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.