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 KimbroFSU Coastal & Marine Lab
Last 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!
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.
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 →
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.
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.
Walking 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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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.
The 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)
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