Tag Archives: oysters

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Notes From the Field: Panama, Where Oysters Grow on Trees

A couple of months ago, we looked at the increasing number of mangroves surviving north of their range in Gulf coast marshes and wondered how it might change that habitat. On a research trip to Panama, Tanya Rogers got a good look at how mangroves interact with many species found in North Florida. There, oysters grow on trees.

Tanya Rogers FSU Coastal & Marine Lab/ Northeastern University

Installing predator exclusion cages in the rocky intertidal at Punta Culebra, on the Pacific coast of Panama.

Travel 1,100 miles due south of Miami, and before you know it you will collide with the Caribbean coast of Panama. Take a look around these shores and what will you find? Not just coral reefs as you might expect, but also seagrass beds, mangrove forests, and oysters – many of the same species, in fact, that are found in Florida, but arranged a bit differently. What are these oysters, seagrasses, and mangroves up to in the tropical parts of the world?

For a brief stint this summer I worked with Dr. Andrew Altieri at the Smithsonian Tropical Research Institute in Panama, exploring ecological questions similar to those we’ve been investigating in Florida. Dr. Altieri, much like my advisor, Dr. Kimbro, is interested in the ecology of marine communities, particularly the role of foundation species and the effects of environmental stress vs. consumers/predators in determining what grows where. In the mangroves, as well as on the rocky shores of the Panamanian Pacific coast, I helped set up several experiments using the same sort of experimental techniques as we used in Florida (cages, transplantation, etc.) to answer questions about species interactions in tropical environments. I hope I have the opportunity to return to Panama in the future as part of my graduate research.

Setting up a mangrove root transplant experiment in Bocas del Toro, on the Caribbean coast of Panama.

One interesting thing about the oysters in Panama (on the Caribbean side anyway) is that they grow almost exclusively on mangrove prop roots, and instead of one species, you can find up to five oyster species co-occurring. The oysters grow near the water’s surface, and below them the submerged roots can host an astonishing diversity of other marine invertebrates, including sponges, tunicates, anemones, and tube worms. I found it fascinating to swim below the mangroves, the roots like a maze of stalactites bedazzled with life of all colors and textures, fish darting through the labyrinth, the occasional crab deciding to take refuge on your head. Be on the lookout though for stinging box jellies, for they also enjoy these galleries. Just as in Florida, the mangroves and seagrass beds (which often border the mangroves), are important nursery habitats for juvenile fishes, which later venture out to the coral reefs.

A suite of co-occurring foundation species in Bocas del Toro: corals, seagrasses, mangroves, and oysters (growing on the mangrove roots).

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.

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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

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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.

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Notes From the Field, Apalachicola: Measure Twice, Cut Once

Waves and wind can make an underwater experiment challenging. But in Apalachicola Bay, it’s getting to where getting enough oysters to run an experiment is a challenge in itself. On Dimensions tonight (Wednesday, May 8 at 7:30 PM/ ET), get an inside look into what it’s like to go oystering during the oyster fishery crisis. We look at the men and women fighting for the bay, and the evolving alliance between those who work the bay, and those who would study it.

Hanna Garland FSU Coastal & Marine Lab

Hanna Garland and Meagan Murdock, Florida State University Coastal and Marine LabGrowing up, I always loved to help my dad with the never-ending list of house and boat projects, but because being a perfectionist is not one of my attributes, it would bother me when he would remind me to “measure twice, cut once.” However, whether taken literally or figuratively, this saying has had more relevance as I have progressed through college and now my graduate career. Take for example: the Apalachicola Bay oyster experiment.

In January, we conducted habitat surveys in order to assess the condition of oyster reefs throughout Apalachicola Bay by quantifying the oysters themselves as well as the resident crustacean and invertebrate species. We found some interesting patterns, but this survey data is just a “snapshot” in time of the oyster reef communities, so we designed an experiment that will investigate the survivorship and growth of market-size oysters in the presence or absence of predators at 12 reefs across the bay.

Live, market-sized Apalachicola Oysters epoxied to posts for an experiment in Apalachicola Bay.Mimicking the design of most of the oyster experiments in the Hugbro lab, we continue to keep the marine epoxy, mesh, and rebar companies in business by securing oysters into predator-exposed or predator-excluded treatments and then installing them onto reefs. While the habitat surveys were conducted via scuba diving (or sometimes walking because the reefs were so shallow!), we decided to give our free-diving skills a test for the oyster experiment installation in order to reduce gear and research costs. Being primarily intertidal researchers we are not accustomed to all of the logistics for subtidal research, but free diving is mostly a mind game, right?

Scuba and snorkeling gear.

The gear needed for scuba diving (left) versus free diving (right).

Wrong! Meagan and I were reminded that we will never be greater than Mother Nature or “the elements.” We were only able to install the experiment on 10 of the 12 reefs throughout the bay and due to unfavorable weather conditions and diving logistics, we were unable to complete the installation on the remaining 2 reefs or check the status of the oysters that had already been deployed. As a result, we will be restarting this experiment in May, but this time via scuba and with learned knowledge and experience of working in the bay, which will allow us to obtain a more complete and accurate experimental data set.

Buoy marking a submerged experiment in Apalachicola Bay.

These buoys mark experiment sites. Having the experiments submerged makes it otherwise invisible to passing boats and their propellors, and to oystermen and their tongs.

As frustrating as it may be to re-do the experiment, I was reminded at the recent Oyster Task Force meeting in Apalachicola, that the answer to the oyster crisis is going to take time; and in order to identify and quantify the environmental or biological stressors in the bay, research and management must be done correctly and entirely. So stay tuned, as there will need to be a lot more “measuring twice and cutting once” before we will be able to identify the key explanatory variables causing the loss of oyster habitat in Apalachicola Bay!

Music in the video by Nekronomikon Quartett.

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

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Notes From the Field: Hermit Crab/Crown Conch Cage Match

Last week David connected the regional dots, noticing similarities in oyster reefs overrun by oyster eating crown conchs across North Florida, from the Matanzas Reserve south of Saint Augustine to Apalachicola Bay. That included a breakdown of what they found during surveys of the Bay. Below, Hanna Garland details one of her experiments mentioned by David in the post.
Hanna Garland FSU Coastal & Marine Lab

Gaining a better understanding of the beautiful yet complex habitats that border our coastlines require a significant amount of time surveying and manipulating organisms (as you may know if you have been following our research for the past three years!), and even so, there can still be limitations in whether or not we truly know what is “naturally” occurring in the system.  Unfortunately, pristine salt marshes, seagrass beds and oyster reefs are in a general state of decline worldwide; however, this only heightens our incentive to investigate further into how species interact and how this influences the services and health of habitats that we depend on for food and recreation.

For the past two and a half years we have been studying the oyster populations along 15km of estuary in St. Augustine, but it did not require fancy field surveys or experiments to notice a key player in the system: the crown conch.  Present (and very abundant!) on oyster reefs in the southern region of the estuary, but absent in the northern region, it was obvious that there were interesting dynamics going on here…and we were anxious to figure that out!

In hopes of addressing the question: who is eating whom or more importantly, who is not eating whom, we played a game of tether ball (not really!) with nearly 200 conchs of various sizes by securing each one to a PVC pole (with a 1m radius of fishing line for mobility) onto oyster reefs.  After six months (and still ongoing), the only threat to the poor snails’ survival appeared to be the thinstripe hermit crab (Clibinarius vittatus)!

Hypothesized that hermit crabs invade and occupy the shell of a larger crown conch in order to have a better home, we decided to further investigate the interactions between crown conchs and hermit crabs by placing them in a cage together (almost like a wrestling match).

After only a few days, the mortality began, and results showed a weak relationship between species and size, and appeared to be more of a “battle of the fittest”.

The implications of how the interactions between crown conchs and hermit crabs influence the oyster populations are still largely unknown, but knowing that neither species have dominance over one another is important in understanding the food webs that oyster reefs support…and that organisms occupying ornate gastropod shells can be lethal as well!

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