Tag Archives: oyster spat


Tile 2.0- Perfecting the Oyster Spat Tile Experiment

As we’ve been getting this post ready, David’s Apalach crew (Hanna, Stephanie, and Shawn) has begun deploying the experiment featured in the video above in Apalachicola Bay.  After years of perfecting it, the tile experiment has become a key tool in Randall and David’s oyster research.  As you can see, there were some headaches along the way.
If you’d like to know more about spat (young oysters), we covered that a few weeks ago in this video.
Dr. Randall Hughes FSU Coastal & Marine Lab

An “open” cage, with full predator access.

One of the primary goals of several projects in our labs involves figuring out where oysters grow and survive the best, and if they don’t survive, why not? Sounds pretty basic, and it is, but by doing this across lots of sites/environments, we can start to detect general patterns and identify important factors for oyster growth and survival that maybe we didn’t appreciate before. Our method of choice for this task is to glue the oysters to standardized tiles, place some in cages to protect them from predators, leave the rest to fend for themselves, and then put them in the field and see what happens over time.

In doing this lots and lots of times, we’ve learned who in the lab has a special knack for placing small drops of marine glue – Zspar (which you can see in the video) – on tiles, and who is better at adding the oysters so that the 2 valves of their shells don’t get glued shut. These are the sorts of crazy job skills that don’t go on a standard resume!

Any of you who have been following the blog for a while may remember the craziness of the our first NSF tile experiment (Tile 1.0) in the fall of 2010, which involved collecting lots of juvenile oysters (“spat”) that had recently settled in the field, bringing them back to the lab, and using a dremel to carefully separate that from the shell they settled on. (If you don’t remember and want to check it out, go here.)


Two of our oyster “families” in the water tables at Whitney Marine Lab

Since the Tile 1.0 experience, we’ve developed more elegant (and much simpler!) methods: we contract with an amazing aquaculturist at a FL hatchery to collect adult oysters from the field, provide just the right ambiance to make them spawn (release eggs and sperm), and then raise the oyster larvae to a perfect size for attaching to our tiles. This year, we added another twist on this theme (Tile 2.0) by collecting adult oysters from different areas in FL, GA, SC, and NC, and then spawning and raising them separately in the same hatchery under identical conditions. We refer to these different groups of oysters as “families”, because all of the spat from a given location are related to one another, but not very closely related to the oysters from a different location (who had different parents).


Evan and Tanya admiring our work after we deployed the first reef in St. Augustine.

By putting out tiles from each family at sites across this same geographic range (FL to NC), we can tell if some sites or regions are inherently better than others for oysters (for instance, as I’m currently learning first-hand, there’s a reason that everyone wants to spend the winter in FL!), or if some families are naturally better than others (think Family Feud with oysters), or if the oysters that came from a particular site do best at that site, but not in other places (like the ‘home field advantage’ that recently helped Maryland beat Duke in basketball). Whew – that was pretty mixed bag of metaphors! But you get the idea.

We’re still processing and analyzing the data from Tile 2.0, but it looks like which site is the best depends on what you’re measuring – the best place for survival is not always the best place for growth. And the different oyster families do look and “behave” differently – some grow quickly and some grow slowly, and some survive predators better than others.

Spat bred from adult oysters from Sapelo Island in Georgia (left) and ACE Basin in South Carolina (right).

Surprisingly, there doesn’t appear to be much of a home field advantage, at least from our initial analyses. And as Meagan pointed out, we’ve learned from other similar experiments for the National Park Service that it’s not just other oysters or predators that these guys have to worry about – it’s barnacles too! But there are still some ‘sweet spots’ out there for oysters, and once we’ve analyzed all of our data, we’ll have a much better sense for where those are.

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Music by Barnacled and Pitx.

In the Grass, On the Reef is funded by a grant from the National Science Foundation.


Experimental spat tiles, open, closed, and partially open.

Fear and the Choices Oysters Make

Last week, Dr. David Kimbro broke nutrients and oysters down for us.  But what if oysters are too scared to eat the nutrient fed plankton they need to survive?  David and Randall take us another step closer to understanding the Ecology of Fear, examining oysters’ choices and how their behavior affects the important habitat they create.  Stay tuned over the following weeks as they unravel the relationships between predators and prey on oyster reefs and their neighboring coastal ecosystems.  We’ll also continue to follow David’s crew in Apalachicola, Hanna and Stephanie, as they research the oyster fishery crisis.

Dr. Randall Hughes FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150I recently moved and was faced with the dilemma of finding a place to live. This can be a touch decision, especially when you’re in a new city or town. Which neighborhood has the best schools? The best coffee shop? Friendly neighbors? Low crime? My solution was to find something short-term while I scope the place out some more, and then I can decide on something more permanent. (As anyone who has me in their address book knows, “permanent” is a very relative term – I have changed residences a lot over the last 15-20 years!) But imagine you had just one shot – one, for your whole life – to decide where to settle down. Talk about a tough decision! That’s what oysters have to do, because once they settle down and glue themselves to their location of choice, they don’t have the opportunity to move around any more. So how do they decide?

This oyster shell, harvested from an intertidal St. George Island reef, had been settled by multiple young oysters called spat. Spat grow into mature oysters with a hard shell, fused with the oyster on which they originally landed. Clumps of attached oysters form a crucial coastal habitat.

It turns out that oyster larvae (baby oysters swimming in the water) can use a number of “cues” to help them in the house-hunting process. First of all, they can detect calcium carbonate, the material that makes up oyster shells (and other things) – if there’s lots of calcium carbonate in an area, that could be a good sign that it’s an oyster reef. (Or it could be a sign that people have put a lot of cement blocks in the water in the hopes that oysters will settle and create a reef – that’s how a lot of oyster restoration projects are started.) Some recent research even shows that oysters can detect the sounds of an oyster reef, and then swim in that direction! Maybe these guys are smarter than we think…

Regardless of how oysters decide, there are times when we are also faced with the question of what makes good oyster habitat, or deciding which area is better than another. As scientists, we turn to experiments. One type of experiment that we have perfected over the years involves getting juvenile oysters- (either from the field, which can be pretty difficult -as you can see from the first round of our tile experiment, or from a hatchery), and gluing them to portable sections of “reef” (ceramic tiles weighed down by bricks). LOTS of ceramic tiles and bricks. We’re talking 800+ ceramic tiles and 700+ bricks last summer alone! That’s enough to make a path that is ~2 football fields long. All moved by truck, hand, boat, hand, kayak, and hand to their temporary location on a reef (and then moved back again when the experiment is done). But I digress.

In the second incarnation of the tile experiment, oyster spat were attached to tiles with an epoxy used in the repair of boat hulls. The tiles in the first version- the ones in the video above- were assembled differently. In a video we'll premiere later this month, we'll look at the twists and turns the experiment took.

After attaching the juvenile oysters to the tiles with a lovely substance known as z-spar, we enclose some tiles in cages to protect them from oyster predators, and we leave others with no cage so they are “open” to predators. (There’s also a 3rd group – the “cage control” – that get 1/2 a cage so we can test whether the cage has effects on the oysters other than keeping out the predators.) Then we take our oyster tiles and put them out in the field at different sites that we want to test. By observing the survival and growth of the ones in the cage (where no predators have access), we can get a general sense for whether it’s a good environment or not. Lots of large, live oysters are a sign of a good environment – plenty of food, good salinity (not too salty or too fresh), good temperature, etc. Also, by comparing the survival of the ones in a cage vs. not in a cage, we can get an idea of how many predators are around – lots of live oysters in the cage and none out of the cage is a pretty good sign that oysters are getting eaten. (If oysters in the cage are dead and oysters outside of the cage are missing, it’s a little tougher to figure out exactly what’s causing it, but it’s clearly not a good place for oysters to live!)

Experimental spat tiles at the Guana Tolomato Matanzas National Estuarine Research Reserve- open, closed, and partially open.

Of course, the oysters themselves don’t know whether they are nice and safe inside our cages, or easy pickings for a predator. So if there are lots of predators lurking around the reef, the oysters may try to “hide”. Obviously, hiding for an oyster does not mean packing up and moving elsewhere, but they do have a few tools at their disposal. In the short term, the oysters can choose not to open up their shells and feed (filter water) as often. This strategy has 2 benefits – 1, they are less vulnerable to predators when their shells are closed and 2, they aren’t releasing lots of invisible chemical cues in the water when they’re closed, so it’s harder for the predators to tell they are there. But as any of you who have been sticking to your New Year’s resolution to lose weight will know, there’s only so long that you can go without eating before that strategy loses its appeal! Over the longer term, the oysters can decide to devote more of the energy that they get from eating to create a thicker, stronger, rougher shell, rather than plumping up their tissues.

So, those are the big-time decisions that an oyster faces: where to live, and when to eat. Sounds kind of familiar…

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In the Grass, On the Reef is funded by the National Science Foundation.

Pea crabs at various stages of development. The ones in the center are young crabs, as they appear in the stages immediately following infection of an oyster. The ones on the right are older, harder-carapaced crabs (most likely males, which may leave their hosts in search of oysters harboring females). The crab on the left is a mature female. The developing, orange-colored gonads are visible through the female’s thin carapace. Since mature females never leave the their host oyster, their carapaces (shells) are very soft and thin. This makes them very… squishy and pea-like.

Pea Crab Infestation!

Tanya Rogers FSU Coastal & Marine Lab

IGOR chip- biogeographic 150Serendipitous results are surely one of the most rewarding parts of experimental research. This past winter, I spent many weeks processing various frozen components of great cage experiment of last summer, including the several hundred spat tiles placed inside the different cages at all sites along the coast. It was while delicately measuring and shucking these little spat that I made one such unanticipated finding: Our oyster spat, unbeknownst to us, had become infested with pea crabs.

Pea crabs at various stages of development. The ones in the center are young crabs, as they appear in the stages immediately following infection of an oyster. The ones on the right are older, harder-carapaced crabs (most likely males, which may leave their hosts in search of oysters harboring females). The crab on the left is a mature female. The developing, orange-colored gonads are visible through the female’s thin carapace. Since mature females never leave the their host oyster, their carapaces (shells) are very soft and thin. This makes them very… squishy and pea-like.

You might have had the surprise of finding an oyster pea crab (Zaops ostreus) while shucking an oyster yourself. These small crabs live inside oysters and are a type of kleptoparasite, meaning they steal food from their hosts. An oyster gathers food by filtering water over its gills, trapping edible particles on its gills, and carrying those particles to its mouth using cilia (tiny hairs). Pea crabs sit on the gills and pick out some of the food the oyster traps before the oyster can consume it. By scurrying around inside oysters, pea crabs can also damage the gills mechanically. The pea crabs, like most parasites, don’t kill their hosts, but they can certainly affect the oysters’ overall health.

pea crabs 2

A gravid (egg-bearing) female pea crab next to the oyster spat in which she was living. The female, like most crabs, carries her eggs until they hatch, and then releases her larvae into the water. The baby crabs, when ready, will locate a new oyster host by smell.

As I was processing the oyster spat from all of our experimental sites (Florida to North Carolina) for survivorship, growth, and condition, I began to notice a surprising number of pea crabs living inside them and started to keep track. What’s interesting was not so much that the oysters had pea crabs, but that the percentage of oysters infected with pea crabs varied geographically. For instance, only about 25% had pea crabs in St. Augustine, Florida, whereas over 70% were infected at Skidaway Island, Georgia. Keep in mind that these spat all came from the same source and the same hatchery, so they all had the same starting condition. What’s more, I found that spat in Georgia which had naturally recruited to the tiles from the surrounding waters (of which there were quite a lot, and for which I also processed condition) rarely had pea crabs. Only about 5% of the recruits had pea crabs at Skidaway Island, Georgia. Why is there this huge difference in infection rate? Do the local oysters know something that the transplants don’t? How do these patterns in pea crab infection relate to other geographic patterns we’re finding? How does pea crab infection affect oyster condition? These and many more questions await to be addressed in further analyses and future experiments.

Spat on a Platter

Tanya Rogers FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150“Spat tiles” are a tool our lab commonly uses to measure the growth and survivorship of juvenile oysters under different conditions, and we’ve used them with varying degrees of success in many of the experiments chronicled in this blog. What these are essentially (in their final form, after a good degree of troubleshooting), are little oysters glued to a tile, which is glued to a brick, which is glued to a mesh backing, which is zip tied vertically to a post. Rob and I have put together a couple interesting slideshows chronicling the growth of these spat over time from two of those experiments. Ever wonder how fast oysters grow? Observe…

This is a time series from our first spat tile experiment, which you can read about in this post. As you may recall, this experiment was largely a failure because the adhesive we used to adhere the spat was inadequate. However, we decided to keep the fully caged tiles out on the reefs to see how they fared over time in different locations. I photographed the tiles every 6 weeks or so, so that we now have a series showing their growth over time. The slideshow shows one of the tiles from Jacksonville. It starts in October of 2010. You’ll notice that not much growth occurs though the late fall and winter, but the spat start to grow noticeably from April-June 2011. From June-September the spat grow explosively and many new spat settle on the tile from the water column and grow equally rapidly. Just as plants (and algae) have a summer growing season, so too do the oysters that feed on them, when conditions are warm and there is abundant phytoplankton in the water to eat.

Next is a series of images from our caging experiment last summer, which you can read about here. Our large cages contained either:


no predators (bivalves only),


spat-consuming mud crabs and oyster drills (consumers),


or mud crabs and oyster drills plus blue crabs and toadfish (predators).

The spat tiles within the larger cages were placed either exposed to potential predators or protected from them in a smaller subcage. Here are typical examples of what tiles looked like at the end of the experiment (about 2 months after starting). You can see how all the spat on the unprotected tiles were wiped out in the consumer treatments, but a good number survived in the treatments with no predators, as we would predict. In the predator treatments, most of the spat on unprotected tiles were removed, but not as fully or quickly as in the consumer treatments, which we would predict if the predators are inhibiting consumption of spat by the mud crabs and drills through consumptive or non-consumptive effects. You’ll see one tiny spat holding on in the predator tile shown. On the protected tiles, most of the spat survived in all treatments, as expected. We plan to further analyze the photographs from the protected tiles though, to see whether spat growth rates differed between them. We may find that protected spat in the consumer treatments grew slower than in the other treatments because of non-consumptive predator effects.

Currently, we’ve recovered most of our arsenal of spat tiles from the field, and I say we have probably amassed enough bricks to pave an entire driveway! Good thing we can reuse them!

The Biogeographic Oyster Study is funded by the National Science Foundation.


Reviewing the Oyster Study in 2010

IGOR chip_ predators_NCE 150IGOR chip- biogeographic 150IGOR chip- habitat 150IGOR chip- employment 150

Dr. David Kimbro FSU Coastal & Marine Lab

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:

Jeb cuts blue crab from shark belly

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.


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.
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The Dirty Work

Tanya Rogers FSU Coastal & Marine Lab

IGOR chip- biogeographic 150IGOR chip- habitat 150IGOR chip- employment 150(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.

striped burrfish

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.
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Yes We Did!

Dr. David Kimbro FSU Coastal & Marine Lab

IGOR chip- biogeographic 150The 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.

Catfish of Alligator Harbor

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.

Till next time,


Day 7: October Oyster Push- Last Day

Rob Diaz de Villegas WFSU-TV

Thursday, October 28- Finish up, head back home


(Farthest to nearest) Hanna, Tanya, and Cristina perform some of the more glamorous work of this trip- cracking oysters apart and finding spat (oyster babies). David needed everyone on his team to perform, or this week would be wasted.

IGOR chip- biogeographic 150A while back, I was talking to Randall or David, I forget which one, and they were telling me about building a research crew.  Obviously you need people who have the knowledge and skills to do what needs to be done- from identifying fish to driving a boat, or setting a gill net.  But just as important, they said, was that you had people you could get along with, since you practically live with them sometimes.

Weeks like this one are where building the team pays off.  When you’re getting bitten up by gnats on an oyster reef at 6:45 in the morning, you don’t want a crew member sniping at another about losing a fish out of the gill net.  David remarked to me that the morale of this team had stayed strong, despite the schedule always changing and everyone having to shoulder more of the load while David got the tiles ready.  They did a lot of work on their own, and made it possible to get everything done even as plans shifted.

On a day like today, it was good that David has the crew he has.


A swarm of gnats hovers over the oyster reef water.

6:45 AM– Retrieved fish from nets, deployed traps.

After a night of battling cockroaches in their “haunted” house, they might have been happier to be out on oyster reefs at this early hour.  They might have, had it not been for the no see-ums.  They were getting eaten alive, which made it hard to work.  And it got worse from there, as if the universe decided to pile it on in this last day.

As early as it was, the birds had gotten to their fish before they did and there were no stomachs to examine.  And then there were the injuries.  David cut his finger on a catfish spine, and then, within about ten minutes, a stone crab got a hold of Hanna’s finger and inflicted some pain.  They’re both okay.  Their truck, however, is a little worse off.

Truck accident in Jacksonville

Banged up over the course of the week, the crew- and their truck- are ready to come home.

When they got back, they glued spat onto tiles one more time to deploy this afternoon.

3:00 PM– Tanya, Hanna, and Cristina retrieved the traps and set the tiles.

7:00 PM– The girls headed back to the FSU Coastal & Marine Lab.  When they got there, they cleaned all of their gear, even though it was late.  They figured that it was better to wash the salt off sooner than later.

So that was the week.  They’ll go back to each of the sites about every six weeks, though it won’t always be this intensive.  David, Jeb (SC/ GA), and Jon (NC) will start to see seasonal patterns in the fish that they find- when do certain fish tend to show up on what reef?  They’ll check in on their tiles and take photos, and over the months the photos should play like a flip book in showing the growth of the oysters on each site.  They’ll gain understanding, and they’ll run into more road blocks.  They have about two-and-a-half years left on this study, so while Thursday was the last day of the push, they’re nowhere near the end of the road.


Assuming no one tampers with them, we should be able to watch these oysters grow up over the next year.

Check back in a couple of weeks for wrap-up posts from David and Tanya.

Tide Times and height (ft.) for Jacksonville, October 28, 2010
Low- 6:44 AM (0.3)

David’s research is funded by the National Science Foundation.

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Day 6: October Oyster Push- Home Stretch

Rob Diaz de Villegas WFSU-TV

Wednesday, October 27- Finish tiles, go to Jacksonville


When not losing sleep over whether the tile experiment will work, David dreams of making the tiles. They'll be back in six weeks to check on the progress of the baby oysters they set upon the reefs.

IGOR chip- biogeographic 150Walking down the hall of our dorm at 7 AM, I heard the familiar sound of the dremel from across the street in the lab area.  This time the whole crew was there- Tanya, Hanna, and Cristina cleaning and separating oysters and David Kimbro slicing shells into similarly sized pieces.  The Jacksonville oysters they’re processing have an entirely different kind of predator than the Marineland oysters have in crown conchs.  The Jax shells were speckled with little greenish spots- these are boring sponges.  They bore holes through the shell and take up residence within it.  The specks were making it harder to spot spat.

I was thinking about predators when I was driving today, in particular the crown conchs here.  A1A runs alongside the intercoastal waterway where the oyster reefs are.  Driving north towards the Matanzas Inlet, which is the northern boundary of the crown conch problem, there is a bridge under construction.  While getting some footage of oyster reefs earlier, I noticed how close many of the reefs are to the road and its runoff.  Overall, the area is more heavily settled than the Forgotten Coast sites where David and Randall do their studies.  This drive I took today put a slightly different light on the work they do.  When I’m shooting on the reefs, or in the salt marshes, it sometimes seem like a different world.  But it isn’t, really.  Not that this sudden and very focused problem may not have an entirely natural cause.  But there are a lot of potential factors in play outside of trophic cascades and water salinity.


Those innocuous looking spots are trying to kill the oyster and take over its shell.

2:00 PM– Hanna, and Cristina drove to Jacksonville to deploy nets at low tide.  Cristina found a deep spot in the mud and sank in waist deep, which is a concern at this site.  The new boat was purchased specifically for this site, as it’s a long kayak trip in somewhat treacherous waters.


So far, so good for the Saint Augustine spat tiles.

4:30 PM– David and Tanya finish making the Jacksonville tiles and spend about two hours cleaning up the lab space.  Tanya kayaked out to check on the St. Augustine tiles they deployed yesterday before heading to Jax.  David said he had lost sleep last night over whether the tiles would still be there, or if the glue would even hold the spat onto the tile.  Jon Grabowski (NC team leader) has a site with easy public access.  This morning he showed up to find his sites being harvested, the tiles already removed.  So you can see where David would worry.  But, at least over the first night, the SA tiles were fine.

David and Tanya joined the rest of the team in Jacksonville for another awesome Tanya-cooked meal.  I feel I did her a disservice yesterday by not mentioning the zucchini bread and double chocolate biscotti she made, so I’ll do so now.  Yum!  Perhaps On the Reef needs a cooking segment.  Everyone is now settled into a house they all think is haunted.  Hanna put together a makeshift tub on their screened-in porch to keep the spat alive to deploy tomorrow.  One more day to go…


On Thursday, the October oyster push concludes and the FL, GA/ SC, and NC teams will start looking at the data and continue establishing patterns.

Tide Times and height (ft.) for Jacksonville, October 27, 2010
Low- 5:56 AM (0.2)
High- 12:25 PM (5.7)
Low- 6:42 PM (0.5)

David’s research is funded by the National Science Foundation.

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Day 5: October Oyster Push- A Change of Plans

Rob Diaz de Villegas WFSU-TV

Tuesday, October 26- Tile Team heads to Jacksonville


The whirring sound, the smell of calcium carbonate dust, the warmth of his face behind the mask and goggles- this is the stuff of David Kimbro's dreams.

IGOR chip- biogeographic 150The WFSU crew stayed the night in St. Augustine to accompany both the Net/ Fish and Tile teams when they headed out at sunrise.  After breakfast, I went out to the lab space (we’re all staying at a research facility very near the reefs they study), and David Kimbro was there, before the sun had made its way out, separating shards of shell with spat on them.  He’d missed all of the field work here up to that point so that this experiment could work.  Until this afternoon, it was all I had seen him do here.  If he was able to focus in on this one aspect of this large an undertaking, it is because Hanna and Tanya have been able to operate independently and pick up the slack.  By the time he actually made it into the field, David followed Tanya’s lead.

Also working hard on this trip are my poor sneakers.  I have an old pair that I designated for my work on this project, shoes I knew I would never wear for anything else.  The reefs in Cedar Key and St. Augustine have torn them up.  I keep stepping in soft mud that hides oysters, or stray clumps cloaked by muddy water.  It might be time to invest in boots.


There's nothing like the smell of dead fish in the morning.

7:30 AM– Hanna, Tanya, and Cristina went out to retrieve the catch from the gill nets, take sediment samples, retrieve the data loggers, and take some fish stomachs (how else would you know what the predators were eating?).  They also replaced the spat sticks, which were still only attracting barnacles.  Tanya noticed, however, that spat would settle on the rebar below the stick.

A couple of Environmental Scientists from the St. Johns River Water Management System agency kayaked up at some point to watch the proceedings.  They are working with David’s lab to determine why these once commercially viable reefs were overrun and depleted by crown conchs.  The problem seems to be very localized, occurring between Ponce Inlet in New Smyrna Beach and Matanzas Inlet.  David is hoping for more “spinoff projects” like this one, in which he and his lab can use applied science to help specific reef systems.

And while we’re on the topic of predatory snails, Here’s that pic of the Atlantic Oyster Drill:


Crown conch, tulip snails, and oyster drills heavily populate these Marineland, FL reefs.

2:30 PM– Hanna and Cristina headed to Jacksonville to begin removing clumps of reef with Jacksonville spat on them. But first they were to inspect the house they were renting to see if there was a suitable area to make their Jacksonville spat tiles. That process involves keeping oysters in large tubs of water, prying shells off of the clump, and using a dremel to make the pieces somewhat uniform in size. If I was renting someone a house, I wouldn’t want them doing that in my bathroom. Hanna determined that the house did not have a workable area, causing a shift in their plans. Hanna and Cristina now had to bring the reef segments back to St. Augustine to process. Instead of deploying nets in Jacksonville Wednesday morning, they’ll have to do this in the afternoon after processing the spat all day. And instead of finishing with Jacksonville on Thursday morning, they’ll be there all day (causing David to make his three hour drive home at night).

5:00 PM– David and Tanya retrieve the small fish traps.  A couple of the fish they catch are pretty colorful, I suspect they’re something that once lived in a saltwater aquarium.  They also deployed the tiles into which so much effort had been expended.  It’s a major part of this study, and David is happy to get started on it just five months after that first day in Alligator Harbor.  And it’s still early enough in this three year study that they can tweak the experiment and try it again next year (experiments of this nature don’t always work the first time).

After all the work was done, Tanya made a tasty four-bean vegetarian chili, and everyone enjoyed a relaxed dinner before convening again at 7:30 AM to process more spat.


David finally makes it out into the field.

Tide Times and height (ft.) for Saint Augustine, October 26, 2010
Low- 8:oo AM (0.3)
High- 2:17 PM (5.2)
Low- 8:41 PM (0.7)
Tide Times and height (ft.) for Jacksonville, October 25, 2010
High- 5:56 PM (0.5)
We’d love to hear from you! Leave your comments and questions below: