Category: Joan Raybourn

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 20, 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: Based on the caption for photo #6 above, in which direction was the ALBATROSS IV traveling when the picture was taken?

Yesterday’s Answer: Our location at 41.39 N and 67.11 W means our goldfinch was 160 nautical miles from Woods Hole. A nautical mile is equal to one minute of latitude and is slightly longer than an ordinary land mile.

Science and Technology Log

In addition to collecting zooplankton samples, we also collect water samples and measure the amount of chlorophyll they contain. Phytoplankton are too small to see, but an instrument called a flourometer can measure their presence. The flourometer shines a beam of light through the water sample and measures how much blue light (fluorescence) is present.

This process is fairly delicate and great care must be taken to get a good representative water sample, and then not to contaminate it during processing. Water samples are collected in two ways: some are collected in water bottles that are attached to the bongo cable, and others are collected from a hose that is pumping sea water into the plankton lab.  In picture #1 above, our chief scientist, Jerry Prezioso, is collecting a sample from the plankton lab hose. The sample itself is poured through a filter into the bottle to remove any large particles that may be present. Then 200 ml of the sample water is pumped through a fiberglass filter (picture #2). The filter traps chlorophyll as the water passes through. Even though the large amounts of chlorophyll in land plants gives them their bright green color, the small amounts present in phytoplankton are not visible, so you can’t see it on the filter. In picture #3, Jerry uses tweezers to remove the filter (a small white circle) and place it into a cuvette, which is a small test tube. The cuvette contains acetone, which preserves the sample. Then it is placed upside down in the cooler for 12 to 24 hours, which allows the chlorophyll on the filter to wash out into the acetone.

When the sample is ready to be measured, it is taken out of the cooler along with a “blank”, a cuvette of plain acetone with no chlorophyll present. The two cuvettes must warm up a little before they are read, because water condensation on the outside of the cuvette can result in a false reading. We use the flourometer to take three separate readings. When we do science investigations at school, we determine which factors are constant (kept the same for each trial) and which are variable (the thing you are changing in each trial). In this case, the variable is the amount of chlorophyll on the filter. In order to make sure we are measuring only chlorophyll, we also “read” two constants: a solid standard, which is contained in its own tube and used for every trial, and the blank containing only acetone. After the chlorophyll sample is read, we can compare the three sets of data to see how much chlorophyll is really there. In picture #4, I am putting a cuvette into the flourometer, which will shine a light through it and display a number value. The numbers for the solid standard, the blank, and the chlorophyll sample are all recorded on the clipboard along with data such as date, time, and where the sample was collected. Later, the data will be entered into a computer for further analysis.

Why do we want to know about chlorophyll in the ocean? Well, chlorophyll is produced by plants, in this case, phytoplankton. By measuring the amount of chlorophyll in the water samples, scientists are able to determine how much phytoplankton is present. Since phytoplankton is the base of the ocean food web, it is one more piece of the ocean ecosystem puzzle.

Personal Log

Today I switched from the day watch to the night watch, but the timing was good because we had a long steam between stations and I was able to get a little extra sleep before doing a double watch. While all the scientists usually eat meals together, we work in teams to cover the watches, so I will be working with a different set of people. I am now on watch from noon to 6:00 p.m. and from midnight to 6:00 a.m. We will be working our way north for the next week, and the probability of seeing whales is increasing. That will be exciting!

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 17, 2005

Weather Data from the Bridge

Latitude: 40’ 17” N
Longitude:  70’ 08” W
Wind direction: NNE (29 degrees)
Wind speed: 19.6 knots
Air temperature: 19° C
Sea water temperature: 22.8°C
Sea level pressure: 1018.1 millibars
Cloud cover: cloudy

Question of the Day: What kinds of animals depend on plankton as a major food source?

Yesterday’s Answer: Phytoplankton are producers, since they make their own food.

Science and Technology Log

On this cruise aboard the ALBATROSS IV we will be taking plankton samples at 90 stations off the coast of New England. The stations are randomly chosen by a computer, so some are close together and some are further apart. The idea is to get a broad picture of the ecological health of the entire region.

The actual process of plankton collection is called a plankton tow, because the nets are towed through the water while the ship is moving slowly, collecting plankton as the water moves through them. Can you guess why the collection apparatus is called a bongo? (Look at picture #2 above.) The frame looks just like a pair of bongo drums! Attached to the frame are two long nets that collect the plankton. The bongo isn’t heavy enough to sink into the water evenly on its own, so a lead ball is added to help pull it down to the bottom smoothly. (See pictures 3 & 4.) The bongo is attached to a cable, which is in turn attached to a pulley system that lowers the bongo into the water and pulls it back up again. Since we only want floating plankton, we have to be sure the bongo doesn’t scrape the bottom. We lower the bongo to about 5 meters above the bottom, and then bring it back up.

The nets bring in all kinds of zooplankton, very small but big enough to see. (Most phytoplankton are so tiny they slip right through the net!) There are lots of copepods, which are related to lobsters, and sometimes arrow worms, which are tiny predators that love to eat copepods! There are other species as well, including some jellyfish. We have to be very careful to save the entire sample so that scientists back on shore can see exactly what was living near each station. When the nets are back on board, we use a hose to wash the plankton down to the bottom of the net. Then we untie the net, dump the plankton into a sieve, and spray some more to be sure nothing is left in the net. At the end of this process, we tie the bottoms of the nets again (so they are ready for the next tow) and take the sieves with the plankton inside to the wet lab for the next step. I’ll describe the process of preserving the plankton samples in tomorrow’s log.

Several kinds of data (besides the plankton itself) are collected on each tow. For example, we take water samples to analyze for salinity and chlorophyll, and the EPA scientists are collecting samples of the ocean floor. In the days to come, I will describe them and explain how computers are used to make all of this work easier. Stay tuned!

Personal Log

I am becoming much more comfortable with the routine tasks of the trip. I can handle the bongo pretty well, and can preserve the plankton samples we get. I am learning to operate the computer end of the process and will soon be able to do that on my own. I can use the tracking system to see where we are going next and how long it will be until we get there. Do I have time to take some pictures? How about to grab a snack? I enjoy talking with the crew, and have discovered that “it’s a small world after all” – our navigator grew up in Virginia Beach and another crew member just built a house in Chesapeake. I can now walk without too much trouble, and this morning I awoke before my alarm went off because I heard the engines slow down as we approached a tow station. There is rumor of a cookout on the deck tonight, so I’d better go get in a nap before then!

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 16, 2005

Weather Data from the Bridge

Latitude: 40’ 17” N
Longitude:  70’ 08” W
Wind direction: NNE (29 degrees)
Wind speed: 19.6 knots
Air temperature: 19° C
Sea water temperature: 22.8°C
Sea level pressure: 1018.1 millibars
Cloud cover: cloudy

Question of the Day:  What is phytoplankton’s place in the food chain? (producer or consumer)

Yesterday’s Answer: Factors that could influence the depth to which sunlight penetrates the sea water include amount of cloud cover and how clear the water is. If the weather is clear, more sunlight makes it through the atmosphere to the surface of the sea. If the water is clear, the sunlight can go deeper than if the water is murky with a large mass of surface plankton, excess nutrients, pollutants, or silt.

Science and Technology Log

In yesterday’s log I talked about phytoplankton. The other group of plankton is zooplankton. Phytoplankton are plants, and zooplankton are animals. If you think of the sea as a bowl of soup, the zooplankton are the chunky parts. They include organisms that spend all of their lives as plankton, as well as the baby forms of other seas animals, such as crabs, lobsters, and fish. Most zooplankton eat phytoplankton, making them the second step up the ocean food chain.

While you would need a microscope to see most phytoplankton, you can see most zooplankton with an ordinary magnifying glass. Many are big enough to see with the naked eye. While phytoplankton need to stay near the surface of the sea in order to absorb the sunlight they need for photosynthesis, zooplankton can live at any depth. Zooplankton have structural adaptations that help them float easily in the ocean currents. Some have feathery hairs to that can catch the current. Others have tiny floats filled with air, and still others contain oil that helps them float. There are even behavioral adaptations that zooplankton have developed to help them survive. One kind of snail makes a raft of air bubbles and floats on that. Some even link together and float through the ocean looking like skydivers holding hands.

Many animals go through several physical changes as they go through their life cycles. For example, a butterfly begins life as an egg, hatches into a caterpillar (larval stage), makes a chrysalis, and finally emerges as a beautiful adult. Many marine animals go through similar changes, and during their larval stage they are part of the mix of plankton in the ocean. These “temporary” zooplankton are called meroplankton. These include baby crabs, lobsters, clams, snails, sea stars, and squid. Permanent plankton are called holoplankton, and include copepods, krill, sea butterflies, and jellyfish.

One of our deck hands joked about having sushi for breakfast right after we completed a very productive plankton tow. We might not like that kind of sushi, but many ocean animals love it, and depend on it as their food source. Krill (shrimp-like zooplankton) are a very popular menu item with penguins, sea birds, fishes, squid, seals, and humpbacks and blue whales. “A single blue whale may devour up to eight tons of krill a day.” (from Sea Soup: Zooplankton by Mary M. Cerullo)

Most of the plankton we are collecting on this cruise are zooplankton. We preserve them in jars, and when the cruise is over they will be sent to laboratories where other scientists will analyze the samples. We also analyze water samples for chlorophyll, though, which is made by phytoplankton and is therefore an indicator of their health. In the days to come, I will describe the procedures used for the plankton collection, as well as those used for the EPA research.

Personal Log

Life on board a research vessel is not all work and no play. During down time, people rest, read, play games, watch movies, work on needlework, or get a snack, much like life at home. When I am not on watch, I write my logs, take and organize pictures, take a shower, do laundry, send email, and sleep. The scientists are usually able to eat meals together around the time we switch watches. We gather for breakfast around 5:30 a.m., for lunch around 11:30 a.m., and for dinner around 5:30 p.m. It’s nice to have a chance to catch up with each other while one group comes to work and the other goes off to bed.