As 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.
Although we’ve busied ourselves this summer by selecting research sites and practicing various aspects of our sampling program, we have still not collected any ‘real’ data concerning the objectives of our biogeographic oyster project. Well, this post will be short because as I write this we are hectically preparing to begin said research. Coincidentally, tropical storm Bonnie has also decided to begin her work in the Gulf at the same time!
See David and his crew in action, and see what animals are on Alligator Harbor reefs.
The title of this blog (a sports metaphor) is how my teacher first introduced me to marine ecology. For our oyster project, this essentially means that we need to establish who is on the oyster reefs before we can begin to make connections among predators, oysters, and their water filtration services….as well as (unfortunately) the impacts of oil.
So far, we’ve identified the organisms on the bottom rung of our food web (think of it has a pyramid): oysters, clams, amphipods, and polychaetes on the bottom rung of the food web and mud crabs and snapping shrimp on the next higher rung of the food web. Our goal this week was to begin quantifying who is at the top of this food pyramid. To do this, we deployed crab traps, bait-fish pots, and gill nets onto each of our reefs during low tide. Following the ensuing flood tide, we returned the next day to count our catch and then promptly release everyone.
the hardhead catfish was the most abundant species trapped during this survey
But after running out of fresh water to drink and profusely perspiring all the moisture out of my body while out on the reefs, it dawned on me that nature of this catch is likely an interesting seasonal pattern (again, I’m new here!): only hardy organisms that can tolerate really hot and low oxygen waters are going to be on Florida reefs right now. Once the rest of this research team begins collecting similar data from Virginia to Florida, it will be interesting to see if these low abundance-diversity patterns might last longer in some areas (e.g., Florida with longer summer) than in others (e.g., NC with shorter summer). If that’s the case, then the cascading effects of higher order predators (things at the top of our food web) down to oysters and their water filtration services may be occur more consistently during the summer in northern than in southern estuaries.
Hmmm…..good thing we are conducting a relatively long-term study and will consistently repeat this sampling in the future to rigorously detect interesting patterns like this one.
Until next time…
The Music in the video was by Jim Crozier. As always, we welcome submissions from local musicians. WFSU’s kayak was provided by Wilderness Way.
David’s research is funded by the National Science Foundation.
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