students.

Today’s Answer: The intermediate directions are those that fall between the cardinal directions, so to find their degree equivalents, find the halfway point between the numbers for each cardinal direction. Northeast would be at 45°, southeast would be at 135°, southwest would be at 225°, and northwest would be at 315°.

August 23, 2005March 18, 2021

Joan Raybourn, August 23, 2005

NOAA Teacher at Sea
Joan Raybourn
Onboard NOAA Ship Albatross IV
August 14 – 25, 2005

Mission: Ecosystem Productivity Survey
Geographical Area: Northeast U.S.
Date: August 23, 2005

Weather Data from the Bridge

Latitude: 44°23’ N
Longitude: 66°37’ W
Visibility: 10 miles
Wind direction: W (270 degrees)
Wind speed: 12.7 knots
Sea wave height: 1’
Sea swell height: 1’
Sea water temperature: 11.1°C
Sea level pressure: 1014.7 millibars
Cloud cover: 1/8 Clear with a few cumulus clouds low on the horizon

Question of the Day: What does “GMT” stand for and how does it affect the date in the log information above?

Yesterday’s Answer: The clock shows 9:17 a.m. There are 24 hours around the clock face. The hour hand is pointing a little past the 9, so that is the hour. To read the minute hand, notice its position. On a twelve-hour clock, this position would indicate about 17 minutes past the hour. Since this clock counts off 24 hours instead of counting to 12 twice, the afternoon and evening hours have their own numbers. For example, 4:00 p.m. on a twelve-hour clock would be 16:00 on a twenty-four-hour clock. There is no need to indicate a.m. or p.m. since each hour has its own unique number.

Science and Technology Log

Today I spent some time up on the bridge talking to the crew about weather. The ship collects all kinds of weather data from on-board sensors, including air temperature, air pressure, wind speed and direction, and relative humidity. It also receives weather data from sources outside the ship via satellite link and email. I was especially interested in how the crew determines visibility, cloud cover, sea wave height, and sea swell height, since these represent subjective data. “Subjective” means that someone uses known data and their own experience to make a judgment. Here are some examples.

Visibility just means how far you can see into the distance. This is very hard to judge on the sea because there are no reference points – no objects to “go by” to decide how far away something is. Radar gives an accurate distance from the Albatross IV to objects such as other ships, and on a clear day, the horizon is about twelve miles away. A navigator learns to estimate visibility by combining radar information with how far away objects look in relation to the horizon. It takes a lot of practice to be able to judge visibility using only your eyes!

Cloud cover just means the amount of the sky that is covered by clouds. This is expressed in eighths. Today the cloud cover was about 1/8, meaning about one eighth of the sky had clouds and seven eighths was clear. To make the estimate, mentally divide the sky in half and ask yourself if about half of the sky is cloudy. If you see that less than half the sky has clouds, then mentally divide the sky into fourths, and then eighths. This can be tricky if the clouds are scattered around because it is hard to see a fraction that isn’t all “together”. Once again, this skill takes a lot of practice.

Sea swell height and sea wave height are both descriptors of how the ocean surface is behaving. These are important to observe because they affect the motion of the ship. Swells are large rolling humps of water that are created by the winds from storms. Navigators can tell how far away the storm is by observing the speed of, and length between, the swells. The ship might rock with long, slow swells caused by a storm hundreds of miles away, or with the shorter, faster swells of a storm that is closer. Waves, on the other hand, are caused by local wind; that is, the wind that is blowing right at your location. Waves might just be rippling the water if the wind is light, but can be large if the wind is strong. Both swell height and wave height are estimated in feet from the trough (bottom) to the crest (top) of the wave. Again, this skill takes lots of practice.

Personal Log

Yesterday we got word that a pod of about seventy right whales had been sighted in the Bay of Fundy. This represents a large fraction of this endangered species’ entire population of fewer than 300. Our route has taken us up a little way into the bay, and we have been eagerly watching for whales. We’ve seen several blows in the distance, and occasionally a glimpse of a long back breaking the water. Most of them have been fin whales, but we did see two or three right whales before it was completely dark. It’s exciting to see these giants of the ocean and we hope to see more when the sun comes up.

August 22, 2005March 18, 2021

Joan Raybourn, August 22, 2005

NOAA Teacher at Sea
Joan Raybourn
Onboard NOAA Ship Albatross IV
August 14 – 25, 2005

Mission: Ecosystem Productivity Survey
Geographical Area: Northeast U.S.
Date: August 22, 2005

Weather Data from the Bridge

Latitude: 42°17’ N
Longitude: 69°38’ W
Wind direction: SE (130 degrees)
Wind speed: 10.3 knots
Air Temperature: 19°C
Sea water temperature: 21.8°C
Sea level pressure: 1016.5 millibars
Cloud cover: High, thin cirrus

Question of the Day: What time does the 24-hour clock in picture #7 show?

Yesterday’s Answer: Sediment is composed of all the small particles of “stuff” that sink to the ocean floor. Near the coast, fresh water is flowing into the ocean from rivers and streams, and human activity creates more matter that is flushed into the ocean. Because there are more sources of sediment near the coast, it collects more quickly there than it does in the open sea.

Science and Technology Log

Advances in computer technology have made the process of collecting plankton and water samples much easier than it was in the past. During a plankton tow or a water cast, many different people are working together from different parts of the ship, and technology makes it easier to communicate, obtain plankton and water samples from precise locations, and protect equipment from damage. The ship’s crew navigates the ship to the exact station location and maintains the location while the samples are collected, there are scientists and crew members on the aft deck handling the collection equipment, a crew member operates the winch to lift and move the equipment, and a scientist operates the computer system that collects data from the Conductivity, Temperature, and Depth instrument (CTD).

The stations, or places where we will collect samples, are designated in advance of the trip and plotted on a computer map. A computer chooses the stations randomly so that we get information from all over the area with no accidental human pattern. The ship’s commanding officer and the head scientist work together to determine the course the ship will take to visit each station. Many factors must be considered, including efficiency, fuel conservation, and weather. Once the course is set, the chief scientist “connects the dots” on the computer map. Then it is easy to see where we are going next, how far away it is, and when we can expect to be there. “Are we there yet?” is a question asked not only by children on vacations, but by scientists and crew at sea!

When the ship approaches a station, the bridge crew makes an announcement so that everyone knows to get ready. “Ten minutes to bongo” means that it is time for the CTD operator to fire up the computer, for the winch operator to get set, and for the deck crew and scientists to get into their gear and make sure the equipment is ready to go. There is a video camera on the aft deck that enables everyone inside to see what is happening on the deck. This makes it easier to coordinate the collection process and to act quickly if there is an emergency.

When the ship is at the exact position of the station, the bridge radios the winch operator. He in turn lets the CTD operator know that we are ready to begin. The CTD person starts the computer program and tells the deck crew to turn the CTD on. The winch operator lifts the equipment and casts it over the side of the ship into the ocean. The “cast” might have just the CTD unit, or water bottles to collect water samples, or the bongos to collect plankton samples. The CTD goes down on every cast since it is collecting data that is important for the success of the tow as well as for further study.

During the cast, the CTD operator watches the computer display to make sure collections are made at the correct water depths. He or she talks to the winch operator over a walkie-talkie so that he knows how far to drop the line and when to pull it back up. Plankton is collected at about 5 meters above the ocean floor. The ship’s computer tells us how deep the water is and the CTD tells us how deep the instrument itself is. By comparing these two numbers, the CTD person can make sure the equipment doesn’t drag the bottom, which would damage it and contaminate the samples. Once the CTD and the collection equipment are out of the water, the unit is turned off and the CTD operator finishes up the data collection process by entering information such as date, time, latitude, longitude, station and cast numbers. We just finished Station #75, and will be doing our 100^thcast at the next station. (More than one cast is done at some stations.) Sample collections at each station can take anywhere from about 20 minutes for a relatively shallow plankton tow to about 2 hours if we are in deep water and collecting plankton, water, and sediment.

During the cast, the CTD operator can watch as the computer creates line graphs showing the data that is being recorded by the CTD unit. In picture #6 above, the line graph on the right shows the depth, while the graph on the left shows the sea temperature in red, the density of the water in yellow, salinity in blue, and fluorescence in green. Density is kind of like how “thick” the water is, salinity is how salty it is, and fluorescence is a measure of phytoplankton. Line graphs show change over time, so we can see how these values change while the CTD is in the water.

Personal Log

Some adaptations take longer than others. Since I switched watches, I have never been completely sure of what day it is, and when I get up in late morning, I’m always surprised to see lunch being served instead of breakfast. However, I have learned to use the physics of the ship’s motion to make everyday tasks easier. Carrying a heavy load up the stairs is easier if you wait for a swell to lift the ship and give you a little boost, and opening doors and drawers, standing up, and even drinking water is easier if you do it with, rather than against, the roll of the ship. As much as I staggered around for the first two days of the cruise, I wonder now if dry land will feel odd when we get there at the end of the week.