NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 23, 2008
Alison, Shrinky Cup Project Director, with the cups before being sent under.
Weather Data from the Bridge
Time: 1919(GMT)
Latitude: 4219.5N Longitude: 6812.5 W
Air Temp 0C: 20.7
Sea Water Temp 0C: 19.6
Science and Technology Log
The Shrinky Cup Caper
A trip to sea is not complete without the classic experiment on ocean depth and pressure— Styrofoam cup shrinking. Styrofoam cups are decorated with markers, and then lowered in a bag attached to the cable during a vertical cast. In our experiments, pressure is measured in decibars (dbar). This means that 1 dbar equals about 1 meter of depth. So 100 dbars = 100 meters; 1000 dbars =1000 meters. For every 10m (33ft) of water depth, the pressure increases by about 15 pounds per square inch (psi). At depth, pressure from the overlying ocean water becomes very high, but water is only slightly compressible. At a depth of 4,000 meters, water decreases in volume only by 1.8 percent. Although the high pressure at depth has only a slight effect on the water, it has a much greater effect on easily compressible materials such as Styrofoam.
Attaching the cups
Styrofoam has air in it. As the cups go down, pressure forces out the air. See the results of the experiment for yourself. The depth of the cast was 200 meters or about 600 feet. (You can now calculate the total lbs of pressure on the cups). Addendum: Alison discovered that putting one of the shrunken cups down a second time resulted in an even smaller cup. The cups were sent to 200 meters again. Below right is a photo of the result of reshrinking the cup. Apparently, time has something to do with the final size as well. Resources: NOAA Ocean Explorer Web site – Explorations; Submarine Ring of Fire. AMNH Explore the Deep Oceans Lessons.
Over they go!
Personal Log
There is a noticeable difference in the amount of plankton we pull in at different depths and temperatures. I can fairly well predict what we will net based on the depth and temperature at a sample site. I’ve also noticed that the presence of sea birds means to start looking for whales and dolphins. I assume that where there is a lot of plankton (food) there are more fish and other lunch menu items for birds and dolphins. A high population of plankton means we are more likely to see more kinds of larger animals.
Animals Seen Today
Salps
Krill
Amphipods
Copepods
Ctenophores
Chaetognaths (arrow worms)
Fish larvae
Atlantic White-sided Dolphins
Terns
Minke whales
Pilot whales
Mola mola (4)
The results of what happened to the cups at a depth of 200 meters. The white cups are the original size.Left, a cup shrunk 2 times; center 1 time; and right, the original size
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 22, 2008
Weather Data from the Bridge
Latitude: 4224.2 N Longitude: 6659.1 W
Sea Surface Temperature: 21.2 C
Depth: 202m
Becky proudly displays her drifter buoy before its deployment!
Science and Technology Log
It’s a buoy! Today has been busy—a vertical cast, baby bongos and the big bongos. But let me tell you about the other things. First of all, Alison and I deployed my very own buoy. NOAA has an Adopt-A-Drifter (buoy) program. Jerry Prezioso, our Chief Scientist, thoughtfully signed me up for it before we sailed. We deployed it today at George’s Bank, the deepest station we will reach.
The deployment consisted of picking up the basketball-sized buoy and throwing it over the side. There is a transmitter in the black float which will allow us to track the buoy’s motion for years. NOAA uses these buoys to assemble weather reports, monitor climate changes, etc. The buoy consists of the round ball with the transmitter and a “drogue” a long “tube” of cloth that fills with water. The purpose of the tube is to make sure it is the ocean current that moves the buoy, not wind.
With a little help, Becky gets ready to throw her drifter into the ocean
There is a diagram on the Adopt-A-Drifter site. The ball and drogue (sounds like an English pub) are attached to a metal ring which anchors the drogue and the ball. Here I am with the MSDE-decorated buoy. You can barely see the metal ring. The drogue is the green thing, folded up. You throw the whole thing overboard. The paper and tape dissolve and the drogue unfurls. It has to be kept tied up so you don’t go overboard with the drifter. NOAA’s Office of Climate Observation sponsors the “Adopt-A- Drifter” program. According to the Web site: “The “Adopt-A- Drifter” program (allows you to access) information about drifting buoys (drifters) that move with the ocean currents around the globe. The drifter floats in the ocean water and is powered by batteries located in the dome. The drifter data that are collected, including location with a GPS, are sent to a satellite and then to a land station where everyone can access the data.
And off it goes on its long journey
Drifters are continually being deployed from ships around the world. They last for a number of years unless they collide with something like an island in the middle of the ocean or a continent. Each drifter receives aWMO ID # (World Meteorological Organization Identification Number) so the data can be archived. The purpose of the drifters is to gather the information necessary for countries to: 1) forecast and assess climate variability and change, and 2) effectively plan for and manage response to climate change.”
This map indicates where the drifty buoy was deployed: where the Labrador Current, the Gulf Stream, and the North Atlantic current converge
We will release it in George’s Basin at 4224.2 N latitude; 6659.1 W longitude. This is an interesting area because of the way currents converge near this site. Above is a map of the area. Below it is a diagram showing the major currents.
A map showing the area where the drifter buoy was deployed from the Delaware II
As you can see, the buoy was deployed where the Labrador Current, the Gulf Stream and the North Atlantic Current encounter each other. There is a chance that the buoy will travel into the Gulf Stream or through the Northeast Channel into the North Atlantic Current. It might also just stay within the basin, caught in the large gyre within the Basin. You can get on-line and track the buoy to see what happens to it.
More from the Web site:
“The Adopt-A- Drifter program provides an opportunity for teachers to infuse ocean observing system data into their curriculum. An educational sticker from each school is adhered to the drifter before deployment and teachers and their students access sea surface temperature and/or sea surface pressure data from the drifter online. Students plot the coordinates of the drifter on a tracking chart as it moves freely across the ocean and make connections between the data accessed on line and other maps showing ocean currents and winds. Drifter data are used to track major ocean currents and eddies globally, ground truth data from satellites, build models of climate and weather patterns and predict the movement of pollutants if dumped or accidentally spilled into the sea. It is important for teachers and students to understand how the data are measured, how often data are downloaded, and what data are available for schools and the general public to access.”
Source: Modified from Follow the world’s ocean currents with NOAA’s Adopt a Drifter Program
Stanitski, D.M.; Hammond, J. OCEANS, 2005. Proceedings of MTS/IEEE
Personal Log
As we move further north, our nets started pulling in krill. I hoped that whales were not far behind. I was not disappointed. Yesterday we encountered dolphins on three separate occasions. One group came very near the ship and I have some good video of them “porpoising” through the waves. We also spotted a whale spout, but I could not see the whale. Later in the day, during our safety drill, I was looking out to sea just as a pilot whale leaped straight into the air. We were able to see that there were a number of these whales feeding in that area. Towards afternoon, we saw a group of Minke whales. In late afternoon, another spout was spotted and we saw a huge tail disappear under the water- probably a humpback whale.
Ocean Explorer related lesson: Islands in the Stream- How geologic feature(s) in the structure of the ocean floor may cause an eddy to form in the current above it
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 19, 2008
Weather Data from the Bridge
Latitude: 4000.7 N Longitude: 6931.5
Sea Surface Temperature: 21.2 C
Depth: 114m
The Delaware’s latest cruise track has taken it from Woods Hole, MA, south past the Outerbanks of North Carolina, and then north again toward Georges Bank
Science and Technology Log
We are heading east out to sea, right now at 4005 N latitude, 6942 W longitude. (Pull out those atlases). We will begin a turn north towards Georges Bank. Georges Bank is a large elevated area of the sea floor which separates the Gulf of Maine from the Atlantic Ocean and is situated between Cape Cod, Massachusetts and Cape Sable Island, Nova Scotia. Georges Bank is (was) one of the most productive North Atlantic fisheries (Grand Banks being the most productive). “Legend has it that the first European sailors found cod so abundant that they could be scooped out of the water in baskets. Until the last decades of this century these banks were one of the world’s richest fishing grounds… (Source: AMNH web site below).
This map shows the location of Georges Bank and the underwater topography.
Northeastern fishery landings are valued at approximately $800 million dockside, of which a large proportion is produced on Georges Bank. Recently, scientists of the U.S. Geological Survey (USGS) and NOAA’s National Marine Fisheries Service (NMFS) have undertaken an effort to document direct interactions between physical environmental factors and the abundance and distribution of fishery species. (Source: USGS below). This means that the water chemistry, temperature and other factors affect how many fish there are, how many kinds of fish there are, and where they are. The article from USGS explains that the sea floor sediments that form Georges Bank came from the time when glaciers scoured the area. Since that time, sea level has risen, covering the glacial sediments, and tides and currents are eroding the bottom. When this erosion happens, small sediment particles are winnowed out by tides and currents leaving larger gravel-sized sediments on the floor. This kind of surface is good for scallop larvae and other small animals so they can settle on the bottom and not get buried by sand. Thus, the type of sediment on the ocean floor helps determine what kinds of animals can live there.
This map shows the continental U.S. Exclusive Economic Zones (EEZs).
Interestingly enough, politics and international relations have affected our trip to Georges Bank. We have been waiting for clearance through the U.S. State Department working with the Canadian government, to get permission to go into Canadian waters. As Wikipedia explains below, part of Georges Bank is “owned” by the U.S. and part is “owned” by Canada. Our route is to take us through the eastern part of Georges Bank, the part owned by Canada. Unfortunately, due to the speed of processing the request, we just this morning found out we got clearance to go there. If the request had been denied, we would have had to sail around the Exclusive Economic Zone (EEZ) to avoid Canadian waters. Fortunately, we are now good to go.
From Wikipedia:
“During the 1960s and 1970s, oil exploration companies determined that the seafloor beneath Georges Bank possesses untold petroleum reserves. However, both Canada and the United States agreed to a moratorium on exploration and production activities in lieu of conservation of its waters for the fisheries.
The decision by Canada and the United States to declare an Exclusive Economic Zone (EEZ) of 200 nautical miles (370 km) in the late 1970s led to overlapping EEZ claims on Georges Bank and resulted in quickly deteriorating relations between fishermen from both countries who claimed the fishery resources for each respective nation. In recognition of the controversy, both nations agreed in 1979 to refer the question of maritime boundary delimitation to the International Court of Justice at The Hague in The Netherlands. Following five years of hearings and consultation, the IJC delivered its decision in 1984, which split the maritime boundary in the Gulf of Maine between both nations out to the 200 NM limit, giving the bulk of Georges Bank to the United States. Canada’s portion of the Gulf of Maine now includes the easternmost portion of Georges Bank.”
It’s been a very quiet day today. We had several station samples this morning. At the first one, around 6:30 a.m. one of the crew members spotted two whales. They were too far away to see what kind they were. I, unfortunately, was inside the ship at that time and missed it. However, we are heading north so maybe we will have a chance to see some.
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 16, 2008
Weather Data from the Bridge
Time: 1807 (GMT)
Latitude: 36.05.40 N Longitude: 75.24.30 W
Air Temp 0C: 25.3 0C
Sea Water Temp: 26.7 0C
On left: small barrel-shaped copepods; Center: white, arrow worms; Top right: amphipods
Science and Technology Log
The most common zooplankton we have seen so far are salps, amphipods, arrow worms and copepods. Pteropods (sea butterfly) have been in a number of samples but are not numerous. Salps look like clear, jelly-like marbles. We’ve encountered these animals in warm, shallow water. They are holoplanktonic relatives of sea squirts (Urochordata). Salps are filter feeders, using cilia to move suspended particles from the water. They feed by pumping water through a sieve to remove bacteria and nanoplankton, and are thus, a very important link in the food chain. Some species of salps form huge chains by budding. They show both sexual and asexual life stages. For more about salps and photos see this website.
Amphipods are also extremely common crustaceans. There is no carapace (shell-like covering), but their bodies are flattened side-to-side, much like a shrimp. Their bodies are segmented with 6 segments in the head, 8 in the thorax and 6 in the abdomen.1 They have a brood pouch on their thoracic limbs. They have a variety of limbs used for feeding, crawling or jumping. One group lives off a host, feeding on salp tissues. Some types live in tubes; others use their back legs to anchor themselves while they sway to and fro in the water column. Some species swim rapidly while others stay near the bottom of the ocean. Many will move vertically in the water column, moving near the surface during the day, and sinking again at night. The species we are catching has large compound eyes that can be seen by the naked eye. For more about amphipods, visit this website.
Becky examines the catch using a hand lens.
Copepods are very common crustaceans, with more than 200 species and 10,000 families. 2 We have found more of these than any other organism. Copepods are omnivorous. Some groups graze on microplankton; other groups of copepods prey on larger plankton, including other copepods. They are an important link in the food chain as well, moving carbon from a microscopic level to a larger trophic (feeding) level. They are eaten by jellyfish, fish, comb jellies and arrow worms. Copepods have “antennae” that have special sensors that detect water movement around them. They are able to move toward prey by contracting a muscle that runs in a circle around their bodies. For more about copepods, visit this website.
Arrow worms (Chaetognatha) are common along coasts, but we did not catch any out away from shore. Arrow worms are classified in their own group, distinct from Annelids (earthworms), round worms and flatworms, which are all separate groups of worms. They are predators, often waiting to ambush their prey. When their cilia detect prey, usually copepods, the arrow worm contracts 2 muscles that run dorsally and ventrally (top to bottom) to strike. Their mouths have spines that grab the prey and smaller “teeth” produce a venom that subdues the prey. The prey is swallowed whole. Arrow worms, in turn, are eaten by jellyfish, copepods and fish.2
Sea Butterflies were not common, but they are very interesting. Sea butterflies (pteropods) are holoplanktonic mollusks, related to snails. Basically, they are shell-less snails. Their foot is modified into winglike structures (ptero= winged) that they flap as they swim through the water. Their bodies are tube-shaped and clear. The bodies and wings of the species we have seen are an orange-pink color. They are predators and are preyed upon by fish, sea birds and whales.
Information for these paragraphs were modified and combined from the following sources: 1 Newell, G.E. and Newell, R.C.; Marine Plankton: A Practical Guide; 5th edition; 1977; Hutchinson & Co; London.2 Johnson, William S. and Allen, Dennis M.; Zooplankton of the Atlantic and Gulf Coasts: A Guide to Their Identification and Ecology; 2005; Johns Hopkins University Press.
Personal Log
This morning we saw dark clouds in the distance. You could see rain falling from the clouds. Nearby we could see the tail of a water spout disappearing into the clouds. We sampled our southern-most station and are now heading north along the coast just south of Chesapeake Bay. The samples we are pulling now have a lot of diatoms.
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 15, 2008
Weather Data from the Bridge
Latitude: 3846.7 Longitude: 7302.1
Temp 25.4 C
Bongo net
Science and Technology Log
In the last post, I explained WHY we are collecting zooplankton. This post will illustrate HOW the samples are taken.
The samples are collected using a device called a bongo net (Yes, like the musical instrument). You can see the metal rings and the nets hang from the metal rings. One net is marked with red and the other green. This allows you to tell the two nets apart. The samples from the red side will be used for the ichthyoplankton study. The samples from the green side will be used for the zooplankton study.
The white device is the CTD (Conductivity, Temperature, Depth). You attach it to the bongo net frame and turn it on. The CTD takes measurements on the way into the water and on the way out of the water. When the bridge clears you, the computer operator (inside) tells the hydraulics operator to start letting out the line and at what speed to let it out and bring it in. You calculate the amount of time in and out using a chart that is based on changing depth. You have to calculate it so you get at least a 5-minute tow.
The CTD
Now the bongo nets are raised on the A-frame. You can see the CTD above the bongos (right picture) and there is a lead weight beneath and between the nets. Next, the A-frame moves the nets over the side of the ship and they are lowered into the water. You cruise for at least 5 minutes. The idea is to get within 5 meters of the bottom, then start bringing the nets back in. The computer operator keeps track of where the bottom is. The idea is to stop the line going out in time so the nets don’t hit the bottom and pull up a bunch of sand. Then you just have to wait for the tow, and eventually for the nets to come back up.
The bongos are removed from the A-frame and brought into the wet lab. You use the hose to wash the plankton down to the bottom of the net. The bottom of the net is put into the sieve. When the net is hosed down to the sieve end, you untie the bottom of the net and let the plankton wash into the sieves. The mesh captures zooplankton, but lets smaller phytoplankton through. Finally you rinse the plankton from the sieves into a jar with 5% formalin for preservation. A label is put into the jar as well as on top of the jar, stating station number, date and time.
NOAA Teacher at Sea, Becky Bell, assists in deploying the bongo nets.
Personal Log
We had a fire drill and an “abandon ship” safety drill. In the picture to the right, I am wearing a survival suit, lovingly known as a “Gumby suit”. If you abandon ship, you have to run to the deck and put on this suit. It is one piece, with inflatable neck rest, whistle and flashing pocket light so you can be spotted. You have to lay the suit out on deck, and sit down in it. Feet go in first, then you stand up and pull the rest over your head, find the arms etc. Look at the look on my face. Not too sure about this! The front flap closes to show only your eyes–on me a little higher. You should try zipping the front zipper with thick rubber gloves that are too big for you. It reminds me of the astronauts trying to fix the space station. I have a new appreciation for how difficult it is too, like, HOLD anything. The best news yet–we get to practice next week again.
Deploying the Bongo netThe A-frameThe nets begin to emerge from the water.Waiting for the nets to come back up after the towBecky rinsing down the netThen she puts the plankton into a jar for preservationBecky dons her survival suit during a safety drill.
