Wednesday, May 7, 2008

Robins Island and Hog Neck Bay test plots

On April 17th Steve and Kim headed out to check on the status of several test plots off Great Hog Neck and Robins Island in Southold. These plots were planted out in fall of 2007 and are part of the site selection work underway for the "Suffolk County Eelgrass Restoration Initiative" funded by Suffolk County. Site selection involves conducting test plantings in fall/winter and following the progress of these transplants over the following year. Plots that make it through August are deemed worthy of further planting scale-up, if not full scale (acre size) plantings. We typically plant out a series of 1m diameter (200 shoots each) circular plots perpendicular to shore running from just below MLLW to a depth of about 2m at low tide. In this way we can determine the most appropriate planting depth at each site. Initial site selection is based on historic presence of grass, water quality, fetch and bottom characteristics.

The Hog Neck site (left) had suffered some losses during early winter that we were already aware of so we knew that the shallowest plots would not be intact. The deeper plots (3&4) were found however and the the plants looked excellent. In addition to the circles, Steve had also added some clumped plantings (see below) in early winter to see how these would fair compared to the circular plots. These also looked good. There was lots of brown drift algae attached to the shoots, but this is to be expected during this time of year when the water is still cold.

The Robins Island plots probably looked better than we have EVER seen for overwinter survival and health in eelgrass in the Peconic Estuary. All plots were intact and the density was very good, especially for the two shallower plots (see "RI2" in top photo). Shoot densities ranged from a low of 181 to a high of 217 with the two shallower plots coming in over 200, actually adding shoots overwinter. It is interesting to note that you can see that plot #2 had lost about 2-4cm of sand just recently (within the week?). If you look close you can see the white sheaths and roots at the base of the plants. These would not normally visible.

As the season progresses we will follow these plots closely to see how they fair in response to lower water clarity and higher water temperatures.


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