Distribution of Calanus finmarchicus on Georges Bank,
1995 - 1999

E. G. Durbin, M. C. Casas, and J. Pierson

Maps of the distribution and abundance of Calanus finmarchicus copepodite stages on Georges Bank are presented for the period February 1995 to March 1999. Data are from 1 m² MOCNESS surveys. Data were log10(N+1) transformed (N is the number per m²) and contoured using the kriging procedure in Surfer. Numbers of adult females and males, and the % males were also contoured. In January of each year only C4-5 and adult males and females were present and these were confined to the Gulf of Maine or were just beginning to spread onto the northern edge of the Bank. Reproduction was beginning and nauplii were present. During February all copepodite stages were present but are very patchily distributed with flow onto the Bank occurring in discrete regions, particularly at the eastern end of the Crest region. No males were present. During March and April there was a build up of all stages over the Bank, although numbers on the Crest remained low. Males began to appear again during March, and both males and females during April, indicating the maturation of the G1 generation. During May C1 copepodites disappear over most of the Bank while older stages remained abundant, except on the Crest. Numbers of males began to decrease again. During June there was a further decrease in copepodites on the Bank, while during July, 1995, an increase indicated the maturation of a new cohort.