Tag Archives: oyster reef

Growing Pains (bigger is definitely not always better)

Dr. David Kimbro FSU Coastal & Marine Lab

California oyster cages

IGOR chip- biogeographic 150The small cages in the photo above were used in an experiment I conducted to study California oysters. The insanely large cages in the photo below are from an experiment designed for our insanely large biogeographic oyster study.

David by cage
While we had planned to install only 18 of these cages along the Atlantic coast of Florida, my crew wound up installing 70 cages over about six weeks. How did we reach such inflation in the number of cages and amount of digging? Well, it mainly stemmed from my ignorance of this area and the St. Johns River, which happens to dump a lot of sediment around oyster reefs. Because this sediment is deep and flocculent, it’s dangerous and almost impossible to work in. In fact, I may design a new study to analyze how oyster reefs manage to keep themselves above this ever-growing mud pit. I digress.

Relative to the abundance of these un-workable oyster reefs, mudflat areas suitable for our new experiment (i.e., near oyster reefs and firm footing) are quite rare. It was our luck (for better or worse, as you will soon read), we stumbled upon a sufficiently and suitable mudflat north of Jacksonville. After three days of hard digging, we managed to create large cages ready to support our experimental treatments. Suspecting that this site seemed too good to be true, we left the cages to fend for themselves for a week. If we returned to discover no problems, then we would proceed with the experiment.

On to St. Augustine- fitting the theme of bigger not always being better, our gargantuan stone crabs burrowed out of cages we had installed there. Even worse, cages without stone crabs were coming out of the ground because they were not dug in deep enough. The stone crab problem represents another example of why I should always run pilot experiments before attempting anything ambitious. Unfortunately, I have not learned this lesson yet. Or, I seem to periodically forget it.

Because I lacked the time to run such a pilot experiment, I ditched the troublesome stone crabs. We then awoke at dawn for the next three days to re-install cages (see the video below) in an over-kill sort of way. For this task, we took digging deep to a whole new level. Nothing was going to get inside or out of these cages without our permission. You can see how much deeper the cage bottoms extended into the ground by looking at the same cage pre- and post- renovation.

Having weathered the St. Augustine mishaps, we confidently headed back to Jacksonville to assess those cages. Upon arrival, I was subjected to a horrific scene: three days of hard labor undone by high flow conditions.

Note to self: mudflats are firm because flow is too high to allow sediment accumulation.

Stubbornly, I decided to force my will upon Mother Nature by digging cages in deeper and reinstalling them at locations behind marshes that would presumably buffer flow. Lacking the time to test this new cage installation, we immediately installed experimental treatments. This leap of faith was necessary in order to stay on schedule with the NC and GA teams.

Okay- cages up, reefs in, bells and whistles turned on. Afterwards, I raced back across the state to help two interns on their projects. Halfway back across the state and late on the Friday of Memorial Day weekend, I managed to blow the old lab truck’s transmission. As if getting a tow truck to Lake City at midnight wasn’t hard enough, getting one that would tow our truck and our kayak trailer was highly unlikely. But, taking pity on us, a wonderfully nice tow-truck driver agreed to load the trailer onto our truck.


Meanwhile, team Georgia was also experiencing problems with flow, sedimentation, and misbehaving predators. In short, we were throwing everything at this experiment and making little progress. At this point, ironically, the relative slackers amongst the three teams- the slow-to-start NC team- moved into first place- the horror!

After the passing of one mercifully tranquil week, we headed back to St. Augustine to check on things and collect data on our tile experiment. Interestingly, the experiment was working and we observed some variation in how predators indirectly benefit oysters; the positive effect diminished with latitude.

But then back again to Jacksonville- destroyed cages followed by some extremely colorful language. There should not have been deep pools of water surrounding the cages at dead low tide.

Phil by wrecked cage

Obviously, it was time to cut our losses by not messing around with this site anymore. As a result, we spent the next three days searching all of northern Florida and southern Georgia to find a new ideal study site: suitable to oysters, no quick sand, firm footing and modest flow. After three days of intensive searching, we can confidently claim that such a site does not exist.

After accepting that this experiment could not be conducted in northernmost Florida, we decided to redirect Jacksonville resources to St. Augustine. There we would conduct a similar experiment that focused on a predatory assemblage unique to Florida: stone crab, toadfish, catfish, and crown conchs. So, nine more cages, nine more experimental reefs, and all the associated bells and whistles were established once again. By this time, my crew felt that they could easily serve in the Army Corps of Engineers.

Although things are now going well and we have a much better understanding of how to initiate this type of an experiment, my general ignorance has kept a Florida State University intern in St. Augustine for 7 weeks after agreeing to be there for only two weeks. Ooopsie!

Stay tuned in for a Hanna update on St. Augustine’s crown conchs and a post from Tanya about the summer madness from a technician’s perspective.


David’s research is funded by the National Science Foundation.
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Oyster Study: Year Two, Under Way in a Big Way

Rob Diaz de Villegas WFSU-TV

IGOR_chip_predators_NCE_100IGOR chip- biogeographic 150I’ve come to Saint Augustine to get the last of the footage I need to finish the In the Grass, On the Reef documentary, and we’ve come a long way from where we started from on this blog.  One year ago today, this site went live and Randall and David introduced you to their research.  The oyster study had just gotten its grant from NSF and we went out with David as he walked out into Alligator Harbor in search of study sites.  It was a slow, messy day- but a necessary first step. Continue reading

How much is a salt marsh worth?

Dr. Randall Hughes FSU Coastal & Marine Lab


IGOR chip- habitat 150IGOR chip- filtration 150IGOR chip- gastronomy 150The answer to this seemingly rhetorical question was the subject of a recent review by Edward Barbier and colleagues in the journal Ecological Monographs. They focused not only on salt marshes, but also coral reefs, seagrass beds, mangroves, and sand beaches / dunes. The impetus for the analysis was the recognition that many coastal habitats are in decline – for instance, 50% of salt marshes are lost or degraded around the world – and the belief that we need a better understanding of the true costs of these losses. Continue reading

In the Grass, On the Reef, Over the Airwaves

In the Grass, On the Reef

June 29, 2011 at 7:30 PM/ ET


Rob Diaz de Villegas WFSU-TV

A little over a year ago, when the FSU Coastal & Marine Laboratory and WFSU-TV – a TV station – started this online enterprise, the understanding was that at some point this would end up being a show.  And so here we are.  As you may have gathered from that video up there, this will be about predators and prey: who’s eating whom, and who’s scaring whom.  We will of course be doing this through the prism of David and Randall’s studies: the consumptive and non-consumptive effects of predators in salt marshes and oyster reefs, and the methods used to shine a light on these interactions. Continue reading

Crown Conchs Galore!

Hanna Garland FSU Coastal & Marine Lab

IGOR chip_ predators_FX 150One of the most fascinating aspects of the field of science is the unpredictable patterns and directions that certain communities can take over a period of time. Whether the change in a habitat occurs due a spontaneous event such as a devastating hurricane or a longer, more gradual event such as climate change; it is important to understand the impacts these changes may have on the resident organisms as well as the future of the community. Studying how organisms respond to each other and their environment are key principles of ecology.

As David mentioned in the previous post, I have recently begun my graduate student work in St. Augustine, where I hope to gain a better understanding of the unique observations we have made while working in the area for the NSF oyster project.
Other than being the nation’s oldest city, St. Augustine is a very dynamic place. From condominiums and restaurants to historic landmarks and beautiful beaches; the area is flooded with snow-birds during this time of year. More notably, St. Augustine has countless state parks, wildlife preserves, and protected habitats; which allow for not only attractions for tourists but areas of research for scientists and most importantly, shelter and nurseries for the resident wildlife. Continue reading

Crown Conchs Overrun Saint Augustine Reefs


Scanning the photo, you can see crown conchs crawling about this Saint Augustine reef. Crown conchs are a normal sight on Florida reefs, but not to the extent seen here. David has tasked Hanna Garland with looking into this very localized phenomenon and its relationship with increasing reef failures.

Dr. David Kimbro FSU Coastal & Marine Lab

IGOR chip_ predators_FX 150Last week I detailed a recent trip to St. Augustine, ending the post with a mention of a side project being embarked upon by my lab there.  Throughout the past year, we’ve noticed that our St. Augustine study site was loaded with tons of crown conchs. Although crown conchs are ubiquitous in Florida, they are abnormally abundant on our St. Augustine reefs and our St. Augustine reefs are mostly dead. All our other sites have relatively healthy looking oyster reefs and few crown conchs.

But a few miles north of our monitoring reefs, we find absolutely no crown conchs and the health of the oysters is great. Because crown conchs, as has been shown by the research of our very own Doc Herrnkind, love eating oysters, it’s easy to conclude that crown conchs have mowed down all the oysters on our monitoring reefs. But why are they restricted only to our monitoring reefs? Is there a predator of conchs present north of reefs but that is absent on our monitoring reefs? Perhaps the environment has changed in a way that killed all of the oysters and the crown conchs are just cleaning up the mess.


Proboscis out (protruding from the bottom of the snail), a crown conch heads towards a clump of oysters. The conch will use its proboscis to pry open the oyster shell and suck out the meat.

Luckily, Hanna has agreed to enter my lab as a graduate student to tackle this research project. So, she spent a number of days collecting coarse-scale data on the spatial extent of this conch-oyster pattern, consulting with locals about when this pattern developed, and talking with an oceanographer about how to learn whether and how the physical environment has lead to this pattern. In a forthcoming post, I’ll let Hanna fill you in on the details of this new project, which we will be implementing quickly. This is really important to the local community because our monitoring reefs and the conch infested area used to be the most productive area in St. Augustine for harvesting oysters and rearing clams. But now, aquaculture leases here have been abandoned and a very large population of crown conchs appears to have taken up residence.

Stay tuned for Hanna’s post later this week, she’ll go into a little more detail on what we’re doing.

David’s research is funded by the National Science Foundation.
On Wednesday, June 29 at 7:30 PM/ET, WFSU-TV premieres the In the Grass, On the Reef full length documentary. David and Randall guide us through the world of coastal predators (like crown conchs). Top predators maintain important ecosystems like salt marshes and oyster reefs- but the manner in which they do this may not be confined to eating prey.  Tune in to find out more!

The New Predator Experiment

Dr. David Kimbro FSU Coastal & Marine Lab

IGOR_chip_predators_NCE_100IGOR chip- biogeographic 150Hey folks,

Where did my winter of catching up on work go? And why is spring quickly hurtling into summer? YIKES!

…Okay, I feel better. All of us here feel a little behind on things, because this past winter and spring have been full of other projects (in addition to the oyster one) such as investigating how the oil spill affected marshes throughout the west coast of Florida and examining what all of those snails are up to out on Bay Mouth Bar. But now that summer is almost upon us, it’s time to move all hands on deck back towards the ambitious summer oyster goals.

Environment versus Predation

Environmental vs. Predator Effects.

To lay the ground work for this summer’s oyster research, I spent a few days in St. Augustine, Florida, which is where we will conduct our colossal field experiment. As a recap of the oyster objectives, we spent year 1 monitoring the oyster food web at 12 estuaries between Florida to North Carolina. Well, we found some cool patterns regarding the food web and water-filtration/ nutrient cycling services on oyster reefs (see the 2010 wrap-up). So, now we want to know what’s causing those patterns. Are differences in oyster reefs between NC to FL due purely to differences in water temperature, salinity, or food for oysters (phytoplankton)? Or, do we have a higher diversity of predators down south that are exerting more “top-down” pressure on the southern reefs? Or, is it a combination of the environment and predators? Continue reading

What are those new images that are popping up on the blog?

Dr. Randall Hughes FSU Coastal & Marine Lab

If you’re a regular reader of the blog, you’ll realize that we often talk about similar research questions or ideas in the context of different projects. As David mentioned in his description of the Baymouth Bar project, this overlap is usually intentional: as ecologists, we’re interested not only in the specific habitats that we study, but also in the underlying factors that affect these habitats and the valuable services that they provide to we humans.

It may appear at times that we’ve been covering a diverse array of topics, and while this is true, all of these topics are interconnected- a web of topics centered around a couple of central themes. The diagram below is the map that shows where every post-topic fits into these central themes. Even the artists, writers, and photographers we occasionally feature have their place amongst ecological processes like sedimentation and the non-consumptive effects of predators. Every post from here on out will have one of these icons on it- if you don’t know what the icon means, just click on it and you’ll be back at this figure with an explanation:

In the Grass, On the Reef master plan

Continue reading

Oystermen Artist Project

Mike Plummer WFSU-TV

IGOR chip- human appreciation 150Michael Harrell is a local artist, brought to WFSU-TV’s attention by one of our viewers. Michael paints in both oils and watercolors and among his nautical themes are depictions of the oystermen of Florida and South Carolina. This video looks at that series of paintings. The thing that I found so beautiful about his work is his ability to capture a sense of time with his portrayal of light. You can find additional information about the artist at MichaelHarrellArt.com.

Our local oystermen, as you see in this video, typically harvest subtidal oyster reefs like those in the Apalachicola Bay.  Michael Harrell also shows South Carolina oystermen harvesting intertidal reefs like those covered in this blog (i.e. Alligator Harbor).  The South Carolina sites of the biogeographic oyster study are sampled by Jeb Byers’ group.

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.
We want to hear from you! Add your question or comment.