Tag Archives: St. Joe Bay

Winter in the marsh

Dr. Randall Hughes FSU Coastal & Marine Lab
Vacuuming bugs out of wrack

Emily and Hanna, in matching green waders, vacuum bugs on "Island 4."

IGOR chip- employment 150IGOR chip- biodiversity 150It has been COLD the last few times we’ve been out in the field. The first time (described accurately by Rob), we did not have sufficient cold weather field gear – David lent us some emergency use chest waders that he had on hand, and they were much appreciated despite the fact that we looked really silly and they were all split open at the feet by the end of the day!

Immediately upon my return to the lab, I ordered my team the trusty neoprene chest waders that I used throughout graduate school in northern California. As Emily and I can attest after going out twice more in the cold since then, they make a big difference!

Winter field gear

Newly purchased neoprene waders and fingerless gloves for winter field work.

Aside from the change in attire, what else is different in the cold? Most obvious is that many of the cordgrass stems in our survey plots are dead. In marshes north of here, the above-ground portions of the plant will actually die back completely in the winter, re-sprouting from below-ground reserves in the spring. Here, there are fewer stems overall, and certainly fewer bright green live ones, but the plants will continue to slowly put up new stems throughout the winter.

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The photos above are of Island 4 over the course of WFSU's documenting this work. The photo on the left is from May 13. The one in the center was taken at the end of Summer. You can see the grass is taller and more verdant, with cordgrass reproductive shoots popping up over the blades. The last photo is from the first of December.

The cordgrass reproductive stems are also now dead – most of them dropped their seeds in late November / early December, so they have done their job. Emily and I made a special trip to all of our survey sites a week or so ago to set out “seed traps”. And what, exactly, is a seed trap? In this case, it’s a Styrofoam bowl lined with Tanglefoot, the incredibly sticky substance that we use on our mesocosms to keep snails from climbing out.

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Any seeds (or seagrass wrack, other plant material, bugs, or anything else, really) that fall into the bowl will stick, allowing us to count the number of seeds that get to each area. We are particularly interested in whether seagrass wrack abundance increases or decreases the number of seeds in an area. We’ll go back in January to pick them up and start counting.

We have some plants in the greenhouse that we’re growing for experiments this spring, and they have been getting a little extra TLC on these cold, cold nights. We cover them with frost blankets at the end of the day, and then uncover them again in the mornings when it’s warmed up a bit. They seem to like the extra warmth!

Frost blankets in the greenhouse

Our greenhouse tables covered in (appropriately) green frost blankets on cold winter nights.

From a logistics perspective, the winter is pretty different for a number of reasons. First, it’s harder to find people available to go in the field. (And on really cold days, it’s not very appealing!) Emily will be back on campus taking and teaching classes next semester, so we’ll probably have to do some portion of the monthly surveys over the weekend, hopefully with the help of some undergraduate interns.

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Looks like we're walking.

The second logistical challenge is the change in the tides. For most of the year, the low tide is in the evening / night, so it is easiest to kayak to our sites during the morning and early afternoon. In the winter, the low tide shifts to the middle of the day, and it’s often made even lower by a strong north wind, making it virtually impossible to kayak anywhere during daylight hours!

Our solution is to walk to the sites that we can, and kayak as close as we can to the others before we start walking. It’s a good thing that St. Joe Bay is shallow!

In January, we’ll be sampling fishes and small crabs in the marsh. We do this every couple of months to see how the abundance of the more mobile marsh community members changes seasonally. I don’t expect that we’ll find much, but I’ll let you know!

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

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.

Stjoe_wind

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!

Just one more thing…

Dr. Randall Hughes FSU Coastal & Marine Lab
Setting up a tank experiment

Emily and Robyn setting up yet another tank experiment that I've dreamed up. (Thanks to Nancy Smith for the pic!)

IGOR chip- biodiversity 150Because of the big focus on oysters over the last month, it may seem as if we haven’t been doing anything “In the grass”. We’ve been busy, though, trying to squeeze in a few additional surveys and experiments in November before it gets cold enough that the animals stop eating (or eating very much, I should say) and the plants stop growing. For a while there, I was coming up with so many end of season ideas that I’m pretty sure my crew hated to see me coming!  We just did finish up before the winter weather arrived (early) in December. (More on what it’s like working in this cold weather in future posts.)

We actually missed the opportunity to do one of our planned studies involving grasshoppers – there was a cold snap two nights before we went in the field to get the hoppers, and they were nowhere to be found.   Those data will have to wait until next spring when the grasshoppers turn up again!

We’ve had better luck with two other projects –

1. Do snails prefer to climb on cordgrass reproductive stems?

More snails climbing on cordgrass reproductive stems

Snails climbing on cordgrass reproductive stems in the field.

Spartina reproductive shoot

A tasty snack for a periwinkle snail?

I’ve mentioned before on the blog that we noticed lots of snails climbing on cordgrass reproductive stems this fall. In collaboration with David and his team, we visited marsh sites along the Panhandle to see if our observations would be supported with rigorously collected data. So far, so good!

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The trusty tank set-up at FSUCML.

We also started a series of experiments in our trusty tanks at the FSU marine lab to tease apart why snails may have this preference: Do the snails simply like that the reproductive stems are taller than regular stems? Or do the reproductive stems “taste” better because of greater nutrient content? Does it matter if predators are present or not? The preliminary results suggest that they like the reproductive stems, regardless of whether they are taller or not. In January, we’ll head into the lab to do the tests for nutrient content that should help us to tease apart why that may be.

2. Does needlerush provide a better predation refuge than cordgrass?

A patch of needlerush surrounded by cordgrass

Needlerush (center patch) is typically much taller than cordgrass (surrounding area) in St. Joe Bay

Last fall I did a tank experiment to look at whether snails prefer to climb on another marsh plant species, needlerush (Juncus roemerianus), and whether this preference increased snail survival when predators were around. The results were interesting, but as usual, the first round of the experiment created additional questions that required more work. In November we started a similar experiment, again in the tanks at the marine lab, looking at snail climbing behavior on needlerush and cordgrass in the presence and absence of the snail’s nemesis, the blue crab.

Needlerush is naturally taller than cordgrass, so to test if this difference in height can explain snail behavior, we “experimentally manipulated” (in other words, used scissors to cut the needlerush down to a shorter height) needlerush height: some tanks have naturally tall needlerush, some have needlerush that is on average the same height as the cordgrass, and some have needlerush that is shorter than the cordgrass. Add a blue crab to half of the tanks, and voilà, the experiment is underway!

blue crabIt’s a bit ironic that each of the experiments we recently finished converged on a similar idea – snails appear to prefer to climb on taller plants. Considering that the taller the plant, the farther they can climb away from predators in the water, it makes sense. The true question is to figure out whether and why it matters that the snails do this. If they climb on reproductive stems, are fewer cordgrass seeds produced? What will that mean for next year’s crop of cordgrass? Also, if snails spend a lot of time hanging out on needlerush to avoid predators, does that mean they don’t eat as much cordgrass? Knowing things as seemingly arcane as which plant a snail prefers to climb on can help us predict and manage the overall abundance and productivity of cordgrass, and the salt marsh in general. And of course, the field work and experiments are fun! Especially when you get to wrestle with blue crabs…

Here are some photos of periwinkle snails in Randall’s latest tank experiments:

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

Did You Say Mangroves?

Dr. Randall Hughes FSU Coastal & Marine Lab

Ed Proffitt and Randall Hughes by a black mangrove

Ed Proffitt with Randall Hughes. If global climate trends continue, mangroves may start to overtake the salt marsh ecosystem along the Gulf coast. What will these new habitats look like?

IGOR chip- biodiversity 150A few weeks ago, Dr. Ed Proffitt from Florida Atlantic University visited FSUCML to give a seminar here and on campus. Ed and I have collaborated on several proposals, so we used the visit as an opportunity to get out in the field and toss around some new ideas.

Ed has done some really interesting work on the interactions between mangroves and salt marsh plants in Tampa Bay and the Indian River Lagoon, and he wanted to see some mangroves in this area. I recalled having seen a few young red mangroves last year at some of our sites, but none of them survived this past winter (which is why we generally don’t find them around here – they can’t withstand the cold temperatures that we get every few years). However, black mangroves do extend into this portion of the Gulf, and I knew of a place where we may find one or two small ones to look at.

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Black mangrove (Avicennia) growing in St. Joe Bay

To my surprise, we found a lot more than one or two! And although they are small (think small shrub, rather than tree), some of them, such as the one shown here, had aerial roots extending out 14-15m, suggesting that they have been around at least 5-10 years (by our best guess).

black mangrove flower

Avicennia flower. These mangroves are insect-pollinated, and we saw lots of bees buzzing around.

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Avicennia propagules growing on the maternal tree.

Also, most of the larger ones had both flowers and propagules (seedlings that are retained on the tree) on them.

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Avicennia propagule that has dropped to the ground and started to take root.

As we looked around, we noticed more and more small mangroves in the marsh – probably the seedlings from some of the nearby larger trees – and we even found some of this year’s propagules that were starting to root in the sediment.

As I mentioned, black mangroves are known to grow in the Panhandle and west into Louisiana and Texas, so it really isn’t that surprising that we found them in St. Joe Bay. What is surprising, at least to me, is that they are as abundant as they are in a site where I previously thought there were only a few. Where else may they be in the bay? And are they increasing in abundance each year? What impact do they have on the marsh plants and animals? The questions abound. With our curiosity and Ed’s insight and experience, we are now starting to pursue the answers.

Randall’s research is funded by the National Science Foundation.
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The Making of a Softshell Crab

Rob Diaz de Villegas WFSU-TV

IGOR chip- habitat 150To clarify, we are looking at the biological process through which a blue crab molts its shell, not recipes (feel free though, to share your favorites in the comments area).  I have to admit that before I started this project, I had thought that softshell crabs were a specific species, or group of species.  Of course, such a species wouldn’t survive very well in the wild. Continue reading