Monthly Archives: January 2013

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What’s the deal with nutrients and oysters?

As David & co. start their new research on the Apalachicola oyster fishery crisis, He and Randall (and their colleagues in Georgia and North Carolina) are starting to wrap up the NSF funded oyster study that we have been following over the last couple of years.  Over the next few weeks, we’ll take a look back at that research through a series of videos.  We’ll cover some oyster basics (how does an animal with no brain behave?), explore David and Randall’s ideas on the role of fear on the oyster reef (what makes a mud crab too afraid to eat an oyster?), and see the day-to-day problem solving and ingenuity it takes to complete a major study.  As these videos are released, we’ll also keep tabs on the work being done in Apalachicola Bay, in which many of the same methods will be used.
Dr. David Kimbro FSU Coastal & Marine Lab

After all, nutrients are basically plant food and oysters are animals.  And how could too few nutrients coming down with the trickling flow of the Apalachicola River possibly explain the record low number of Apalachicola oysters?

This is the perfect time to use the favorite idiom of my former mentor Dr. Ted, “The long and the short of it is….”

The short of it: Plants love nutrients and sunlight as much as I like pizza and beer. But unlike my favorite foods, these plant goodies make plants grow fast and strong. This works out well for us because we all need nutrients for basic body functioning, and because we get them by eating plants and/or by the eating animals that previously consumed plants.

For our filter-feeding bivalve brethren, they get nutrients and energy by eating plant-like cells (phytoplankton) that float in the water. So, it is possible that the trickling flow of the Apalachicola River is bringing too few nutrients to support the size of the pizza buffet to which the Apalachicola oysters are accustomed. But this idea has yet to be tested.

Hanna Garland and Stephanie Buhler harvest oysters from sample reefs in Apalachicola Bay.

The long of it: Long before the flow of the Apalachicola River slowed to a trickle, there weren’t a lot of nutrients. That’s why the numbers of humans used to be so low: too few nutrients meant too few plants and other animals for us to eat.

How could this possibly be the case given that 78% of the air we breathe is made up of a very important plant nutrient, nitrogen? And there is a lot of air out there!

Well, only a precious few plants exist that can deal with the nitrogen in our air and these are called nitrogen-fixers. Think of these as single-lane, windy, and bumpy dirt roads. In order to help create a plant buffet for all of us animals, a lot of atmospheric nitrogen (bio-unavailable) has to travel down this very slow road that the n-fixers maintain. As a result, it naturally takes a long time for the land to become fertile enough for a large buffet. And, it only takes a couple of crop plantings to wipe out this whole supply of bio-available nitrogen that took so long to accumulate.

guano island

Sea birds on a guano island off the coast of Peru. (zand.net)

Turns out that the ancient Inca civilization around Peru was not only lucky, but they were also pretty darn smart. Lucky, because they lived next to coastal islands that were basically big piles of bird poop, which is very rich in bio-available nitrogen. I’m talking thousands of years of pooping on the same spot! Smart, because they somehow figured out that spreading this on their fields by-passed that slow n-fixing road and allowed them to grow lots of food. Once Columbus tied the world together, lots of bird poop was shipped back to European farms for the same reason. That’s when the European population of humans sky-rocketed.

Turns out that humans in general are pretty smart. Through time, some chemists figured out how to create artificial bird poop, which we now cheaply dump a lot of on our farming land. So, in these modern days, we are very, very rich in bio-available nutrients.

Where am I going with the long of it? Well, on the one hand, these nutrients wash off into rivers and then float down into estuaries. This is how the phytoplankton that oysters eat can benefit from our solution to the slow n-fixing road. In turn, oysters thrive on this big phytoplankton buffet.

Slide by Ashley R. Smyth, Piehler Lab, UNC Chapel Hill Institute of Marine Sciences.

But, on the other hand, too much of these nutrients flowing down into our estuaries can create big problems. Every year, tons of nutrient-rich water makes it way down the Mississippi and into the shallow Gulf of Mexico waters. There, this stuff fuels one big time buffet of phytoplankton, which goes unconsumed. Once these guys live their short lives, they sink to the bottom and are broken down by bacteria. All this bacterial activity decreases the oxygen of water and in turn gives us the infamous dead zone. Because nutrient-rich run-off continues to increase every year, so too does the dead zone.

I’ll close with the thought that oysters themselves may help keep the phytoplankton buffet from getting out of control by acting like anti-nitrogen fixers. In other words, they may help convert an excess of useable nitrogen back into bio-unavailable nitrogen. While this might not have been a great thing to have in low nutrient situations, we currently live in a nutrient-rich era. What’s even cooler is that it all has to do with poop again! But this time, we are talking oyster poop.

Oyster Summit 6

Dr. Mike Piehler, presenting to his collaborators Dr. Jeb Byers (Right), Dr. Jon Grabowski (reclined on couch), Dr. Randall Hughes and Dr. David Kimbro (out of frame). These five researchers have worked on oyster reef ecology since their time at the University of North Carolina. Three years ago, the National Science Foundation funded research into their ideas about predators and fear on oyster reefs.

So does this really happen? Yes. Check out an earlier post for the details. But we don’t fully understand it and that’s why it is a major focus of our research. Our collaborator, Dr. Michael Piehler of UNC-Chapel Hill, is leading this portion of our research project. Read more of Dr. Piehler’s work on this topic here.

So, hopefully this post explains why the relationship between nutrients and oysters is not so simple. But it sure is interesting and a worthy thing to keep studying!

Cheers,
David

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

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steph_tongs

Notes From the Field: Becoming an Oyster Woman

Stephanie Buhler is the newest addition to the Hug-Bro family (the HUGhes and KimBRO labs).  She and Hanna Garland have been alternating Scuba diving duties for David Kimbro’s new Apalachicola Bay study.  Stephanie was nice enough to let us strap a GoPro camera to her head as she dove, allowing us to capture images of the floor of the bay.  The images give an indication as to the severity of the fishery crisis. We will continue following this study. Tomorrow, we begin a series of videos looking at David and Randall Hughes’ NSF funded oyster study. Over the course of that research, they honed many of the techniques they’re using in Apalachicola Bay. The videos will take you into that study, and into the lives of oysters and the animals that make use of the reef.

This post was written on Sunday, January 20, 2013.
Stephanie Buhler FSU Coastal & Marine Lab

Today marks our sixth day out in the Apalachicola Bay surveying the oyster reefs. It could not have been a more beautiful Sunday with the sun shining bright and a crisp-cool breeze as we drove to our first reef. While Hanna and I definitely have our methods down to a routine at this point, today we had the opportunity to learn a “new” technique for grabbing oysters that did not require a single regulator. This morning our boat captain, Shawn Hartsfield, brought his oyster tongs on the boat for us, and we had a blast trying to get his method down for picking up the oysters.  Comically, he did not inform us that the metal tongs alone were about 40 lbs. as he watched our attempts in bringing our bundle of oysters to the bow of the boat. Best back and arm work out I have ever had!

Bringing the tongs onboard could not have happened on a more relaxed day.  Typically Hanna and I alternate days being the boat tender/diver, but today all of our reefs were extremely shallow and no dive equipment or assistance was needed. A fantastic hassle-free Sunday of work.

Hanna harvests oysters in shallow water.

The Apalachicola Bay study is funded by Florida Sea Grant.  In the Grass, On the Reef is Funded by the National Science Foundation.

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New Study Tackles Apalachicola Oyster Fishery Crisis

Rob Diaz de Villegas WFSU-TV

IGOR chip_ predators_NCE 150Last Thursday morning, an oyster boat departed East Point and disappeared into the fog.  Despite the crisis level lack of oysters in Apalachicola Bay, you can still see several boats working for what little is left.  That’s not what this boat was doing, however.  It was carrying two divers working for David Kimbro out of the FSU Coastal and Marine Lab.  A foggy day is appropriate for the first day of a research study. All of the knowledge is out there, just like the St. George Bridge or the island beyond it are out beyond one’s field of vision.  Eventually the sun comes out and everything is revealed.

They’ll need a little more than the sun to reveal the specifics of the oyster crisis.  It’s easy enough to say that the record low flow of the Apalachicola River combined with harvesting pressure to decimate the reefs.  But the forces at work are a little more nuanced than that.  That’s why newly hired lab technician Stephanie Buhler and graduate student Hanna Garland are plunging into the murky waters of the bay and monitoring up to 20 sites within it for a Florida Seagrant funded project.  The techniques they use will resemble those used by David and his colleague Dr. Randall Hughes in the NSF funded oyster reef study that we have been following over the last two-and-a-half years.  The reefs they’ve worked on for that project were exposed at low tide.  These are not, and so they’ll be diving.  I’m curious to see how it goes in March, when they construct experiment cages on the floor of the bay.

From left to right- Shawn Hartsfield, their captain; Stephanie Buhler; and Alex Chequer, FSU’s Dive Safety Officer. Alex went along on the first day to ensure that all of their dive equipment was operating safely.

One thing they’ll look at with the cages is the interaction between oysters and one of their predators.  So, alongside the environmental data they’ll accumulate- salinity, availability of plankton and nutrients, oyster recruitment (new generations of oysters growing on the reef)- they will look at how the crown conch is affecting oysters in the bay.  If you think it’s as simple “they’re just eating them all,” there’s a chance you might be right.  But what David and Randall have found is that the fear of being eaten can be even more powerful than just removing an oyster.  For a creature with no brain, oysters exhibit behavior and can be influenced by fear.  In a couple of weeks, we’ll have a series of videos chronicling their pursuit of this idea over the last couple of years to see, in David’s words, “Does it matter?”  It’ll be interesting to see how those dynamics might be at play here, where the higher salinity has invited a larger number of oyster consumers.

Another way this study is different from the NSF study is that one end result will be a recommendation as to how the resource is managed.  David’s other collaborator on this project, Dr. J. Wilson White, will develop an Integral Projection Model for the reefs.  Essentially they will take the data collected over the next few months and use it to project how the reef will do in different scenarios.  Those scenarios will depend on the amount of water that flows down the Apalachicola River, which in 2012 was at an all time low.  In these drought conditions, water is low across the entire Apalachicola/ Chattahootchee/ Flint basin.  The basin is managed by the Army Corps of Engineers, whose Master Water Control Manual gives priority to stakeholders in the rivers upstream of the Apalachicola.  That Manual is being updated, and Monday is the last day that they are taking public comment on it.  You can lend your voice to that discussion here.

Have you submitted comments to the Army Corps? Would you mind sharing what you wrote? Add your question or comment.

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

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The Story of 2012

Rob Diaz de Villegas WFSU-TV

I love how David’s story evolves in the segment above.  At first, he concentrates on the oysters and their point of view in the Apalachicola fishery crisis.  It’s the biological approach.  After workshopping his story with Randy Olson, his story takes on a different aspect.  It’s about why he’s getting involved.  It’s the personal approach.  The story is still about David and his colleagues studying the reefs in Apalachicola Bay to determine how best to rehabilitate them, but the hook is different.  It’s one of the stories we’ll be following in what should be another busy year on In the Grass, On the Reef.

Before we look forward to 2013, though, I wanted to look at the stories that made 2012 our busiest year to date:

Funded by the NSF

It took a couple of years, but in July we received a Communicating Research to Public Audiences grant from the National Science Foundation.  The name of that grant is meaningful, and it embodies a background narrative of this project: the work it takes to make an average person care about scientific research.  Researchers know why their work is important, they just don’t always know how to present why it’s interesting.  That’s why we had Dr. Olson come in and put on a workshop for research students (and Randall and David).  So why is Randall and David’s research important?

Ecology is Economy

In short, biology affects people’s livelihoods.  The seafood connection is obvious: over 90% of the species that are commercially fished in the Gulf of Mexico spend some part of their life cycles in one of the three estuarine habitats that we follow: oyster reefs, salt marshes, and seagrass beds.  We saw that oysters offer more to the seafood industry than their meat.  And we’re starting to see the effects of a full-scale ecosystem failure on a community (more on that below).  The non-seafood related benefits were surprising to me.  A rugby field sized patch of salt marsh can save $8,000 in storm surge related property damage.  Seagrass beds are the most effective habitat at storing carbon from the atmosphere.  And in a state as reliant on tourism dollars as Florida, you can’t overlook the ecotourism potential of our coastlines.  Last spring, we went down to the St. Marks National Wildlife Refuge when migratory shore birds were making their way through.  The refuge’s vast salt marshes are an all-you-can-eat buffet for those birds, and you have to figure that without healthy rivers and coasts, our state’s multi-billion dollar wildlife watching revenue would be imperiled.

Away from the coasts, I enjoyed exploring the geology of the Aucilla Sinks and the rare plants of the Saint Joseph Bay State Buffer Preserve.  The Buffer is part of the Apalachicola River basin, and those plants rely on that water just as the oysters in the bay do.  Which brings us to:

The Apalachicola Crisis

Apalachicola Oysters on the Half Shell

Earlier that afternoon, oystermen were demonstrating how few oysters there were in Apalachicola Bay for the Army Corps of Engineers. At a reception later that night at the Apalachicola National Estuarine Research Reserve, they shucked oysters for community members. Despite doubling in price over the last year, there aren't enough oysters to maintain the fishery.

At this time last year, when we were waiting to hear whether we got the NSF grant, I was looking forward to some of the things we would do.  I knew that, as we explored the economic benefits of oysters, I would end up on an oyster boat.  It would be fun to watch tongs bring up mounds of succulent Apalachicola oysters.  My first time on an oyster boat didn’t exactly go that way.  As the year wore on, I started planning for RiverTrek 2012.  That was every bit as amazing an experience as I expected it to be, but Helen Light’s presentation on the state of the basin that first night underscored everything that happened after.  Crisis drives a lot of media coverage; it attracts viewers.  I don’t think Apalachicola needs crisis to be interesting, though.  I first visited in 2002 while working on WFSU’s Our Town series.  Each Our Town episode first aired during a pledge drive, and Our Town: Apalachicola was far and away the most successful, with over 50 new members pledging their support to our station.  And it was my favorite.  A couple of months after we premiered it at the Dixie Theatre, I came back for my birthday.  My wife and I camped out on St. George Island, went across the bay to get oysters and had drinks at the Gibson Inn.  So this isn’t the story I wanted to tell.  But there is something to be learned from this about oyster reef ecology and our connection to it.

As David and his crew gear up to investigate more closely, that story will continue here.  Also, Randall and David’s two multi-year, NSF funded studies are concluding.  They put their ideas to the test:  Does the fear of being eaten by large predators have a significant effect on coastal ecosystems and all that they give us?  And, it’s a word we hear a lot, but what role does biodiversity play in the success of a salt marsh and its services?  Stay tuned.

We want to hear from you! Add your question or comment.

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