If you remember, last December G2 sent in water samples from Antipoison Creek to Abby Barrows at Adventure Scientists (see this former post). Abby has been documenting the presence of microplastics in global waters. Microplastics are bits of microscopic plastic debris. A major source of this debris is clothing. As synthetic fibers (many clothing items such as fleeces are made with synthetic fibers) are put through the washing machine, plastic debris from these items come out of homes as wastewater, and eventually make their way to streams, rivers and oceans. Preliminary evidence suggests that marine species are reacting negatively to the ingestion of microplastics. The team at Adventure Scientists has been accepting water samples from around the globe to determine how prevalent pollution from microplastics is. You can check out their online map to see which waters have not been sampled yet, and sign up to sample if you see an opportunity to contribute.
G2 received results from the Antipoison Creek samples. One blue microfiber was found from our samples. The results were shared via the Adventure Scientists blog here, which also includes a post on Abby’s lab process and overall project results thus far. Go check it out!
We have been collecting water quality data on Antipoison Creek for about 11 months now, sampling for nitrate-nitrites (NO23), phosphates (PO4), ammonium (NH4), and chlorophyll. Our data collection extends from last September to this May (with sampling ongoing). Last month, Gary, Libby and I visited with Dr. Lora Harris, an associate professor at the University of Maryland’s Center for Environmental Science (UMCES), who specializes in systems ecology and ecosystem modeling, to get input on how to analyze our water quality data.
Dr. Harris gave us several suggestions, one of which was to create a Nitrogen Loading Model (NLM) for Antipoison Creek, to determine if the creek is primarily fed by nitrogen coming in from the Chesapeake Bay, or from the watershed (land-based activity and runoff, groundwater leaching, and atmospheric deposition). Harris described the NLM as a type of box model, showing inputs and outputs in and from a watershed. (See Figure 1, from the NLM instruction manual below).
The Nitrogen Loading Model, created by Mark J. Brush (VIMS), Lora A. Harris (UMCES), Juliette C. Giordano (VIMS), and Joanna K. York (UDEL) allows a user to put in data on land use and activity in a specific watershed- for us, Antipoison Creek. The model pulls in miscellaneous information on the watershed, such as atmospheric deposition, loads from point sources, and surface area of the creek. It also pulls in data on non-agricultural and agricultural land cover, as well as the fertilization rate and agricultural yield of each crop grown in the watershed.
Using a mix of applications including a GIS operating system (QGIS) and GoogleEarth, as well as a number of sources on Antipoison Creek and Lancaster County, we came up with estimates for the needed parameters. Once all the inputs were entered, and the model generated kilograms of nitrogen for groundwater input, wastewater input, direct atmospheric deposition onto water surface, and a total annual load of nitrogen (kg) entering the watershed, we contacted Dr. Brush to discuss our procedure and results.
Now that we have an annual watershed load for nitrogen to the estuary, we must determine if Antipoison Creek has a greater flux of nitrogen coming from the watershed and emptying out into the Bay, or if the Bay is primarily feeding the creek with an influx of nitrogen.
We will be working with Dr. Brush on this next step, as well as a more in-depth paper to share our work on the NLM model.
Source: Brush, M.J., L.A. Harris, J.C.P. Giordano, and J.K. York. 2015. Delmarva Coastal Bays Nitrogen Loading Model. Virginia Institute of Marine Science, Gloucester Point, VA. Available at: http://www.vims.edu/research/departments/bio/programs/semp/models/index.php.
By Gary Greenwood
This past Saturday was a beautiful summer day on Antipoison Creek. As we were sitting outside enjoying the view and breeze, we would occasionally hear a loud splash just off the shore. We would look up just in time to see the osprey surface and try to gain altitude with a fresh-caught fish in his talons. We named him Sam.
There is an osprey nest on a pole not too far from our shore, close to the oyster farm. It’s on a piling, not as high above the water as it should be, but the osprey population is increasing, so they use any suitable platform they can find. Last year it was just a piece of plywood, and in a storm the nest was at risk of blowing away. So in late March my neighbor Glenn and I added some nice 6-inch walls around the edge of the plywood. We had no sooner gotten back to shore than we saw two osprey pairs checking it out. Sam and Louise won out, and proceeded to build a nice nest.
After Sam caught the fish, we could see Louise through the telescope, chattering away. Soon Sam came along with the fish, and two young chicks stuck their heads up for dinner. The feathers are all dark grey, and the necks are long. Louise would pick a piece of meat off the fish and feed it to the chicks. They aren’t ready to fly, but they do a good job eating and sleeping.
I didn’t get any good pictures on Saturday, so the next day, even though it was rainy, I went over and got a nice picture of a very wet Louise watching over her chicks. Unfortunately, the chicks weren’t sticking their heads up unless there was a fish, so you can’t see them in the picture.