Examining some rocks recovered from 3000 meters.

Some granite and basalt recovered from the box corer.

Michael deploying a late night cast in search of some zooplankton.

Throughout the cruise I have been running experiments on photodecomposition of methylmercury in seawater. The samples in the left incubation chamber are covered in foil to block light and observe decomposition by microbiology while the samples in the right chamber are exposed to study decomposition by sunlight. Both chambers recieve a constant supply of fresh seawater in order to maintain the same temperature conditions as the ocean surface.

-Katlin

Flux Core Experiment

Me placing a flux core in the incubation chamber.
I'd also like to give a shout-out to Mr. Geyer! :)

Currently on the cruise, my research involves sediment flux cores. The box corer is sent down at a pre-determined depth and is used to collect sediment and pore water. Afterward, a long core tube is used to collect the sediment and overlying seawater and capped off to create a flux core. At each station, my job is to obtain three of these flux cores, filter and collect the seawater from each and measure the height of initial water column before placing them in an incubation chamber. After the cores have incubated for a 6 hour period, I again filter and collect the water and measure the height of the remaining water column for each before filling the core with fresh seawater previously collected at that station. Then, the cores are placed in the incubation chamber again and the same process is repeated for a 12 hour incubation period and an 18 hour incubation period. The ultimate goal of my research is to find out how much mercury is entering the seawater from the sediment after each incubation period. This will allow us to hopefully disprove the hypothesis that much of the mercury found in the ocean comes from the deep sea sediment. Recently, we were able to obtain sediment from a depth of 3,200 meters for the flux cores!!!

-Deepthi =)

Chad works with his sediment cores in an oxygen free glove box.

Deepthi hard at work!

Waiting for the rosette to surface.

Prentiss and Tristan attach tag lines to the rosette to minimize swaying and safely bring it on board.

Michael and Kati with a fresh batch of krill! These little guys will be analyzed for carbon content and methylmercury concentration.

Here is a close-up of the sample Michael and Kati are holding.

We sent a bag of decorated styrofoam cups down to 3200 meters with the CTD (conductivity/temperature/density sensor). The pressure at depth pushes out all of the air in the styrofoam and shrinks the cups!

Before...

...and after!

Box coring success!

Tonight the sediment team was able to successfully core 3200 meters deep, that's about 1.8 miles below the surface! The box core is designed to collect an undisturbed sample of the ocean floor; that's sediment and overlying pore water with minimal disturbance. By box coring we are able to bring up to the surface a piece of the ocean floor, quite a unique environment to study!

Dr. Hammerschmidt and students admiring the first core.

Here is what the ocean floor looks like 2 miles below the surface! This picture was taken looking down into the box corer.

Cores are carefully placed within the box to collect sediment. The cores are plastic cylinders, plugged at the top with rubber stoppers to create suction. Once all of the cores are in place, they are slowly pulled out and a sponge and cap is placed on the bottom to hold everything in place. Pictured here are the cores and rubber stoppers before being pulled out and capped.

Jaclyn admiring a perfectly undisturbed core.

A handful of ocean mud :)

Deep Station

We are currently sitting about 2 miles above the ocean floor at our deepest station (the first blog post is a cruise path, we are at station 12). Deep stations are challenging with changing winds and currents and certainly more time consuming! Right now we are deploying a rosette for water samples; the whole process will take approximately 4 hours. Melissa and Avani are taking turns operating the wench that lets out the line. Once the rosette is at the bottom they will have to stop at intervals (the wench has a wire read-out so they know how deep the rosette is) to allow time for the bottles to trip.

More box coring!

A beautiful sunset Tuesday evening.

On Monday there were three different dolphin sightings. During one sighting in particular, the dolphins were as close as fifty yards from the ship!

Deepthi is demonstrating how to properly don a safety immersion suit during our safety training.

Tristan "clean hands" Kading would like to give a shout-out to his family!

Methylmercury in the water column

Mercury in the environment can be present in four differnt forms; one of these species, methylmercury, is of particular concern because it is able to bioaccumulate and work its way up the food web into the fish we eat. The focus of my research on this cruise is to examine methylmercury in the water column to identify the source and distribution of this toxic mercury species in the ocean. To do this, I analyze a series of seawater samples collected at various depths:

Water is collected using a trace-metal clean rosette. The rosette holds 11 Go-Flo bottles that are electronically set to trigger at specific depths according to pressure sensors.

Once the water is collected the Go-Flo bottles are detached from the rosette and transfered into a sterile clean van with HEPA air filtration (you can see the grey bottles hanging up on the walls). The water is filtered from the Go-Flo bottle into an acid-cleaned Teflon bottle used for methylmercury analysis. Melissa is wearing a gown, gloves, head cover and special clean van shoes to prevent any metal contamination to the seawater.

Finally, the 2-L bottles are transferred into the main lab for analysis. Reagants are added to the water to free methylmerucry from solution. The sample is then purged with nitrgoen and the methylmercury is collected on a small glass trap filled a material called Tenax. The Tenax trap is then burned, and methylmercury is identified by a detector and integration system.

-Katlin :)

Wright State's mercury team: (front) Katlin Bowman, Avani Naik, Deepthi Nalluri, Jaclyn Klaus, Melissa Tabatchnick (back) Dr. Hammerschmidt

Bosun Clindor helping to deploy the box corer.

Deepthi and Jaclyn are helping Chad collect sediment from the box corer.

Dolphins in the distance!

The mercury cruise is well under way with two stations completed! We all have our sea legs by now and have even spotted a few pods of dolphins swimming near the boat. We arrived at our first station Monday around 6PM. As a comprehensive study of mercury in the ocean there are a lot of different projects and different types of sampling that happen at each station. Michael and Katie, two PhD students from the University of Connecticut, are studying zooplankton; Chad, Deepthi, Jaclyn, Avani (Wright State) and Alan (UConn) are studying ocean sediment, and Melissa, Katlin (Wright State) and Tristan (Woods Hole PhD student) are evaluating seawater at various depths.

Welcome to Woods Hole! We've been in Massachusetts for two days, loading the ship and setting up our on-deck laboratories. We've been busy getting everything organized and preparing for the trip, but will post more once we are settled and under way! Here is a picture of the Oceanus, our new home for the next two weeks.

2010 Cruise Path