Lately, the Hugh-Bro (Hughes and Kimbro) Lab has covered a lot of miles. Dr. David Kimbro and Dr. Randall Hughes have accepted positions at Northeastern University in Boston. Tanya Rogers is David’s first graduate student at NEU, though her dissertation is on Bay Mouth Bar at the mouth of Alligator Harbor. Hanna Garland (who had spent a year living in Saint Augustine Beach for her graduate work with David) and Stephanie Buhler are covering Apalachicola Bay, though Stephanie will start her PhD. work in the Bahamas soon. We’ll let Ryan Coker tell you of his East coast adventures helping Meagan Murdock wrap her National Park Service tile experiment…
Ryan CokerFSU Coastal & Marine Lab
Timucuan - Here I am inspecting a tile as we made our way to the next reef. Looks like these particular oysters didn't fare well, but we saw plenty that did!
For the last couple months, a lot of my responsibilities around the lab have shifted from working out in the field to processing samples from our salt marsh projects (recently, measuring the organic content of sediment samples, i.e. setting dirt on fire and calculating the missing weight). This past week I was happy to be recruited from my normal lab duties to help out on Meagan’s National Park Service oyster experiment, recovering our oyster-covered paving bricks from the experimental reefs for analysis. This meant packing my bags to leave for a six-day field trip to visit our reef sites at Timucuan Ecological & Historic Preserve in Jacksonville and Cumberland Island National Seashore, a barrier island off of Georgia’s coastline. I was told to prepare for precarious treks through oystershell, leg-swallowing mud, and swarms of no-see-ums who, in spite of their name, were determined to get noticed. I prepared for these challenges in earnest, with thick boots and quick feet and enough bug spray to at least suggest that eating me alive wasn’t in any insect’s best interest. But what I wasn’t ready for was the sheer beauty of these places. I feel immensely lucky to have found my calling in ecology—I do the work I love, and I get to do it in the loveliest places.
Timucuan - Meagan decided to test the depth of this mudflat to see if we could access one of our oyster reefs at very low tidal height. As she progressed downward at a rate far exceeding her forward gains, it was clear that we were going to have to wait out the tide and try again. Thank you, Meagan, for being such a champ and getting completely mud-covered while I waited on the boat, laughing and taking pictures. Here she is using my leg to pull herself out of the muck as I perched on the ledge of the pontoon boat.
Because we had a free half-day on Cumberland Island while we waited for the National Park Service to come and ferry us back to the mainland, Meagan and I set off to explore the island. We traded our boots and waders for sneakers and shorts long, bug-proof pants. Transitioning from a field tech to a tourist for just a few hours, I ran up and down the island in an attempt to see it all. It was gorgeous.
The forest was intercut with dirt paths canopied by towering palms and the twisting limbs of immense Live Oaks. The infinite beach, its width rolled out flat from delicate high-blown dunes to where it dips below the lapping ocean tide, is home to shorebirds and “wild” packs of roaming horses.
What I found most striking, though, were the crumbling skeletal remains of Dungeness, a mansion built in the 1880s, abandoned in 1925, and burnt to ruins by the 1960s.
Imagining this place in its glory, I filled in the gaps of the walls and floors where they were collapsed and covered by weeds and rubble. There’s not much left, and I didn’t dwell on my fiction overmuch, but I sure would have loved to see that mansion as it stood. It made me think about the impacts we make on the world, the legacies we’re trying to build before we go. I feel really good about the work I contribute to in the lab. To the metaphorical library of scientific knowledge, I’d like to think the work I do is helping to add-on another room. We’re in the ecology wing, expanding it out, adding just a bit to the collection. It’s our mansion, and at the very least, it’s fireproof.
Of course, mostly I just thought “Holy cow, this is gorgeous,” as I snapped away, already daydreaming about the next spectacular place I might have the opportunity to visit with the lab.
In the Grass, On the Reef is funded by a grant from the National Science Foundation.
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.
Meagan Murdock is a lab technician in the Hughes and Kimbro Labs, operating out of the FSU Coastal and Marine Laboratory. The experiment she describes in the following post is a central staple in the research conducted by Dr. Randall Hughes and Dr. David Kimbro into oyster reef ecology. They seek to measure factors affecting the health of an oyster at a given location by monitoring the growth of young oysters (spat) in a controlled unit- the spat tile. We’ll be further exploring the use of spat tiles in their NSF funded oystern study in the next couple of weeks. David Kimbro is also gearing up to deploy a tile experiment in Apalachicola Bay, with the goal of measuring conditions there (see photo below).
Meagan MurdockFSU Coastal & Marine Lab
Beautiful reef backing up to red mangroves (Rhizophora mangle) in Mosquito Lagoon, FL. Notice our experiment on the reef!
Mosquito Lagoon of Canaveral National Seashore is in the northern section of possibly the most diverse estuary in North America, the Indian River Lagoon. But don’t let the name “Mosquito” Lagoon scare you off! This lagoon is an expanse of mangrove islands, oyster beds, and home to charismatic animals like manatees and dolphins (maybe a few mosquitoes, but where in Florida can you not find mosquitoes??). Eight months ago, we set up a rendition of the “Tile Experiment” at three National Park Service units in hopes of elucidating factors contributing to oyster spat (spat=newly settled oyster) survival and growth. Last week we ventured out to Mosquito Lagoon to check on our baby oysters and this is what I found. The tiles were covered in BARNACLES!
Tile 75 pictured after being deployed for 2 months and 8 months.
I felt bad for the little oysters. Not only are these spat expected to survive through adverse environmental conditions and hope they do not become some crab or fish’s dinner, but they also are competing for space and resources with other filter feeders. Geez it must be tough being an oyster! But-yeehaw!-the oysters are persevering and I got to enjoy the nice weather of Central Florida.
Barnacles overtaking the experimental oysters.
As Meagan continues to monitor the growth of her Canaveral oysters, David is having Stephanie Buhler and Hanna Garland deploy some test tiles in the subtidal (always submerged) oyster reefs of Apalachicola Bay. The tiles will be protected by a steel cage which will allow access to researchers while protecting the experiment from an oysterman’s tongs. Different prototypes of tiles and cages were deployed last week with the full experiment to begin in the coming weeks:
In the Grass, On the Reef is funded by a grant from the National Science Foundation.
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
I 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…
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.