Chesapeake under Congressional Attack
This Week in the Watershed

Good News about Oysters

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3.2 million spat on shell were planted in the South River this July. Photo by Erika Nortemann.

Persuading microscopic oyster larvae to "set" on old shells is as simple as placing plenty of both into a large round tank of circulating Bay water and leaving them together for several days. Right?

Not hardly. This Chesapeake miracle is absolutely dependent on good water quality. Some years, successive sets die off, handcuffing restoration programs.

But not this year, at least so far. CBF's MD Oyster Restoration Center at Shady Side has been able to produce a record number of spat (i.e. baby oysters) on shell, the universal currency of restoration. "The spring and summer have been extremely kind to us," said Capt. Karl Willey as he deftly maneuvered Patricia Campbell, CBF's 60' oyster planter, around Thunder & Lightning, an oyster reef in the South River that is open to harvest by watermen wielding hand tongs. "The hatchery at the University of Maryland Horn Point Laboratory started producing larvae early—in April—and has continued. We've seen strong spat sets in our tanks since then. We've actually gotten ahead of schedule, with 31 million spat set on shell and placed on restoration reefs in the Little Choptank...Now we have July to work small projects with some of our partners. That's why you found Kate [South River Federation Executive Director Kate Fritz] and me counting spat on the dock this morning." 

Indeed, as Dan Johannes, Pat Beall, and intern Patrick McCabe loaded spat on shell into the large bins on either side of Patricia Campbell's long foredeck, Karl and Kate carefully examined a random sample of several dozen shells, counting the pinhead-sized spat on each. Eight-to-twenty spat on each shell allowed him and Kate to estimate how many spat the big boat would be planting on this day: 3.2 million. 

Loading and counting completed, the crew and several volunteers, including Kate's Board Chair, Kevin Green, climbed aboard for the one-hour run up to South River. We slowed briefly to watch a large pod of dolphins fishing in the river's mouth, then got down to work on a sanctuary reef 11-14' deep off Larrimore Point. As Kate and Kevin watched on the foredeck, Dan started up the hydraulic system that tilts the bins full of spat on shell inward to the conveyor belt that runs down the center of the foredeck. Pat and Patrick began to regulate the flow of 1.4 million spat on their shells into a steady stream on the belt, all moving forward to drop onto a rotating "planter wheel" at the bow that throws them out in a circle 10-12' in diameter. Meanwhile, a GPS antenna mounted beside the wheel sent a continuous signal of our track to the electronic display in front of Karl at the helm, recording the data on a memory card. This technology arms Karl with the data to know everywhere this program has planted since 2003.

We dropped another 0.5 million spat on shell on an 8' sanctuary reef tended by John Flood, an South River Federation Board member emeritus, and 0.3 million on another sanctuary off the mouth of Little Aberdeen Creek. Finally, we moved to Thunder & Lightning, to drop the last 1 million in 10-12' where local watermen partners would be able to harvest them once they grow out in two-to-three years.

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CBF's oyster planting boat, the Patricia Campbell. Photo by Erika Nortemann.

Tiny predators like mud crabs that live on the reefs eat spat, but survival from spawn to adult for these guys set in concentration in our tanks is higher than natural sets in the wild," Karl said. "The density at which we plant [5 million spat on shell per acre] produces dense clusters." 

At the end of the month, Patricia Campbell and her crew will partner with the Coastal Conservation Association/Maryland to set 72 concrete reef balls with spat and place them onto the MD DNR's Tilghman Island Artificial Reef, in 18-20' of water due west of the island. The reef balls themselves have a special story: they have all been built by high school students in masonry classes, expressly for this purpose.

After three decades of bad news about oysters, imagine being able to get ahead of schedule with good news. Here's hoping we can make it last...

—John Page Williams, CBF's Senior Naturalist

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