Last week, David and I (along with all the students and technicians in our labs, and over 500 other ecologists/students) attended the Benthic Ecology Meeting in Mobile, AL. You may well wonder – what goes on at a meeting of ecologists? And what does “benthic” mean anyway?
Emily and Robyn setting up yet another tank experiment that I've dreamed up. (Thanks to Nancy Smith for the pic!)
Because 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!
Snails climbing on cordgrass reproductive stems in the field.
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!
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?
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!
It’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.
Last week we had a post on what it was like on an oyster reef, the idea being that many people have never really seen one. Continuing with that theme, I thought it might be interesting to take a closer look into a salt marsh. This is a trickier proposition because, well, what is a typical salt marsh? Some of them grow in muddy waters next to oyster reefs, or they can be found along beaches, in wide expanses or in small islands just off the coast. I’ll keep today’s imaginary journey confined to marshes in St. Joseph Bay, where Randall Hughes conducts her biodiversity study- that is what I am most familiar with.
The Panhandle has been my home for most of my life and the older I get, the more fun I have looking at – and photographing – it in an “up close and personal” manner.
There is great fun in “really seeing” something for the first time and being surprised by just how beautiful it is.
The slideshow above was photographed by Beth at Alligator Point, not too far from where David Kimbro is studying oyster reefs, and many of the photos are of salt marshes, such as those studied by Randall Hughes. So I knew when I saw them that they would be a great fit for this site.
You may know Beth Switzer as Executive Director and on camera personality at The Florida Channel, and before that on WFSU-TV. I was surprised, after years of watching and occasionally working with her, to discover that she liked to photograph nature. What’s not surprising is that she has forged a connection with the natural splendor of our area. Those of us working in broadcasting in the panhandle end up seeing a lot of the area, and meeting a lot of the people. It’s impossible to work in TV here and not love it here.
We’re two months into “In the Grass, On the Reef,” and so far the winds have been kind to Randall and David’s sites in St. Joseph Bay an Alligator Harbor. When Deepwater Horizon exploded, we stepped up production on the project thinking that oil would arrive at any moment, and that we should get as much footage as we could before it hit. Now, the more I go to these places, the less I think about oil while I’m there. I hear about it on the radio as I’m driving to and from the shoots, but then I’m walking in water, planting my tripod in mud to get a steady shot of a periwinkle climbing a blade of cordgrass, or trying to see through my lens a stone crab that looks only slightly different than the oysters surrounding it. In those moments, it just doesn’t feel like it will happen. I know it will most likely happen, but it never feels like it will.
One of the pleasant developments of doing this has been having artist features like the one above. So far we have had photographers and musicians, and we are talking to some writers as well. We want to hear from artists in any medium who depict or are inspired by the coastal habitats of the Forgotten Coast. Photographers, painters, musicians, writers: share your art with us! You can e-mail us at firstname.lastname@example.org.
And, as always, comments and questions are welcome.
Watch Dr. Hughes’ species diversity experiment. The results could help determine how best to restore marshes affected by oil.
With oil arriving on FL beaches, the race is on. We’ll be out in our sites this week collecting more data. We want to be sure that we know as much as possible about:
(1) the condition of our sites before oil arrives;
(2) the amount and specific location of any oil that does reach our sites; and
(3) the response of the marsh plants and animals to this oil.
We expect that there will be considerable variability in the degree and extent of damage to our sites, both because oil exposure will likely be patchy (at least at first), and because marshes are likely to differ in their ability to either withstand or recover from oil. And this variation in marsh response provides a prime opportunity for us to learn more about the specific marsh characteristics that either hinder or promote recovery, information that could be valuable in the aftermath of this disaster.
"marsh 2," location of the species diversity experiment
One aspect of marshes that may aid in the response to oil is plant species diversity. A substantial number of scientific studies in the ocean and on land illustrate that having more species in an area can reduce the impacts of disturbance. For example, research by David Tilman and colleagues shows that drought impacts are less severe in Minnesota grasslands with more plant species. A number of different processes can contribute to these positive effects of diversity, but they generally result from the fact that individual species typically differ in their life history (the timing of growth, reproduction, etc.) and in their response to specific disturbances. Thus, if you have more species, you’re more likely to contain one or two that are able to withstand disturbance as it occurs, or that are able to re-grow quickly following the disturbance.
So, back to salt marshes and oil. We know from previous studies that different marsh plants have different tolerances for oil (1,2). Because the chances of a more tolerant plant species being present are greater when there are more plant species around, it seems possible that marsh plant diversity could reduce the negative impacts of oil exposure. We’ll get some idea of whether or not this is the case from our surveys of natural marshes – we know the plant species diversity before oil gets there, and we’ll be able to record the impacts to the marsh once oil arrives to see if the negative effects are reduced in areas with more species. But to get the “real” story (i.e., a story not complicated by characteristics other than plant species diversity that vary from marsh to marsh), we need to do an experiment.
Recently, we did just that – we set up an experiment to test whether marshes (“plots”) with more species (3) are less impacted by oil than marshes with few species (1). 3 species may not seem particularly diverse, but it’s on par with what we find in natural marshes. There’s a chance that our experimental site won’t get any oil, which quite honestly will be fine by me. (In that case, we’ll simply look at how marsh productivity and growth differ due to marsh plant species diversity.) But, if it does, we’ll be positioned to examine how marsh plant species diversity affects the response to oil contamination.
Randall’s research is funded by the National Science Foundation.
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