Tag Archives: science

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Learning to Tell a Story

Like Randall Hughes and David Kimbro, Dr. Randy Olson is a scientist who wants to make science understandable to a general audience.  Dr. Olson’s passion for communicating science led him to USC School of Cinema and a second career in film making.  He will be here next week to help bring the inner storyteller our of twelve graduate students, and he’s brought his latest film with him.  We hope you can join us.
Dr. Randall Hughes FSU Coastal & Marine Lab

Stories of high school football never grow old!

There’s nothing like lots of time with family over Thanksgiving to drive home the fact that some people are inherently better storytellers than others. How else could you stand to listen to the same story about the come-from-behind, last-minute win (that I witnessed first-hand) year in and year out? Or have someone recount something as mundane as a TV commercial and have you falling out of your seat laughing? Or watch an impersonation of a dog’s attempts to garner some attention that is funnier than the original video? My family is blessed with a number of good storytellers, and I’ll confess that I’m not one of them. So is there any hope for me?

If you’d asked me that question a few years ago, I would have answered with a resounding “No”. I’ve always considered storytelling as one of those innate gifts that some people have and others don’t, with me in the latter category. For one, I prefer to write things down, organizing and re-organizing my thoughts on the page until I get them just right. That way, if I forget the ‘punch line’, I can come back to it later, a strategy that definitely doesn’t work well when telling a joke aloud! Also, I’m much more comfortable coalescing others’ ideas into an organized fashion for a fact-based paper than creating a novel story from scratch (think English 101 vs. Creative Writing). But other than not being the most entertaining relative at family gatherings, does my inability to tell a good story really matter?

Early mornings in the field do wonders for sibling relationships!

This time, I’d have to answer “Yes”. Over the last several years, I’ve become more and more concerned about the disconnect between the scientific world and the “everyday” world. (The fact that it’s acceptable to suggest that science is somehow divorced from everyday life without raising lots of eyebrows is an indication of what I’m talking about.) And I think part of the responsibility for fixing this divide lies with scientists, in that we need to do a better job of explaining to our friends and family (for starters) why our work matters to them. But only the closest and most devoted of relatives (thank you, Mama Jennie!) will read my scientific publications, and only the most in need of a job (here’s looking at you, Jules!) will commit to working as my research assistant for a summer to learn the ins and outs of what I do. So we’re back to the need for me to tell a story, and a good story at that, to grab people’s interest and inspire them to want to know more.

Randall being interviewed by WFSU producer Rob Diaz de Villegas at the FSU Coastal & Marine Lab in July 2010.

Enter my collaboration with WFSU. Just prior to the Deepwater Horizon oil spill, I had a meeting with Kim Kelling-Engstrom about the possibilities of a joint effort to communicate David’s and my research to a general audience with help from the professionals at WFSU. When the spill occurred, the impetus to document our research on the amazing coastal ecosystems of northern Florida became even more urgent, and we launched this blog. For someone who rarely agrees to having my picture taken, it was a big leap to regularly go in front of a camera and talk about what I do, and why I think it’s important. And it’s been a steep learning curve! But I’m beginning to realize (hope?) that telling a story is a lot like playing sports – some people start with a leg up in the talent department, but everyone gets better with practice.

So how do you learn to tell a convincing story? What are the tricks of the trade? To find out more, David and I have invited Dr. Randy Olson, the self-described scientist-turned-filmmaker, to come give a workshop at FSU this month on just this topic. The workshop is for science graduate students interested in learning how to better communicate their ideas and research to a general audience. Randy went to graduate school at Harvard and had a tenured faculty position in marine biology at the University of New Hampshire until he decided to leave his job and enroll in the University of Southern California School of Cinema. Since finishing film school, he’s directed several entertaining and thought-provoking films, as well as written a book about communicating science. So he’s rather uniquely qualified to speak about the particular pitfalls that plague scientists when it comes to telling a good story, as well as how to overcome them.

I’ll be listening in carefully during the workshop, and I’m sure I’ll have some useful tips to share with you (and implement) on this blog in the weeks following. We’re also excited that Randy has offered to do a screening of his movie Sizzle: A Global Warming Comedy at the FSU Student Life Cinema at 7pm on Tuesday, December 11. The movie will be followed by a panel discussion featuring Dr. Olson and several FSU faculty members. The event is free and open to all who are interested, so come join us!

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

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.

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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.

In the Grass, On the Reef, A World Away

Dr. Randall Hughes FSU Coastal & Marine Lab

IGOR chip- biogeographic 150IGOR chip- habitat 150David and I are in Sydney, Australia, on visiting research appointments with the University of Technology Sydney. We arrived the first of the year, and after recovering from jet lag and getting our bearings, we embarked this week on setting up a couple of new experiments.  We have great local “guides” – Dr. Peter Macreadie (UTS), Dr. Paul York (UTS), Dr. Paul Gribben (UTS), and Dr. Melanie Bishop (Macquarie University) – to introduce us to the field systems and collaborate with us on these projects.

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Our seagrass and razor clam experiment is set up at Point Wolstoncroft in Lake Macquarie (north of Sydney).

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A long time in the making

Dr. Randall Hughes FSU Coastal & Marine Lab

IGOR chip- biodiversity 150

As I mentioned in my last update, we have been working to set up a new marsh experiment in St. Joe Bay. The goal of the experiment is to see whether the genetic diversity of marsh cordgrass (Spartina alterniflora) affects how quickly or abundantly the plants grow, or influences the number of fiddler crabs, grasshoppers, snails, and other critters (like Ibis??) that call the plants home. But what is genetic diversity, exactly, and why do we think it may be important?

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A flock of Ibis resting among our experimental marsh plots.

Spartina is a clonal plant, which means that a single “individual” or clone made up of many stems can dominate a large area (low diversity), or there can be lots of different individuals mixed together (high diversity). In our surveys of marshes in the northern Gulf of Mexico, we find that there can be as few as 1 and as many as 10 clones in an area of marsh about the size of a hula-hoop. You may notice that our experimental plots are about that same size, though we used irrigation tubing rather than actual hula-hoops (not as fun, but more practical and less expensive!). We’re testing whether the differences in genetic diversity (1 vs. 10 clones) that we see in natural marshes has any influence on the marsh community.

A single experimental plot of Spartina that is 1m in diameter.

But why genetic diversity? We know from experiments by other researchers that Spartina clones grown individually differ in height, how many stems they have, and other characteristics. These same plant traits affect the critters that live in and among the plants – for example, periwinkle snails preferentially climb on the tallest plants. Because different animals may be looking for different plant traits, then having greater diversity (genetic and trait) may lead to a greater number of animal species that live in that patch of marsh. Or, a single clone may be the “best”, leading to higher numbers of animals in lower diversity areas.

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A view of the existing marsh behind our experiment.

As my title alludes, this experiment has taken a long time to come to fruition, in large part because it’s impossible to look at any 2 stems in a marsh and know for certain whether they’re the same individual or not. Unlike some clonal plants such as strawberries, where there are multiple berries connected by a single above-ground “runner”, Spartina has runners (aka, rhizomes) that connect stems of the same genetic individual under the ground, making it difficult to tell which stems are connected to which. We have 2 ways to get around this problem: (1) we use small snippets of DNA (analyzed in the lab) to tell clones apart, and (2) we start with single stems that we know are different clones and then grow them separately in the greenhouse until we have lots of stems of each different clone. It’s this latter part that has delayed this experiment – it has taken much tender loving care from Robyn over the last 2 years to get our Spartina clones to grow in the greenhouse to the point that we have enough of each clone (36 small flowerpots of each, to be exact) to plant in our experiment.

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Emily and Robyn work to remove existing rhizome material from around the plot edges.

But plant we finally did! With lots of help from members of the Hughes and Kimbro labs, we got all the sand in the experimental plots sieved (to remove any existing root material) and all the plants in the ground the Thursday and Friday before Thanksgiving.

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Team Hug-bro (Hughes and Kimbro) helping sieve sand!

 

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Meagan and Randall get the easy job - planting the plants.

Now we get to wait and see (and take data) whether Spartina genetic diversity matters for the marsh plant or animal community. There won’t be any quick answers – the experiment will run for at least 2 years – but we’ll be sure to keep you up-to-date!

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

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:

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no predators (bivalves only),

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

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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.

 

Tricks or Treats? And more on the effects of predators in marshes.

Dr. David Kimbro FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150Unlike most of the experiments that I’ve conducted up to this point in my career, the oyster experiment from this past summer does not contain a lot of data that can be analyzed quickly.

For example, predator effects on the survivorship of oysters can be quickly determined by simply counting the number of living as well as dead oysters and then by analyzing how survivorship changes across our 3 experimental treatments (i.e., cages with oysters only; cages with mudcrabs and oysters; cages with predators, mudcrabs, and oysters).  But this simple type of data tells us an incomplete story, because we are also interested in whether predators affected oyster filtration behavior and whether these behavioral effects led to differences in oyster traits (e.g., muscle mass) and ultimately the oyster’s influence on sediment characteristics.  If you recall, oyster filter-feeding and waste excretion can sometimes create sediment conditions that promote the removal of excess nitrogen from the system (i.e., denitrification)

oyster_exp_3box

As we are currently learning, getting the latter type of data after the experiment involves multiple time-consuming and tedious steps such as measuring the length and weight of each oyster, shucking it, scooping out and weighing the muscle tissue, drying the muscle tissue for 48 hours, and re-weighing the muscle tissue (read more about this process here).

After repeating all of these steps for nearly 4,000 individual oysters, we can subtract the wet and dry tissue masses to assess whether oysters were generally:

(a) all shell…“Yikes! Lot’s of predators around so I’ll devote all of my energy into thickening my shell”

(b) all meat…“Smells relaxing here, so why bother thickening my shell”

(c) or a mix of the two.

For the next two months, I will resemble a kid with a full Halloween bag of candy who cannot wait to look inside his bag to see whether it’s full of tricks (nonsensical data) or some tasty treats (nice clean and interesting data patterns)!  I’ll happily share the answer with you as soon as we get all the data in order.

Because of this delay, let’s explore some new research of mine that examined how predators affect prey traits in local marshes and why it matters.

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There are two main ingredients to this story:

(a) tides (high versus low) dictate how often and how long predators like blue crabs visit marshes to feast on tasty prey.

(b) prey are not hapless victims; like you and me, they will avoid risky situations.

attach.msc1In Spartina alterniflora systems, periwinkle snails (prey) munch on dead plant material (detritus) lying on the ground or fungus growing on the Spartina leaves that hover over the ground.  Actually, according to Dr. B. Silliman at the University of Florida, these snails farm fungus by slicing open the Spartina leaves, which are then colonized by a fungal infection.  If snails fungal farm too much, then the plant will eventually become stressed and die.

So, I wondered if the fear of predators might control the intensity of this fungal farming and plant damage.

For instance, when the tide floods the marsh, snails race (pretty darn fast for a snail!) up plants to avoid the influx of hungry predators such as the blue crab.

After thinking about this image for a while, I wondered whether water full of predator cues might enhance fungal farming by causing the snail to remain away from the risky ground even during low tide.  Eventually, the snail would get hungry and need to eat, right?  Hence, my hypothesis about enhanced fungal farming due to predator cues.   I also wondered how much of this dynamic might depend on the schedule of the tide.

Before delving into how I answered these questions, you are probably wondering whether this nuance really matters in such a complicated world.  Fair enough, and so did I.

Addressing this doubt, I looked all around our coastline for any confirmatory signs and found that Spartina was less productive and had a lot more snail-farming scars along shorelines subjected to a diurnal tidal schedule (12 hours flood and 12 hours ebb each day) when compared to shorelines subjected to a mixed semidiurnal schedule (2 low tides interspersed among 2 high tides that are each 6 hours).  Even cooler, this pattern occurred despite there being equal numbers of snails and predators along both shorelines; obviously density or consumption effects are not driving this pattern.

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Ok, with this observation, I felt more confident in carrying out a pretty crazy laboratory experiment to see if my hypothesis might provide an explanation.

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Enter Bobby Henderson.  This skilled wizard constructed a system that allowed me to manipulate tides within tanks and therefore mimic natural marsh systems; well, at least more so than does a system of buckets that ignore the tides.

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Within each row of tide (blue or red), I randomly assigned each tank a particular predator treatment.  These treatments allowed me to dictate not only whether predators were present but whether they could consume & frighten snails versus just frightening them:

-Spartina only

-Spartina and snails

-Spartina, snails, and crown conch (predator)

-Spartina, snails, blue crab (predator)

-Spartina, snails, crown conch and blue crab (multiple predators)

-Spartina, snails, cue of crown conch (non-lethal predator)

-Spartina, snails, cue of blue crab (non-lethal predator)

-Spartina, snails, cues of crown conch and blue crab (non-lethal multiple predators)

attach.msc6After a few weeks, I found out the following:

(1) Predators caused snails to ascend Spartina regardless of tide and predator identity.  In other words, any predator cue and tide did the job in terms of scaring the dickens out of snails.

(2) Regardless of tide, blue crabs ate a lot more snails than did the slow moving crown conch and together they ate even more.  This ain’t rocket science!

(3) In this refuge from the predators, snails in the diurnal tide wacked away at the marsh while snails in the mixed tide had no effect on the marsh.

diurnal-mixed_2box

Whoa…the tidal schedule totally dictated whether predator cues indirectly benefitted or harmed Spartina through their direct effects on snail predator-avoidance and farming behavior.  And, this matches the observations in nature… pretty cool story about how the same assemblage of predator and prey can dance to a different tune when put in a slightly different environment.  This study will soon be published in the journal Ecology.  But until its publication, you can check out a more formal summary of this study here.

If this sort of thing happens just along a relatively small portion of our coastline, I can’t wait to see what comes of our data from the oyster experiment, which was conducted over 1,000 km.

Till next time,

David

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

Scared hungry?

Dr. Randall Hughes FSU Coastal & Marine Lab

A hardhead catfish, one of a mud crab's primary predators on North Florida oyster reefs.

IGOR chip_ predators_NCE 150As David has mentioned previously, predators can affect their prey by eating them (a very large effect to the prey individual concerned!) or by changing their behavior. And exactly how the prey change their behavior can have large consequences for the things that they eat. For instance, if you’re out camping and hear a bear lumbering around, do you quickly pack up all your food and put it out of reach of the bear and yourself? Or do you quickly eat as much as you can?

This summer we worked with Kelly, an undergraduate from Bridgewater College, to document how mud crabs deal with this dilemma of getting enough to eat but not getting eaten themselves.

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Kelly with the broken down truck on an ill-fated return trip from St. Augustine.

Specifically, we wanted to know how they respond to the presence or absence of catfish, and how this response affects the survival of juvenile oysters. Sounds straightforward, right? Well, yes, in concept, but as Kelly quickly discovered, putting that “on paper” concept into reality at the lab took a lot of time and effort!

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First, she had to get the “mesocosms” (aka large tubs) ready to serve as adequate habitat for the crabs, with plenty of sand and dead oyster shell for them to hide in.

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Next, Kelly took individual juvenile oysters, or “spat”, and used a marine adhesive to attach them to small tiles that we could distribute among all of the mesocosms.

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Juvenile oysters attached with Zspar (a marine adhesive) to a tile so we could assess mud crab predation.

 

You may have noticed that I mentioned catfish, and that these mesocosms are not particularly large relative to the size of a catfish. Never fear – because we wanted to separate the effects of catfish cues from the effects of catfish actually eating mudcrabs, the catfish were kept in a much larger tank, and then water from this tank was pumped into the mesocosms receiving catfish cues. (Setting up the pump and tubing to 60+ tanks was a several-day effort in itself!)

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The catfish tank, with tubing carrying catfish "cues" to individual mesocosms.

Once everything was in place, it was time to collect the mud crabs. We couldn’t collect the crabs gradually, because they like to eat each other when confined in small spaces in the lab, so we garnered as much help as we could and held our own little mud crab rodeo. (And got caught in quite a thunderstorm in Alligator Harbor, but that’s another story).

Finally, it was time to start the experiment! We measured the size of each of the mud crabs, added them to the mesocosms, and let them eat (or not). Each day, Kelly would count the number of live oysters remaining, and she would remove a few mud crabs from some of the mesocosms to simulate catfish predation. There were a lot of moving parts to this experiment, and Kelly did a great job managing it!

And what did we find? Turns out that individual mud crabs actually eat more juvenile oysters when they are exposed to catfish cues and the removal / disappearance of some of their neighboring mud crabs, compared to just the removal of neighboring mud crabs or the absence of catfish cues. But overall, the the removal of mud crabs have a positive effect on oyster survival. (Even though individual crabs may eat more, there are not as many crabs around, so it’s a net positive for oysters.)

Slide1

Mud crabs ate more oysters per individual in buckets with exposure to catfish cues and high rates of manual removal of mud crabs (to simulate predation).

Kelly has returned to classes, so we’ve now recruited a new assistant, Meagan, to help us with an experiment to address the additional questions that inevitably arise as you learn more about a system – for example, do mud crabs behave differently if catfish are around all the time versus only some of the time? We’ll keep you posted…

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

Switching gears: from kayak to office cubicle

Hanna Garland FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150As fast as summer approached, it is now over; and for myself, it marks the closing of an intense field season and the beginning of my first year as a graduate student. However, this does not mean that the experiments, laboratory work, and data collection is put on hold. There is still plenty of work to check off the “to do” list that seems to never get any shorter.

My last post introduced the scientific question I was hoping to answer and the reason for studying the relationship between crown conchs and oysters in the Matanzas River as opposed to a different location. While I did not answer the question entirely (that would be far too difficult to accomplish in one summer), I was able to establish a strong, preliminary data set that I can now analyze and re-configure in order to improve upon this research next season.

Similar to methods described in David and Tanya’s posts, the construction of my experiment consisted of (much smaller) trenches dug for cage installation, Z-spar for attaching oyster spat to tiles, bumblebee bee tagging kits for marking appropriately weighed and measured oyster clusters, and various amounts of PVC for expensive data logger equipment housing. The fun meter never stopped ticking this summer in St. Augustine!

As I sit in my cubicle in my new office on campus, my mind cannot help but wander back to my life this summer driven by the time of low tide and whether I would have enough sunlight or energy to kayak out to one more site. To my surprise, the running of my experiment was manageable and actually became a relaxing routine. Data collection was divided into three categories: conch surveys, oyster health, and data logger maintenance. The number of conchs found on the experimental reefs was recorded in order to quantify the varying densities of these predators at each site. The health of the small oysters attached to tiles as well as the tagged larger clusters were assessed based on the number of live and dead. The data logging instruments record the water temperature, salinity and amount of tidal inundation occurring at each of my six experimental oyster reefs every five minutes (so there are a lot of data points to be analyzed here!) and require periodic scrubbing to remove algal and barnacle growth.

While the daily workload may seem light as far as stress levels; the fine print of every step of an experiment can be a tremendous mix of emotions. The hope for not just data but “good” data is something that all scientists share; however, this does not mean that conducting research needs to be filled with anxiety. The outlook that I aimed to have this summer was more based on the feelings of excitement and opportunity rather than high expectations that may or may not be met. To be able to conduct this study in such an ecologically rich environment surrounded by intelligent, supportive, and proactive people and institutions is an accomplishment in itself.

While my data set still requires endless hours of manipulation and analysis, the general outcome of my experiment this summer revealed that there is in fact an oyster health gradient occurring along the Matanzas River, with a change in health occurring around the Matanzas Inlet. In tandem with this increasing oyster mortality moving from my sites north of the inlet to the sites south; are high densities of crown conch populations on the southern reefs, with a decrease in these populations moving towards reefs north of the inlet. Furthermore, environmental factors (water temperature, salinity and tidal inundation data collected by my instruments) will be considered when looking at these patterns.

As a way to better quantify the health and size of the oyster community as well as the density of the resident species (such as crabs, worms, and other amphipods) that inhabit oyster reefs; I surveyed and sampled background reefs at each of my six experimental sites. Long story short, this meant that I randomly selected four new oyster reefs at each site in which I collected environmental data and basic reef characteristics (type of reef, location, dimensions), conducted conch surveys, and collected every living oyster cluster, dead shell, crab, piece of biota, etc. inside of a 0.25 x 0.25 meter quadrat. After washing away the mud, extracting the living organisms and preserving them in ethanol, and weighing, measuring, and recording each live and dead oyster, I have developed a solid database of the oyster reef communities at each of my sites. This will help to better describe the type and abundance of species present at each site.

Oyster reef communities impact us in more ways than providing a tasty appetizer at a restaurant. Not only do they provide a habitat for commercially and ecologically important species, but they also serve to locally improve water quality and prevent erosion. Oyster reefs are complex communities that are in a state of decline along the Florida coast. Unfortunately, unhealthy oysters cause unhealthy or collapsed resident species communities because these organisms depend on oyster reef habitats for food, shelter, and other important aspects of their life cycle. This experiment and preliminary data set provides insight to changing food web dynamics occurring not only along the Matanzas River but in all oyster reef communities.

Apalachicola oysters

Tasty as they are, oysters have a far greater ecological- and economical- value when they're alive in their oyster reefs.

Whether you are enjoying seafood for dinner or driving on a bridge over estuarine environments, keep in mind the important role each individual species plays in a larger community structure. Our actions upstream of these fragile habitats impact everything from microscopic worms to the maturing oyster spat and larger fish populations. As my project evolves, I hope to not only strengthen the scientific community but also raise awareness among people who unknowingly influence an aspect of oyster reef habitats.

 

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.

Cheers,
David

David’s research is funded by the National Science Foundation.
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Horse Conchs Rule the Seagrass Bed

In the Grass, On the Reef: Testing the Ecology of Fear

Premieres on WFSU-TV Wednesday, June 29 at 7:30 PM, 6:30 CT.  In high definition where available.

Rob Diaz de Villegas WFSU-TV

IGOR_chip_predators_NCE_100This clip is a short segment on one of the predators featured in this program: the horse conch.  It’s practically an ecosystem onto itself, as you can see in the video’s poster frame above.  Barnacles, crepidula, bryozoans, and other marine creatures that affix themselves to hard surfaces settle on its shell.  In the video you’ll see its bright orange body as it roams the seagrass beds of the Forgotten Coast.  And you’ll see it eat another large predatory snail, the lightning whelk.

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