Renee Renn : Week #6 : Leaching

This week I am learning how to process the sediment samples that we have collected from our cruise.  On the ship, once we were through extracting the pore water from the centrifuge tubes the samples were then placed in a freezer.  While out to sea, one of the cores that we collected was cut up into twelve intervals instead of nine like the rest.  Once we got back to campus, this was the core that I began to process.  The first step is to take the samples to the core lab on the south side of campus.

Since 1960, the College of Earth, Ocean and Atmospheric Sciences (CEOAS) at Oregon State University (OSU) has maintained an active program in Marine Geology, and CEOAS continues to be one of the leading oceanographic institutions involved in exploration, research and the collection of marine samples. To preserve these materials for future research, Drs. Ted C. Moore and LaVerne Kulm in 1971 established the OSU Core Lab, now known as the OSU Marine Geology Repository.  At present, the OSU Marine Geology Repository archives 6,094 sediment cores totaling 15,952 m of core, 10,025 rock samples from 545 dredges, 2,200 deep-sea manganese nodules, 1,627 sediment trap samples, 693 plankton tow samples, and other materials, including lake sediments and lake drill cores. Sample requests are increasingly high with more than 27,000 samples distributed over the last three years and more than 175,000 since 1972.
(from:  http://core-repository.coas.oregonstate.edu/about-us/#history)

I enjoy going to the core lab because it is like walking into a marine sediment museum.  You are sure to find something fascinating to look at!  But alas, we take our samples there because they have freeze dryers that are available for use.  Since the samples are in centrifuge tubes, it takes about two days for them to be completely freeze dried.  After they are done, we then take them to the lab and break up the sediments and pour them into appropriately labelled bags.  The next step is to break up the sediment and then use the scale to weigh out approximately 2-3g of sample.  We keep the samples separated by interval, and we place the samples into falcon tubes that have previously been cleaned with nitric and Milli-q water.  Falcon tubes are tubes that can be used in a centrifuge, but they are nicer then the ones used on the cruise because they have measurement marks.  Milli-q water is water that goes through a purification processes involving successive steps of filtration and deionization to achieve a purity expediently characterized in terms of resistivity.

  

The next step for the samples is to complete a process called leaching.   In this process, we are removing soluble or other constituents from by the action of a percolating liquid.  There are two reagents that we use on the sediments to complete the leaching.  The first one is buffered acetic acid, and the second is hydroxylamine.

   The first thing I do in the morning to prepare for leaching is to make these reagents from a recipe that they have been using to leach all of the sediment samples from this proposal.

Next, I begin the process by using Milli-q (MQ) to wash the sediments and putting them in the centrifuge and repeating this step three times.  Then, we add the first reagent, buffered acetic acid.  Then we use the vortex to shake the samples for the next two hours.  The vortex is simply a machine that moves back and forth shaking the samples you have placed on it.

After they are done shaking, I then put them into the centrifuge, and after they are done spinning I very carefully pipet 12mL out of the tube and put it into a teflon vial.  This is the sample that will carry through to the next step, and I will learn how to continue processing them next week.

Next, I do the entire process over again, except on the second time I use hydroxylamine.  In this leaching process we are attempting to remove the ferromanganese coating that develops around each sediment particle.  This is also called the labile phase.  We are looking at this phase to find out how does the biology react, and also is there a way to balance the Rare Earth Elements, and the Neodymium (Nd) in the ocean.  The microbes make these coatings, and we extract the coatings by reducing with the hydroxylamine.

Overall, I have really enjoyed working on this part of the process.  It is relatively time consuming, and one must be very detailed oriented on the follow through.  Next week, I will be heading back into the clean room for the next step.     

Renee Renn - Other interesting things about going to sea

After going through the rest of my pictures from going out to sea, I thought it would be interesting to share some that had to do more with life on a ship.  These I am posting just for fun!  Enjoy! 

Before we left dock, everyone had to learn how to put on an immersion suit.  This is something you would have to wear should you need to abandon ship and spend time in the cold ocean until rescued. 

 

The next group of pictures are of the living quarters which is right below the main deck.

I had the top buck.  Some nights I felt like I was going to fall out of bed!  Luckily that never happened! 

 Sometimes we caught sea life in our core deployments! 

We were fed very well on the Oceanus! 

And now I will leave you with some of my favorites from the cruise!  

 

Natasha Christman: Rest and Respiration

Part of my research this summer is to analyze the respiration of phytoplankton at particular sites in Bellingham Bay and to apply this data to better illustrate the biological processes and characteristics of the region. Phytoplankton are part of a delicate balance of photosynthesis and respiration; while they can fix carbon dioxide and emit oxygen through photosynthesis, without light they also respirate, which means they actually consume oxygen and produce more carbon dioxide. The reduced oxygen levels resulting from this process contribute to the overall drop in dissolved oxygen and the pattern of hypoxic increase. Our goal is to better link and understand these relationships.

So how might one go about measuring the metabolic output of tiny marine microscopic organisms? On our research cruise on July 17th, we collected additional water samples from a point just outside the bay, called Eliza, and the known and regular center point of the hypoxic zone in Bellingham Bay, referred to as BB6. Samples from about a meter off the site bottoms were taken for a "deep" sample, in addition to surface sample collection. These bottles were brought back to the lab and then transferred to air-tight BOD bottles so no transfer of additional oxygen would skew the samples' own dissolved oxygen levels. Using a chemical reaction, half of the samples were "fixed", essentially freezing the respiration of the plankton for an initial value. Then, after 36 hours, the second set of bottles were fixed, showing how the respiration of the plankton changes the chemical composition of the seawater.

The bottles were stored during this period in a cooler much bigger than this
and with cool seawater flowing through it to keep the samples incubated.
Additionally, the cooler provided a nice dark environment.

After the incubation of the samples, I was ready to analyze the final levels of oxygen present in the samples. To accomplish this, I used a Winkler titrator to invoke a chemical reaction and find a subsequent equivalence point. This equivalence point indicates a specific amount of oxygen that was present in the sample at the time it was fixed. Then, through a series of calculations, the respiration rate of the plankton is able to be found, giving us more data on the plankton community and relationship with the hypoxia present in the bay.

The titrator and a sample during the chemical reaction.
Upon reaching equivalence, the yellow color of the sample turns clear.

Payton Hermanson - Week Four

On Fieldwork

Apart from processing various preserved samples (Counting, tallying and preparation for future counting and tallying), the other major component of my duties as an intern is fieldwork. In fieldwork, tasks include collecting samples for later analysis, counting and tallying on the spot, utilizing a (likely expensive) piece of equipment to generate some numbers for you, or preparing a site for the execution of any of the above.

There are several reasons why these processes, which would generally be considered quite mundane, become matters of significantly greater difficulty while accomplished under the banner of fieldwork. Firstly, being in the field implies being outside. This is a region in which the weather happens. On the Oregon coast, the weather is not often content to remain in a condition compatible with a lightly garbed human being, necessitating much layering. Aside from rude temperature, the wind also plays a large role, determining whether waves will be whipped to a frenzy (In this case the wind may even prevent fieldwork from being performed at all, in the case of boat) or notebooks swept away. Even if the thermometer remains in a decidedly balmy range and the wind does not even so much as stir,the fact remains that in the field of marine biology, fieldwork is often conducted near the ocean. The ocean is quite wet and quite powerful, and if approached on a day of ill tidal condition (Too high a high or low, too great the surge), it can be very dangerous, or downright impossible, to accomplish any work at all.

The other major complication arising during fieldwork is that most everything must be taken with you if one is to use it in the field. While this may not seem to be very pressing, keep in mind that in the lab there is often access to anything you may possibly need if some vital component happens to break, requiring repair or replacement, or an unexpected situation arises.In the field, you must bring the component, all of its support, backups, and anything else you can think of possibly needing, all the while knowing that you must carry all of this to the site and back. As sites are at times in rather remote locations, this can be bothersome.

Despite its particular challenges, fieldwork is still one of my favorite parts of interning this summer. The sites themselves are often magnificent, and the opportunity to be out on a boat or go hiking around on the Oregon coast almost daily is not to be missed.

Cris - Week 4

Fluorescein dye in the inner basin

This week I went out to all six sites and did a measurement of the current. To do so I used fluorescein dye, which in its concentrated form is a red/orange color that changes to neon green once mixed with water. It allowed me to compare the water flow patterns in both basins by tracking the time it took the dye to cover a distance of 2 meters. These data will provide additional information as to why specific fouling organisms settle more in certain areas than others.

Botrylloides violaceus in fluorescein

treated water

I have also used fluorescein to identify how the water enters and exits tunicates, such as Botrylloides violaceus to the right. The two streams of dye going toward the top left of the photograph are coming from the tunicate's excurrent siphon. The pharyngeal basket is facing down in the frame with the incurrent siphon at the bottom. The tunicate draws water in with cilia located on its pharynx and filter feeds using the mucous produced by a ciliated groove called the endostyle.

Thamnophis sirtalis, common garter snake

Polychaete worm

The segmented worm on the right belongs to the class Polychaeta in the phylum Annelida, each segment bearing its own pair of parapodia. I noticed it while looking through the microscope and studying my plates. Its sudden appearance in the lens startled me as I did not notice it when I first grabbed the plate. To the left is a garter snake (in the genus Thamnophis) that resides in and around the stream here at OIMB. Along with this garter snake live frogs and rough skinned newts. Rough skinned newts produce tetrodotoxin, lethal to humans and other animals except the common garter snake. Lucky for the snake the stream is plentiful with newts. That's all for this week, cheers!

Zac - How do we know what we are doing?

One of the biggest questions in scientific research is - how do we know that our results are reliable?  This is one of the most important questions that a young budding scientist can ask - and he/she should ask it frequently. So how do we know? 

For example, my work in the Maslakova Lab involves injecting cells with morpholinos and/or fluorescent markers.  If we see changes in the morphology of the cell and/or the development of the resulting embryo, how do we know that they are due to to the morpholinos?  Could the effects that we see possibly be due to the fact that we just stuck a great big needle into these cells and injected them with a foreign liquid?  How do we know that the morpholinos are not causing some non-specific cell toxicity? Could it be possible that the morpholinos we are injecting - which are supposed to knock down the production of a single protein with high specificity - are also halting the production of other proteins unrelated to our target of interest?

These are very important questions that we must continually ask ourselves, and if we are ever to draw any conclusions from the results we see, we must prove without a doubt that the changes we see are a result of the things that we say they are.  Herein lies the importance of including an experimental control: a series of experiments of a known outcome that demonstrates the reliability of one's materials and methods.

In the context of our experiments using morpholino injections it is extremely important to eliminate any possibility that the morpholinos are doing anything except what they should be doing: knocking down the production one (and only one) protein. As a positive control we injected morpholinos designed to knock out the production of Beta-catenin. This experiment has been done previously (by Henry et al 2008) and it produced a known phenotype in the larvae of a related nemertean: Cerebratulus lacteus. By performing the same experiment on Micrura alaskensis we demonstrate not only that morpholinos have an effect in M. alaskensis, but also that the effect is the same as previously demonstrated in C. lacteus. As a negative control we intend to inject a controlled morpholino sequence designed to do absolutely nothing. If we inject this control morpholino and subsequently see anything other than a perfectly normal looking embryo we will know that we ought to think twice about the specificity of our other morpholino injections.  

Another experiment that we intend to perform - the gold standard for demonstrating that the morpholino we inject is targeting the gene that we think it is targeting - is referred to as an mRNA rescue. Remember: morpholinos deplete a growing embryo of a specific protein by blocking the translation of that protein from the endogenous mRNA within the cell.  If one were to inject a morpholino against a particular gene and simultaneously inject a solution of mRNA coding for that exact protein - but modified ever so slightly as to render it immune to morpholino treatment - one would expect that the developing embryo would no longer display the phenotype expected from the injection of that morpholino.  This technique, in concert with various staining and imaging techniques, can confirm within a shadow of a doubt that our morpholinos are depleting the proteins that we say they are depleting.  

This coming week will largely be consumed with staining fixed larvae with antibodies and other fluorescent labels specific to certain tissue types.  These techniques will allow us to see some of the effects of these morpholinos otherwise invisible with light microscopy.  Stay tuned for some fluorescence microscopy pictures!

Week 4 - Luc

This past week has been an adventure. Right from the get go Steve, Justin and Mitch scheduled me to volunteer with SeaCor, which is a team of ODFW research biologists working on estuary habitat assessment along the coast. SeaCor’s current project in Newport involved comparing samples from two different locations in Yaquina Bay to see wether or not particularly Gaper clams were relocating in a recently disturbed location near the newly built NOAA docks. The sampling work is being done as part of a mitigation deal between the Port of Newport and the Department of State Lands. Due to the habitat loss from the installation of the docking facilities for the NOAA fleet, considerable large scale dredging took place, most likely killing any shellfish present. So now the Port of Newport must sample the disturbed site and compare it to a undisturbed site once a year for a seven year period to see if shellfish are recolonizing beneath the dock. My part in this project was very simple. I was assisting the team by throwing point buoys and boat buoys. Point buoys indicate where the divers go to dredge. And boat buoys provide the dredging boat with a pre set anchor point to secure themselves to while they run the dredge for the divers. It took two full days to sample two sites, and man is pulling and throwing anchors all day hard work! But it was very satisfying being able to sort through the dredging samples with the biologists and look for shellfish among the silt and shell tailings sitting at the bottom of the bay.

If Monday and Tuesday weren’t busy enough. Thursday I was invited to accompany Mitch and Kristan to the Oregon Coast Aquarium where they did a talk for a summer education program called “Edible Oceans”. Watching them communicate scientific information with the group was a real treat and got me thinking about my own public interactions and how I can improve them when implementing my survey.

Outside of work things have been good. I’ve been making lots of trips to Olalla Lake up near Toledo, where I’ve been swimming regularly in the relatively warm water. Along with exercising my right to surf as much as I can in the great Pacific. One thing I'm very excited about is repairing an old surf board shaped by a local shaper down in Florence that I recently found by the dumpster! Steve is stoked on the idea as well and is willing to help me out with it. I’m super lucky to have such great supervisors and friends here at Hatfield.

Cheers,

Luc

Ella-Week 4-Adventures at Sea

This week, Katlyn and I got the opportunity to go out to sea on the infamous aluminium research vessel, The Elakha. Known for its roller coaster like ride, this boat has the well earned nickname of The Vomit Comet. The trip was funded by Pisco, a marine research program that focuses on investigating the physical and chemical properties of the intertidal and how they affect marine ecology. The particular lab group that we went out with is headed by Francis Chan, an assistant professor at OSU’s Zoology Department. Chan's lab group specifically focuses on the effects of ocean acidification and hypoxia. As our historic data set has been used to study hypoxic events, this was an excellent opportunity to not only get some sea time, but also to get some background on our project.

The stern of the Elakha as we leave
 Yaquina bay in the misty morning

We headed down south to a place called Strawberry hill, near Cape Perpetua, where the group has stationed some moorings that are checked up on a monthly basis. The objective of this trip was to get readings on the various instruments attached to the moorings that record abiotic factors such as dissolved oxygen and carbon levels. These two factors are then used in studying hypoxia and ocean acidification, respectively.

Helping to deploy a mooring (I'm on the left). 

Pictured below is one of the plots from an instrument at 13 meters of depth offshore of Strawberry hill. This plot reflects some of the recent upwelling off the Oregon coast. Upwelling happens when northerly winds push nearshore surface waters offshore, allowing deep, cold water to replace that water in the nearshore. This colder water from the deep has low oxygen and high saline concentrations, therefore, an upwelling signature can be seen on this chart as low temperature and oxygen levels, with an increase of salinity. Upwelling is occasionally balanced out with southerly winds, which cause a “downwelling” event ( an increase in temp and oxygen, decrease in salinity). You can see from this chart that the downwelling caused oxygen levels to get as low as .6 ml/l (that is milliliters of oxygen per liter of water).   This is relatively low as “severe hypoxia” is considered to be 0.5 ml/l .

Oxygen, Temperature and Salinity over days, near Cape Perpetua, Oregon

Here is a link to a much more detailed explanation of upwelling, complete with diagrams.

http://oceanexplorer.noaa.gov/explorations/02quest/background/upwelling/upwelling.html

The crew and us on our return trip back to Yaquina bay,
enjoying the sun and comfy bean bags up on the observation
 deck (I finally succumbed to the power of the Dramamine). 

In preparation for departure, I took a “less sleepy” Dramamine, which never the less, pretty much knocked me out for most of the morning on board. Despite being desperately sleepy and still a little seasick, I was still able to chat about the mission with Tully Roher, who was acting as the chief scientist in Chan’s stead for the day. I was also able to help out a little with some simple tasks. The group would bring up the moorings using winches aboard the Elakha, gather the data from the instruments, clean off the algal growth with a pressure washer and then deploy the moorings again. At each station that we stopped at, a water sample would be taking by dropping a “niskin bottle”, an empty water container which is open at both ends, down a line. Once the bottle reached a desired depth, we would send a “messenger” down, which is a simple metal clip that would drop down the line, land on top of the niskin bottle and close it off, ensuring that the sample reflected the water at this depth. Dropping the messenger was my major contribution to the work done aboard the Elakha on that day, but I am still very grateful to have been able to be a part of the crew and experience science aboard a research vessel.

Natalie week 4: Anatomy of a shrimp's foregut

This week I finished collecting the mapping points for Katelyn Bosley's population estimate and  model for burrowing shrimp in Yaquina Bay.  I also went out with my trusty slurp gun and collected samples of Upogebia puttegensis and Neotrypaea californiensis and started dissections of their gastric mills--an organ similar to a crop in grasshoppers that is full of grinding teeth to mash up food in the foregut.  My original goal was to look for calicfied structures such as the gastric mill and eye stalks and use them to age the crustaceans by counting annuall rings.  This technique has worked in other crustaceans but as I set out to try this techniqu on mud and ghost shrimp I discovered that the eyestalks of both shrimp, particularly the N. californiensis were too small and not feesible to use as an accurate measure of age or calcification.  Now I am focusing on getting intact lateral teeth from the mill and embedding them in epoxy resin, much like you would an otolith, to cut the sections small enough that I can mount them on a slide, photograph them, and count and measure the annual rings (if there are any...). The complete gastric mill is shown below under 4X magnification.

This week I also helped Dr. Dumbauld collect more shell bags which were used to attract Dungeness crabs to different areas in the estuary.  The samples we take of the sea grass and crabs will help us see how the biodiversity of the estuary is affected, if at all, by the Zostera japonica invasive sea grass.

I also had the incredible opportunity to tour a NOAA (National Oceanic and Atmospheric Administration) research vessel, the Bell Shimada. Officer Michael of NOAA Corps gave us a guided tour of the vessel, including the bridge with an almost 360-degree view and the trawl nets that they use to collect hake and sardines.  This is the first NOAA vessel to target collection surveys of two species of fish at once, and the trawl doors even empty into a hopper that ends in a conveyor belt leading straight to the wet lab.  Here, the scientists can efficiently determine the size, sex, and weight of the fish they collect. During the tour, I felt as if I were onboard the starship Enterprise and it was truly amazing to see all of the work and equipment that goes into each research cruise.

I had another wonderful week at Hatfield and am looking forward to cutting and mounting my specimens to identify growth patterns next week.

A view of the Pacific from South Beach, Newport

Anna Russell - Culturing Labyrinthula

Wow, I can't believe this internship is already half over. I have learned so many things in the past four weeks and I know many more experiences await in the next month. This week I learned how to culture and isolate diseases. When we visited Ship Harbor a few weeks ago, I picked some eelgrass shoots with lesions resembling eelgrass wasting disease. By taking tiny pieces of the shoots and putting them on petri dishes with SSA agar media, I was able to create an isolate of the disease. The UW Friday Harbor Labs also gave us two different isolates of eelgrass wasting disease which I have been culturing in both SSA agar and broth media.
I spent Wednesday making the SSA agar and broth media. This involved autoclaving supplies and seawater, then adding antibiotics and horse serum. The resulting mixture was poured into plates (for the agar plates) or left in the original bottle (broth). The next day, I transferred some of the isolates from Friday Harbor Labs to the broth. Labyrinthula spp. grows faster in broth solution but it is easier to see the growth in the agar plates so there are pros and cons to both types of media.
Here are some of the pictures from this week:

One of the UW isolates. The outlines show the growth each day. 

This one has grown a lot in three days.

This is one of the original isolates from the UW. The yellow is  the Labyrinthula spp. growing on top of each other.

These are pieces from infected shoots at Ship Harbor. At the bottom, there is contamination, making that plate unusable for culturing. 

These vials are of SSA broth and Labyrinthula spp.

Eelgrass that is going to be used in my experiment

Katlyn: Week 4 - Helping with other projects

Ella and I (left) on the Elakha

Putting the equipment back in the water

This week Ella and I were able to get out of the office and help with other projects around Hatfield. One of the main projects that we were able to help out with and learn about was Francis Chan's physical oceanic factors data collection. We went out on the Elakha (an Oregon State research vessel) with Francis' crew and were able to help out with their data collection off the coast of Lincoln City. It was a one-day cruise and it was quite the experience for me because I had never been on the ocean before. It was exciting to be able out in the field and collect data with these scientists. It was also exciting to learn about what they were doing and how they do it. I learned that they collect the pH, temperature, salinity, and dissolved oxygen of the water with equipment that is attached to what they call a mooring, which is an anchor attached to a buoy. They do these cruises in order to collect the data that the equipment has been gathering and to do maintenance on the equipment. Being able to help wash the equipment and put it back in the ocean was a lot of fun. This was also a great experience because everyone on the boat was very welcoming, helpful, and willing to teach me about their work. The fact that the sun came out for the second half of the cruise was also nice.

View from the observation deck on our way back to the dock

Ella, Natalie, and I (middle) in front of the
 mudflat with the slurp guns and shrimp

Another project that we were able to help with this week was Natalie Coleman's project. She is collecting mud shrimp in order to retrieve their gastric mill, which is a grinding apparatus near the stomach of the shrimp. After retrieving these gastric mills from the gut of the shrimp she will mount them on a microscope slide and look for growth rings in them so she can determine the age of the shrimp. Ella and I were able to help her with this project by going out onto the mudflats behinds Hatfield with slurp guns, which are suction tubes used to get shrimp out of their burrows. We then collected around 20 mud shrimp with these slurp guns, which was fun because we were able to be out in the mud and the sun. This was a week full of fun helping other people with their field work! I am so glad we were able to gain a broader range of skills by being a part of these different experiences!

Renee Renn : Weeks 2-5 : Field Work aboard the Oceanus

Greetings!  Yesterday I returned from a ten day cruise aboard the research vessel Oceanus.  I have had the amazing opportunity to experience first hand the fragile and laborious process of collecting data in the field.  I had the pleasure of sailing with twenty six other individuals, scientists and ship crew, and overall I had a positive experience learning the ways of conducting research on a ship.  Now I would like to take you on a journey of the incredible adventure.

 
PRE-CRUISE:

Two days before we set sail, we were up bright and early loading all the supplies onto a flat bed truck at OSU.  We then made our way to Hatfield Research Center in Newport, OR to where the Oceanus is docked.  We spent the day loading our supplies onto the ship and setting up all of our equipment  in the various lab spaces we would be using throughout the next ten days.  There are three main lab areas that we utilize to proceed through the steps of processing samples.  Under the next section, I will go through the steps of this process in depth.

UNDERWAY:

This image is of the apparatus used to collect sediment samples on the ocean floor.  It is called the muli-core collector.  It can collect eight samples with each deployment.  On this cruise we collected samples from a depth of 200m.  After waiting for several minutes while the crane is lowering the muli-core collector in the ocean, we hear the crane operator over the walkie state that they have reached the floor and that they are coming back up.  We all stand by for recovery of the apparatus.

Once the muli-core collector is back on deck, it is now time to inspect the the sediments retrieved and determine which ones will be kept for processing.  Although the apparatus can collect eight samples at a time, it is very rare that all eight will be worthy of keeping as useable data.  Sometimes not all eight core tube arms will activate.  This is the part that will swing down under the core to keep the sediments from spilling out on its journey back to the surface.  To get a better idea, here are a few images of the apparatus up close.  

After the careful inspection of each core, the best ones are then gently removed from the apparatus and carried in the cold van lab.  The lab is located on the main deck toward the back of the ship.  It is a special lab that is kept at 34 degrees.  To maintain the composition of the sediments it is imperative to keep them at cooler temperatures.  In the cold van, we work in a glove bag to separate the core into nine intervals starting at the top and working our way down through the layers of sediment.  A glove bag is able to seal off.  We are then able to run a line of nitrogen gas into the bag as to not expose our samples to oxygen at this point.  The samples are spooned into centrifuge tubes.  We take samples at nine intervals for each core.  The following are some images of the cold van.  In the first one we are setting up the table that we did all of our work at in the the van.

    
The next step in the process is to then take these tubes, and run them through the centrifuge.  We run each sample for 15 minutes at 10,000 rpm.  In this step we are essentially separating the sediment from the pore water.  Pore water, also known as interstitial water, is the water that is trapped in between the sediment particles as they settle to the ocean floor.  Fun fact... the centrifuge is suspended in a special table that allows it to swing back and forth because the ship is in constant motion and in order for the centrifuge to function properly is must always remain in a vertical position.  There are also lead weights that we place on top of the centrifuge to help it maintain this position throughout its cycle.   

As gently as we can on a rocking ship, the next step is to take the samples up to the lab that is located on the top floor.  The next step is also done in a glove bag filled with nitrogen gas.  We are extracting the pore water from each tube with a syringe and pushing the sample through a filter.  It is still important at this step to not expose the samples to oxygen.  The collection of pore water is kept organized by interval level.  When we return from sea, there are a series of lab experiments that will take place on these samples in the lab at OSU.  The experiments are done to take a closer look at the Rare Earth Elements (REE) which is also the lanthanide row on the periodic table.  REE's are important because their geochemical properties enable them to be powerful tracers of chemical process.     

Overall, I feel incredibly lucky to have been a part of this field work experience.  I learned a lot from my mentors, Jim and April about how to collect good data and also how to maintain a level of attention to details in an environment that is always working against you.  It is definitely an experience I would repeat.