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Jul 06
2012
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On the first day of summer, a near 100 degree day, I was able to join the Chesapeake Bay Foundation in planting over 2 million baby oysters, called spat, on oyster leases held by POWeR. POWeR stands for Project Oyster West River and has been maintaining multiple oyster leases that it keeps as sanctuaries to provide crucial habitat for oysters and countless other underwater animals. The journey that these young oysters take is quite a story and really shows the great lengths that we will go through to restore this priceless resource.
The oysters that we planted started their lives’ at the University of Maryland Center for the Environment, Horn Point Lab in Cambridge. Here the massive lab places adult oysters in shallow tanks and gives them optimal conditions for them to start breeding. Once the oysters finish releasing their eggs and sperm into the small tanks the water/ egg mixture is transferred to huge ten feet diameter by over ten feet tall tanks to allow them to grow and mature for about two weeks. At this stage in their lives these oysters have developed what is called an “eye” and a foot. These eyed oysters are able to swim to seek out a hard surface to settle on and live the rest of their lives’ as the stationary adult that we are familiar with. Of course the Horn Point lab doesn’t want these oysters to live out their days in the tanks so employees filter the larvae out of the water and cool them so they can be delivered throughout the Bay region.
One place that the oyster larvae are delivered is the Oyster Recovery Center (ORC) located right behind the Riverkeeper office in Shady Side. The ORC is run by the Chesapeake Bay Foundation (CBF) and serves as their center of operations for oyster restoration in this region of the Bay. The ORC is composed of a small office/ workshop area, 4 large “setting” tanks, the Chesapeake Bay Foundation’s restoration vessel, the Patricia Campbell, and many piles of drying oyster shell. CBF staff loads dried and cleaned shell into the large setting tanks and pumps water from the West River into them. Once the water fills the tanks it is re-circulated through the tanks and heated to a temperature that allows the greatest number of larval oysters to set. The refrigerated larvae are then allowed to warm up slowly underneath a microscope in the office and in five gallon buckets next to the tanks. CBF staff then monitors the larvae under the microscope until they start swimming. Once the larvae start swimming they are ready to be dumped into the tanks, so staff take their buckets and gently pour the larvae over the cages of shell in the tanks. Larvae are allowed to swim freely in the tanks for 3 to 5 days; by that time they have settled onto a shell and glued themselves down. This is called “setting” and what were once oyster larvae are now called spat, which are simply baby oysters that have glued themselves to a spot permanently. The tanks are then opened back up to the waters of the West River so that the young spat can eat all the algae that get pumped through the tanks.
After a few days of eating well and getting stronger in the tanks its time for the spat to be “planted” on a reef. To do this CBF staff and volunteers load the cages, which weigh several hundred pounds, onto the Patricia Campbell. Fortunately the Patricia Campbell is well equip for this task and uses its very own crane to lift the cages of shell and dump the shell into giant hoppers on its deck. After the shell is all loaded its time for the boat to depart and really get to work. On the day that I was helping we took the young spat to POWeR’s lease in the West River and started to unload our precious cargo. This is accomplished by uncovering a conveyor belt located below the hoppers on deck that pulls the shell containing spat to the front of the boat where there is a spreader that distributes the shell evenly throughout the location.
After a few hours of hard work getting the shell running smoothly down the conveyor belt and out to the spreader POWeR’s leases were the happy recipients of millions of new oysters. These oysters may now live out their lives safely on the bottom of the West River, filter our water and provide happy homes for fish, crabs and countless other critters.
