Life in the Dead Zone Posts
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We are still transiting to our northern, more hypoxic station, so we have a little down time. We will be stopping in Solomon’s MD at the Chesapeake Biological Lab shortly to pick up one of our principal investigators for the last half of the cruise, but in the meantime I had a delicious lunch and took some pictures. I point this out only for the irony of it, but I found an iPhone app made my Microsoft (!) that helps you create panorama photos that can be manipulated using the Microsoft Silverlight plugin on your browser. I’ve gone ahead and linked to two of them below because wordpress.com does not allow embedding of these types of objects.
The first is of the stern of the ship, where we do our work. In it you can see some of the equipment we use including the MOCNESS, Tucker Trawls, and Scanfish, not to mention quite a lot of the ship’s winches, A-frame and ‘dog house’ where the engineers operate the winches and cranes. The second one is the view from the “science” chair on the bridge. It’s a great view up there and I tend to wander up and watch the world go by during the little down time I have out here. It’s a nice chance to chat with the crew too, who have become real friends after all the time we spend out here.
Enjoy these, because tomorrow is going to be a busy day and I’m not sure what I’ll be able to write. In the coming months I hope to keep up with this blog on a weekly basis on shore and more frequently on cruises. We’ll have students and teachers working with us over the summer, and so hopefully I can get some guest blog posts in addition to my ramblings. ‘Til then, enjoy the panoramas!
We’re moving along now, with some gear problems have been sorted out and we’re back in the swing of things. We’re heading to our northern station shortly, as soon as we squeeze in another MOCNESS tow. The retermination of the conducting cable went well, and the first tow with the MOCNESS was a smashing success. Pictures to follow, and I’ll be posting Twitpics on @planktoneer
As far as the science goes, I’ve been trying to figure out what to say, but it’s such a different year and different from our expectations that it’s hard to categorize other than the comments I’ve already made. Since arriving at our southern station though, salinity has been climbing. It’s not likely due to evaporation, though it’s awfully hot out on the steel deck in direct sun. It’s more likely due to the spring freshet finally abating. All of the snow received in the northeast, particularly Pennsylvania has been causing high river flows into the Chesapeake watershed, dropping surface salinity well below the long term average. This suggests that there may be a lot of hypoxia this year, or perhaps just earlier hypoxia depending on what happens later in the summer. All of that extra flow into the bay brings nutrients and enhances stratification, which means that there is a bigger difference between surface and bottom salinity this year than in an average year. That salinity difference causes something of a barrier to oxygen and nutrient exchange. So, the algae in the surface will use up all those nutrients coming in with the freshwater, grow really fast and either be eaten or die. Either way, the remains (either dead cells or “processed” by the animals eating the algae) sink to the bottom and get decomposed by bacteria. That decomposition process uses up oxygen, and voila – hypoxia. Now, the only way to get oxygen into the water is either by photosynthesis of algae or exposure to air. Deep water has little light, and even less on a year like this because of the high algae production and detritus in the freshwater. Plus, the enhanced stratification keeps the mixing between deep and surface water to a minimum.
Of course it could never be that easy. There is some new work coming out from some folks at Old Dominion University in Virginia suggesting that wind direction, more than magnitude even, and help ventilate the deep water of the Chesapeake. What happens is basically that the wind can blow some of the surface water away, causing something of a hole, which gets filled in by deeper water. This allows more contact between the deep water and the oxygenated surface water, or in some cases directly with the atmosphere. Couple that to dropping nutrient inputs throughout the summer as the spring freshet subsides, and suddenly hypoxia is not nearly as strong as it could have been if it were just up to nutrients alone.
These are some of the ideas that drive a program like ours, particularly in regards to sampling repeatedly throughout the year to track monthly or seasonal changes. The differences between years highlight the need to make measurements over even longer time intervals too, because there is a lot of variability between years that must be accounted for. If this was our first year of the project, we would likely have very different expectations for what was going to happen next year than we did at the end of last year.
Science is like puzzle, and it keeps us on our toes. The most fun part for me is putting all the pieces to gather to see how they fit, and then trying to find the stories in the data. The data always tells a story, and often we learn the most when it’s a very different story from the one we were expecting.
Now, it’s time to get more data.
Here is a quick screenshot of a MOCNESS tow. Sorry the light is low but we are running chlorophyll samples in the same lab, which necessitates dim red light.
For those in the know this may not look like a very pretty tow but it’s not easy towing this gizmo in 19 m of water.
Here we sit, gear in pieces, scientists anxiously waiting. Seems to be a ghost in the machine that is this cruise; some kind of bad moo. Without going into too many details lets just say we’ve had a few set backs with the equipment, but fortunately everyone is healthy and morale hasn’t plummeted yet. We’ve got a backup plan, but it involves equipment that is suboptimal. The data will come in and the samples will be processed, but it’s definitely plan B.
So what is the good news? Well, we’re making it happen and both the ships crew and scientists seem to have endless determination to make this cruise a reality. It’s partly economics; ship time is expensive and the right way to approach it is to squeeze every last bit out of a cruise from a science perspective. Plus, we have a good mix of early career and well established investigators whose attitudes and experiences are complementary. But I think more than that I think this ship has assembled a “Can Do Crew” – their own self-applied motto – and that attitude really helps when things go wrong. Stay tuned for pics. We’ll be back in the water sampling shortly, and plan B, though suboptimal, will tell us what we need to know.
But now I’m going to make another cup of tea with honey. The chief engineer brings honey from his own hives, and it’s awfully good.
We’re off and running for field season 2011, and things are … going. It seems I’ve been blogging about oceanography cruises for two years, and the bulk of my talk has been about equipment problems. I’m not sure why, but it seems to pervade my work these past couple of years. I think it mostly has to do with the fact that much of our equipment is getting up in years. We try to keep it in good shape, but it gets a lot of use, and as I’ve said before – dragging electronics through saltwater tends to cause problems. Fortunately we’ve got a great team that can keep us in business under all but the most dire of circumstances, and so we’re at it still.
I haven’t had a chance to get data up, but I will try to do that tonight or tomorrow. Take my word on it though, this year things look awfully different from 2010. Starting with the water properties, it is fresher at the surface and dissolved oxygen is much lower in large portions of the Bay. Temperature is a bit cooler too, though the difference is not as great for the salinity and oxygen. But the biggest difference so far is in the smallest critters we look at. Our resident phytoplankton/ microzooplankton has said that the composition of those organisms is vastly different from last year. This time last year the algae (phytoplankton) was dominated by diatoms. These are photosynthetic, single-celled organisms that make a silica covering called a frustule. If you’ve every bought or heard of “diatomaceous” earth, it is the product of millions of these organism sinking out and dying over millennia, which creates an organic and silica rich dirt that lots of plants love. Instead of diatoms there is a mixed bag of other things, including dinoflagellates and cryptophytes. These are other single-celled organism that can often photosynthesize AND eat other organisms. We call this lifestyle “mixotrophy”, and it is likely much more prevalent in the plankton than we had thought a few years ago. As for the copepods, my favorite multi-cellular animals, the species composition is mostly what we expected, but there are more freshwater species this year than last. That’s not at all surprising, considering the salinity differences, but the interesting thing is that the ones we’re seeing that like lower salinities are usually found in the deepwater in the tributaries of the Chesapeake, but here they appear to be in the surface. It is likely that they are getting washed out into the Bay where we are sampling, but that has yet to be confirmed.
It’s important to note that all of these findings are preliminary, and the final results could change a little when we get back and really pour through the samples and data. Note I didn’t put any numbers on the preliminary findings. That is simply because when you are spending all your energy collecting data in a responsible and consistent manner, it sometimes precludes the analysis. I would bet that many of our shipboard, anecdotal findings will hold up with the more thorough lab based analyses, but you never know until you do it. As my highschool calculus teacher used to tell us, “I’m from Missouri, ‘SHOW ME’!”. So we let the data do the talking, but you can’t rush it because you want it to make sure it gets all the parts of the story right. Think of that picture of FDR holding the newspaper saying “Dewey Wins!”…
In other news, I’m trying something new on this trip – twitter. My handle is @planktoneer, and I’m neither consistent nor terribly witty with it. I think I will likely use it more for ‘twitpics’ to show some of life on the ship, with the occasional commentary. I’m not going to link it to my Facebook profile yet or anything like that, but at the bottom of the blog posts you will see some recent tweets. We’ll see how this goes, and any useful feedback is welcomed…
’Til next time, dear readers, ’Til next time.
I’m sitting in the dry lab of the RV Hugh R Sharp as I write this. The Scanfish is in the water, the sun is shining, and the coffee is hot. It’s been 7 months since I was last on a ship, and it’s good to be back. Last summer was busy; we began a big NSF funded project on hypoxia in the bay and also mounted a cruise to the Gulf following the Deepwater Horizon oil spill. When we got off that last cruise I couldn’t bear the thought of going to sea again, but now I’m ready. Research cruises are a big part of why I got into this business, and though four straight months of cruises took it’s toll on my last summer, when I’ve been off the ship for a while I certainly miss it.
We’re back for a second year of our hypoxia project, DeZoZoo, which stands for Dead Zone Zooplankton, and though we’re only 2 hours into the sampling, things are going well. That’s not a trivial thing though, because having been off 7 months can mean forgetting lots of stuff. There’s still plenty of time to do that, but instruments are working (so far) and the weather report looks good, which makes it easier to get things done and fix problems. We’ve got a top notch group of scientists on board, and the crew of the Sharp is as good as ever. We spend a lot of time on this ship, and it’s nice to catch up with friends and acquaintances.
Stay tuned. I’ll be posting data tonight once we get our initial survey done. As I write this we are about 6 miles south of the Bay Bridge (38 54.6 N, 76 23.4 W) and the water is VERY fresh, and the deep dissolved oxygen is already pretty low. In fact it’s near zero. Should be an interesting contrast with last year, when we cruised on almost the exact same days. In a few hours we’ll be stopping in Solomon’s to pick up some more scientists and then it’s back to the survey.
As a scientist, I find it somewhat ironic that in some sense I am no stranger to self promotion – paying my way (from grant money) to go to conferences and tell people how wonderful and important my research is – while at the same time I feel slightly embarrassed when I hear or see myself on a news piece. Well, I’m working on that and below are two recent pieces in which I’m featured, in some sense of that word.
The first audio link is from a local NPR radio program, The Marc Steiner Show that does a piece called On Delmarva each week. My part comes in at about 23:00 and lasts for about 25 minutes, but I encourage you to listen to the whole hour because it’s all about the health of the Chesapeake Bay, with some commentary from me about the Gulf of Mexico, and Marc Steiner is a very good interviewer (he says, after two interviews in his life).
The second piece is from National Geographic, as part of a series they are doing on science from the Deepwater Horizon oil spill. It’s about 3 minutes long and is very well produced.
More pictures from our Yalie volunteer Jessica! Note the pictures of the enormous moon jellyfish with a spider crab, and the large red ctenophores. Oh, and the sunsets. The lovely sunsets.