Tuesday, August 10, 2010

August Oyster Growth Update

It has been an exciting time for the Oyster Project. Mortality has been very low in the oysters we placed in cages last fall and, in some cases we have seen substantial growth. Our volunteer divers and measurers have had some excitement including our first 4 inch long oyster! Size matters because reproducing size is considered to be 3 inches. So if we can get them to that size, then there is hope for a reproductive event when the water gets warm enough. Interestingly, once the oysters get to be around that 3 inch size the growth tends to shift more to thickness. It is fascinating to watch.

We have been sharing data with our regulators at the Massachusetts Division of Marine Fisheries. So, we are beginning to generate data indicating the oysters can survive and grow in the harbor.

Two of our larger oysters. The left is more the classic tear drop shape.

On the other hand, we have not yet shown reproduction, although we placed an impressive specially designed device for young oysters to settle on should they be created. (Thank you Dave!) And we did see extensive predation of our loose oysters by starfish and crabs. (They like eating oysters too!) This will need to be considered as we seek to establish a self-sustaining population.

Here is Dave with the apparatus. and the medicine ball like floats that support it. In the lower right of the photo you can see the "cages" we place oysters in on the bottom.
Overall, we are pleased with the progress from an oyster front and we are learning a lot! How to place the oysters, methodologies for measurement, apparatus that can be used, etc.

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