What’s floating in the Pond?

Some of you may have noticed the oddly shaped objects floating in Edgartown Great Pond.  Sam Hartman, our summer intern has the answer.IMG_20160721_060355877


Oyster Cage, upside down

The odd floats that have been spotted around the pond are oyster cages. These cages are placed at places not naturally conducive to oyster growth due to their sandy bottoms, and give the oysters a “rocky” place to grow. This type of habitat is artificially achieved by attaching bags of scallop shells to the cages, allowing the oyster larvae released by oysters on the pond bottom (and in the cages) to float into these bags, attach to a hard substrate, and begin to grow. By adding adult oysters into the cages, the chances of oyster larvae reaching these bags increases. The cages float so that the shells are near the surface of the water, where it is warmer and oysters can grow earlier in the season.


Scallop Shell Bag

The cages are part of an effort to reintroduce oysters into the pond in order to help aid in the filtration of nitrates and other contaminants from the pond. They will most likely be in the pond until late August, but should not pose a problem to boating or other pursuits. Petey Jackson, who is implementing the oyster restoration in the pond, has placed these cages so that they do not interfere with regular pond activity. The use of the cages with additional shell bags attached and the placement of loose shells on the sandy pond bottom (mostly along the western coast of the pond) will expand the area where oysters can grow in the pond. The expansion of both the oyster population size and distribution will increase pond health by filtering a much larger volume of water; therefore removing a greater amount of contaminants from the pond, and decreasing the likelihood of algal blooms.