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How Can We Prevent Salt Marsh Die-Off?

2 Minute Video: Do Marshes Combat Die-Off Through Biodiversity?

Data on “cold” and “warm” episodes compiled by NOAA and the National Weather Service correlate warm episodes with events Randall and David care about: the ruining of oyster reefs south of Saint Augustine by crown conchs in 2005, the Apalachicola oyster fishery crash last year, and the die-off of salt marsh habitats at the turn of the millennium.  These episodes are part of a normal climatological cycle, though recent droughts during warm years have been severe.  
Dr. Randall Hughes FSU Coastal & Marine Lab/Northeastern University

Mineral Springs Seafood's Dusty Murray empties a crab trap by a salt marsh off of Ochlockonee Bay.  Blue crabs are one of the many animals that make use of the salt marsh habitat.

Mineral Springs Seafood's Dusty Murray empties a crab trap by a salt marsh off of Ochlockonee Bay. Blue crabs are one of the many animals that make use of the salt marsh habitat.

IGOR chip- biodiversity 150We’re going to shift our attention a bit to another intriguing intertidal habitat – the salt marsh. We’ve focused a lot recently on oysters, and how David is applying what we’ve learnedfrom our oyster research the last few years to try to understand the crash of the Apalachicola oyster fishery. There is something inherently interesting and fascinating about oysters, despite the fact that they look a lot like not much more than really sharp rocks. And of course, there is urgency to understand the oyster problems in Apalachicola because of the very real and immediate human costs associated with the fishery collapse.But now, my goal is to convince you that the salt marsh is just as fascinating as oyster reefs, even if it is not a highly visible fishery in trouble. Think of me as the parent trying to get you to appreciate your broccoli, after David already gave you your chocolate cake. I’m going to get you to LIKE your broccoli.

The “broccoli” in this scenario is none other than salt marsh cordgrass, Spartina alterniflora, a familiar character on this blog. In addition to oysters, cordgrass has been the focus of most of my research in FL. Why, you may ask? Why study broccoli when you could be studying chocolate cake all the time? The parent in me is tempted to use the catch-all phrase “Because it’s good for you!” But I’ll refrain, and instead give you a few actual reasons:

1. Oyster and cordgrass really aren’t all that different.

What do oysters and cordgrass have in common? At first glance, it may not seem like much. Oysters are animals; cordgrass is a plant. Oysters are tasty (depending on your palette); cordgrass is inedible. Oysters support a community of fishermen, at least in better times; cordgrass doesn’t.

Except this last distinction, which may seem intuitive, is not actually true. Cordgrass, and salt marshes more generally, support a wide range of fishery species including blue crabs (as you can see in the video), mullet, and sea trout. Studies in Florida estimate that marshes provide up to nearly $7000 per acre for recreational fishing alone. And like oysters, salt marshes provide more benefits for us than simply what we can eat, including protection from storms, increased water quality, and erosion control.

2. Plants are cool.

I know I don’t have to convince any of you gardeners out there about the beauty of plants. Give them a little sunshine, some nutrients, and a little water, and they do their thing. And cordgrass can even manage in salt water! There’s something to be said for low maintenance study organisms.

An AmeriCorps volunteer waits for students on Choctawhatchee Bay.  They will be planting Spartina alterniflora as part of the Grasses in Classes Program.

A year ago, that full-bodied marsh in the background looked just like the rows of small cordgrass shoots leading up to it. Both were planted by Laurel Hill School students as part of the Choctawhatchee Basin Alliance's Grasses in Classes program.

Not only that, but you can plant a single cordgrass stem, leave it alone for a few months, and return to find that it has expanded to 20 stems, all from the same individual!  (Or, if you’re lucky enough to be part of Grasses in Classes, you can admire successive years of growth from single transplants.) This “clonal expansion” is impressive, and it makes answering some of the research questions that I’m interested in pretty easy to address – I can test whether some individuals are better at expanding than others, or whether they withstand stresses like grazing better, or whether having a mix of individuals is better than lots of stems of the same individual. I can ask these questions using oysters too, but it is a lot more difficult. Even we ‘eat your vegetables’ advocates like taking the easy way out sometimes.

3. Marshes are in trouble too.

Although not in the headlines of the local papers at the moment, cordgrass has experienced significant declines in the Gulf of Mexico in the past, and salt marsh loss is a historic and ongoing problem in many parts of the world. And in some cases, the same problem can contribute to the loss of marshes and oysters. For instance, drought has been linked to salt marsh die-off in the Gulf, and drought-induced stress can make the plants more sensitive to other stresses such as grazing by snails. (As we’ve discussed before, drought and increased salinities can also make oysters more sensitive to predators and disease.) Because of the many benefits that marshes provide, it is in our best interest to understand the causes of these losses and try to prevent / counteract them.

Marsh Periwinkle (Littoraria irrotata) climbing cordgrass (Spartina Alterniflora) in a St. Joe Bay salt marsh.

Marsh Periwinkle (Littoraria irrotata).

For these reasons and more, I’ve been conducting lots of experiments the past few years to (a) understand what factors increase / decrease how sensitive cordgrass is to it’s major grazer, the marsh periwinkle, and (b) figure out if having more cordgrass individuals (or “genotypes”) makes the marsh less sensitive to change. We’ll highlight these experiments in the coming weeks as part of our quest to spark your fascination with the salt marsh!

Music in the video by Cross(o)ver.  The maps used in the animation were generated by the National Drought Mitigation Center.  Special thanks to Mineral Springs Seafood for taking us along as they emptied their crab traps.

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.

Turtle seen on Slave Canal, Florida kayaking trip.

Paleo River Adventure on Slave Canal

Rob Diaz de Villegas WFSU-TV

Video: Slave Canal EcoAdventure

Much like Slave Canal connects the Aucilla and Wacissa Rivers, this post serves as a bridge between our oyster reef and salt marsh videos (not that we’re done talking about Apalachicola by a long shot).  One of my favorite things on this blog is when we can make connections between rivers and the coast.  Of course, rivers provide much needed nutrients and fresh water to the estuarine ecosystems I just mentioned.  But to the many cultures that predate european settlement of our area, they served as the equivalent of Woodville or Crawfordville Highway.  It’s how they got to their Forgotten Coast seafood.
Old Growth Cypress Tree off of Slave Canal

An old growth Cypress tree fortunate not to have been logged. Judging from the size of its base, Joe Davis estimates that it could be as much as 1,000 years old.

Slave Canal is one of those places I started hearing about a lot when we started doing our EcoAdventure videos.  As soon as you get into the braided channels of the lower Wacissa, it’s easy to see why it’s one of the popular river expeditions in north Florida.  You’re paddling in a canopied river swamp where people have been paddling for several thousand years.  And minus some old growth cypress trees that have been logged in the last century or so, it looks much the same as it did when various native groups made use of the waterway to make seafood runs to the coast.  But it doesn’t look quite as it did when people first got there.

Evidence excavated at the Page/ Ladson and Ryan/ Harley sites points to people inhabiting what is now the Aucilla Wildlife Management Area for 12,000 years or longer.  At that time, Florida Fish and Wildlife’s Joe Davis told us, the ice ages were ending, sea level was lower, and the coast was further away.  Those first men and women walked on dry land where our canoes and kayaks passed over.  I can almost envision paleolithic man standing on one of the many ancient midden mounds as everything happens around him in time-lapse mode.  Rivers fill and flow to the Gulf, mastodons vanish, and different cultures come and go, piling shell and bone on to that same mound.  Pretty heavy stuff to think about on a fun Florida kayaking trip.

Slave Canal signSo how do you get there?  Here are links to a couple of maps. Florida Department of Environmental Protection put this PDF together with driving directions to two put in points along the Wacissa Paddling Trail. One is for the headwaters of the Wacissa, though Goose Pasture is closer by ten miles. It depends on how long you want to kayak or canoe. It’s about five miles from Goose Pasture to Nutall Rise on the Aucilla.  Goose Pasture is also a camp ground (first come first served, call 800-226-1066 in Florida or 386-362-1001 for more information).  Scroll down in the PDF for advice in finding the entrance to Slave Canal (hint- stay to the right). If you don’t find it amongst the braided channels of the lower Wacissa, you won’t find your take out at Nutall Rise.  You may also want a map you can take with you on the water.  The Rivers of AWE (Aucilla, Wacissa, and Econfina) Explorer’s Guide is available on the Wildlife Foundation of Florida’s web site.  It has detailed maps of the rivers with tips and suggestions, and is printed on water resistant paper.  It’s the map that Liz uses at the start of the piece.

Slave Canal is our third EcoAdventure on the Aucilla Wildlife Management Area.  We paddled the upper Wacissa and got some underwater footage of Big Blue Spring.  We also hiked the Florida National Scenic Trail along the Aucilla Sinks, where the Aucilla River goes intermittently underground, peeking out in “Karst windows.”  The WMA is a marvelous synthesis of history and prehistory, wildlife, and geology.  And, well, it’s full of these cool looking places.

Nigel Foster paddles Slave Canal

This is Nigel Foster, of Nigelkayaks. This link is to the trip gallery on his website.  As you can see, he’s been a few places.

Russell Farrow on Slave Canal

And this is Russell Farrow, Liz’s other guest. Russell is a co-owner of Sweetwater Kayaks in St. Petersburg, and you can see he’s been a few places as well. One of his passions is getting kids into the outdoors (and away from their screens).

Oyster shell on Slave Canal mound

I do one thing on this blog all year that takes place away from the coast, but I can’t escape oyster shells. For how many thousands of years have people eaten oysters on the Forgotten Coast? This shell was on Coon Bottom Mound, the largest mound on Slave Canal.

Turtle seen on Slave Canal, Florida kayaking trip.

I’m looking forward to the next EcoAdventure, whatever that might be.  If you have any suggestions, leave a comment.

Music in the video by Philippe Mangold.

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Oyster Research Needs Your Help In Apalachicola Bay

Oyster drills infest one of David Kimbro's Apalachicola Bay experimental spat tile cages.

In January, David Kimbro’s lab did a preliminary survey of Apalachicola Bay oyster reefs, looking at the overall health of oysters and the presence of predators. They followed this up with an experiment meant to monitor oyster health and predator effects over time. Many of their experimental cages were displaced, likely due to the buoys marking them breaking off. But what they found in the cages that remained intact was that oyster drill numbers appear to be exploding in warmer waters.  David is looking for help keeping tabs on them.

Dr. David Kimbro Northeastern University/ FSU Coastal & Marine Lab

Wishing that you were wrong is not something that comes naturally to anyone. But that is how I felt at the most recent oyster task force meeting in April. There, I shared some early research results about the condition of the oyster reefs. In our surveys, we found that the oyster reefs in Apalachicola Bay were in really bad shape and that there were not any big bad predators hanging around the reefs to blame. Even though I had originally shot off my big mouth about the oyster fishery problem being caused by an oyster-eating snail, I hoped that our first bit of data meant the snails were never there. Or better…that they were gone. The story of the boy who cried wolf comes to mind.

But an alternative of this David-cries-wolf story is that our January sampling didn’t turn up many predators because it’s cold in January, and because they were hunkered down for a long winters nap. Unfortunately, this option is looking stronger.

Experimental cages to be deployed in Apalachicola Bay.

Experimental cages to be deployed in Apalachicola Bay.

Since the task force meeting, we have been figuring out how conduct field experiments in Apalachicola. To be honest, an underwater environment without any visibility is an experimentalist’s worst nightmare. Still, we deployed fancy equipment, big cages, and then little mini experiments inside each big cage to figure out how much of the oyster problem is due to the environment, to disease, or to predators.

Even though we lost over half of our experiment and instrumentation, we recovered just enough data to show that the problem could be predation and that the culprit is a voracious snail.  So, after learning some lessons on how to not lose your equipment, we decided to take another crack at it. In fact, Hanna and crew just finished sampling half of our second experiment today. We got the same results….lots of snails quickly gobbled up all of the oysters that were deployed without protective cages. But the oysters that were protected with cages did just fine.

This photo illustrates what Apalachicola oyster reefs are dealing with. This is one clutch of eggs laid by one adult snail. Within each little capsule, there are probably 10-20 baby snails. After a long winter’s nap, these snails are hungry.

We are going to keep at this, because one week long experiment doesn’t really tell us that much. But if we keep getting the same answer from multiple experiments, then we are getting somewhere.

In addition to updating y’all, I wanted to ask for your help. Because my small lab can’t be everywhere throughout the bay at all times, there are two things you could do if you are on the water.

Click the link to the right for GPS coordinates.

First, if you come upon our experiment, can you let me know when you happened upon them and how many buoys you saw? If you report that all buoys are present, then I’ll sleep really well. And if you alert us that some buoys are missing, then I’ll be grateful because we will stand a better of chance of quickly getting out there before the cages are inadvertently knocked around, so that we can recover the data.  Click here for GPS coordinates and further instructions.

Second, if you are tonging oysters, then you are probably tonging up snails. It would really help us to know when, where, and how many snails you caught.  Take a photo on your phone (Instagram hashtag #apalachcatch – Instagram instructions here) or e-mail them to robdv@wfsu.org.  We’ll be posting the photos and the information you provide on this blog.

This is kind of a new thing for us, attempting to use technology and community support this way.  There may be some bumps along the way.  If you’re having trouble trying to get photos to us, contact us at robdv@wfsu.org.

Thanks a bunch!

David

David’s Apalachicola Research is funded by Florida Sea Grant

In the Grass, On the Reef is funded by a grant from the National Science Foundation.

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Recycling Oyster Shells for Choctawhatchee Bay

Rob Diaz de Villegas WFSU-TV
Choctawhatchee Basin Alliance staff from L to R: Brandy Foley, Jeff Murphy, and Rachel Gwin listen as Allison McDowell explains how the reef is to be laid out.  She had previously laid the section visible under the water.

CBA staff from L to R: Brandy Foley, Jeff Murphy, and Rachel Gwin listen as Allison McDowell explains how the reef is to be laid out. She had previously laid the section visible under the water.

IGOR chip- sedimentation 150

I’ve been wanting to do a video on Choctawhatchee Basin Alliance‘s Oyster Recycling program for some time.  I decided to do it now because we’ve been covering restoration efforts in Apalachicola Bay, and while the two efforts appear to have similar goals, they’re both using different methods and aiming at different goals.  In Apalachicola, they’re trying to restore their fishery.  They want oyster spat to settle on their shells and grow into market sized (3 inches or more) adults.  In Choctawhatchee, they’re rebuilding their coastline.  It’s an ecosystem service we have mentioned in the past but have struggled to show, how oyster reefs (and salt marshes) prevent erosion.  You can see in the video above how the coastline is retreating and exposing tree roots where these natural barriers have been removed.  And you can see how the sand just accumulates where they’ve replaced shell.  It’s one of the many beautiful things an oyster reef does.

With 85% of the world’s oyster reefs having already been lost, and with more being threatened, restoration is critical.  Many of those efforts center around what’s left in your basket when you leave the raw bar.  Every part of the oyster is valuable.  The animal itself cleans the water and provides income for oyster harvesters.  But it’s also a builder, and an oyster reef provides shelter for various fish, crab, and snail species, many of which we eat.    The shells that make the reef are the best place for a larval oyster to land.  So those dozen or two shells you walk away from have their value as well.  Thankfully, people like the Choctawhatchee Basin Alliance staff and volunteers are doing the hard work of collecting them and putting them back to work for the reef.

This is a refrigerator at Busters in Santa Rosa Beach.  Donnie Sellers shucked 75 dozen oysters the day we were there, and that was before tourist season.  All of the restaurant's shells end up in blue recycle bins.

This is a refrigerator at Busters in Santa Rosa Beach. Standing behind the bar, Donnie Sellers shucked 75 dozen oysters the day we were there, and that was before tourist season. All of the restaurant’s shells end up in blue recycle bins.

Music in the Piece by Red Lion.

In the Grass, On the Reef is funded by a grant from the National Science Foundation.

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Researchers and Oystermen Fighting for Apalachicola Bay

Last week, Hanna Garland showed us how the Hughes/ Kimbro Lab adapted their techniques for underwater research in Apalachicola Bay. She talked about their difficulties with the weather, and as you can see in the video above, it was difficult for their oysterman collaborator (as it is for Apalachicola oystermen these days) to find enough healthy adult oysters to run the experiment. Below, David Kimbro looks back at the big Biogeographic Oyster study and what it has taught them about how oyster reefs work, and how they’ve been able to take that knowledge and apply it to the oyster fishery crisis.
Dr. David Kimbro Northeastern University/ FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150IGOR chip- biogeographic 150IGOR chip- employment 150

Does our study of fear matter for problems like the Apalachicola Bay oyster fishery crash? Absolutely.

Bear with me for a few sentences…

I like to cook. My first real attempt was a chicken piccata and it was a disaster. After ripping off the recipe from my brother (good cook), I quickly realized that the complexity of the recipe was beyond me. To save time and fuss, I rationalized that the ordering of ingredients etc. didn’t matter because it was all going into the same dish. Well, my chicken piccata stunk and I definitely didn’t impress my dinner date.

Way back in 2010, David paddles to one of the St. Augustine sites used in the lab's first tile experiment. Since then they have done two spat tile experiments and two cage experiments ranging from Florida to North Carolina.

2010: David paddles to a St. Augustine oyster reef during his lab's first tile experiment. Since then they've done two spat tile experiments and two cage experiments ranging from Florida to North Carolina.

Around this same time… long, long ago, a bunch of friends and I were also working on a basic science recipe for understanding how oyster reefs work and it only contained a few ingredients: predatory fish frighten crabs and this fear protects oysters….a beautiful trophic cascade! But years later, we figured the recipe was too simple. So, we overhauled the recipe with many more ingredients and set about to test it from North Carolina to Florida with the scientific method.

Now that we finally digested a lot of data from our very big experiment (a.k.a. Cage Experiment 1.0), I can confidently say that the fear of being eaten does some crazy things to oyster reefs. And even though most of the ingredients were the same, those crazy things differed from NC to Florida. While our final recipe isn’t perfect, we now have a better understanding of oyster reefs and that the recipe definitely has many more ingredients.

For instance,

  1. Mud crab hearing testThe fear of being eaten has a sound component to it. Previously, we thought fear was transmitted only chemically, but now we know that crabs can hear. This is huge!
  2. Oyster filtration and oyster pooping can affect the amount of excess nutrients in our coastal environment. Our collaborator (M. Piehler, UNC-CH) showed that in some places, this can remove excess nutrients and that this services makes an acre of oyster reef worth 3,000 every year in terms of how much it would cost a waste water treatment facility to do the same job.
  3. In a few months, I hope to update you on how sharks, catfish, drum, and blue crabs fit into the recipe.

In addition to uncovering some new ingredients, our pursuit of this basic science matters because it allowed us to figure out what methods and experiments work as well as what things don’t  (Watch how they reinvented one of their most depended upon tools: The spat tile experiment). In short, the fruits of this basic science project can now be shunted into applied science and the development of interventions to improve the Apalachicola Bay oyster fishery.

But given that the lack of oyster shell in the bay is clearly the problem and that re-shelling the bay would bring the oysters back, why do we need to conduct the research? Well, then again it could be the lack of fresh water coming down the Apalachicola River and/or the lack of nutrients that come with that fresh water. Oh, don’t forget about the conchs that are eating away at oyster reefs in St. Augustine, Florida and may be doing the same to those in Apalachicola.

Shawn Hartsfield tonging for oysters to be used in the Apalachicola Bay experimentLike the chicken piccata recipe, Apalachicola Bay is awesome, but it’s complicated. Clearly, there are lots of things that could be in play. But if we don’t understand how they are all linked, then we may waste a lot of effort because fixing the most important part with Ingredient A may not work without simultaneously fixing another part with Ingredient B. Even worse, maybe Ingredient B must come first!  Only through detailed monitoring and experiments will we figure out how all of the ingredients fit together.

Luckily, my brother shared the fruits of his basic culinary experiments so that I could quickly solve my applied problem: cooking a good dinner for the second date. Similarly, it’s great that we received funding from NSF to conduct our biogeographic oyster study, because now we can quickly apply the same methods and personnel to help figure out what’s ailing the Apalachicola Bay oyster fishery. Basic and Applied science, Yin and Yang.

–David

What’s next?

David’s colleague, Dr. Randall Hughes, takes us through another ecosystem that has been affected by drought in recent years, the coastal salt marsh.  As severe droughts become a normal occurrence, coastal ecosystems like marshes or the oyster reefs of Apalachicola Bay stand to take a beating.  Randall is looking at what makes a marsh stronger in the face of drought and other disturbances.

In the Grass, On the Reef is funded by a grant from the National Science Foundation.