COMMERCIAL LENGTH, CATCH EFFORT, AND LANDINGS OF SOFT-SHELL CLAMS (MYA-ARENARIA) FROM AN UNDUG INTERTIDAL POPULATION AT MACHIASPORT, MAINE

An undug population of soft-shelled clams, Mya arenaria, in the Machia s River at Machiasport, Maine, was opened to depuration digging on 33 low tides between 2/7/86-8/4/86. Information on catch/effort, and land ings was recorded for all 33 tides. Commercial size information was co llected on 18 tides, Diggers removed between 644-4,923 lbs/tide and a total of 65,692 lbs. The mean length of clams harvested per tide varie d between 59.03-72.57 mm with an overall weighted mean of 66.63 +/- 1. 17 mm (xBAR +/- ISE). The commercial length frequency distribution var ied between 38-100 mm and 3.09% of the commercial catch was less than 2 in. (51 mm). An exponential relationship exists between mean commerc ial clam length harvested and the actual low tide level recorded at Cu tler, Maine (U.S. Navy radio station). Clams were dug at a mean rate o f 64.99 +/- 1.11 (xBAR +/- 1 SE) lbs/hour. When both digging and picki ng were employed, clams were harvested at a mean rate of 108.63 +/- 4. 99 lbs/hr. Digging gear was described from measurements taken on 12 co mmercial hoes used in the harvest of Mya arenaria from the study area.