Tag Archives: oyster reef

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.

newstudybanner

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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Split the Difference: Applied vs. Basic Science

Dr. David Kimbro FSU Coastal & Marine Lab
Looking over the catch

Shannon Hartsfield and Colonel Donald Jackson of the Army Corps of Engineers South Atlantic Division look over their catch during an oystering demonstration at Cat Point Bar. This demonstration was meant to show the problems caused by low fresh water input into the bay. Below, David talks about starting to work towards a possible solution.

Tonight on WFSU-TV’s Dimensions program, watch Part 2 of RiverTrek 2012.  Tune in at 7:30 PM/ ET on WFSU-TV. In case you missed it, you can watch Part 1 of RiverTrek 2012 here

IGOR chip- gastronomy 150IGOR chip- employment 150

Spread offense or Power-I formation? Man-to-Man or Zone defense? Austerity or Stimulus spending? And most importantly, Batman or Batgirl?

Whether leading a team of athletes or a population of countrymen, deciders frequently confront such either-or decisions or binary outcomes (i.e., yes or no).

Because time is one of our most limiting resources, natural scientists confront such a dilemma right out of the gate: should I pursue Applied or Basic scientific research?

By applied, I mean research that focuses on immediate solutions to societal problems: How can we deal with a new infectious disease (e.g., avian flu)? Where did the BP oil go?

By basic, I mean research that focuses on improving our knowledge about the nuances of the natural world: How many galaxies are there in the observable universe and how were they formed (I just saw a must-see iMax movie, Hubble 3D, at the JFK Space Center Visitor Complex)? Why is biodiversity so much greater in the tropics?

Flashing back to my childhood hero, I realize that Michael Jordan will likely remain the best basketball player to ever play not solely because of his offense (which was certainly top tier), but also because he worked relentlessly to become a top-tier defender as well. Obviously, few people can master both sides of a spectrum, and sometimes a focus on both or on splitting the difference can come with great cost. For example, my favorite college football team (UNC) is implementing a hybrid defense (i.e., a 4-2-5 instead of a 4-3 or a 3-4) this year; we LOST 68-50 this last Saturday…in FOOTBALL!

Because my plans for playing in the NBA and NFL obviously aren’t working out, let’s get back to science and the merits of focusing on both ends of the science spectrum.

Recently, I talked about this topic with a leading research and clinical Psychologist at Florida State University, Dr. Thomas Joiner. Ignorantly, I thought FSU was only great in Football…turns out that they also have the best Psychology department in the nation. In a recent book Lonely at the Top, Dr. Joiner weaved together many interesting and Basic research studies to show how gender and evolutionary forces cause nuanced interactions all the way from neurons and one’s health to one’s social behavior. It was fascinating to learn how these interactions can promote the loneliness that facilitates suicides.

But while all of these powerful connections lined up well for the main argument of his book, I am equally interested by a conversation we recently shared together about there being many applied problems that can’t wait around for further testing of nuanced ideas. For instance, Dr. Joiner recently began working with the US military to study and reduce the causes of suicide within the military. As Dr. Joiner indicated, the military probably couldn’t give a darn about Basic research findings. They just want some realistic solutions and they want them yesterday.

If you stuck it out this far, you are probably wondering, “how does this relate to oysters, predators, etc.?” Well, the motivation of my Basic research is to increase our knowledge about how predators keep the lights on for many of the natural systems that we depend on like oyster reefs, salt marshes and seagrass beds. But in pursuing this research over the past three years, I have confronted a very important applied problem that needs immediate solutions: the oyster fishery of Apalachicola, Florida presently contains too few oysters to support the local economy (Download a PDF of the Department of Agriculture and Consumer Services report here).

So, if you follow this blog, you’ll get to see whether my attempt to be like Mike (if you’ve seen my vertical leap, it’s obvious we’re talking research and not b-ball), to emulate the approach of Dr. Joiner, and to split the Applied–Basic difference is a success or a bust. I’ll be working with a lot of good researchers (Florida Sea Grant, UF Oyster Recovery Task Force), state organizations – Florida Department of Agriculture & Consumer Services (FDACS) and Florida Fish & Wildlife Conservation Commission (FWC)- and the local community to examine the following:

David accompanies FDACS on a sampling trip in Apalachicola Bay as part of a new collaboration.

(1) How in the heck do you work in such a large and logistically challenging system?

(2) What is the extent of the problem…how far gone is the resource?

(3) After getting some research under our belts, what our some realistic options to this problem?

(4) Because we all want answers to these questions yesterday, can we explore the existing data, which was impressively collected by FDACS for the past 30 years, to get a head start?

Finally, I suspect that this Applied perspective may help inform the merits of my Basic interests. There are a ton of things that could be contributing to the failure of the oyster fishery such as climate change, drought, fresh-water extraction, over-harvesting, disease, nutrient inputs, and water quality. Whether or not any of our predator ideas help explain the lost of this fishery represents a very big test. In other words, relative to other explanations, is all of this predator stuff really important?

Ok, as the locals along the Forgotten Coast say “let’s get’er done”.

Best,
David

Take the RiverTrek 2012 photo tour down the Apalachicola River. You can zoom in and scroll across the map for greater detail. Later we’ll post a map with more of the basin and bay as well, from our other EcoAdventures in the area (River Styx, Graham Creek, etc.). Also, many of the locations are approximate. We did not geotag the location of every houseboat on the river, but the photos do show up in the same general vicinity (with the exception of more recognized landmarks such as Sand Mountain, Alum Bluff, etc.).

Related Links

For more information on the Apalachicola RiverKeeper, visit their web site.  (They’re also on Facebook).

The Army Corps of Engineers is updating the Apalachicola/ Chattahoochee/ Flint Master Water Control Manual, and they are taking public input.  You can let your voice be heard here.

The Franklin County Promise Coalition is coordinating aide efforts for families that are being affected in Franklin County through their Bay Aid program.   As Dan told us in his original interview, over half of the residents of Franklin County depend on the river for their livelihoods.  Learn more about volunteering and other Bay Aid opportunities here.

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

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