Tag Archives: crown conch

Cold and Wet: Field Research in the Winter

Waves on Cape San Blas rocks

Rob Diaz de Villegas WFSU-TV

IGOR chip- employment 150I was driving to Stump Hole with my production assistant Kevin when we saw these waves crashing on the rocks on the beach side of Cape San Blas.  Like any good production people, we knew the only thing to do was to climb the rocks and get footage and stills of the scene.  The same wind pushing the waves at us rocked us a little bit as we balanced- only slightly precariously- on the big stones.  It was a little after 8:30 AM and we had some time to kill before Randall and her team showed up.  And then we would kayak into the bay just across the street.

In early December I made my first winter forays into coastal environments.  Randall has already written about the seasonal shift from Summer to Autumn, where the flora and fauna are reproducing and animals are abundant in the marshes.  Winter is an entirely different beast, as I would see when we got to their sites.  But first, we actually had to get to these sites.

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After everyone was there, we kayaked east from Stump Hole with a stiff north wind pushing us on our left.  Rowing to the left was like rowing into a wall, and there were a couple of marshes in our way where we had to get out and lug the kayaks to the other side.  Saltwater splashed into my eyes and onto my glasses.  I kept my squinty eyes forward and we got to a site that for the purposes of this study is known as Island 4.

The research crew went about their normal survey work, with Randall taking a quadrat to several specific spots within the marsh to see how much grass and other species were within its PVC boundary, how tall the grass is and how many Spartina shoots were dead.  Using markers and a GPS, they’ll have data from these precise spots over a span of three years.  Emily and Hanna vacuumed bugs out of the grass and surveyed seagrass wrack.  They will, as always, search for patterns over time, and I suspect the data collected in the winter months will quantify some of what we saw with our own eyes.

Sea Urchin shell washed up on marsh

While we didn't see the usual critters swimming and crawling about, some cool stuff washed in from the bay, such as sponges, lightning whelk egg casings, and this sea urchin shell.

Last time I was at this site, some male blue crabs were fighting over a female.  They were so engrossed that I was able to get fairly close without their bolting away.  All manner of predatory snails oozed about, little fish darted in and out of the sparse shoots at the periphery, and a ray laid low in an adjacent seagrass bed.  Today it looked like they had all packed up and left for the season.  And, when it came time to go our next site, so had the water in the bay.

A combination of the tide and the strong wind left the south side of the bay somewhat empty.  Taking a few steps with our kayaks in hand, we decided instead to leave them at the island while we walked our gear over to a mainland marsh known as Wrack 5.

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This was another site where I had always seen an abundance of fauna. Hundreds, sometimes thousands of fiddler crabs would scurry away from me into the grass in this one corner of the marsh.  As Randall explained to me, the fiddlers bury themselves in the winter.  Blue crabs swim into the deeper part of the bay, to the north.  Randall didn’t know exactly what happened to the crown conchs, though when digging cordgrass up for an experiment she had come upon a buried conch.  And with their predators all gone, the marsh periwinkles had descended to the bottom of the spartina plants.

Lightning Whelk shellOne thing I did see a lot of were lightning whelk shells.  I picked them up and looked inside, wondering, are they more cold tolerant than the other species?  They’re not.  But their shells were pretty.

The following Monday I went to Alligator Harbor with Tanya and Hanna, and it was a lot of the same.  We dragged our kayaks from the ramp to the first site and walked between the islands to the second and third sites.  It was a much muckier walk than in St. Joe Bay (the oysters like it mucky), and I was breaking in a new pair of crappy old sneakers to be my oyster reef shoes.  This is how they fared:

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Now that I’ve muddied my hands pulling my shoe out, where’s all that water?

Have any of you trekked out into the cold coastal waters this season? Share your stories!

Day 6: October Oyster Push- Home Stretch

Rob Diaz de Villegas WFSU-TV

Wednesday, October 27- Finish tiles, go to Jacksonville

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

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

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

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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.

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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…

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

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

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

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Day 5: October Oyster Push- A Change of Plans

Rob Diaz de Villegas WFSU-TV

Tuesday, October 26- Tile Team heads to Jacksonville

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

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

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

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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:

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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.

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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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Day 4: October Oyster Push “Sweet Boat”

Rob Diaz de Villegas WFSU-TV
David Kimbro’s crew has been split into two teams, the Net/Trap team (N/T) and the Tile team (TI). For a closer look at how David’s team nets and traps larger fish and crabs, click here. To learn more about what the Tile team will be doing, click here. And if you click On the Reef under categories in the sidebar, you can track David’s progress over the course of this study.

Monday, October 25- Both teams in Saint Augustine

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That grey spot (dead center) on the shell is spat. After landing on existing shells, they'll build their own and expand the clump.

IGOR chip- biogeographic 150When I got to St. Augustine, David was chiseling out shards of shell containing oyster spat (baby oysters) from clumps so that he could glue them onto tiles, as he described in Friday’s post.  I got a good look at what spat actually was.  You can see it in the photo here, basically a small oyster with no shell, seeking out a hard surface (often another oyster’s shell) upon which to settle.  David stayed behind doing that as the rest of his crew, and our crew, piled into the boat for this evening’s activities.

This new experiment- placing tiles with the same number of oyster recruits at all sites on every reef across the study- will give them a more precise picture of how young oysters survive at each site.  It also means a lot of extra work, as the spat that goes on the tiles has to be from the specific location to be entirely accurate- spat is harvested one day, immediately chiseled off and made into tiles and placed on the reef, in the span of about two days.  And this is in addition to the other sampling and trapping.  The previous tile method worked fairly well for the NC and SC/GA teams, but for the sake of being consistent, they’ve also had to adapt this method (while cursing David Kimbro’s name).

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Crown conchs in St. Augustine making a snack of an oyster.

As previously noted on this blog, the reefs did have plenty of crown conchs crawling on them.  David and Tanya have also started noticing Atlantic Oyster Drills, a smaller snail we don’t see in the Gulf.  I’ll look for some tomorrow and get a photo or two up.

8:00 AM- Hanna and Randall (N/T team) retrieved the nets that they set last night in Cedar Key.  This is low tide work, as that’s when it’s best to empty the nets.  They got to their first reef after the vultures did, losing a bit of their catch but still able to identify some species from the fish heads left behind.

1:00 PM- Hanna headed to Saint Augustine and Randall headed home.  As Hanna was gassing up the truck and boat, an elderly gentlemen circled the boat, in awe of David’s creation.  Eventually, he said, “sweet boat.”

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A sweet boat.

5:00 PM- Deploy nets, take water samples, and reference water level.  The two teams combined activities that would have kept them out past dark, and finished just as the sun was setting.  They then helped David glue spat onto tiles for another hour or so before heading out to dinner.

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That was the day.  As you see, field work involves a lot of rethinking (as in the tile experiment), thinking on your feet, dealing with circumstances (vultures eating your catch), and coming up with unusual solutions (refitting your boat in a way some might find strange).  It’s pretty late now (as I type this, even though I plan to post this in the morning).  Time to head to bed so that I can get up and shoot that sunrise.

Tide Times and height (ft.) for Cedar Key, October 24, 2010
Low- 10:oo AM (-0.3)
Tide Times and height (ft.) for Saint Augustine, October 25, 2010
High- 1:35 PM (5.3)
Low- 8:41 PM (0.6)

We’d love to hear from you! Leave your comments and questions below:

The search for patterns

Dr. Randall Hughes FSU Coastal & Marine Lab

IGOR chip- biodiversity 150The end of summer is a good time to pause and think about any general patterns that emerge from observations over the course of the last year(s). Sometimes it is easy to get swept up in the minutiae of individual projects and forget about the big picture. Of course, these patterns aren’t definitive (i.e., don’t quote me on this!), but they can be useful to think about, particularly when considering future avenues of research.

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Marsh island in St. Joe Bay viewed from the waterand marshes on the edge of the mainland.

So what sort of patterns can I describe to you after two summers in the marshes of St. Joe Bay? One that doesn’t take a PhD to recognize is that there are two distinct types of marshes that we sample: marsh islands and marshes on the edge of the mainland.

But aside from the obvious fact that one is an island and the other is not, there are some additional interesting differences:

1. The slope of marsh islands is typically greater than mainland marshes, so that you move quickly from plants that can tolerate frequent flooding (cordgrass) to plants that are more “terrestrial” (pickleweed, saltwort, etc.). On islands this transition can occur within a few steps of the water’s edge, whereas mainland marshes typically have a large area (I like to think of it as a football field) dominated by cordgrass.

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Elevation on islands changes rapidly compared to the mainland. Even slight differences in height can influence plant communities.

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Sampling a mainland marsh in St. Joe Bay.

2. Marsh islands tend to have fewer periwinkle snails than mainland sites, although they are certainly present.

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Abundant snails in a mainland marsh.

My guess is that the snail predators (blue crabs, crown conchs) that lurk just at the water’s edge have greater access to snails on the islands at high tide, because they can move in from all sides of the island. In contrast, the predators near mainland sites have only one point of entry into the marsh.

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Blue crab lurking in the seagrass at the edge of the marsh during low tide.

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Crown conch foraging for snails in a lab experiment.

3. Perhaps not surprisingly given that they are surrounded by water, the marsh islands typically have fewer grasshoppers jumping around. We’ve also had far fewer snake encounters on islands, which I consider a good thing. Probably because land-based predators such as snakes, raccoons, etc., are less frequent on islands, we also observe greater numbers of nesting birds on the islands than at mainland sites.

4. One clear difference that I can’t explain but hope to examine in the future is that cordgrass plants collected from the islands (which can only be done with a special permit from the Department of Environmental Protection) survive better in our greenhouse at the lab than those from mainlands. It may simply be the growing conditions, or island plants may be hardier overall. Stay tuned.

As we continue to process, enter, and analyze data, there should be additional trends emerging. And we’ll likely find out that some of the patterns we think we see don’t hold up to the test of actual data. And so goes the process of science!

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