Category Archives: Salt Marsh Ecology | In the Grass

 

Dr. Randall Hughes, among other things, studies biodiversity in salt marshes, and how it affects the habitat’s ability to cope with disturbances.  Does having a greater variety of plant species benefit a salt marsh?  Does having more genetic individuals of smooth cordgrass help when environmental or man made catastrophes strike?  Randall is looking at several factors, from the animals that eat the cordgrass (the foundation species of the marsh), to which combinations of plants work best together, or how seagrass wrack affects the health of a marsh.

Most of her study is centered on St. Joseph Bay, on Florida’s Gulf coast.  On this blog you will also see some of her side projects looking at black mangroves are starting to become more prevalent in Gulf salt marshes and why seagrass beds around the world are dying off.

 

Meet the animals of a coastal salt marsh.

Kayaking Bald Point | Adventure on a Living Coastline

At Bald Point State Park, we kayak past a little bit of everything that defines Florida’s Forgotten Coast.

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Rob Diaz de Villegas WFSU Public Media

When we get to the mouth of Chaires Creek, the tide has gone out enough to see the tops of some oysters.  It’s a little after 1 pm-  high tide was 10:16 am, and low tide is 4:02 pm.  If we stay too much longer, the mouth of the creek will be choked by oyster bars, and sand bars will make the kayak back to Tucker Lake slow going.

Continue reading Kayaking Bald Point | Adventure on a Living Coastline

Crown Conchs, Parenting, and Walks Along the Gulf Coast

We’re pleased to introduce our newest blogger, Jessie Mutz. A graduate student in the Florida State University Department of Biological Science, Jessie will be taking a closer look at some of the many fascinating plants and animals in our area. In the process, she’ll introduce us to FSU students and faculty conducting research across various ecosystems.  She starts in a place familiar to this blog when it comes to FSU research- our very own Forgotten Coast.
Jessie Mutz Graduate Student, FSU Department of Biological Science

With summertime officially and emphatically here in North Florida, many of us are coastward bound. Like long walks on the beach?  As it turns out, you’re not the only one.

Low tide on the Gulf Coast. Photo by Scott Burgess.
Low tide at the FSU Coastal & Marine Lab, St. Teresa, FL. Photo by Scott Burgess.

Meet Dr. Scott Burgess, a marine evolutionary ecologist and one of the newest faculty in FSU’s Department of Biological Science. Although it’s only the start of his first full summer in Tallahassee, Scott has already been hitting the beach – a prime location for researching the reproductive strategies of intertidal invertebrates like the crown conch, Melongena corona. “This area has a lot of species with an unusual life history type, one that is typically less common in other areas,” he says. “So that’s a big interesting thing: Why are there lots of these weird ones here? Why have all of the species chosen this particular life history in this area of the world?” Continue reading Crown Conchs, Parenting, and Walks Along the Gulf Coast

Does Diversity Matter in the Salt Marsh? A Look Back

Dr. Randall Hughes has collaborated with WFSU on this blog since 2010. We have spent years visiting her research sites in Saint Joseph Bay, where Randall conducted a multi-year study on salt marsh biodiversity funded by the National Science Foundation. The study has concluded, and Randall has published several papers on her findings. Here is what she has found.

This is Saint Joe Bay week on the Ecology Blog.  Wednesday, August 20th, at 7:30 pm ET: WFSU premieres the eighth season of Dimensions, and our Saint Joseph Bay scalloping EcoAdventure. 

Dr. Randall Hughes Northeastern University
Just a bunch of grass? Not to the larval shrimp, juvenile mullet, pinfish, fiddler crabs, mussels, periwinkle snails, and blue crabs that make use of the habitat, or the birds and sea turtles that go hunting there.
Just a bunch of grass? Not to the larval shrimp, juvenile mullet, pinfish, fiddler crabs, mussels, periwinkle snails, and blue crabs that make use of the habitat, or the birds and sea turtles that go hunting there.

As you drive along Highway 98 towards St. Joseph Bay (SJB), one of the most common views outside your window is of the salt marsh.  From the car, it looks like a beautiful but monotonous meadow of green and/or brown, depending on the season, often intersected by tidal channels. So I won’t blame you if “diversity” is not the first word that comes to your mind as you gaze out the window. But diversity is exactly what I set out to find out about when this project first started – how much diversity is there in the marshes of St. Joe Bay, and what (if any) effects does it have? And now, several years later, I finally have answers to share!

Continue reading Does Diversity Matter in the Salt Marsh? A Look Back

Black mangrove propagules.

VIDEO- Mangroves and Cold, & Oyster Doctors Airs on WFSU

Rob Diaz de Villegas WFSU-TV

Wednesday, March 19 at 8 PM on WFSU-TV, catch the broadcast premiere of the new In the Grass, On the Reef documentary: Oyster Doctors.

Withered Black Mangrove
Although it was a relatively mild winter, one or two harsh cold snaps provided Randall an opportunity to test black mangrove survivorship in north Florida marshes, where it has become a more frequent resident.

Lately I’ve been preoccupied with wrapping up the National Science Foundation grant that funds a lot of what appears on this blog, and thinking about the future of the project.  The last major piece of funded content is our latest documentary, Oyster Doctors, chronicling four years of research conducted by Dr. Randall Hughes and Dr. David Kimbro.  On the one hand, the show is about learning how coastal ecosystems work.  And it’s about how the inner workings of salt marshes, oyster reefs, and seagrass beds provide people with jobs, clean water, and protection from erosion and storm surge.  But it’s as much about the ecologists as it is about the ecology.

Randall and David, and their graduate students- Tanya Rogers, Hanna Garland, and Althea Moore– are people who get inspired to pursue a line of research.  They get excited by an idea, like predators affecting prey more through fear than through their eating them.  They get excited about places.  David gets geeked out about predatory snails on Bay Mouth Bar.  Hanna falls in love with Apalachicola and wants to figure out its oyster problem.  Randall makes observations about things she sees in St. Joseph Bay marshes and it sets her on a path.  In one case, that path led her to the video above. Continue reading VIDEO- Mangroves and Cold, & Oyster Doctors Airs on WFSU

Free Events Across Forgotten Coast Celebrate New WFSU Documentary

Update March 9, 2014 – We’d like to thank everyone who came out for one or more of our events on Saturday. It was a pleasure to meet all of you (photos will be posted soon).  If you missed the premiere, Oyster Doctors will air on WFSU-TV on Wednesday March 19, 8 pm/ 7 ct.  Look for it online shortly after.

(L to R) Graduate student Hanna Garland, WFSU videographer Dan Peeri, oysterman Shawn Hartsfield, and WFSU producer Rob Diaz de Villegas look on as Stephanie Buehler dives in to survey oysters in Apalachicola Bay.
Rob Diaz de Villegas WFSU-TV

Almost four years ago, WFSU began the coastal adventure that is In the Grass, On the Reef.  Now, we want you to join the adventure.  And not through the magic of video- we want you physically there with us (but yeah, we’ll still make a video). Continue reading Free Events Across Forgotten Coast Celebrate New WFSU Documentary

Video: Turtles, Octopus, & Crabs at the Gulf Specimen Lab

Video: Critters galore at the Gulf Specimen Marine Lab in Panacea

Rob Diaz de Villegas WFSU-TV
Jack Rudloe feeding Nurse Sharks at Gulf Specimen Marine Lab
Gulf Specimen Marine Lab founder Jack Rudloe feeding nurse sharks.

If there’s one thing we have learned in 3-plus years of doing this project, it’s that everything eats blue crabs.  If you’ve watched our videos over the years, you’ve seen a gull eating one on Saint George Island.  You’ve seen (and heard) a loggerhead turtle crunch into one.  And in the video above, two octopi wrestle for the tasty treat at the Gulf Specimen Marine Lab in Panacea, Florida (That turtle shot was taken there as well, a few months back).  Lab founder Jack Rudloe spent some time with us, feeding sharks, hermit crabs, and various fish species.  It gave us a great chance to see many of the species that we cover in this blog, and many that we don’t, in action. Continue reading Video: Turtles, Octopus, & Crabs at the Gulf Specimen Lab

Seagrass Wrack in the Salt Marsh – Blessing or Curse?

2-Minute Video: Seagrass wrack kills part of the marsh, but do its benefits outweigh the destruction?

Our videos to date have centered on biodiversity in the marsh and how it can make a marsh stronger against disturbances. As we see in this video, at least one type of disturbance might actually promote genetic and/ or species diversity.
Dr. Randall Hughes FSU Coastal & Marine Lab/ Northeastern University
This snake was found in a seagrass wrack experiment in the Saint Joseph Bay State Buffer Preserve. Blue crabs were often found taking shelter in their experimental plots as well.
This snake was found in a seagrass wrack experiment in the Saint Joseph Bay State Buffer Preserve. Blue crabs were often found taking shelter in their experimental plots as well.

This time of year if you look around salt marshes in our area, you’ll probably see a strip of dead plant material, or “wrack”, resting on top of the salt marsh plants around the high tide line. Look closer, and you’ll see that it’s mostly made up of seagrass leaves that have either been sloughed off naturally (seagrasses produce lots of new leaves in the summer and shed the old ones) or, occasionally, uprooted by boats driving through shallow seagrass beds. Look even closer (say, by picking it up), and you may just find a harmless marsh snake (or worse, a cottonmouth!) – in our experience, they like to hang out in the cool, moist areas under the wrack. Continue reading Seagrass Wrack in the Salt Marsh – Blessing or Curse?

Dr. Randall Hughes inspects a black mangrove growing in the Saint Joseph Bay State Buffer Preserve.

Black Mangroves: Strangers in a St. Joe Bay Marsh

2-Minute Video: Mangroves don’t love the cold, but relatively mild winters have seen them multiply north of their range.  Randall takes a closer look at black mangroves in  the salt marshes of Saint Joseph Bay.

Dr. Randall Hughes FSU Coastal & Marine Lab/ Northeastern University

IGOR chip- biodiversity 150

A few years ago, I took my colleague Dr. Ed Proffitt to check out the marshes in St. Joseph Bay. He asked to see mangroves, and I thought he was crazy. Mangroves up here? No way! But we had only been in one Buffer Preserve salt marsh together for a few minutes before I realized that the small “shrubs” that I had previously ignored were actually small black mangroves! And the more we looked, the more we found. They aren’t everywhere, but they can be quite abundant in some places.

Shrubby black mangroves (Avicennia germinans) are an increasingly common site in the Saint Joseph Bay State Buffer Preserve.
Shrubby black mangroves (Avicennia germinans) appear to be an increasingly common site in the marshes of the Saint Joseph Bay State Buffer Preserve.

Mangroves typically occur below the “frost line”, or in areas that don’t experience hard freezes. Lore has it that mangroves have become more common in the northern Gulf of Mexico in recent years due to a series of mild winters. I haven’t been monitoring them long enough to say whether or not there are more now than there were, say, 10 or even 20 years ago, but it’s not hard to see that the ones that are here are successfully reproducing, with small seedlings surrounding the adult trees.

There are even red mangroves lingering around – they are less cold-tolerant than the black mangroves and a surprise to find in our marshes!

Dr. Randall Hughes inspects a black mangrove growing in the Saint Joseph Bay State Buffer Preserve.I definitely have not seen any significant dieback in the last 5 winters, even when we have had hard freezes. And I would not be surprised if they become more common and abundant as the climate continues to change.

Mangroves in the marsh raise a number of interesting questions. Will they take over? What will that mean for the services these areas provide to people? Will the fishes and crabs that we like to eat become more or less abundant if mangroves dominate over marsh grasses?

A study conducted in Texas marshes looked at conditions under which mangroves best survived in marshes.

Unfortunately, I don’t have the answer to these questions. But I can say that the mangroves that occur in St. Joseph Bay aren’t necessarily “better” at surviving in the northern Gulf than mangroves from farther down south. And why should they be?  Well, if a group of mangrove propagules arrived in St. Joe Bay, we may expect that only a subset of them would be able to survive the colder temperatures, and when these propagules grew into adult trees and produced propagules of their own, they should pass that “benefit” to their offspring (the process known as natural selection).

Black mangrove propagules.
Black mangrove propagules.

How do we we test whether St. Joe Bay mangroves are better equipped to live here than mangroves from down south? We have 2 ongoing experiments where we’ve planted “propagules” (young mangroves that look a lot like seeds) from different locations throughout FL in St. Joe Bay and followed them through time to see which ones survive and grow the best. There’s a lot of variation, but the St. Joe Bay propagules (which were largely the “runts” of the bunch to begin with) did not do as well as propagules from some of the areas down south such as Cedar Key and Cape Canaveral. These results suggest that it doesn’t take a particularly special propagule to survive in the northern Gulf; instead, there probably aren’t just many propagules that make it up here to begin with.

Of course, we’ve only been monitoring these propagules for 1-2 years; maybe the St. Joe propagules have an advantage when they get old / big enough to reproduce. We don’t want to speed up the mangrove take-over, so we’ll remove the seedlings in our experiment before that happens. But we’ll definitely continue to monitor the ones that already made it here on their own accord to see what they do next!

The Guana Tolomato Matanzas National Estuarine Research Reserve (NERR) south of Saint Augustine is where Randall and David have done a lot of their oyster research.  There, mangroves mingle with marsh cordgrass. Could salt marshes in St. Joseph Bay (or north Florida in general) one day look like something approximating this?

Music in the video by pitx.

This material is based upon work supported by the National Science Foundation under Grant Number 1161194.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Diversity- Getting by With a Little Help From (Salt) Marsh Friends

2-Minute Video: Marsh cordgrass, needlerush, sea lavender, mussels, periwinkle snails, and fiddler crabs: diversity in the salt marsh.

In Randall’s last post, she looked at whether genetic diversity within the salt marsh foundation species– smooth cordgrass- made for a stronger marsh (and by stronger, of course, we mean better able to shelter yummy blue crabs for people and sea turtles). In today’s post and video, Randall examines how the combination of plants and animals around cordgrass- the species diversity of a marsh- might play a role as well.
Dr. Randall Hughes FSU Coastal & Marine Lab/ Northeastern University

IGOR chip- biodiversity 150Even though salt marshes often look like one big sea of green in the intertidal, there are plants and animals other than marsh cordgrass around. And even though I devote a lot of effort to understanding the effects of diversity just within cordgrass, these other species are also important – no marsh is an island. (Well, actually they are, but you get the analogy.)

Fiddler crab found in a St. Joseph Bay salt marsh.So who is important, and why? There are at least two animals that can be classified as “friends” of cordgrass – fiddler crabs and mussels. Fiddler crabs create burrows that allow oxygen to get down in the sediment, and cordgrass roots appreciate that oxygen. The fiddler crabs also aerate the sediment during their feeding, and they can excrete nutrients that the plants use to grow.

As an aside, fiddler crabs are also irresistible for kids (and maybe adults too!).

Mussels aren’t quite as charismatic as fiddler crabs, but they like to nestle around stems of cordgrass, and the byssal threads that they use to attach to one another and to the sediment can help prevent erosion. In addition, they excrete nutrients and other organic material as a byproduct of their filter-feeding, and the plants take advantage of these nutrients.

While investigating the relationship between mussels and marsh cordgrass, Randall’s graduate student, Althea Moore, noticed that mussels also seemed to often accompany sea lavender in the marsh. This led to a separate study for Althea.

So who is MORE important, mussels or fiddler crabs? We did an experiment to test that question, or really, to test whether having mussels and fiddler crabs together is better than having just one or another. The answer? As with much in ecology – it depends. For one, it depends on what you measure. If you look at the number of cordgrass stems, then fiddler crabs are the better friend – cordgrass with fiddler crabs does better than cordgrass without fiddler crabs, regardless of whether you have mussels or not. But if you look at how tall the plants are (another important characteristic in the marsh), then mussels are the better friend, but only when fiddlers aren’t around. And if you look at the amount of organic content, mussels increase organic content at the sediment surface, whereas fiddlers increase it belowground. In the end, the take-home message is that the more things you measure about the marsh, the more important it becomes that you have both mussels and fiddler crabs in order to be the “best”.

In the process of doing the experiment I described above, Althea (my graduate student) noticed that when she was out in the marsh, she often found mussels in and around sea lavender (Limonium) plants more often than she found them around cordgrass. She became interested in finding out whether the mussels benefit the sea lavender, the sea lavender benefits the mussels, or a little bit of both. She’s still working on the answer, but it just goes to show that although we often tend to focus on who eats who (think Shark Week) or who can beat who (Octopus vs. Shark, anyone? Or, for kids, there’s always Shark vs. Train – a favorite at my house!), there are just as many instances of species helping one another (not that they always intend to).

Of course, it’s not just animals helping (aka, facilitating) plants – plants can help other plant species to. We’ve shown through a series of experiments that cordgrass benefits from having its tall neighbor needlerush (Juncus roemarianus) around, but only if the snails that like to graze on cordgrass are also present. Nothing is ever as simple as it looks in the marsh…

Music in the piece by Revolution Void.

This material is based upon work supported by the National Science Foundation under Grant Number 1161194.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.