Grass in Coecles Harbor, Shelter Island

Our first dive of the season took place on January 10th 2008 in Coelces Harbor, Shelter Island and involved looking for whatever eelgrass could be found. I had received a call from the Shelter Island Town Attorney asking that I come in and make a brief presentation to the Town Board on the status of eelgrass in Town waters. The Board was considering funding habitat related work to support their shellfish restocking efforts (also part of CCE) and knew that we had been working with eelgrass in the waters just off Cornelius Point, SI. Since I was not aware of any grass in town waters I figured that we had better get in and take a look at the long-fabled grass meadows in Coecles regardless of how cold the water was.

After making a couple calls, I was able to narrow down the search to an area just south of the marina. A quick look at recent aerial maps on Google Earth confirmed what looked like grass in this area, but the Goolge images are old so there was no guarantee that what I saw on the aerials was still there. Since our normal boats were layed up for the winter our only alternative was the aquaculture barge, named the "ShellStar". Kevin Cahill the ShellStar's captain was more than happy to accommodate us on our venture.

Upon anchoring in Coecles, we did find grass right where we saw it on the aerials and looked great. One interesting aspect of the grass here is that it is growing in extremely muddy bottom in about 8-10ft of water. There was no grass to be found on the sandier shallow bottom where I would have expected it. This is interesting because we have lost most of the grass in our muddy bottom harbors and creeks throughout the Peconic Estuary. Most of our existing grass in the Peconics grows in higher energy sandy sites that are exposed to some wave energy and currents. Bullhead Bay in Southampton is the only other known exception to this rule that we are aware of.

Another interesting aspect of the Coecles Harbor meadow was the fact that once I started pulling away the dense macroalgae layer that surrounded the grass I found thousands of small seedlings poking out of the bottom. Although the adult shoot density was fairly low and somewhat patchy, seedlings appeared to cover much of the open bottom (see above). I was so intrigued by the seedlings I had to take a few back to the lab to have Kim take close-up pictures and document what we had observed (right). Apparently, seedling recruitment is an essential part of meadow maintenance at this site. It is not often that we see this many seedlings in the field. The only other sites where we have seen this include Noyack Creek and Bullhead Bay in Southampton.

Stay tuned for a spring recon dive to further our understanding of this interesting site.

ChrisP