The costs of providing giant clam seed in Australia using existing techniques are examined for alternative annual volumes of production. Considerable economies of scale in production are available both in relation to labour costs and non-labour costs (mostly capital costs). In Australia, direct labour costs appear as though they would account for between 40-60 percent of total costs depending on volume and production levels. It is possible that these costs would be lower in some of the less developed countries which could produce clams. The fall in per unit full cost of producing giant clam seed is considerable when annual production is expanded from 100,000 to 500,000 seed clams per year. At 10% rate of interest, full cost for seed clam falls from $1.43-2.01 at a production level of 100,000 to $0.41-0.54 at a production level of 500,000. Operating costs also fall. They decline from $1.01-1.22 to $0.29-0.35. Although lower cost levels may be achieved in the future, and with different techniques in other countries, the cost of clam seed can be expected to be much higher than for oyster spat.