Wednesday, November 5, 2008

Cruise Update: Day 6

Position: 29 05.514 N Latitude
091 56.312 W Longitude
Steaming East

Today has been a very productive day aboard the Pelican. We completed our westernmost transect today and have begun steaming east with plans to sample a few more coastal sites before making our way back to Cocodrie, LA, on Friday morning.


Water and sediment samples were collected from all of today's stations and Caroline (our visiting high school teacher) helped deploy her third boxcore of the cruise.
As we steamed toward the coast this afternoon, we encountered the very obvious front marking the transition from greenish-blue shelf water to turbid Atchafalaya River water.

Many scientists onboard analyze their samples as they are collected. Now that the cruise is winding down, we are beginning to compare our data and speculate about their implications. Radium isotope data collected by Jim Krest's group from USF St. Pete has revealed that, in addition to the Radium supplied to the region by the ocean and by the rivers, there are additional sources of the isotopes being supplied to the region. The excess Radium may be a result of groundwater input, offshore oil and gas production, and/or resuspension of the sediment on the seafloor by dredging, shrimp trawling, etc. Also, Wei-Jen from the University of Georgia, has determined that dissolved inorganic carbon (DIC) concentrations from the Mississippi River are more elevated that those from the Atchafalaya River. The implications of these results are still being explored, and collaboration among the scientists will continue throughout the coming months.


The weather continues to be warm and sunny with calm seas and magnificent sunsets.

We got a special treat today when Iuri joined our cook, Steve, in the galley to make ceviche from fresh fish caught overnight. Ceviche is raw fish cured in lime juice and mixed with celery, tomatoes, and onions, served cold with tortilla chips. It was excellent!

Tuesday, November 4, 2008

Cruise Update: End of Day 5

View Position on Map
Position: 28° 43.37' N latitude
092° 55.87' W longitude

We are on the westernmost transect of the research cruise, and have just finished the last station for the night. We expect a fresh start early tomorrow so that we can finish this transect and move on to some other sites as we head back to the Pelican's home port in Cocodrie, LA.

In the meantime, everyone is busy processing samples from the day's efforts to free up space for tomorrow. For the radium samples, our counting equipment has been going non-stop, and we have the lab bench lined with samples waiting to be counted. Plus, we still have seven barrels processing on the back deck which will have to be counted as well. So, at least for the crew from USF, there won't be much rest tonight. With less than three days left of the cruise, we will be doing all we can to collect samples from as many stations as possible.

But, it's not all work and no play. In between stations we have had a lot of fun, enjoying the beautiful weather and getting to know each other. Joining us on this second cruise is Caroline Coker, a science teacher for the Mobile County Public School System in Mobile, Alabama.

Caroline has been a great help with sample collection, and we've even got her helping to process some of the samples for Total suspended solids (TSS) and dissolved radon. So far, Caroline has helped to collect 2 box cores, and obviously doesn't mind getting dirty.

Also joining us is Iuri Herzfeld, a PhD candidate at the University of Hawaii, Department of Oceanography. Iuri is working on finishing up his dissertation at UH, but is interested in gaining a variety of oceanographic experience along the way. Most of his research has been from small boats (and he has even taken water samples from coral reef systems in Hawaii using personal water craft), so he was excited to come along on the Pelican. He, too, has been a great help with the sample collection and processing, and he managed to learn the procedures in record time. He is also a master of disguise...

(Hold mouse over image for Iuri's quick change)

(you may have to be patient if you have a slow connection)

A Respite

While most of our time at sea is spent working, sleeping, or eating (see “Battle of the Bulge” post from a few days ago), there can be significant free time when stations are spaced far apart. That is the case now as we are on a six-hour steam west. Some people are catching up on work, be it calculations, sample processing, or instrument maintenance. Others are napping or watching TV (currently showing a bizarre foods show via satellite...sauerkraut pie anyone? ).

But this is also a time to enjoy the sea and sky. Today the weather is nearly perfect: warm and sunny with little breeze and there are low puffy clouds in the sky. We are far enough away from the coast that the water is blue, as one classically thinks of the sea. But along this coast one also finds brown water, laden with suspended sediments from the river. And, between the brown and the blue, there is green water, colored by the microscopic plants that thrive on the nutrients from the river, but which need to wait for the brown sediments to settle out and allow life-giving light to penetrate the water. It is the plant productivity of these green waters that provides organic matter (i.e., “food”) to bottom waters on the shelf, thereby increasing respiration and driving the oxygen depletion that is problem here during the spring and summer.

One thing that is in short supply aboard ship is silence, or even quiet. The ship is essentially a big diesel power plant, so it is noisy most everywhere. On the Pelican, you can find relative quiet on the bridge as well as outside on the bow or forward areas of the fo’c’sle or 01 deck (the deck above the main deck). The only time I’ve come across silence at sea was accidentally. Several of us were on a zodiac in the North Atlantic south of Greenland. We had headed away from our noisy research ship in order to collect uncontaminated water samples when the outboard motor on the zodiac quit. Suddenly we were silent, rolling on five-foot ocean swell. We were not actually in any danger, so this was a rare and sublime chance to enjoy the sea estranged from human sound.

Monday, November 3, 2008

Cruise update Day 4

Position: 29° 16.33 N latitude
091° 36.80 W longitude

We are enjoying a slower-pace day at sea today. Some of the crew have taken our smaller boat up into the Atchafalaya River to collect water samples for studying the change in salinity from fresh river water to open Gulf water, much like we did in the Mississippi River a few days ago.


The weather has remained in our favor with calm seas and warm temperatures. Most of us were anticipating rough seas and are delighted to be able to stow away our foul weather gear for this cruise. We've also enjoyed some beautiful sunsets at sea!


Because we are awaiting the return of our small boat, no stations have been completed yet today. However, Caroline (our high school teacher) got to try her hand at box-coring this morning. We collected the core from nearshore waters south of the mouth of the Atchafalaya River and extruded the sediments at exact volumes. This allows us to study the pore water contained within the sediments, as well as study the grain size of the sediments. As with most cores from this region, it consisted of dark brown, jello-like mud with lots of pore water.


The situation in the galley remains one of pure temptation, as Alan mentioned earlier. Last night (11/02/08) we enjoyed King Mackeral for dinner, caught by the crew of the Pelican on 11/01/08. That was accompanied by a spicy seafood soup, roasted potatoes, squash, broccoli, salad, fresh bread, beef brisket, and ice box cake for dessert. Lunch was a Mexican feast with fish tacos, quesadillas, beans and rice, enchiladas, chiles rellenos, and homemade guacamole.

Saturday, November 1, 2008

Battle of the Bulge

One thing that everyone comments on at sea is the food. It is usually quite good (the crew insists on it) and it is certainly always plentiful....too plentiful. For breakfast this morning, the standard order was a mound of scrambled eggs, some bacon, and buttered toast. For lunch the selection consisted of vegetable soup, warm ham and cheese sandwiches, eggplant lasagne (my favorite), huge boiled shrimp (amazingly succulent), caesar salad (with anchovies), and biscuits. Last night’s dinner consisted of chicken filets with cilantro-garlic mayonnaise (that topping would make an old shoe taste good), tuna in filo rolls, Portobelo mushrooms stuffed with goat cheese and bacon (first rate!), potatoes served two different ways, soup (didn’t see what type), and jello with a mixture of berries.

Ah, but the food doesn’t stop with the meals! Always on the table in the galley are containers of candy and cookies, a bowl of trail mix, and fresh fruit in case you decide you want to be healthful. Of course, if the candy and cookies aren’t enough for you, there is a freezer full of ice cream that you are always welcome to invade. In fact, you can pretty much eat anything that’s available.

Now this plethora of food might sound like paradise at sea, but it’s a problem. In the waiting time between stations, the galley is the main place aboard ship that people can gather. So, one sits there in the waiting boredom amidst temptation. The vast selection at mealtime doesn’t really provide one with choice: since the food is all good, one wants to sample it all. Many people also find that the slow rolling motion of the ship tends to make them a little tired and hence they lose what little remaining self-control they had.

The marine tech aboard ship tells me that he has gained 20 lbs on long deployments (only to lose it on spending extended time at home). The more fit looking crew tend to take one moderate plate of food and immediately leave the galley. I had a friend who once confessed to gaining 36 lbs on a 36-day cruise. And, for those of you tempted to just increase your level of exercise, remember there’s no place to jog aboard ship and no exercise room either (at least on modest sized ships like the Pelican).

So, what’s a poor boy like me (with loss of self-control) to do? One strategy (following that of the more fit crew), is to avoid the galley....but as chief scientist, I shouldn’t go into hiding. Another is to skip a meal (but then there are those ever-present snacks calling my name). You can also invent a special diet for yourself. For instance, one can readily become a quasi-vegetarian. I say quasi because, although the cook would certainly oblige a vegetarian or any other special diet, no one on this cruise has requested such a consideration. And, I don’t care to ask the cook for special food preparation on his part just because I’ve lost control.

Well, it’s almost dinner time. So, I’ll just go contemplate this problem in the galley. It’s a rough life.

MAG-Mix2 Day 2


The weather so far this trip has been much, much nicer than during MAG-Mix1. We have moderate breezes, sunny skies, and the seas are not nearly as rough as our first cruise in May. The mornings and evenings have been a little chilly but perfect during the middle of the day.


The sampling has been almost nonstop. Last night (10/31/08) we sampled the change in salinity from open water in the Gulf of Mexico to freshwater in the Mississippi River. During MAG-Mix1, the Mississippi River had high discharge so we didn't have to travel very far upriver to reach freshwater. However, during this trip we had to go all the way to Venice, LA, and still didn't reach truly freshwater (0 PPT). During high river discharge like we had in May, the freshwater can push the salt water all the way out of the river, but when the river flow slows, the salt water comes back in.

Near Venice, LA, we collected extra water from the lowest salinity water we sampled. This water will be used in a series of mixing experiments later in the cruise. A lot of our measurements look at what is dissolved in the water, but we have to remember that the river also carries a lot of sediment, and when the river water mixes with the salt water, a lot of chemicals wash off of the sediments, which increases their concencentrations in the river water.

Other things can be changing the chemical concentrations at the same time, so we like to perform a mixing experiment to determine how much of the change comes from just this mixing process, and how much comes from other processes. A few of the other things which might change the chemical concentrations are 1) organisms could be using the chemicals when they grow, or releasing them when they die; 2) chemicals could be coming in from other sources, like ground water; 3) chemicals may be being removed from the water as the sediment clumps together and settles out.

Science Party:

It seems like everyone on the boat is in good spirits this trip. With the modest sea conditions, no one has really been suffering from the mal de mer. at least not as much as during MAG-Mix 1. Also, we started off on a bit of a holiday, so the mood has been very light-hearted as people occasionally popped up on deck in costume.