Posted Nov. 23, 2016- At the time of the previous update on the Camp Kekoka oyster reef project, the shells to be seeded with oyster larvae had been bagged, washed and assembled on the dock in Pittman’s Cove. They were ready to be seeded with larvae. We had bagged about 150 bushels of shell into 225 bags. Each bag was about 2/3 of a bushel and held roughly 335 shells.
TOGA member Dudley Biddlecomb recommended a method he successfully uses to set spat on shell. It involves placing the bagged shell in silos--circular wire cages lined with filter cloth that are set directly in the water. This method allows water flow, but prevents the larvae from escaping. It contrasts with commercial operations that place the shell in tanks on land and then circulate water through the tanks. TOGA did not have the space or the funds to duplicate that method.
Dudley loaned the reef project three of his silos. Volunteers increased two in height to allow for the greater water depth at Pittman’s Cove. With the help of TOGA volunteers, the two silos were successfully placed in the cove on August 25th, only to discover that when filled with about 100 bags each, the uppermost bags would be out of the water at low tide, killing any set larvae. Thus, the third silo was hastily made ready with filter cloth and ten bags each from silos one and two transferred into it. An additional 25 bags were placed on the existing reef shell base. These were to serve as a control to determine whether any natural strike was occurring in in the cove at the time the silos were seeded.
In the late afternoon of August 26, Karen Hudson of VIMS released 3 million wild diploid larvae into the silos (see photo on left). A week later a bag was pulled from a silo and examined for evidence of strike. Using a magnifying glass, Karen was able to see some spat on shell, but recommended waiting another ten days to re-examine the bags and then determine the date to lift the bags out of the silos. At that time, a sample count of the strike would be made and the spat on shell distributed over the shell base of the reef.
The counting of the strike, lifting of the bags from the silos, and distributing the shells over the reef occurred on Friday and Monday, October 7th and 10. In silos one and two, two bags were sampled from three levels of the silo: top, middle, and bottom. From silo three (containing only 20 bags), bags were sampled only from the two levels. Fifteen shells were taken at random from each bag and counted for strike, i.e. a total of 240 shells. The result of the sampling was that we had a setting efficiency ratio of 3.6 % or roughly 110,000 spat on shell. Compared to a “good” commercial setting efficiency ratio of 12% our ratio is low. However, our cages were not sealed on the bottom and many of the shells that were sampled showed multiple scars. That was an indicator that predators, most likely mud crabs, were having a feast on our spat. In contrast, the bags that had been placed on our reef base showed no evidence of strike, indicating that there were no wild larvae present and, also, that none our larvae had escaped from the silos.
Apart from the bags of shell that went into the silos and onto the reef base, in early July we had hung a bag from the side of the dock in Pittman’s Cove. When we examined it in September, we were pleasantly surprised to note that we had a good number of healthy strike. That is a strong indicator that in future seasons the reef will attract significant wild strike and that we can expect a healthy growth of our reef.
In October, while we were busy with the working on the establishment of the reef, through contacts made by Dave Turney, we had the good fortune of receiving two significant donations, which will be of great help in the ongoing project of expanding the reef over the four acres of bottom leased in Pittman’s Cove. Jack Blaine donated a floating dock. It will be essential for moving and distributing oyster shell going forward. Up to now we have had the use of a dock on loan to us from Ben Smith. He had originally wanted it returned by July, but graciously consented to let us use it for the remainder of the season. Without Ben’s dock, our progress could not have been accomplished. Additionally, Curt Bluefield donated a small barge to us. This gives us our own boat and we will no longer have to borrow the skiff belonging to Camp Kekoka. They were most generous in making it available to us for the past two years. The floating dock and barge were located up in the Western Corrotoman. Madison Boyd and John McConnico towed them down to Carters Creek where they handed them off to Ken Hammond and his son, who had boated down from Reedville. The tow from Carters Creek, down the Rappahannock and through the Bay into Indian Creek and Pittman’s Cove turned out to be more than they bargained for. Increasing winds and oncoming seas turned a difficult tow into an ordeal. Our thanks to Ken and his son for the extraordinary effort they made. Finally, Albert Pollard donated a silo float to TOGA. This is a very special structure designed to hold ten silos that are about two feet in diameter and four feet high. They can be raised and lowered via a hoist on the float. Going forward we will be able to use the float for our efforts to set spat on shell. TOGA is extremely thankful for these generous and very useful donations.
In conclusion, we have established the beginnings of an oyster reef that will provide a living lesson of oyster aquaculture in the Chesapeake Bay area to the members of the Oyster Club members of the Boys and Girls Club of the Northern Neck. We have an initial success, but much needs to be done to further expand the reef to the full four acres of our bottom lease. In particular, we need to find additional large quantities of shell, and a small outboard motor to power our newly acquired barge would be nice. Anyone who has information on where to obtain shell or an outboard, or would like to volunteer, should contact Madison Boyd, the project coordinator. He can be reached by email at firstname.lastname@example.org , or by phone at
1 (703) 946 4945.
Posted August 5, 2016
In the Fall 2015 newsletter, Mike Sanders reported on the plans for the Kilmarnock Boys and Girls Club Oyster Gardeners to create a living oyster reef in Pittman’s Cove. The cove has uncontaminated water and is an ideal location for the project.
During the Winter and early Spring, funding was secured; the dock was repaired; shell collection from local restaurants continued; and plans were made to complete the project. These included obtaining another trailer load of oyster shell from the Chesapeake Bay Foundation; constructing a second bin for the additional shell, and constructing a floor from exterior sheathing to provide a clean base on which to store bags of oyster shell that would be used to provide the shell for oyster larvae to strike on in protected wire cage silos.
The construction of the bin and laying down the flooring base was done by the group of TOGA seniors who are volunteering on this project under the guidance of Madison Boyd. For moving shell off the trailer and into the bin and bagging the shell, Lady Luck was smiling on us.
Jessie Mandirola, a graduate student at James Madison University in Harrisonburg, Virginia, was looking to establish a partnership with a group through which she could work to test her master’s thesis. It involves finding an economical substitute for natural oyster shell for the larvae to strike on, as natural shells are becoming scarce and expensive. Her thesis aims to prove that you can use shell made of concrete containing a high level of calcium carbonate to attract the larvae (it has been documented that calcium carbonate on natural shell acts as a signal to attract larvae in the water column). Jessie is mixing the concrete and pouring it into molds she made to create the pseudo shells. To test her thesis she needed access to water. She was referred to TOGA and Mike Sanders and an agreement was reached that in exchange for providing TOGA help with our oyster reef project, we would let her use our dock in Pittman’s Cove to hang bags with her concrete shells.
In early- and mid-June, Jessie and a group of fellow students came from Harrisonburg. They first helped us move about 60 bushels of shell from a trailer to the holding bins and then on the next occasion, helped us bag about 140 bushels of oyster shell into net bags. It turns out moving oyster shell is not an easy matter. They are very difficult to move with a shovel or mulching fork. Even a rake is not very effective. The best way is to scoop them with gloved hands into a bucket. It is very labor intensive and the students were great workers.
The bagged shell next had to be moved from the holding area to the dock where they were to be washed using a pump and water from the cove (larvae strike best on clean shell). For that project we got help from a group of young counselors-in- training from Camp Kekoka. Again, they were a great group of helpers.
At the time of this writing, holding silos for the bagged shell have been constructed and lined with filter cloth which will prevent the diploid larvae from escaping and encourage them to strike on the bagged oyster shell.
The next steps are to move the silos into the water, fill them with the bagged shell, and seed the silos with purchased diploid larvae. After allowing three days to a week for the larvae to strike, we will either remove the bags and place them on the substrata for the reef that we have established with the remaining oyster shell, or if that is not yet quite completed, we will remove the filter cloth from the silos to allow free flow of water, oxygen and nutrients and move the bags when the base of the reef is completed.
The results will be reported in the winter newsletter and on this page.
Klaus Boese (MOG in training)