Tag Archives: Cedar Key

Day 3: October Oyster Push “No Nap Time”

Rob Diaz de Villegas WFSU-TV
David Kimbro’s crew has been split into two teams, the Net/Trap team (N/T) and the Tile team (TI). For a closer look at how David’s team nets and traps larger fish and crabs, click here. To learn more about what the Tile team will be doing, click here. And if you click On the Reef under categories in the sidebar, you can track David’s progress over the course of this study.

Sunday, October 24- Net / Trap team in Cedar Key

Randall places traps on a Cedar Key reef

Randall places traps on a Cedar Key reef.

IGOR chip- biogeographic 150After months of walking around In the Grass, Dr. Randall Hughes stepped out On the Reef Sunday, pitching in for some fieldwork with David’s tech, Hanna Garland. They were the Net / Trap team working Cedar Key, while Tanya Rogers is heading up the Tile team in Saint Augustine. Randall, in addition to heading the salt marsh biodiversity study we also follow on this blog, is the co-PI (Primary Investigator) on this biogeographic oyster study. With her other study taking so much of her time and David having things well in hand with this one, she hadn’t made it out into the field until Sunday.  We tagged along with her today.

This was our first time documenting this study outside of Alligator Harbor (which is located a short hour from WFSU-TV) and, actually, it was my first time on any oyster reef other than those. I noticed that the water was a little clearer- I could actually see some of the oyster clumps for a foot or so under water as opposed to not at all. Few of the oyster reefs were as large as in AH, tending more often than not to stay a collection of clumps than an expansive reef. There were also stretches where reefs had been, and all that remained were broken shells. Randall told me that these had either been harvested or that the reefs had just plain failed (Tanya recounted finding two of the Cedar Key reefs obliterated in her last post).

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Scientific equipment being used in an entirely lawful way. This machine filters the sediment floating in the water- including the phytoplankton that oysters eat.

If you take a look at the schedule below, you can see that the events are spread out based on the tide schedule; and there are a couple of days during this push where they start around sunrise and work well into the night. So there are breaks from fieldwork built into the day. I had assumed that this would be “nap time.” To my surprise, this is actually “lab time.” The water samples they had taken on our boat ride had to be filtered, and the filters frozen as fast as possible to prevent bacteria from contaminating them. They set up their “lab” in the kitchen of a condo they were renting. The apparatus they use is a collection of PVC pipes, tubing, and a motor into which they pour the liquid from clear test tubes. Randall had seen a news story this last week where some college kids were arrested for turning their dorm room into a crystal meth lab. She wondered aloud whether someone looking in their window might suspect the same of her and Hanna.

8:00 AM- Travel to Cedar Key

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Boating from reef to reef, we would see places like this where a reef had been decimated. Two of the original Cedar Key sites for this study were destroyed. These are the kinds of things that happen outside of the controlled environment of a laboratory.

12:23 PM- Deploy traps, collect spat sticks, water samples. They once again made use of the new boat, though the public boat ramp is on the other side of the island from where their sites are located. They were going to look for a boat ramp closer to their sites to save a little more time.

The spat sticks so far have only collected barnacles at all of their sites, meaning that they may have started using them past the season in which oysters spawn.

6:00 PM- Retrieve traps, High tide activities: reference water level, replace spat sticks (if possible).

9:00 PM- Deploy nets. Randall and Hanna will retrieve these in the morning before Hanna heads to Saint Augustine to meet up with David Kimbro and the rest of the crew.

Tide Times and height (ft.) for Cedar Key, October 24, 2010
Low- 9:23 AM (-0.3)
High- 3:48 PM (3.3)
Low- 9:13 PM (1.4)

Sunday, October 24- Tile team in Saint Augustine

1:00 PM- Tanya Rogers and new crew member Cristina drive to Saint Augustine.

7:00 PM- Retrieve tiles/oysters.

Tide Times and height (ft.) for Saint Augustine, October 24, 2010
Low- 7:21 PM (0.5)
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Roctober!

Dr. David Kimbro FSU Coastal & Marine Lab

IGOR chip- biogeographic 150I went to graduate school in northern California. Locals along the coast of NorCal used to refer to the month of October as Roctober because it was the most beautiful time of the year.  Well, I think the Forgotten Coast should also be privy to this monthly description because things have been beautiful around here this month.  Looking at the oyster reefs, I get the sense that things are really starting to get busy in there.  But I wonder if the ecology on oyster reefs in NC is starting to slow down.  Where are predators really having a big effect? We shall soon see.

For the past week, we have been trying to figure out how to do a lot of ambitious seeing and learning on all of our reefs.  All three teams (i.e., NC, SC/GA, and FL) need to not only sample fish and invertebrate predators on reefs (for the second time and in the dark…all because of the timing of tides in the autumn), but each team also needs to simultaneously squeeze in an experiment.  Oh, I just remembered that we also need to pay attention to other things that can explain oyster patterns: oyster food in the water (phytoplankton), water temperature, tides, and sediment properties.  So, add those to our to-do list as well!

Because this will be a ton of work to do in a short amount of time, we are sending a new crew member of the Florida team (Alicia Brown) up to help out the South Carolina/GA team.  We are going to send her up with a video camera, so it will be fun to get a glimpse into their lives over the next week.

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Jon Grabowski holds up a fish for Tanya to measure. David was Jon's lab tech at UNC.

In addition, one of the leaders from North Carolina (Jon Grabowski) has been down with us in Florida for the past week to help make sure that all three teams are doing the same thing.  While he was here, we also worked with a wonderful assistant up in Georgia (Caitlin Yeager) to figure out how to manufacture our experimental products.  The first part of this experimental puzzle involved figuring out how to remove baby oysters (spat) from oyster clumps in the field and to attach them to a standardized surface (tile).  Across all of our sites, we all want to start out with oysters of roughly the same size and age; otherwise, differences in our experiments among sites could simply be due to differences in starting oyster size or density, rather than to differences in predator diversity etc.   After we get all the spat attached to our tiles, we then built (well Tanya built most of them- thanks Tanya!) structures to put around our tiles, or not…

Tile Experiment

A partially open cage (cage control) that lets predators eat the oyster spat.

Our first structure was built to exclude all predators from munching on our oysters (i.e., predator cage).  Our second structure was a modified exclosure that mimics physical characteristics of the exclosure, but still allows predators to munch oysters (cage-control).  Finally, we have naked tiles that receive no structure or cage.  At 2 sites in NC, 2 in Georgia, and 3 in Florida), we will put each of these ‘treatments’ on all of the reefs (15 tiles/estuary or 105 tiles total).

But why do this crazy experiment thing?  Well, we will come back each month and monitor the traits of oysters and their survivorship.  With these results, we will compare survivorship or oyster traits from cages to that of the naked tile (“control”) to see if excluding predators improved oyster survivorship.  But because any improvement of oyster survivorship by the cage could simply be due to the physical structure (not to predator absence) providing shade during low tide or somehow changing flow (and food delivery), we will then compare cage results to that of the cage-control; now we can tell just how important predators are.

Another cool thing about the cages is that it may exclude predators from eating oysters, but they will not prevent predators from affecting traits of the oysters through intimidation.  So, do the traits of oysters surrounded by cages in Florida (maybe more oyster consumers) differ when compared to caged oysters in NC (maybe fewer oyster consumers).   Or, perhaps it’s that FL has more oyster food this time of year than NC and that better explains trait differences in oysters, not predators.  Or, maybe larger fish predators in Florida means less oyster consumers and less influence of oyster predation in Florida compared to NC, where there may be fewer large fish predators to eat the smaller crabs that love to munch on oysters.

To pull off this extra work, my Florida team will divide and conquer over the next week and a half.  Out of a team of four, 2 people will trap and gill net while the other two folks will set up the experiment.   This will involve ½ the team moving a head of the other team members at certain points.  But we’ll all overlap at each site for at least a few hours, which will then result in interesting stories about what each team has been observing.  Because we want to share this circus show with you over the next week, we’ll post updates every day.  We hope that this gives you a feel of what it’s like to get all of this done (both the good and the bad!).

Well, I need to go stockpile some sleep.

See ya,

David

David’s research is funded by the National Science Foundation.
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A closer look into the reefs

IGOR chip- habitat 150The following photos are of samples taken at each of Dr. Kimbro’s sites, as mentioned in his previous post.  After surveying the reefs to see what large fish and crabs were living in the reefs, he and his team turned to looking at the oysters and the creatures living under them in the mud.  That’s what you’re seeing here.  Click on any photo to make it larger.

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Counting the Catch

Tanya Rogers FSU Coastal & Marine Lab
Tanya Rogers

Tanya Rogers

IGOR chip- biogeographic 150IGOR chip- habitat 150As Dr. David Kimbro’s research assistant, I help out with all aspects of the biogeographic oyster project in the field and at the lab. David, myself, and Evan Pettis (an intern from FSU) have returned from our big sampling effort to characterize the predator community on the oyster reefs at our chosen field sites. Over the course of a productive yet exhausting week, we successfully deployed and retrieved nets and traps at Alligator Harbor, Cedar Key, and St. Augustine and found very interesting differences in the abundance and diversity of fish species between sites. St. Augustine had by far the greatest diversity of large fish species, including redfish, snapper, toadfish, flounder, jack, ladyfish, bluefish, and menhaden. At Cedar Key and Alligator Harbor we caught longnose gar, a fascinating and very ancient fish with extremely hard scales and a long toothy snout. The largest fish we encountered were black drum, which we only captured at Cedar Key. Pinfish, hardhead catfish, and striped mullet were present at all of our sites, although in varying abundances.

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