ST. MARY’S CITY, Md. – Over the past month, executive director Bob Lewis, program director Jack O’Brien, and a number of hardworking volunteers have deployed reef balls, concrete rubble, and oyster shells on the five acre restoration site adjacent to St. Mary’s College of Maryland in the St. Mary’s River Oyster Sanctuary. The manufacturing and deployment of reef balls and other substrates has been an ongoing project for the summer work teams of the St. Mary’s River Watershed Association (SMRWA). This year the team has deployed 354 reef balls bringing the total number of reef balls on the 5-acre reef site to well over 2000. (We have another 75 to deploy this spring.)

Of the 429 reef balls planned for deployment this year, 273 were manufactured last summer in partnership with Carruth & Son at their Lexington Park concrete plant. Coastal Conservation Association Maryland (CCA) provided an additional 135 reef balls that they made two years ago. Both SMRWA and CCA have worked to engage numerous elementary, middle, and high school students to construct reef balls as a part of educating them about the health of waterways and the importance of oysters in the Chesapeake Bay ecosystem.

The life cycle of a reef ball begins one year before it will be placed into the river. Building and “hatching” of reef balls is a two day process; the first day is spent setting up the molds and pouring the concrete, the second is spent taking the molds off and gingerly rolling the balls off their platforms. Next the reef balls are moved into the spot where they will spend the next year “conditioning” so that the PH of the concrete becomes more hospitable for oyster larvae. Finally, when the time comes to deploy the structure into the river, it is transported to the St. Mary’s College waterfront, rolled down the dock onto a barge and pushed into the river. Once in the river the reef balls are placed into position depending on the structure of the reef being constructed. The five acre reef site contains thriving artificial reefs of many shapes and sizes.

Over the past years the methodology to deploy reef balls has been refined to be more and more efficient with each reef ball that has been deployed. The team has been able to deploy as many as 60 reef balls in four hours (that’s a reef ball in the river every four minutes!). However, the most rewarding part of reef ball deployment is not when the day is over and all of the reef balls are in the river, it’s when you are in the water moving the structures into place and one looks around at a reefs that were deployed years ago to see them completely covered in oysters, hook mussels, barnacles, and other aquatic life.

In addition to reef ball deployment, the SMRWA team has also spent time in the past month hardening bottom with oyster shells. The oyster shells are being placed on a site in the reef that contains few oysters and a firm mud bottom. The goal is to harden the bottom to three inches thickness of shells thus providing natural larvae a hard surface where they will live the rest of their lives. Timing is important: the reef balls and shell are being placed into the river ahead of the wild oyster spawn. Hopefully good reproduction this summer will populate the shells and reef balls and the substrates could be completely encrusted in one inch oysters by late fall.