THE GREEN CRAB CARCINUS MAENAS IN TWO NEW HAMPSHIRE ESTUARIES. PART 1: SPATIAL AND TEMPORAL DISTRIBUTION, SEX RATIO, AVERAGE SIZE, AND MASS

The spatial and temporal distribution of the green crab, Carcinus maenas (Linnaeus, 1758) was studied in two New Hampshire estuaries, NW Atlantic, over a one-year period from November 2009 to October 2010 using baited traps. Green crab catch peaked in December and March in the Great Bay Estuary (GBE), and in November and April in the Hampton-Seabrook Estuary (HSE). Catch per unit effort was higher in the HSE than in the GBE, and more than 14 times as many green crabs were captured in the HSE (n = 35 788) than in the GBE (n = 2337). Catch of green crabs generally rose with increasing distance up-estuary in the HSE, while in the GBE, catch peaked mid-estuary. Quantity and species diversity of by-catch was greater in the GBE than in the HSE. In the HSE, sex ratios were skewed toward females in summer and female catch was maximized in salinities 30-31 ppt. In both estuaries, sex ratios favored male crabs most in the spring (March-April). Male and female green crabs in the GBE were larger (carapace size, weight), on average, than those in the HSE. This is the first study to compare seasonal green crab populations throughout and between NH estuaries.