North Atlantic – Page 7 – NOAA Teacher at Sea Blog

August 15, 2008April 5, 2021

Rebecca Bell, August 15, 2008

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

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.

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.

The nets begin to emerge from the water.

Becky waits for the nets to come back up after the tow — Waiting for the nets to come back up after the tow

Then she puts the plankton into a jar for preservation — Then she puts the plankton into a jar for
preservation

Becky dons her survival suit during a safety drill.

August 14, 2008April 5, 2021

Rebecca Bell, August 14, 2008

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 14, 2008

Weather Data from the Bridge
Time: 134628 (GMT)
Latitude: 40.33.06N Longitude: 72.47.36W
Air Temp ⁰C: 22.1
Sea Water Temp: 22.3 ⁰C

Science and Technology Log

We sailed from Woods Hole, MA on Wednesday, August 13, 2008 on the first of three legs as part of the Ecosystem Monitoring Program. There are two main objectives of the cruise. The first is to see how well the fish population is doing by sampling and counting fish larvae. The number of fish is important to the fisheries industry- those folks who bring cod and other fish to your table. The second objective is to monitor the zooplankton population. Fish feed on the zooplankton, so a healthy zooplankton population may mean a healthier fish population. We also are monitoring the physical properties of the water; in this case, salinity and temperature. These influence where fish larvae and zooplankton can survive and where and how far they can be dispersed.

There are 125-130 sites randomly selected for sampling. At each site, a pair of bongo nets are dropped and the two samples are collected side-by-side, for a total of 250-260 samples. One sample is designated for the ichthyoplankton (fish larvae) study, and the other for the study of zooplankton composition, abundance and distribution. Near-surface along-track chlorophyll-a fluorescence, which indicates abundance of phytoplankton (i.e. food for the zooplankton), water temperature and salinity are constantly measured with the vessel’s flow-through sampling system. We will also be collecting a separate set of samples as we approach the Chesapeake Bay. These will be used to study aging of fish larvae.

Zooplankton include both unicellular and multicellular organisms. Many can easily be seen with the naked eye. Zooplankton can be classified in a number of ways. One way is to classify them by life history. Holoplankton are those that are planktonic during their entire life cycle (lifers). Meroplankton refers to those plankton in a developmental stage, like eggs and larvae (shorttimers). These larvae will grow into larger organisms such as jellyfish, mollusks, fish, starfish and sea urchins, crustaceans, copepods and amphipods.

The term “plankton” comes from a Greek word for “wanderer” or “drifter”.¹This may imply that these organisms are passively moved about by currents. However, many can power around on their own, using several different methods such as cilia, muscle contraction, or appendages on the head, thorax or abdomen. They also move vertically in the water column, up toward sunlight during daylight hours and downward at night. Krill (whale food), on the other hand, do the opposite- travel downward during the day and up at night.

The first two samples contained a vast number of salps. A salp is holoplanktonic and is related to sea squirts (urochordates). They are filter feeders, catching bacteria and extremely small plankton in mucous-covered “nets” that act as sieves. Salps are an important part of the ocean food chain.

Samples 3-5 show a greater variety of organisms- comb jellies (ctenophores), arrow worms (Chaetognatha) fish larvae and amphipods. Samples 6-8 are dominated by copepods. There are salps, too, but not nearly as many (about 1/3 fewer) as we saw in the first 2 samples.

So I am looking at these results and wondering: Are there patterns to the distribution of these assemblages? Are salps found in warm water or cooler water? Does temperature matter at all? Do they like deeper water? Higher or lower salinity? Combinations of any of these? Are they found where another organism is found?

Personal Log

We began our first work shift today, er, last night, um, this morning at 3 a.m. I work the 3 a.m. to 3 p.m. shift. That means to bed around 7pm., rise and shine at 2:30 a.m. Well, rise, anyway. Not much shining till later.

As I sat on the deck in darkness, waiting to reach our first sample site, I spotted the light from another ship on the horizon. I watched as the light traveled up a wave, then down a wave then up, up, up, up, still up. I could not believe how high it was going, knowing we were doing the same thing. It’s a good thing it doesn’t feel like that. We are now heading south, back towards the Chesapeake Bay. It is getting hotter and muggier, just like home.

We saw dolphins today. A large leatherback turtle was spotted from the bridge. The 3pm- 3am. shift reported seeing flying fish.

Animals Seen Today

Salps
Amphipods
Copepods
Ctenophores
Chaetognaths (arrow worms)
Fish larvae
Sea butterfly
Dolphins
Gulls (4 species)

¹Source: Online Etymology Dictionarywww.etymologyonline.com.

August 5, 2008April 2, 2021

Tiffany Risch, August 5, 2008

NOAA Teacher at Sea
Tiffany Risch
Onboard NOAA Ship Delaware II
July 28 – August 8, 2008

Mission: Clam and Quahog Survey
Geographical Area: South of Long Island, NY
Date: August 5, 2008

Tiffany uses a measuring board to obtain quahog lengths.

Weather Data from the Bridge

Partly to mostly cloudy, with patchy a.m. fog
Surface winds: West-Northwest 10-15 knots
Waves: Swells 3-5 feet
Water temperature: 16^oCelsius
Visibility: 7 nautical miles

Science and Technology Log

We’ve almost completed the entire research cruise here on the DELAWARE II. With a few more stations to cover, it is amazing how so many clams can be processed in only a week and a half at sea. Here on the DELAWARE II, scientists use digital recording devices such as scales and measuring boards to obtain accurate records. They also use computer programs that are specialized for the research being done.

When a tow is completed and the catch sorted, each surf clam or quahog goes through a series of measurements. Each bushel of clams is massed, and then each one is digitally measured. With sometimes over 2,000 clams to process, this technique is helpful because we can complete a station in as little as 30 minutes. The computer program used for this purpose asks the measurer to select the species, and then it automatically records whatever the clam measures width wise on the measuring board.

There are only about twelve stations left to go before we arrive in Woods Hole, Massachusetts. Most stations turn up a moderate number of surf clams and quahogs. Tonight, we ended up hitting an area that contained a lot of rocks. All of them must be cleared from the dredge by the crew before the next tow can be performed. This sometimes can take as long as an hour, depending on what is collected. Scientists then sometimes question whether there could be surf clams and quahogs in this specific area, so they’ll prepare to do a set-up. A set-up involves towing the region five times with intervals of 200 yards separating each tow. This allows scientists to examine what exactly could be=2 0in a specific area, and if it was just chance that allowed so many rocks to be brought up in one specific tow. Also in the future, this clam survey will be done by commercial vessels; therefore a calibration needs to be done using the current dredge versus a commercial one. Set-ups help with this process.

Something else found in a recent tow: Scallops!

Personal Log

I am very happy that I had this experience as a Teacher At Sea. In the past two weeks, I have gained a wealth of knowledge regarding surf clams and quahogs, bur also what life at sea is like, and who the people are that conduct research to hopefully understand more about populations dynamics. I also have not been as tired before as I have been on this trip! Getting used to a time change by working through the night, and conducting so m any tows in a twelve hour period leaves your body fatigued. At 1:00pm when I’m finished with lunch, all I can think about is sleep.

When tows are brought to the surface, a neat variety of other things are often brought up as well. I have significantly contributed to my seashell collection by finding lots of different whelk, scallop, and snail shells, along with some sand dollars. I also kept a surf clam and a quahog shell as a reminder of my trip. Because each shell has its matching other half, they are each known as a clapper. I can’t wait to share all of my interesting stories, pictures, and experiences with my students back in Coventry, Rhode Island when I return. I could only hope that people who truly have an interest in science could experience something like this one day!

August 2, 2008April 2, 2021

Tiffany Risch, August 2, 2008

NOAA Teacher at Sea
Tiffany Risch
Onboard NOAA Ship Delaware II
July 28 – August 8, 2008

Mission: Clam and Quahog Survey
Geographical Area: South of Long Island, NY
Date: August 2, 2008

Weather Data from the Bridge

Mostly cloudy with isolated showers
Surface winds: 5 to 10 knots
Waves: Swells 2-4 feet
Water temperature: 23^oCelsius
Visibility: 7 nautical miles

The dredge being brought back up onto the ship after being deployed

Science and Technology Log

As I began my shift, I noticed on the map hanging in the dry lab that we are working our way towards an area southeast of Nantucket called Georges Bank. Georges Bank is a shallow rise underwater where a variety of sea life can be found. Before long, we were called to the deck for our first station of the morning. We set the dredge, hauled it back, sorted the catch, measured and recorded data, and moved on to the next station. Recording data and sorting are two of my favorite things to do, especially when it involves shucking the clams for the meat to be measured! My watch seemed to be on a record pace, as we managed to complete seven hauls all before breakfast at 5:00am. This process happens around the clock on the DELAWARE II, maximizing the amount of data we collect while at sea for two weeks.

Later in the day, the winch that is used to haul the dredge back from the water suffered a power problem. I and the person controlling the dredge noticed this right away, as one of my jobs is to switch the power on to the pump that the dredge uses. I alerted my watch chief, and also the chief scientist for this cruise who quickly began to assess the situation. Over the next hour or so, things became very busy on the back deck as the captain, engineers, and scientists tried to solve the problem. They did manage to get the power back to the winch again, which enabled the dredge to be brought back onboard the ship. The amount of talent exhibited by so many people on this ship continues to amaze me. They always have answers for everything, and Plan B for any situation is always on their minds!

Collecting and sorting the variety of marine life that we find. Here, TAS Risch holds up some sea stars.

Personal Log

Today was a really exciting day of sorting, as my watch found a variety of different organisms. I actually saw a live scallop clapping in the bucket after it was hauled up! Other interesting creatures included a Little Skate (Raja erinacea), which is a fish made of cartilage and is closely related to rays and sharks, a sea robin, sea squirts, hermit crabs, some sea stars, and even a few flounders. One of the more unusual characters that we encountered onboard was called a Yellow boring sponge, otherwise known as a Sulfur sponge or “Monkey Dung”. We take measurements of all of these things and quickly return them to their home in the ocean. Very early this morning, around 1:00am I visited the bridge, or the area where the captain controls and steers the ship from, to see what everything looks like at night. Crew member Claire Surrey was on the bridge tonight, making sure the ship stayed on its course. The area was very quiet and dimly lit by the various monitors that broadcast

information back to the officer in charge. The ocean was pitch black, and I could only see faint lights of a few other ships bobbing up and down in the waves very far away. What a cool experience to see the ocean at night, with a starry sky, and know that all types of instruments are guiding my voyage through the sea!

New Words/Terms Learned

Min-logs: sense temperature, depth, and pressure underwater on the dredge, and are brought back to the surface and recorded via computer.

Starboard: the right side of a ship

Port: the left side of the ship

July 30, 2008April 2, 2021

Tiffany Risch, July 30, 2008

NOAA Teacher at Sea
Tiffany Risch
Onboard NOAA Ship Delaware II
July 28 – August 8, 2008

Mission: Clam and Quahog Survey
Geographical Area: South of Long Island, NY
Date: July 30, 2008

Weather Data from the Bridge

Hazy in the morning with less than 6 miles visibility
Calm seas with little cloud cover
Wind speed = 5 knots
Waves = Wind drives waves < 1 foot
Water temperature: 23^oCelsius

Science and Technology Log

Today started with an early morning shift, working from 12:00 am to 12:00 pm. As my watch took over, the DELAWARE II began steaming towards the first station of the day to conduct a survey of the surf clam and quahog size and abundance inhabiting this specific area. In order to complete a survey of the area, a dredge is used to capture any surf clams or quahogs that are pushed out of the bottom sediment. On the top of the dredge are hoses that push pressurized water onto the bottom to loosen up any bivalves. A bivalve is an organism that has shells consisting of two halves, such as in a clam or a scallop. The dredge is towed behind the DELAWARE II for five minutes at a speed of 1.5 nautical miles per hour. Attached to the dredge are sensors which transmit dredge performance information back to scientists in the dry lab to record and analyze. The accuracy of the survey depends greatly on the credibility of the sensor data, and therefore, scientists must monitor variability of the dredge. After the dredge is brought back to the surface, the load must be sorted, measured, and then discarded.

After listening to a presentation by Larry Jacobson, I learned a lot of new facts about both Atlantic sufclams (Spissula solidissima) and Ocean quahogs. Surf clams live only about 15 years, grow very fast, and can inhabit ocean waters stretching from Cape Hatteras in North Carolina to Newfoundland. These bivalves are found in waters less than 50 meters of water. Ocean quahogs on the other hand can live for greater than 100 years, are very slow growing, and are found in ocean waters between 50 and 100 meters deep from Cape Hatteras, around the North Atlantic to the Mediterranean.

Scientists on this cruise are also interested in studying other aspects of the clam populations, such as a condition called Paralytic Shellfish Poisoning. Because bivalves are filter feeders, they eat by filtering food out of the waters around them. Sometimes, algae can contaminate clams using a toxin that is harmful to humans. When this happens and humans eat the shellfish, they themselves can become quite sick. Samples of clam meats are being taken during this research cruise to be studied back at a lab and determine what exactly is happening in regards to Paralytic Shellfish Poisoning.

Personal Log

Today has been quite interesting, as I moved through the many stations that are involved with conducting this survey. I was trained on how to measure clams in the wet lab, how to apply the power to the dredge in the dry lab, and even how to shuck a clam to retrieve the meat which is also measured. I was also quite amazed regarding how efficient everyone is on the ship, as we all have a job to do, and it all gets done before we arrive at the next station.

One of my highlights today was overcoming my sea sickness and finally getting my sea legs! Everyone is so supportive, from the officers, to the scientists, and to the volunteers who are all so nice and helpful. I’m looking forward to my next eight days at sea and learning more about the research being conducted.