Thanks for Waiting

    We officially moved onto the RVIB Nathaniel B. Palmer one week ago and we have already sampled ocean water for our first incubation. You have been patient with me as I explained the use of the FlowCam, learned how to sample nutrients and walked you through the requirements for trace metal clean procedures and incubations. I have also told you about the rough seas, long hours and cold temperatures that go along with this type of oceanographic research. I would not be surprised if you have asked yourself why researchers go through these extensive steps and travel to these extreme conditions to study microscopic organisms. I think you have waited long enough to hear about the star of the show.

    Guest Writer - Alexa Sterling

    Alexa Sterling from the University of Rhode Island (who you have seen featured in previous journals) is going to tell you a little about diatoms.

    Alexa Sterling boarding the RVIB Palmer
    Alexa Sterling prepares to board the RVIB Nathaniel B. Palmer. This is Alexas first research cruise.

    Dynamic DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality.

    DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. are an important group within the marine plankton and they are found in all the world’s oceans. These microscopic organisms depend on photosynthesis for their source of nutrition, by converting carbon dioxide, water, and the sun’s energy into oxygen and food (stored energy).

    Overview of photosynthesis and some required nutrients
    This slide shows an overview of the photosynthesis reaction used by diatoms and other types of phytoplankton to produce food.

    Because of this, diatoms make up the base of the food web as primary producers. They play a similar role in the oceans as plants play on land by being a tasty meal for many animals. In the Southern Ocean, diatoms feed many animals ranging from tiny krill (small shrimp-like crustaceans) to huge filter-feeding whales, like minke and humpbacks. Even their oxygen production is important because they provide us every 5th breath we take!

    Antarctic diatoms
    This photo shows three individual diatoms of the same species. Notice how these three boxes look like 'glass houses'. This 'house' is called the silica frestule. Photo by David Honig, Courtesy of Amber Lancaster (PolarTREC 2012), Courtesy of ARCUS

    DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. are a type of phytoplankton, or marine plankton that photosynthesize. PlanktonPlankton are small or microscopic organisms that float or drift in fresh or salt water, especially at or near the surface, and serve as food for fish and other larger organisms. drift along with the water currents as they are unable to actively swim. DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. have special adaptations that help control their water depth without having to swim. It is important for diatoms to be in the part of the ocean that receives sunlight (photic zone) in order to photosynthesize. When the conditions such as light, water temperature, and others are particularly good, diatoms can reproduce rapidly forming blooms.

    Tiny Creatures

    There are about 14,000 – 18,000 different species of diatoms alive in the ocean today! All are unicellular, meaning that they are only made of one cell. Everything they need to survive is provided within that one cell: chloroplasts for photosynthesis, stored food energy, structures for reproduction, protection from predators, etc. They range in size from 2 um (micron) to 2 mm. Read the caption below the ruler picture to learn more about the size of a micron.

    Metric ruler
    A micron (micrometer) is a metric unit of length, but it is not possible to see on a metric ruler. To visualize a micron, imagine 1000 lines in between each milimeter (or small set of lines on the above ruler). The distance between each one of the 1000 lines represents 1 micron. Photo courtesy George Hoday public domain pictures.

    We need microscopes to see individual diatoms, but we can see a brown-green tinge to our filtered water samples. This color is from pigments in their photosynthetic chloroplasts letting us know there are phytoplankton in the sample. As you can see from the pictures of diatoms below, they can look drastically different from one another, but there are similarities. For instance, all diatoms live in “glass houses". Their cell wall is made of silica which is called a frustule. It fits together like a Petri dish, with one half larger than the other. There are two main shapes of the frustule: centric and pennate. Centric diatoms are circular while pennate diatoms are boat-shaped. Can you see examples of these two shapes in the pictures below?

    FlowCam image of Southern Ocean Diatoms 2
    Another screen shot showing more sizes and shapes of the Southern Ocean diatoms. The large diatoms just to the left of center shows how the silica frustules can extend away from the main part of the diatoms 'skeleton'.

    FlowCam image of Southern Ocean Diatoms 1
    This image is a screen shot from the first run of the FlowCam using samples from the first incubation station. The various sizes and shapes of the individual diatoms are easy to see. Each photo represent a diatom magnified four times its normal size.

    Their frustules can have interesting unique features, and diatoms have been compared to works of art. Frustules may have spines, ridges, setae (hair-like extensions), and pore (hole) patterns. These distinguishing features help us tell different species apart. They also serve as useful adaptations in the challenging ocean environment. Spines can help increase the diatom’s buoyancy helping it float in the photic zone and not sink. Setae are long hair-like extensions that make it difficult for predators with small mouths like krill to eat them. Can you find examples of these characteristics in the diatom pictures?

    DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. may be individual solidary cells, but often they are found connected together living in colonies. Colonies are made of diatoms of the same species. Colony formation is another adaptation that prevents predation by making the cells too large for a krill to eat. DiatomsDiatoms are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. can also attach to other surfaces in their marine environment. For example in the Southern Ocean, there are sea-ice diatoms which attach themselves to floating sea ice using mucus they produce. Just like looking at the filtered sea water, we know they are attached to the sea ice by the brown-green color of their pigments. We will be collecting sea-ice diatoms during this cruise.

    Microbiology Vocabulary

    You may have noticed many bold vocabulary words in this journal. Keeps your eyes peeled for many more vocabulary words as we start to find out what the scientist are doing with all of these dynamic diatoms!

    Author
    Date
    Location
    Southern Ocean
    Weather Summary
    Overcast and cold with light winds; Sea conditions: large chunks of ice and icebergs
    Temperature
    0C/32F
    Wind Chill
    -17C/1F

    Comments

    Jessica A, Block F

    Why are some diatoms so different from each other?

    Anastasia Z, Block B

    How are diatoms formed and how do diatoms multiply fast?

    Maria Block F

    What happens if a diatom gets too close to the waters surface? If enough diatoms are together can it change the surface color of the water ( like when you have a collection of algae on your pool floor or walls.) Also what happens if a diatom gets too deep in the ocean. Is it possible for an ocean current to carry the diatom into waters that are too cold or too hot for the diatom to survive?

    Cara Pekarcik

    Morgan, there is always that possibility! It would be exciting! Many of the microscope work and FlowCam analysis will be done after the
    cruise is over, so we will have to wait to find out.

    On 2016-09-26 06:50, PolarTREC wrote:

    Jake O, Block A

    Could it be possible for diatoms to grow in the waters near New England?

    Cara Pekarcik

    Diatoms are the most common, however there are other types include cyanobacteria and dynoflagellates. Other types of bacteria are also
    included as types of phytoplankton.

    On 2016-09-15 15:56, PolarTREC wrote:

    Danny F, Block A

    What is the lowest temperature you have encountered on your way to Antarctica and has it impacted your research?

    Jake O, Block A

    I assume in the middle of the ocean there is absolutely NO internet. How do you post your journals to the internet if there is no internet?

    Steven L, Block B

    What kind of clothing do you wear, from top to bottom? Do you wear a special type of mask or goggles?

    Britney B, Block B

    Is there other types of diatoms other than the ones that attach themselves to sea ice and the ones that float on top of the surface?

    Katrina D, Block E

    If diatoms' left the photic zone, how long could they survive? Also, what are blooms and what do they benefit?

    Jenny T Block F

    Are these diatoms in the water equivalent to what a plant is on land?

    Lindsay lee

    Why are the diatoms such an Important part of Marine plankton

    Cara Pekarcik

    Hi Katrina - I am not sure that anyone has measured exactly how long a diatom would survive without light. The blooms that I mentioned are
    rapid growth phases. They benefit the entire food chain in the Southern
    Ocean because diatoms are the primary producers.

    On 2016-09-15 19:23, PolarTREC wrote:

    Cara Pekarcik

    Hi Steven - you can see more about the ECW (Extreme Cold Weather) gear in a few of my previous posts. We also wear thermal layers, wool socks
    and other cold-weather gear. Many of the folks aboard have face
    coverings and we were given goggles to bring on the research cruise.

    On 2016-09-15 18:08, PolarTREC wrote:

    Cara Pekarcik

    Alexa said: This is a good comment. I vaguely remember a study on diatoms on whales but I could be compeletly wrong, I miss Google.....

    On 2016-09-15 14:06, PolarTREC wrote:

    Cara Pekarcik

    Hi Danny - we have experienced temperatures in the teens, but the wind chill puts us below zero. This area of Antarctica is a little milder
    than areas like the South Pole. So far, we haven't been impacted by the
    cold, but we have had to change plans for ice and rough seas.

    On 2016-09-13 15:37, PolarTREC wrote:

    Jeri Sever

    Cara, do you have to travel so far to do this study and does it have to be in cold water?

    Fairoz basha

    Mam it's good for me....I'm res arch schloar.my research interest in Marine diatom isolation and feed formulation.please I need a article to 18 s rdna isolation of Marine diatom.if you are possible please help my research......need also best primer design and methods

    Cara Pekarcik

    From Alexa:Too close to the surface where the sunlight is too strong - it may
    damage the diatom's ability to photosynthesize and/or kill it because of
    that.

    Yes, when diatoms bloom you can sometimes see a discoloration in the
    water. Sometimes in freshwater systems, enough diatoms blooming you can
    see a brown slippery layer they form.

    If a diatom gets too deep, it will not be able to receive sunlight,
    photosynethesize, and subsequently die.

    Yes, ocean currents can carry diatoms since they are drifting
    phytoplankton. Some diatoms can survive a range of temperatures, others
    cannot.

    On 2016-09-15 16:50, PolarTREC wrote:

    Cara Pekarcik

    As mentioned above, diatoms undergo photosynthesis. It's through this process they produce oxygen which is released into the air we breathe.
    Because diatoms are so abundant in the oceans, they produce a large
    portion of the oxygen in the air.

    On 2016-09-13 12:13, PolarTREC wrote:

    Cara Pekarcik

    Yes, as mentioned above diatoms are found in oceans across the globe. There are the same types of diatoms that are found in both New England
    waters and the Southern Ocean even! - Alexa

    On 2016-09-13 15:35, PolarTREC wrote:

    Cara Pekarcik

    As mentioned earlier, diatoms are an important part of the marine plankton because they act as the base of the food web and produce oxygen
    we breathe. - Alexa

    On 2016-09-13 17:31, PolarTREC wrote:

    Cara Pekarcik

    Yes, diatoms can attach to many other surfaces in the marine environment such as seaweed. Most diatoms live floating in the ocean
    water. Diatoms are also found in freshwater water, some damp soils, and
    even in the air if there's moisture present in some cases! - Alexa

    On 2016-09-13 16:46, PolarTREC wrote:

    Cara Pekarcik

    As mentioned above, diatoms play the same role in the food web as plants play on land. They are both primary producers that undergo
    photosynthesis. - Alexa

    On 2016-09-13 17:24, PolarTREC wrote:

    Jason W, B Block

    How many different genera of diatoms are there in antartica?

    James A

    would any storm or change of water currents affect the incubation?

    James A

    would a change in water current change the amount of diatoms you collect?

    Cara Pekarcik

    The incubation happens aboard the ship, so currents wouldn't affect the process. The rough seas could certainly make it more difficult to
    transfer samples.

    On 2016-09-14 08:21, PolarTREC wrote:

    Cara Pekarcik

    Hi Jeri! Thanks for following along and for the question. Diatoms are found in both salt and fresh water all over the world. So, do we HAVE
    to travel this far and into such cold water? No. Do we WANT to travel
    this far and into such cold water? Yes. The scientists that I am
    fortunate enough to work with on this trip are specifically interested
    in Antarctic cold-water diatoms and iron interactions. Each have
    studied diatoms in other areas of the world, but this research trip is
    specific for this type of diatoms.

    On 2016-09-14 04:33, PolarTREC wrote:

    Nha H, Block A

    Are diatoms prone to drastic temperature changes?

    Mia

    Hello! I was curious if you are all monitoring the concentrations of nitrates, phosphates, and silica and their relationships with the iron concentrations in the water. Additionally, if silica is a limiting nutrient, why do diatoms decide to use this nutrient in their frustule? Thank you!

    Victoria H, Block G

    How will the diatoms get the sunlight

    Cara Pekarcik

    Hi Mia - yes, the science team is monitoring all of the nutrients. They can relate them to the iron concentrations, but can also relate
    them to other sets of data to look for trends. Silica is called a
    limiting factor because the amount of silica in the water generally
    limits the presence of diatoms. Because diatoms use silica to make the
    frustules, they are not expected to be found in areas of low silica.
    Also, diatoms presence can eventually reduce the amount of silica in the
    water because they use it to make the frustules as they divide and grow.

    On 2016-09-18 12:34, PolarTREC wrote:

    Ryan G, Block F

    How long is it before the diatoms dies?

    Cara Pekarcik

    As long as the water surrounding the diatoms does not change drastically, the diatoms will be ok

    On 2016-09-14 11:04, PolarTREC wrote:

    Ryan G, Block F

    Do you catch different diatoms is different areas?

    Cara Pekarcik

    Jake - this is such a great question! One of the ship's IT staff gave me a little tour of the ship's satellite Internet capabilities today.
    We actually have more of a connection than I expected. I send my
    journal's through email to the staff at PolarTREC and they format the
    journal for publishing. I found the process of sending emails off the
    ship to be pretty interesting, so I am actually going to write a journal
    on it when I have time. Keep checking back for an update.

    On 2016-09-13 15:40, PolarTREC wrote:

    Cara Pekarcik

    Hi Victoria - sunlight can pass through the water column to certain depth. This area of the water is called the photic zone and it's
    maximum depth is determined by the clarity or transparency of the water.
    It can be different for different part of the world.

    On 2016-09-14 11:31, PolarTREC wrote:

    Cara Pekarcik

    Ryan - if you look at the diatom photos from the FlowCam (they are included with this journal), you can see that there are many different
    types of diatoms in the images. These diatoms were all collected from
    the same sample area.

    On 2016-09-14 12:00, PolarTREC wrote:

    Morgan Murphy

    How do spines help diatom's buoyancy?

    Cara Pekarcik

    Jessica - the diatoms can be different from each other just like birds, fish and bears can be different. Different species can form if events
    occur that cause genetic changes.

    Melissa Z, Block A

    Hi Ms. Pekarcik, Are there any other organisms that contain cell walls made of silica (frustules) besides Diatoms? If so, could you name some of them?

    Cara Pekarcik

    Hi Melissa - Great question! Frustules appear to be specific to diatoms!

    On 2016-09-14 15:01, PolarTREC wrote:

    Julia Brady, Block G

    How long does it take for the diatom to die?

    Jeffrey Diep

    Hello Mrs. Perkarcik, I was wondering why diatoms don't just die as they are always in constant freezing temperatures or is it because they are at a certain depth in the ocean so they don't freeze.

    Anh D Block F

    How do diatoms produce oxygen?

    Anh D Block F

    How do diatoms produce oxygen?

    Angela Y, Block F

    What will happen to the diatoms if they are not in areas part of the ocean that receive sufficient sunlight?

    Cara Pekarcik

    Hi Jeffrey - as Alexa explained, these diatoms are cold-water diatoms. They are adapted for life in cold temperatures.

    On 2016-09-14 17:49, PolarTREC wrote: