Although the oyster project’s fieldwork has attracted most of the attention on this blog (indeed, it is where most of the action happens), our time at the lab deserves a bit of discussion as well, as much progress on the oyster project also happens behind walls. This is especially the case nowadays, in the winter, when fieldwork is kept to a minimum on account of weather and the general inactivity of animals on the reefs. What better time to catch up on processing the zillions of samples we’d collected over the past many months, but never quite had time to get to.
Labwork is a whole different beast than the energetically-demanding, volatile nature of fieldwork – I wouldn’t go so far as to call labwork boring, but it is often incredibly repetitive, time-consuming, and demanding of extreme patience. It’s certainly not as exciting, sensational, or enjoyable as fieldwork (in my opinion), but it is just as much an integral part of the science, and anyone who goes into research will probably spend much of their time sitting at a bench, repeating the same procedure twenty-thousand times in pursuit of the great dataset (that is, until you hire techs and grad students to do it for you). Yet labwork has an appeal and mystique all of its own that’s not to be overlooked.
Certain tasks in marine biology necessitate learning skills used in commercial seafood. Here, Tanya shucks an oyster to remove the meat and weigh it.
So while David retires to his office and catches up on the uncountable tasks at hand there, I’ve holed up in the lab and plodded steadily through the several hundred samples of ours waiting patiently in the freezer. Lately, this has involved two major tasks. The first was to process the sediment organic matter (SOM) samples from our (and Jeb Byers’s) oyster reefs collected every 6 weeks since August. A total of 640 samples needed to be transferred from bags to aluminum dishes, dried for 3 hours at 105°C to evaporate any water, weighed, combusted for 3 hours at 525°C to incinerate and volatilize any organic material, and reweighed to determine the percent of the sediment composed of organic material. This analysis will allow us to compare how oysters affect the amount of organic material in the sediment across latitude. In case you ever wanted to know, 525°C (977°F) is pretty dang hot, and the smell of burning sediment that wafts down the hall during the first half hour or so in the furnace apparently smells exactly like an electrical fire.
Mmmm... oyster jerky!
My second task was to process samples of oysters we’d collected from our reefs during our intensive August surveys. After thawing them out, this involved measuring the total weight, wet and dry tissue weight, and various shell dimensions of 400 individual oysters. From these data we’ll be able to calculate an oyster condition index (health indicator), which we’ll be able to compare across sites. Obtaining wet and dry tissue mass required removing and weighing the meat (my oyster shucking skills increased greatly after this exercise), and reweighing it after drying for 48 hours at 70°C (this generated some quite odorous and not-all-too-appetizing looking oyster jerky). Between the sediment and oyster samples, I admit I had a monopoly of the marine lab’s drying ovens for a short while. I can say though that sticking your face in a drying oven is a great way to warm up on a cold winter’s day.
There are a variety of ways researchers try to liven up the tedious nature of labwork. Many listen to music or books on tape, or play movies in the background, or chat with labmates if others are around. Sometimes I’ll do these things, but other times I find the quiet monotony of labwork to be rather peaceful. There’s no stress or distractions or real need for thinking – just you, the calipers, the oysters, the datasheet. You kind of get in “the mode” and it can be rather, I don’t know… zen? At least for a little while. It’s a nice contrast to the intensive and unpredictable nature of science in the field.
David Kimbro’s research is funded by the National Science Foundation.
David's collaborators, from left to right- Dr. Jeb Byers, Dr. Mike Piehler, Dr. Jon Grabowski, and Dr. Randall Hughes.
As you can see from the video that summarized our efforts over 2010, it was a busy 6 months of research. After taking a great break during the holidays, the entire oyster team (Jon = Gulf of Maine Research Institute, Mike = University of North Carolina at Chapel Hill, Jeb = University of Georgia, Randall = Florida State University and me) met for a long weekend to figure out what we accomplished and where we are going in the future.
You might think that our 2011 research plans should already be set given that we received funding. Well, we did receive funding to carry out some outlandish field experiments in 2011, but these experiments were dreamed up in our offices and may not address the most ecologically relevant questions for our system. Checking in with the monitoring data is probably the best way to determine if our planned experiments were on target or if they needed to be adjusted and hopefully simplified!
Prior to the oyster summit last weekend, I hounded all of the research teams for all of their data. Given the huge volume of data and everyone’s busy schedules with teaching classes and other research projects, this was quite the task. Once Tanya meshed all the data together (also not a simple task), I then moved on to the next task of analyzing our data.
Well, the initial excitement quickly turned into a stomach churning feeling of….where the heck do I begin? Similar to the way that too many prey can reduce the effectiveness of predators, the data were swamping me…I was overwhelmed and the draining hourglass wasn’t helping (people were flying into town in two days…yikes!).
After multiple cups of coffee, the anxiety passed and I decided to revisit some basic questions:
David's team used gill nets to catch the larger fish around the reefs, many of which are top predators in that habitat.
(1) With the gill nets, we obtained predatory fish data. So how do the abundance and biomass of these fishes vary across latitude? And does this pattern change with season (i.e., summer versus fall)?
(2) Then I thought back to the fond memories of ripping up oyster habitat to check out the abundance of things that consume oysters (e.g., mud crabs). Oh…the memory of that work gives me a warm and fuzzy feeling; I bet Tanya, Hanna, Linda and everyone else that helped feel the same way! How do the abundances of these things change across latitude? Are there larger crabs up north or down south? How does the mud crab picture mesh with the predatory fish picture?
This spat stick is made of calcium carbonate, the same substance as oyster shell, and is ridged to simulate the ridges in those shells. That makes it an attractive landing spot for oyster spat (larval oysters), which tend to settle on oyster shells.
(3) Working our way down the food web and sticking with the oyster samples we ripped up back in August, how do oyster densities and oyster size change across latitude and how do these patterns mesh with the mudcrab and predatory fish data?
(4) Finally, I wanted to revisit the data from our instrumentation to see how temperature and salinity changed across latitude and with season, as well as the data from our spat sticks to see how oyster recruitment differed.
It’s pretty amazing that six months of work can be summarized so quickly into four topics. Well, I kept hitting the coffee and got all of these data worked up in time for the first portion of our oyster summit. Surprisingly, all inbound flights arrived on time and we all assembled last Friday to go over the data. I’ll briefly lift the research curtain to illustrate what our data looked like:
The Georgia reef gill nets trapped a lot of sharks. Here Dr. Jeb Byers is removing blue crabs (also an oyster reef predator) from shark bellies. The trapping done on these reefs is clarifying the food web for these habitats.
(1) Although we predicted predator abundance to increase at lower latitudes, predator abundance and the number of different predators peaked in Georgia/South Carolina. This is because lots of the species we have in Florida were also in Georgia. And, Georgia has lots of sharks! Needless to say, Jeb’s crew has been the busiest during gillnet sampling. Jon and Mike’s crew have had it pretty easy (no offense)! The workload reduced for everyone in the fall, but the differences across latitude stayed relatively the same. The really cool result was the pattern that hardhead catfish are extremely important and the most abundant predatory fish on Florida reefs; I love those slimy things.
(2) Interestingly, mudcrab biomass peaked up north where predatory fishes were less abundant.
(3) And the abundance of large, market size oysters was highest where predatory fish were most abundant (GA/SC).
(4) Amazingly, we all did a good job selecting oyster reefs with equivalent salinities (this can vary a lot just within one estuary) and temperature was the same across all of our sites until December….instrumentation up north got covered in ice! Glad I was assigned the relatively tropical reefs in Florida. Finally, oyster recruitment in NC and Florida appears to proceed at a trickle while that of GA/SC is a flood-like situation during the summer.
A month after first being deployed, Tanya and Hanna inspect an Alligator Harbor tile. You can see that some of the oysters have definitely started growing, but also that some of the spat became unglued. When they run the experiment again, they'll use a different adhesive more suitable for a marine environment.
After we all soaked that in, we then talked about the tile experiment. While these data were really cool (mortality presumably due to mudcrabs was lowest where predatory fish were most abundant = GA), we worried about being able to tease apart the effects of flow, sedimentation, and predation. Unfortunately, this experiment seems to uphold my record with experiments: they never work the first time. We’ll probably repeat this in fall of 2011 with a much better design to account for flow and sedimentation.
Before breaking for a nice communal dinner at my place, Mike summarized the nutrient cycling (sediment) data that we have been collecting. In short, having lots of living oysters really promotes de-nitrification processes and our sampling picked this up.
Putting this all together, it looks like there are latitudinal patterns in fish predators that may result in mudcrab density and size patterns. Together, these may help account for latitudinal patterns in oysters (highest in GA). This all matters because more oysters = more denitrification = healthier estuarine waters.
END DAY 1
On day 2 of the summit, we worked through what made us happy about the monitoring data, what things we could add on to make us happier, and that we should continue this monitoring through the summer of 2011. This actually took all morning.
On day 2, the oyster summit moved into the more comfortable location of the Marine Lab guest house.
After a quick lunch break, we then reconvened in another room with a better view (nice to change up the scenery) to go over how we should experimentally test the linkages I mentioned above. This is where the saw blade of productivity met a strong wood knot. Personally, I became horribly confused, fatigued and was utterly useless. This resulted in lots of disagreement on how to proceed and possibly a few ruffled feathers. But nothing that some good food and NFL playoff football couldn’t cure.
After taking in a beautiful winter sunset over the waters off the lab, we ditched the work and began rehashing old and funny stories about each other.
Amazingly, we awoke the next morning and fashioned together a great experimental design that we will implement beginning June 2011. To Jeb’s disappointment, this will not involve large sharks, but we will get to play with catfish!
But now it’s time to prepare for our winter fish and crab sampling. It will be interesting to see what uses these reefs during the dark and cold of winter!
Thanks for following us during 2010, and please stick around for 2011 as I’m sure things will get really interesting as we prepare for our large field experiment.
David’s research is funded by the National Science Foundation.
In keeping with all of the other end-of-year top 10 lists, I’ll wrap up 2010 with my own observations and highlights from In the Grass –
10. No tarballs – yet??
The over-riding event of the 2010 research season was undoubtedly the Deepwater Horizon oil spill. (In fact, that was the impetus for the start of this blog!) Early in the summer, I thought our marsh field sites in St. Joseph Bay were doomed to be covered in oil. I am very relieved to say that is not the case – there are no visible signs of oil at our sites. It’s too soon to say we’re in the clear, because there is still a lot of oil that is unaccounted for, and there could certainly be “invisible” traces only detectable by laboratory analyses. However, we’re in much better shape than I would have predicted back when this all began, and that’s as good a way as any to start a new year!
Members of Team Hughes surveying the marsh.
9. It takes a lot of people to conduct scientific research.
I had a lot of help over the course of the last year – Team Hughes consisted of (in no particular order) Robyn Zerebecki, Ryan Corley, Emily Field, Althea Moore, Liz Hibner, Kristin Berger, Michele Sosa, Prathyusha Pamidi, and AJ Gelin, and we often enlisted members of Team Kimbro as well.
But even that list does not really represent all of the many people who help to get the work done. There are friends and family (thanks, Mom!) that get roped into helping when no one else is available. In addition, there’s an entire staff here at the FSU Coastal and Marine Lab who see to it that we have all the necessary paperwork complete, decks and tables for our experiments at the lab, seawater flowing to our tanks, irrigation systems in the greenhouse, boats and vehicles to get to our sites, and any number of other odd requests that we come up with. They don’t get nearly enough recognition for the critical role that they play!
8. It’s not as scary as I thought to have a camera documenting my every move in the field.
Field work is neither glamorous nor graceful, so I was a bit worried when we started this blog about having goof-ups documented on video. Thanks to the great work of Rob and his team, it’s actually been quite fun! I hardly even notice their presence when we’re in the field, and I love having so many good photos of critters and field sites, since I’m notoriously bad about taking pictures. Most importantly from my perspective, Rob has a great eye for what is important to include (the science, and the people and process behind the science) and what is not (my team and me clumsily getting out of our kayaks, which never fails to look silly!).
Lightning whelks grace many of the habitats studied by Randall and David.
7. Marine plants and invertebrates are really cool.
Ok, this observation has nothing in particular to do with 2010, but I have to put in a plug for the amazing critters that don’t immediately come to mind when you think of charismatic marine animals. I’m talking snails, crown conchs, fiddler crabs, sea hares – all the little guys – and the habitats they live in – salt marshes, seagrass beds, and oyster reefs. Even nondescript sand bars are amazing. I was out last week with Cristina, a visiting researcher in David’s lab, on a sand bar near FSUCML. We found all sorts of large predatory snails (horse conchs, tulip snails, lightning whelks) as well as tons of sand dollars, clams, and worms. Just walking around, looking at, and counting these critters made for one of my most fun field excursions in recent memory. (It didn’t hurt that it wasn’t freezing cold.)
6. Sometimes things are hiding in plain sight.
When Dr. Ed Proffitt visited in the fall, I told him that I thought I may be able to find a spot in St. Joe Bay with 1 or 2 black mangroves for us to look at. Turns out, it’s harder to find a spot that does NOT have 1 or 2 black mangroves! I’m really interested to follow their abundance over the next few years to learn more about their response to climate change and their potential impacts on salt marsh systems in this region.
5. Going out on the reef is pretty fun, too.
Though I spend most of my time in the salt marsh, it was fun to return to oyster reefs this fall to collaborate with David, his team, and our more distant collaborators. A lot of the more mobile animal species in the marsh are also found on the reef (crown conchs, blue crabs), which is a reminder that we shouldn’t treat these different habitats in isolation of one another.
Snails climbing on cordgrass reproductive stems in the field.
4. Snails are more complicated than you think.
It seems pretty straightforward – periwinkle snails climb on cordgrass to escape their predators and consume dead leaves / stems. Except that sometimes they prefer to climb on plants that they apparently don’t eat. And sometimes they create razor-like cuts in live cordgrass and graze the fungus that colonizes the resulting scar. And sometimes they climb up the plant but don’t eat anything, waiting instead until the water retreats and they can return to the sediment surface to consume plant litter…
On a related note, for Christmas my parents gave me the wonderful book The Sound of a Wild Snail Eating. The author, Elisabeth Tova Bailey, provides a compelling account of the delightfulness and intrigue of snails.
Grasshopper grazing damage on a cordgrass stem
3. Grasshoppers eat a lot.
Snails are really abundant in the marsh, and because they don’t move very quickly, it’s impossible not to notice them and wonder about their effects. However, there’s a whole suite of bugs that don’t stay put long enough to be counted as easily (unless of course you suck them into a bug vacuum or catch them in a sweep net), grasshoppers being key among them. Our tank experiments show that the grasshoppers can consume lots of living plant material in a short period of time, serving as a useful reminder that I should wonder about the things I don’t see as much as those I do see.
2. It’s fun to do science with friends.
A recent study indicated that scientific collaborations have a greater impact if the researchers work in close physical proximity to one another. I don’t doubt the results – who doesn’t find it easier to reach a consensus in person than over a Skype conference call? However, I’m happy to be working with David, Jon, Jeb, and Mike “on the reef” despite the geographic distance. Not only are they the right people in terms of research expertise, but our shared history makes it easier to communicate (including to give each other a hard time!).
Rainbow over St. Joe Bay on Christmas Day 2010 (photo credit: L. Hughes)
1. Did I mention that my research sites are not covered in oil? Hooray!
Best wishes in 2011!
Randall’s research is funded by the National Science Foundation.
Emily and Hanna, in matching green waders, vacuum bugs on "Island 4."
It has been COLD the last few times we’ve been out in the field. The first time (described accurately by Rob), we did not have sufficient cold weather field gear – David lent us some emergency use chest waders that he had on hand, and they were much appreciated despite the fact that we looked really silly and they were all split open at the feet by the end of the day!
Immediately upon my return to the lab, I ordered my team the trusty neoprene chest waders that I used throughout graduate school in northern California. As Emily and I can attest after going out twice more in the cold since then, they make a big difference!
Newly purchased neoprene waders and fingerless gloves for winter field work.
Aside from the change in attire, what else is different in the cold? Most obvious is that many of the cordgrass stems in our survey plots are dead. In marshes north of here, the above-ground portions of the plant will actually die back completely in the winter, re-sprouting from below-ground reserves in the spring. Here, there are fewer stems overall, and certainly fewer bright green live ones, but the plants will continue to slowly put up new stems throughout the winter.
The photos above are of Island 4 over the course of WFSU's documenting this work. The photo on the left is from May 13. The one in the center was taken at the end of Summer. You can see the grass is taller and more verdant, with cordgrass reproductive shoots popping up over the blades. The last photo is from the first of December.
The cordgrass reproductive stems are also now dead – most of them dropped their seeds in late November / early December, so they have done their job. Emily and I made a special trip to all of our survey sites a week or so ago to set out “seed traps”. And what, exactly, is a seed trap? In this case, it’s a Styrofoam bowl lined with Tanglefoot, the incredibly sticky substance that we use on our mesocosms to keep snails from climbing out.
Any seeds (or seagrass wrack, other plant material, bugs, or anything else, really) that fall into the bowl will stick, allowing us to count the number of seeds that get to each area. We are particularly interested in whether seagrass wrack abundance increases or decreases the number of seeds in an area. We’ll go back in January to pick them up and start counting.
We have some plants in the greenhouse that we’re growing for experiments this spring, and they have been getting a little extra TLC on these cold, cold nights. We cover them with frost blankets at the end of the day, and then uncover them again in the mornings when it’s warmed up a bit. They seem to like the extra warmth!
Our greenhouse tables covered in (appropriately) green frost blankets on cold winter nights.
From a logistics perspective, the winter is pretty different for a number of reasons. First, it’s harder to find people available to go in the field. (And on really cold days, it’s not very appealing!) Emily will be back on campus taking and teaching classes next semester, so we’ll probably have to do some portion of the monthly surveys over the weekend, hopefully with the help of some undergraduate interns.
Looks like we're walking.
The second logistical challenge is the change in the tides. For most of the year, the low tide is in the evening / night, so it is easiest to kayak to our sites during the morning and early afternoon. In the winter, the low tide shifts to the middle of the day, and it’s often made even lower by a strong north wind, making it virtually impossible to kayak anywhere during daylight hours!
Our solution is to walk to the sites that we can, and kayak as close as we can to the others before we start walking. It’s a good thing that St. Joe Bay is shallow!
In January, we’ll be sampling fishes and small crabs in the marsh. We do this every couple of months to see how the abundance of the more mobile marsh community members changes seasonally. I don’t expect that we’ll find much, but I’ll let you know!
Randall’s research is funded by the National Science Foundation.
I was driving to Stump Hole with my production assistant Kevin when we saw these waves crashing on the rocks on the beach side of Cape San Blas. Like any good production people, we knew the only thing to do was to climb the rocks and get footage and stills of the scene. The same wind pushing the waves at us rocked us a little bit as we balanced- only slightly precariously- on the big stones. It was a little after 8:30 AM and we had some time to kill before Randall and her team showed up. And then we would kayak into the bay just across the street.
In early December I made my first winter forays into coastal environments. Randall has already written about the seasonal shift from Summer to Autumn, where the flora and fauna are reproducing and animals are abundant in the marshes. Winter is an entirely different beast, as I would see when we got to their sites. But first, we actually had to get to these sites.
After everyone was there, we kayaked east from Stump Hole with a stiff north wind pushing us on our left. Rowing to the left was like rowing into a wall, and there were a couple of marshes in our way where we had to get out and lug the kayaks to the other side. Saltwater splashed into my eyes and onto my glasses. I kept my squinty eyes forward and we got to a site that for the purposes of this study is known as Island 4.
The research crew went about their normal survey work, with Randall taking a quadrat to several specific spots within the marsh to see how much grass and other species were within its PVC boundary, how tall the grass is and how many Spartina shoots were dead. Using markers and a GPS, they’ll have data from these precise spots over a span of three years. Emily and Hanna vacuumed bugs out of the grass and surveyed seagrass wrack. They will, as always, search for patterns over time, and I suspect the data collected in the winter months will quantify some of what we saw with our own eyes.
While we didn't see the usual critters swimming and crawling about, some cool stuff washed in from the bay, such as sponges, lightning whelk egg casings, and this sea urchin shell.
Last time I was at this site, some male blue crabs were fighting over a female. They were so engrossed that I was able to get fairly close without their bolting away. All manner of predatory snails oozed about, little fish darted in and out of the sparse shoots at the periphery, and a ray laid low in an adjacent seagrass bed. Today it looked like they had all packed up and left for the season. And, when it came time to go our next site, so had the water in the bay.
A combination of the tide and the strong wind left the south side of the bay somewhat empty. Taking a few steps with our kayaks in hand, we decided instead to leave them at the island while we walked our gear over to a mainland marsh known as Wrack 5.
This was another site where I had always seen an abundance of fauna. Hundreds, sometimes thousands of fiddler crabs would scurry away from me into the grass in this one corner of the marsh. As Randall explained to me, the fiddlers bury themselves in the winter. Blue crabs swim into the deeper part of the bay, to the north. Randall didn’t know exactly what happened to the crown conchs, though when digging cordgrass up for an experiment she had come upon a buried conch. And with their predators all gone, the marsh periwinkles had descended to the bottom of the spartina plants.
One thing I did see a lot of were lightning whelk shells. I picked them up and looked inside, wondering, are they more cold tolerant than the other species? They’re not. But their shells were pretty.
The following Monday I went to Alligator Harbor with Tanya and Hanna, and it was a lot of the same. We dragged our kayaks from the ramp to the first site and walked between the islands to the second and third sites. It was a much muckier walk than in St. Joe Bay (the oysters like it mucky), and I was breaking in a new pair of crappy old sneakers to be my oyster reef shoes. This is how they fared:
Now that I’ve muddied my hands pulling my shoe out, where’s all that water?
You’ve heard about research from a lab tech’s perspective from Tanya, and from a Principle Investigator (PI)’s perspective from Randall and David, so I thought I’d give you a graduate student’s insight. Being a grad student is kind of like being a mash-up of a tech, a student, and a PI: you do a lot of the “dirty work,” but you also have to be able to direct other students and manage your own research. You’re taking classes, but you’re also teaching. You’re writing grant proposals for future projects, but you’re also trying to figure out how to analyze data from past projects. And while this might sound hectic enough to create split personalities, I love it! I get to develop my own projects, take challenging and interesting classes, and help Randall with her projects. In fact, my favorite thing about work is that it’s such a tumbled mix of things: my time is split between the lab, field, classroom, and desk. Life as a grad student is never boring!
Emily and Robyn getting gear ready to collect porewater samples.
I moved to Florida in May 2009, right after graduating from University of Rhode Island, and worked for Randall as a tech before starting school in the fall. It was a great way to familiarize myself with the system and learn appropriate sampling techniques for the area. I came in thinking that I wanted to work with epiphytes (small seaweeds that grow on other plants/seaweed) on seagrass. I did develop a project working with Chris Stallings on his huge Big Bend survey looking at the epiphytes throughout the region, but as I was working for Randall, I became more and more interested in developing my own project in the salt marsh. I am now studying the effects of wrack in the marsh. The epiphyte project is ongoing, and a marine certificate student, Michele Sosa, took over the project this summer so that I would have more time to develop my wrack research.
I think that is one thing I’ve learned as a grad student: there’s so much you could do, that it can be hard at first to pick one thing to develop into an interesting and informative project. If you’re not careful, you might end up with a bunch of semi-related “side projects.” I definitely owe Randall a lot for helping me stay focused and develop a clear project with a solid theoretical basis. As Tanya said, when there is a lot of work to do, it’s easy to get bogged down in the details and forget the big picture –which you definitely can’t do when you’re in charge of the project!
Dr. Randall Hughes and Emily Field.
The other trick to grad school is balance, which can have a steep learning curve! One of the first things they tell you when you enter school as a graduate student is that you’re expected to work 60 hours a week: 20 on your coursework, 20 on teaching or your advisor’s research (depending on what you’re being paid for), and 20 on your own research. Of course, every week does not break down into this perfect division, but I think the main point to remember is to balance all of your responsibilities. Which is much, much easier said than done. As I’m writing this post, I’m thinking about the various other tasks I should probably be doing. My bugs need sorting, that paper needs reading, those buckets need mending… the list goes on. But, hey, I knew what I signed up for when I decided to go to grad school. I was warned. However, if you ever see me talking to myself, do me a favor and send for the nice men in the white coats?
Emily and Robyn setting up yet another tank experiment that I've dreamed up. (Thanks to Nancy Smith for the pic!)
Because of the big focus on oysters over the last month, it may seem as if we haven’t been doing anything “In the grass”. We’ve been busy, though, trying to squeeze in a few additional surveys and experiments in November before it gets cold enough that the animals stop eating (or eating very much, I should say) and the plants stop growing. For a while there, I was coming up with so many end of season ideas that I’m pretty sure my crew hated to see me coming! We just did finish up before the winter weather arrived (early) in December. (More on what it’s like working in this cold weather in future posts.)
We actually missed the opportunity to do one of our planned studies involving grasshoppers – there was a cold snap two nights before we went in the field to get the hoppers, and they were nowhere to be found. Those data will have to wait until next spring when the grasshoppers turn up again!
Snails climbing on cordgrass reproductive stems in the field.
A tasty snack for a periwinkle snail?
I’ve mentioned before on the blog that we noticed lots of snails climbing on cordgrass reproductive stems this fall. In collaboration with David and his team, we visited marsh sites along the Panhandle to see if our observations would be supported with rigorously collected data. So far, so good!
The trusty tank set-up at FSUCML.
We also started a series of experiments in our trusty tanks at the FSU marine lab to tease apart why snails may have this preference: Do the snails simply like that the reproductive stems are taller than regular stems? Or do the reproductive stems “taste” better because of greater nutrient content? Does it matter if predators are present or not? The preliminary results suggest that they like the reproductive stems, regardless of whether they are taller or not. In January, we’ll head into the lab to do the tests for nutrient content that should help us to tease apart why that may be.
2. Does needlerush provide a better predation refuge than cordgrass?
Needlerush (center patch) is typically much taller than cordgrass (surrounding area) in St. Joe Bay
Last fall I did a tank experiment to look at whether snails prefer to climb on another marsh plant species, needlerush (Juncus roemerianus), and whether this preference increased snail survival when predators were around. The results were interesting, but as usual, the first round of the experiment created additional questions that required more work. In November we started a similar experiment, again in the tanks at the marine lab, looking at snail climbing behavior on needlerush and cordgrass in the presence and absence of the snail’s nemesis, the blue crab.
Needlerush is naturally taller than cordgrass, so to test if this difference in height can explain snail behavior, we “experimentally manipulated” (in other words, used scissors to cut the needlerush down to a shorter height) needlerush height: some tanks have naturally tall needlerush, some have needlerush that is on average the same height as the cordgrass, and some have needlerush that is shorter than the cordgrass. Add a blue crab to half of the tanks, and voilà, the experiment is underway!
It’s a bit ironic that each of the experiments we recently finished converged on a similar idea – snails appear to prefer to climb on taller plants. Considering that the taller the plant, the farther they can climb away from predators in the water, it makes sense. The true question is to figure out whether and why it matters that the snails do this. If they climb on reproductive stems, are fewer cordgrass seeds produced? What will that mean for next year’s crop of cordgrass? Also, if snails spend a lot of time hanging out on needlerush to avoid predators, does that mean they don’t eat as much cordgrass? Knowing things as seemingly arcane as which plant a snail prefers to climb on can help us predict and manage the overall abundance and productivity of cordgrass, and the salt marsh in general. And of course, the field work and experiments are fun! Especially when you get to wrestle with blue crabs…
Here are some photos of periwinkle snails in Randall’s latest tank experiments:
Randall’s research is funded by the National Science Foundation.
This week’s videos look at Dr. David’s Kimbro’s collaborators in the NSF funded biogeographic oyster study. While he has been the face of the study for On the Reef, he is one member of a team of scientists. Today’s videos feature Dr. Randall Hughes (In the Grass) and Dr. Jon Grabowski. Later this week, we’ll have a short video with Dr. Jeb Byers. Randall and David’s posts accompanying the videos are reminiscences on their early days in marine ecology in North Carolina, where they and their fellow team members met while in school.
Dr. Randall Hughes FSU Coastal & Marine Lab
Getting my first taste of marine ecology.
In my last semester as an undergraduate at the University of North Carolina-Chapel Hill, I took a class in marine ecology from Dr. Charles (Pete) Peterson and Dr. Mark Hay.
At the time, I was a double major in biology and public policy analysis, and despite being just a few months from graduation, I was still very uncertain what I was going to do next. So when Pete asked me if I would like to work as a summer research assistant at UNC’s Institute of Marine Sciences for his graduate student, Jon Grabowski, I accepted with little idea of what I was getting myself into.
Jon’s project involved comparing the value of restored oyster reefs in different locations in the marsh (next to marsh edges, sandwiched between marsh edges and seagrass beds, or isolated on sand flats) as habitat for important fishes and crabs. What that meant in reality was that in the summer of 1997, we used ~2 tons of dead oyster shell to create 12 intertidal oyster reefs in Middle Marsh, NC – largely by carrying the shell in orange baskets from one big pile to the specific places where we needed it.
One of the reefs we built in 1997 on a sand flat, pictured here in 2002.
In the process, I learned to trailer and drive a boat, build 30+ fish traps that involved welding rebar together and dipping the whole contraption in “net dip” (the most disgusting substance known to man), deploy and retrieve those traps and happily (well, at least begrudgingly) handle the blue crabs, toadfish, and other critters that we caught, and various other tasks that made my parents wonder why I needed a B.A. degree for this job. But by the end of the summer, I was hooked!
Jon, before he was Dr. Grabowski.
After that first summer, I returned to work with Jon for 3 more field seasons until starting graduate school myself in 2000. (David and my paths crossed at IMS, working for Jon together in 1999.) During the “off-season” I taught school, first in Mexico and then in NC, because I wanted to be sure that becoming an ecologist was really the thing for me. I love teaching, but I love research even more, and so going to graduate school seemed the logical way to combine the two.
Much like the no-see-um story from Jacksonville, the long hours and hard work involved with Jon’s project generated a lore surrounding that first (and subsequent) years. Here’s just one of my favorite stories from the summer of 1997 –
Dr. Pete Peterson in Middle Marsh, NC.
Once the reefs were created (and lots of stories could be told about that process), the plan was to sample them once a month over consecutive daytime and nighttime high tides. Because we couldn’t sample all of the sites at the same time, this involved 48 hours of effort with only short breaks in between times in the field. The first time attempting this sampling happened to fall the 2 days before I was scheduled to leave to start my job teaching in Mexico – oh, and on my birthday. After day 1, we realized that returning to the lab from our field sites and then going home to get cleaned up before getting some rest was burning lots of valuable sleep time, so we decided that the second night we would camp on one of the barrier islands close to our sites. Jon packed most of the gear, including a giant and heavy cooler, and off we went. Of course, it was the middle of the night when we finished up in the field and drove the boat over to Shackelford Island, and we hadn’t bothered to set up camp earlier in the day. Jon thought he knew of a shortcut to cross over to the ocean side, which had a nice breeze and far fewer mosquitos. Unfortunately, we didn’t find the shortcut immediately, and we ended up carrying the heavy cooler and all of our other gear while swatting and cursing mosquitos for quite a while. About 5 minutes from the beach side of the island (though we didn’t know that at the time), I snapped, announcing to Jon that I was NOT walking any farther and so we better set up camp in that spot. (I had maintained a fairly mild-mannered and easy-going persona all summer, but there was nothing mild about my ultimatum that we stop walking.) I was in better spirits after a few hours of sleep, feeling more than a little chagrined at my outburst when I realized how close we were to the beach, and especially when learned that the primary object in that heavy cooler was a chocolate birthday cake for me! I have since apologized many times, and Jon and I laugh and re-tell that story virtually every time we get together.
Of course, beyond the friendships, funny stories, hard work, and good food, we also learned a heck of a lot about oyster reefs and the animals that live on and around them. That’s why our current collaboration “On the Reef” is so satisfying – it’s a way to return to our roots scientifically, professionally, and personally.
The biogeographic oyster study is funded by the National Science Foundation.
(Editor’s Note. Although David refers to Randall’s participation on this study, her role was not elaborated upon in this video. That will be a part of the next video, on David’s collaborators, as Randall is David’s Co-PI- or Primary Investigator)
Tanya measures a fish caught in a gill net.
It’s been said that research techs are those who do the dirty work in science. Although true in many ways, I love being where the action is, collecting the data, turning ideas into reality. That said, here is some of my perspective on what went into our October trip and what days in the field were like.
A busy field trip like our October sampling push typically takes at least as many days to prepare for as the length of the trip itself. Although the daily blog posts covered our time in action, David and I spent most of the previous couple weeks just planning for this trip so that it could run as smoothly as it did. I feel it worth mentioning the many hours I spent pouring over tide charts and editing and re-editing our complicated schedule so that we could accomplish everything as efficiently as possible, factoring in all manner of time and tidal constraints, travel time, land and sea transportation, overnight stays, and numerous other variables, plus designing it with enough flexibility that we could adjust our plans in the field at a moments notice (and indeed we did). In addition to scheduling I also had to make sure we had all the materials we needed to for our trip, that those materials were all in working order, and that they are all packaged up accordingly and conveniently in our two vehicles. The last thing you want is to be out in the field and realize you’re missing some critical piece of equipment.
As they conduct these initial sampling trips every few months, they keep finding new and interesting species living in and around the reefs. Here, Tanya is taking measurement of one of her favorite finds of this last trip, a striped burrfish.
Out in the field, going to retrieve our traps and nets is always the most exciting for me, since you never know what we’re going to catch, and I was interested to see how the October fish community compared with that of July. We caught a few new fish species in our traps this round, including a beautiful spotfin butterflyfish (Chaetodon ocellatus), juvenile snapper (Lutjanus sp.), and a couple tiny pufferfish (technically striped burrfish, Chilomycterus schoepfi – they were very adorable). Equally exciting was getting to use the new motor on our skiff for the first time at our sites. Although noisy and bizarre-looking, it performed admirably in shallow water, as it was designed to. At least in terms of temperature and humidity, conditions on the reefs were considerably more pleasant for us than during the summer. It was wonderful not to be wiping sweat from your face every 10 minutes. The dramatic increase in the no-see-um population at dawn and dusk was not so pleasant however, as David has duly noted. The dawn low tide at Jacksonville brought the worst swarms we’d ever encountered in the field. Incredibly irritating both physically and mentally, they made work nearly impossible, and forced me to spend the subsequent week covered in uncountable numbers of ravenously itchy welts.
Despite its exotic look, the spotfin butterfly fish is a native of both the Gulf and Atlantic coasts of Florida.
When not out on the reefs, there was rarely a moment when something didn’t need to be done – whether filtering water samples, rinsing gear, or (most frequently) extracting spat. Our only breaks seemed to be for the necessities of eating, showering, sleeping, and making coffee. (For David, coffee appears to rank just below data and samples in terms of his most valued possessions in the field.) Our biggest and most time-consuming challenge was whether we could get all of the spat extracted and tiles made for our predator-exclusion experiment in the time allotted between netting and trapping. The process of isolating spat was incredibly tedious to say the least, and particularly frustrating when, after you’ve been working on a spat for several minutes, your tool slips and the spat gets crushed, or it flies across the patio, never to be seen again. You couldn’t help but feel the spat always picked the most inconvenient places to settle. It was also quite a messy process, with water and oyster bits flying everywhere and various crabs skittering across the counter. The oysters also love to slice your fingers open during the few moments when you neglect to wear gloves. Yet in spite of the tedium, we couldn’t help noticing new and interesting critters living amongst the oysters as we broke them apart. For instance, we noticed considerably more porcelain crabs (Petrolisthes sp.) and Boonea impressa (a small, white snail that parasitizes oysters) than we’d seen in previously collected oyster samples. We also found an oyster pea crab (Pinnotheres ostreum), which lives on and steals food from the gills of oysters, and a number of dark brown cylindrical mussels (Lithophaga bisulcata) that bore into the calcareous shells of oysters. It always amazes me how many different animals can be found living within the structurally complex habitat created by species like oysters.
Young oyster spat, beginning their new careers in science.
I remember on one of the last days of our trip, I kayaked out to our St. Augustine reefs for a final service and check while David finished up the dremeling. I remember looking upon reef #5, seeing our newly deployed, spat-covered tiles and cages, our cleaned tidal data logger housing, and our newly replaced spat stick, arranged so neatly on our marked reef, and feeling delighted at our accomplishment, knowing how much effort has gone into this setup. I remembered that in my position it’s easy to get sucked into the details, but it’s equally important to remember the big picture, and how this research will contribute to our greater understanding of oyster reef ecology.
After our field trip, as we recover from battle wounds and wait for the mud to work its way out from under our fingernails, work on the oyster project continues at the lab. For me this has meant entering lots of data and starting to process our many samples. Before you know it though, it’s time to start to preparing for our next journey onto the reefs and the adventures that await.
The Kimbro, Hughes, et al. biogeographic oyster study is funded by the National Science Foundation.
The following is the first of three or so videos on the big October oyster trip. In this one, you get a long busy day in the field condensed into two minutes (it’s much less exhausting that way). We’ll have videos in the next couple of weeks on David’s co-collaborators (including video of the Georgia/ S. Carolina team and all the sharks they caught) and a video on David’s own team.
The "October Oyster Push" had many objectives, but none took as much time to implement than the tile experiment. Seeing how these baby oysters- spat- grow over the next few months will give David an idea how oysters typically fare at each reef over the course of their lives.
I spent most of this past week feeling pretty darn good about having just finished our October sampling and experimental objectives out on the oyster reefs. Of course, this glow continued into the weekend as my football team pulled out a W in Tallahassee.
But back to the science. Although Rob chronicled each day of our crazy road trip, I want to relive it once more just to give the trip from my perspective. So, here are my top-ten thoughts:
Number 1: Planning the details of the road trip (housing, which team is going where and when) as well as figuring out how to set up the tile experiment (see video) was pretty stressful. Thank goodness I had Tanya around to bounce scheduling ideas off of. Because I kept chaning my mind, I think Tanya made like 6 different versions of our schedule.
Number 2: I talked the NC and SC/GA teams into doing the aforementioned experiment with oyster spat to examine how actual predation and the fear of being eaten affects oysters up and down the coast. I successfully convinced the teams partly because I emphatically claimed that the additional work load would only be five hours of more work at each site. Well, I got that wrong. It was probably triple that estimate. That’s one of my flaws: I always underestimate how long research tasks take, which is bad because you constantly feel behind as a result of being over-scheduling. Rule of thumb: always multiply my work estimates by at least 2.
Number 3: I never want to see a dremel again. With dremel in hand one evening at Saint Augustine, I had only extracted ¼ the spat I needed for the experiment but the time spent on this task had already surpassed my previous estimate. That’s when coffee and the ability to lose yourself in the task become extremely important. I guess I took it one oyster spat at a time.
(L to R) Tanya, Hanna, and Cristina pick up the slack while David dremels away back at the lab space.
Number 4: I could not have lost myself in the task of setting up the experiment if it hadn’t been for Tanya, Hanna and Cristina. Knowing that they were fully trained to carry out the sampling objectives, I did not have to busy myself with those numerous tasks, such as setting gill nets and traps (and retrieving the catch), taking sediment and water samples, etc. In fact, after finishing the sampling objectives and follow-up lab work, they would immediately begin helping me with the experiment by cleaning adult oysters and identifying spat for me to extract with the dremel. With that help, I was able to focus solely on dremeling.
Number 5: Dremeling 1080 spat out of adult oyster shell stinks. Did I already say that? Well, this task deserves two spots on the top-ten list. In tact, I probably attempted to extract over 2,000 oysters because I would often slip with the dremel and accidentally kill the oyster spat that I had spent five or so minutes on.
Hardhead and sail catfish seem to be the dominant predator of the Florida Gulf sites. By eating mud crabs that predate oysters, these fish perform an important function on oyster reefs.
Number 6: we couldn’t have asked for better weather. In fact, I think there were some temperature records being set. Despite these warmer than usual temperatures, there was about ½ the diversity and number of predatory fish on our reefs. So, going against my expectations, these Florida sites are experiencing some seasonality in the assemblage of predators. Interestingly, all teams were catching red drum on their reefs; guess it’s their time of year. The red drum mostly had smaller fish in their stomachs. The SC/GA team was still catching lots of sharks. And catfish was still the most abundant predator on our reefs. Those slimy things are definitely major players on southern oyster reefs because they had lost of mud crabs (who eat oysters) in their guts. Final detail about the Florida sites is that my northern locations (Alligator Harbor on Gulf and Jacksonville area on Atlantic) had more predatory fishes than did the more southern sites in Florida…. intriguing.
Number 7: We had to change plans at the end of the week and this mid-course change actually went smoothly. This change came about because the housing space near our Jacksonville site was not conducive for setting up the tile experiment. Luckily, Hanna and Cristina ventured up to Jacksonville to figure all of this out for me. This “divide and conquer” strategy allowed Tanya and me to finish up the sampling and experimental objectives in Saint Augustine, while Hanna and Cristina began sampling in Jacksonville to keep us on schedule. And rather than resting up in Jacksonville, Hanna and Cristina ripped up oyster habitat and drove it back down to Saint Augustine. They looked pretty rough upon that later return to Jacksonville. But after a good dinner and a few hours of sleep, their oyster delivery allowed us to work on the materials for the Jacksonville experiment in a much better laboratory setting.
Number 8: Team morale and will to finish objectives hit a low point once we reached Jacksonville. The lodging for the first evening was haunted with cockroaches: this is Hanna’s kryptonite. Luckily, Tanya whipped us up some good pasta to help keep our minds off of the roaches. The next morning, cockroaches began to seem not so bad. When we got to the boat-launch and found there to be no wind, I knew it was trouble because this site had the reputation for being particularly buggy. So, we headed into the mouth of our creek and hit the first reef. Not too bad… actually, no fish in the nets. Only a few bugs and two free hands to swipe them away. But as we ventured further into the belly of the creek/bug hell and found tons of fish in our nets, I began to worry about mutiny. As I was exhorting the crew to extract tons of fish from the next set of nets, I realized that freeing this many fish would take twice as long because we needed to spend an equal amount of time cursing the no-see’ums and keep them out of our ears and noses; kind of hard to do with fish in your hands. While taking fire from the no-see’ums, we then began sustaining additional injuries from other natural agents. I suffered my first good-sized oyster cut. Hanna got her finger nearly cut off by a large stone crab. For the pain finale, a decent sized catfish stabbed my hand with the barb of its dorsal fin. I don’t blame it, but daggum that hurt. At this point, the unpleasantness was almost comical. Note to self: buy hats with bug nets to combat no-see’ums.
Number 9: All of the pain and stress of that week is now good fodder for the lab to laugh about and bond over. That’s one of the perks of conducting research as a team. And that’s one of the reasons why Big Jon, Randall and I are still collaborating.
David walks away from the tiles he and his team spent so much time putting together. He won't know how successful the experiment was until he travels back to these sites.
Number 10: Now that we have all caught up on sleep, have relived our stories, and have begun to look at the data, I now stress about whether the tile experiment will actually work. Like most experiments I conduct, I put a lot of effort into something that has a 50% chance of not succeeding. For example, the spat that I extracted and adhered to tiles may have been overheated by the dremel/extraction process…are they dead already? And then, oh boy…what if the glue doesn’t hold? That’s what really keeps me up at night.