Hard clam aquaculture is one of the most widespread forms of marine aquaculture on the U.S. east coast and it employs large numbers of former shellfish harvesters. High density culture is taking place from Massachusetts through Florida and billions of clams are being produced. This production is based on clams spawned in hatchery and grown to a size where they can be placed in protected areas of shallow bays. This process is called planting and small clams are called seed.

   Significant winter mortalities (over 50% in many cases) occur if this seed is too small or planted too late in the year. The reasons for the variable success of late seed plantings have not been systematically investigated, but are believed to be related to seed "condition" (stored energy reserves) and its interaction with environmental variables or pathogens. One solution to late planting mortality is to hold the clams in nursery systems during winter. Unfortunately a second, but apparently related, mortality occurs when seed clams are overwintered in nursery systems. Once seed begin to die in these systems, losses can be as high as 5% per day.

   The current work is developing and testing methods that could be used by culturists to evaluate the "condition" of seed clams prior to planting or overwintering. The work underway will evaluate whether disease (bacterial or other infections), lack of energy reserves or their interaction is the primary cause of winter mortalities. The goal is to provide a quantifiable means of evaluating alternatives to mitigate losses and establish an economically viable method of increasing seed survival.