Members of the Fodrie lab install Artificial Seagrass Units (ASUs) at the Oscar Shoal. The shoal was nearly covered with seagrass as late as the 1990’s, but has been depleted due to erosion and increasing water temperatures.
An artificial seagrass unit lies on the boat before being installed in the water. This year’s experiment uses over 760 units.
Amy Yarnall, a UNC PhD student, installs an artificial seagrass landscape. There are 16 of these in the shoal, each containing 48 ASUs. The difference between each is in its design, ranging from one large, continuous seagrass patch to many, fragmented patches.
Research tech Grace Roskar organizes lawn staples used to pin down ASUs in the water. Over the past two years, Fodrie’s lab has put in thousands of hours of work into the seagrass project. With additional help from volunteers, he estimates they have spent up to 6,000 hours for construction of the ASUs alone. “We try to do things at pretty ambitious scales,” he says. “Ecologists are sometimes limited by logistics, but we tend to pull off experiments at the scales that we think matter and not necessarily the scales that logistics may lean toward.”
It’s mid-July in Beaufort, and the temperature is nearly 100 degrees. Research techs Savannah Swinea and Jade Danford-Klein hop out of the small boat, happy to cool down. After pulling up minnow traps from the seagrass landscape, they wade back to the boat with their catch in tow. Onboard, they unhook and dump the traps, peering over at what surprises are in store.
Danford-Klein, a UNC junior studying biology and marine science, holds out a female blue crab carrying an egg sack on her underbelly before releasing her back in the water. The team finds a variety of small marine life on their excursions such as pinfish, swimming crab, pig fish, and black seabass.
Swinea measures a specimen while Yarnall takes notes. The group gathered four minnow traps at each site — two within the bed and two on the outer edge — totaling 32 traps in all.
Yarnall logs data on specimen found in the traps, including the species name, number of each specimen, size, and whether they were caught centrally within the seagrass bed or in the outer edge.
Preliminary results from last year suggest that larger, patchier landscapes support more animals and greater biodiversity. Yarnall explains they think that is because patchy seagrass beds incorporate two types of habitat — seagrass and sand flats.