Exploring Husbandry and Equipment Solutions to Infestations of Polydora sp. on a Maine Oyster Farm

Project Overview

Project Type: Farmer
Funds awarded in 2009: $9,365.00
Projected End Date: 12/31/2011
Region: Northeast
State: Maine
Project Leader:
Jesse Leach
Bagaduce River Oyster Co.

Annual Reports


  • Animals: shellfish


  • Animal Production: general animal production

    Proposal summary:

    Current issue

    Polydora spp. Is a genus of marine worms that inhabit the calcareous shells of marine bivalve mollusks, such as oysters and scallops. They are common on some aquaculture farms in Maine, in some locations in the Atlantic Canada, and certainly down through the US Mid-Atlantic bight. As pests, they often do not present a direct threat of mortality to the individual oyster, although reduced condition index can occur, which may limit an oyster’s ability to combat disease and survive the winter season. The real damage that Polydora does is in the marketplace: high infestations will weaken the shell, which then often breaks during shucking and results in the release of mud and worm waste onto the half-shell oyster. These oysters become undesirable to the consumer and purchases from the individual oyster farm can be adversely affected.

    Project objectives from proposal:

    We propose to experiment with husbandry and equipment changes that will allow my farm to cope with Polydora, and by extension, our results will be applicable to other farmers in the state and the region. Specifically, we plan to test the effectiveness of air exposure, dip treatments and biological biofouling control on the levels of Polydora in our oysters. By using different approaches, we will understand what can be effective, under what conditions, and to what extent. We will also gather observations to better understand the precise times for Polydora spawning and settlement so that our control measures can be best targeted to limit or prevent new infestations.

    We will transfer our results to other growers in Maine and the region through several avenues. First, we will offer farm visits to other growers so first hand experiences can occur. Secondly, we will draw up a report in lay language for distribution to growers via the local extension network , the Maine Sea Grant Program and the East Coast Shellfish Growers Association. Lastly, we will seek opportunities to present the project at relevant meetings such as the Main Shellfish Working Group, the Maine Fishermen’s Forum or the Northeast Aquaculture Conference and Expo (NACE) and will produce an article submitted to an industry and/or refereed publication such as Fish Farming News, Northern Aquaculture or the Journal of Shellfish Research.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.