Tag Archives: oyster reef

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Tile 2.0- Perfecting the Oyster Spat Tile Experiment

As we’ve been getting this post ready, David’s Apalach crew (Hanna, Stephanie, and Shawn) has begun deploying the experiment featured in the video above in Apalachicola Bay.  After years of perfecting it, the tile experiment has become a key tool in Randall and David’s oyster research.  As you can see, there were some headaches along the way.
If you’d like to know more about spat (young oysters), we covered that a few weeks ago in this video.
Dr. Randall Hughes FSU Coastal & Marine Lab

An “open” cage, with full predator access.

One of the primary goals of several projects in our labs involves figuring out where oysters grow and survive the best, and if they don’t survive, why not? Sounds pretty basic, and it is, but by doing this across lots of sites/environments, we can start to detect general patterns and identify important factors for oyster growth and survival that maybe we didn’t appreciate before. Our method of choice for this task is to glue the oysters to standardized tiles, place some in cages to protect them from predators, leave the rest to fend for themselves, and then put them in the field and see what happens over time.

In doing this lots and lots of times, we’ve learned who in the lab has a special knack for placing small drops of marine glue – Zspar (which you can see in the video) – on tiles, and who is better at adding the oysters so that the 2 valves of their shells don’t get glued shut. These are the sorts of crazy job skills that don’t go on a standard resume!

Any of you who have been following the blog for a while may remember the craziness of the our first NSF tile experiment (Tile 1.0) in the fall of 2010, which involved collecting lots of juvenile oysters (“spat”) that had recently settled in the field, bringing them back to the lab, and using a dremel to carefully separate that from the shell they settled on. (If you don’t remember and want to check it out, go here.)

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Two of our oyster “families” in the water tables at Whitney Marine Lab

Since the Tile 1.0 experience, we’ve developed more elegant (and much simpler!) methods: we contract with an amazing aquaculturist at a FL hatchery to collect adult oysters from the field, provide just the right ambiance to make them spawn (release eggs and sperm), and then raise the oyster larvae to a perfect size for attaching to our tiles. This year, we added another twist on this theme (Tile 2.0) by collecting adult oysters from different areas in FL, GA, SC, and NC, and then spawning and raising them separately in the same hatchery under identical conditions. We refer to these different groups of oysters as “families”, because all of the spat from a given location are related to one another, but not very closely related to the oysters from a different location (who had different parents).

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Evan and Tanya admiring our work after we deployed the first reef in St. Augustine.

By putting out tiles from each family at sites across this same geographic range (FL to NC), we can tell if some sites or regions are inherently better than others for oysters (for instance, as I’m currently learning first-hand, there’s a reason that everyone wants to spend the winter in FL!), or if some families are naturally better than others (think Family Feud with oysters), or if the oysters that came from a particular site do best at that site, but not in other places (like the ‘home field advantage’ that recently helped Maryland beat Duke in basketball). Whew – that was pretty mixed bag of metaphors! But you get the idea.

We’re still processing and analyzing the data from Tile 2.0, but it looks like which site is the best depends on what you’re measuring – the best place for survival is not always the best place for growth. And the different oyster families do look and “behave” differently – some grow quickly and some grow slowly, and some survive predators better than others.

Spat bred from adult oysters from Sapelo Island in Georgia (left) and ACE Basin in South Carolina (right).

Surprisingly, there doesn’t appear to be much of a home field advantage, at least from our initial analyses. And as Meagan pointed out, we’ve learned from other similar experiments for the National Park Service that it’s not just other oysters or predators that these guys have to worry about – it’s barnacles too! But there are still some ‘sweet spots’ out there for oysters, and once we’ve analyzed all of our data, we’ll have a much better sense for where those are.

We want to hear from you! Add your question or comment.
Music by Barnacled and Pitx.

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

 

Mud crabs (like the one pictured here), oyster drills, and crown conchs are the primary consumers of oysters on the reef.

How Do Predators Use Fear to Benefit Oysters?

Over the last few weeks, we’ve explored the concept of the ecology of fear on oyster reefs. But, as David asks in the video, “does it matter?” Exactly how much does fear affect oyster filtration, or their ability to support commercially and ecologically important species? And how does fear affect the benefits we receive from ecosystems such as salt marshes and seagrass beds? Coming up, we see how David and Randall took these big questions and broke them down into a series of experiments and investigations geared at creating a clearer picture of fear in the intertidal zone.
Dr. David Kimbro FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150A few weeks ago, we had a bayside conversation about the important link between nutrients and oysters. But there is something else that may dictate whether a reef thrives: predators.

Academically, the importance of predators dates back to the 1960s. Some smart people proposed that the world is green because we have lots of big animals, which eat all of the smaller animals that would otherwise consume all the plants…hence the green world.

busycon eating moon snail

Busycon spiratum eating an Atlantic Moon snail on Bay Mouth Bar. These seagrass beds off of Alligator Point are home to the greatest diversity of predatory snails in the world. In the late 1950s and early 1960s, Dr. Robert Paine investigated the effect of the horse conch, the most dominant predator among the snails, on the habitat. David and his crew have similarly used the dynamic invertebrate population to test their theories on the ecology of fear. (click the photo for more on Bay Mouth Bar).

Now, that’s a pretty simple yet powerful concept.  Since then, lots of studies have tested the importance of predators and how they keep our world spinning. For example, Bob Paine relentlessly braved the icy waters of the NW Pacific for a decade in order to chunk ravenous sea stars from one rocky cliff, but not the other. After several years, the cliff with sea stars still had a tremendous diversity of sea creatures (algae, anemones etc.) and the cliff without predatory sea stars did not. The absence of sea stars allowed pushy, bullying mussels to outcompete all other animals for space and this gave the rocky cliff a uniform and boring mussel complexion.

The same concept has been tested on land. Ripple and Beschetta showed us why the national parks out west no longer have the really important and woody trees (aspen, willow, and cottonwood) that they historically had. By suppressing wolves for the last 50 years, we allowed elk numbers to explode and the elk have overrun the really important woody species.

But predators don’t just eat.  Enter my vivid memory of trying out for the Nash Central 8th grade football team in rural North Carolina. Contrary to my father in-law’s belief (who is a hall of fame football coach in Georgia), I wanted to play football instead of soccer.  But when it came time for try-outs, fear prevented me from pursuing this line of work.  To practice breaking tackles, each player had to lie on the ground and the rest of the team formed a circle around this player.  Unbeknownst to the guy on the ground, the coach secretly selected three players to tackle the football player at the sound of the whistle.  For twenty minutes, I watched physically un-developed friend after late-blooming friend get crushed by other guys who were definitely not late bloomers. The sights and sounds of this drill kept me nauseous until it was my turn. When my turn came, I couldn’t deal with the fear, didn’t perform well, and consequently became a soccer player.

My point is that fear is very powerful. Of course, I knew the charging football players were not going to eat me. But if I was paralyzed with fear from football, then imagine what it’s like for something that has to worry about being eaten. Going to back “the world is green” story: what if we overlay the concept of fear on that? How does the story change?

Well, the next generation of predator studies has examined how the fear of predators can be just as important as the appetite of predators. In addition, because predators can only eat only one animal at a time but can simultaneously frighten many more, fear can create powerful “remote-control effects”. In Australia, the fear of tiger sharks causes dugongs to avoid certain depths in a bay. As a result, only a small portion of the seagrass beds get grazed down by dugongs, possibly being one of the main reasons why areas like Shark Bay still have huge and lush seagrass meadows.

Mud crabs (like the one pictured here), oyster drills, and crown conchs are the primary consumers of oysters on the reef.

For the next few weeks, we will look at some work that my friends and I have conducted for the past three years on how predators and the fear of predators influence oyster reefs and the services that they provide us throughtout the southeast. Although we have the same predators and things that like to eat oysters from North Carolina to Florida, we suspect that differences in the environment will cause the effect of predators to play out differently.

In parting, I just want to say that this predator stuff is really interesting and I think it’s very important for oyster reefs. But of course, when you are dealing with an ecosystem that may be on the verge of collapse like Apalachicola Bay, the distinction between the appetite and fear of predators may not matter that much. But, we will soon see because we are now investigating this important system too.

We'll be following the Apalach study as well. Here, Stephanie Buhler, who we had previously seen diving in Apalachicola Bay, welds a cage to house an upcoming experiment in that research. It's a variation of the tile experiments that became such a staple of the NSF oyster study. In a few days, we break down the tile experiment, and David's collaborator, Dr. Randall Hughes, talks about what the results are telling them so far.

Music in the video by Revolution Void.

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

Barnacles overtaking the experimental oysters.

Notes from the Field: Overwhelmed Oysters

Meagan Murdock is a lab technician in the Hughes and Kimbro Labs, operating out of the FSU Coastal and Marine Laboratory. The experiment she describes in the following post is a central staple in the research conducted by Dr. Randall Hughes and Dr. David Kimbro into oyster reef ecology. They seek to measure factors affecting the health of an oyster at a given location by monitoring the growth of young oysters (spat) in a controlled unit- the spat tile. We’ll be further exploring the use of spat tiles in their NSF funded oystern study in the next couple of weeks. David Kimbro is also gearing up to deploy a tile experiment in Apalachicola Bay, with the goal of measuring conditions there (see photo below).
Meagan Murdock FSU Coastal & Marine Lab

Beautiful reef backing up to red mangroves (Rhizophora mangle) in Mosquito Lagoon, FL. Notice our experiment on the reef!

Mosquito Lagoon of Canaveral National Seashore is in the northern section of possibly the most diverse estuary in North America, the Indian River Lagoon. But don’t let the name “Mosquito” Lagoon scare you off! This lagoon is an expanse of mangrove islands, oyster beds, and home to charismatic animals like manatees and dolphins (maybe a few mosquitoes, but where in Florida can you not find mosquitoes??).  Eight months ago, we set up a rendition of the “Tile Experiment” at three National Park Service units in hopes of elucidating factors contributing to oyster spat (spat=newly settled oyster) survival and growth. Last week we ventured out to Mosquito Lagoon to check on our baby oysters and this is what I found. The tiles were covered in BARNACLES!

Tile 75 pictured after being deployed for 2 months and 8 months.

I felt bad for the little oysters. Not only are these spat expected to survive through adverse environmental conditions and hope they do not become some crab or fish’s dinner, but they also are competing for space and resources with other filter feeders. Geez it must be tough being an oyster! But-yeehaw!-the oysters are persevering and I got to enjoy the nice weather of Central Florida.

Barnacles overtaking the experimental oysters.

As Meagan continues to monitor the growth of her Canaveral oysters, David is having Stephanie Buhler and Hanna Garland deploy some test tiles in the subtidal (always submerged) oyster reefs of Apalachicola Bay.  The tiles will be protected by a steel cage which will allow access to researchers while protecting the experiment from an oysterman’s tongs.  Different prototypes of tiles and cages were deployed last week with the full experiment to begin in the coming weeks:

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

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.