On a recent hot summer day, two scientists donned heavy scuba gear and slipped below the ocean’s surface in a protected cove on Maine’s midcoast. Surrounded by support boats and a team of sweltering colleagues, these divers weren’t exploring a reef, they were building one. This was the beginning of a project to test oyster reef development techniques in the waters just off the Basin Preserve in Phippsburg.
Oyster reefs and shellfish beds provide critical habitat for fish, crabs, shrimp, and other near-shore creatures. They also improve water quality as the oysters filter-feed on phytoplankton and tiny pieces of debris, removing excess nutrients and suspended particles. The cleaner, clearer water then allows for species such as eelgrass to thrive, further improving the health and productivity of the area. Reefs also help stabilize sediments and provide natural shoreline protection as storms become more frequent and powerful. And they’re tasty!
Launched by The Nature Conservancy in Maine in partnership with local, state and private agencies and organizations, the project involves setting on the seabed special one-foot by one-foot tiles resembling cement sand castles that are designed to reproduce the ideal surface for young oysters to attach and grow. As part of the test, some of the tiles have been “seeded” with very young oysters called spat. Other tiles without spat were also placed in the test area to see if they will naturally colonize with ‘wild’ oysters. Additionally, bags filled with old oyster shells, with and without spat are being tested in the same grid area.
Over the next three years, scientists will monitor the different surfaces and conditions to compare their effectiveness at building solid reefs. The results of the effort will help determine the potential growth rates, ideal habitat conditions, costs, and scalability of oyster reef introductions in the region.
The Conservancy is receiving support and guidance from the Town of Phippsburg, Maine Sea Grant, Casco Bay Estuary Partnership, the University of New England Marine Science Program, and the Department of Environmental Protection Marine Program.