Tuesday, July 20, 2010

Through the Lurking Grass...


In this week's Adventures "Through the Lurking Grass"...!

This summer my research and field work involve acoustically mapping seagrass beds, ground-truthing the acoustic data by snorkeling and measuring the seagrass found in 1 square meter quadrats, identifying seagrass samples to verify species identification, pressing and preserving seagrass for our own little herbarium, and analyzing seagrass video.

"Through the Lurking Grass" posts will follow your heroine as she reflects on her seagrass adventures in coastal North Carolina...

This past week one piece of our equipment had to be sent back to the manufacturer for repairs. We had grand plans of field work for last week and part of this week, but that is all on hold until we hear back from the manufacturer and have our equipment back. So, I'm focusing on seagrass video analysis this week.

For our collaborators at NOAA, we identify the presence or absence of seagrass species in the video at the 1st frame of every 3rd second in the video. We have also started adding an estimate of the percent cover at that frame, and I'm "quartering" my television screen (in my mind) in order to get an estimate of 25, 50, 75, or 100% cover. That estimate really just gives us a very general idea of how much seagrass is in the viewing area of the video camera during that 1st frame of the second...which we can use to cross-reference with our acoustic data in order to further ground-truth our acoustic results. All this is important, because it is necessary to confirm and cross-check data from one method with another.

In this week's Adventures "Through the Lurking Grass," your heroine is spending her week analyzing the video transects...and today she wished to be in the water, snorkeling, seeing the images on the television screen through her own eyes...

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