Wg. Ambrose et Pe. Renaud, DOES A PULSED FOOD-SUPPLY TO THE BENTHOS AFFECT POLYCHAETE RECRUITMENT PATTERNS IN THE NORTHEAST WATER POLYNYA, Journal of marine systems, 10(1-4), 1997, pp. 483-495
Recently, researchers have discovered that deep-sea species from many
phyla exhibit distinct seasonality in reproductive effort. Many of the
se studies describe the seasonality as correlating with pulsed sedimen
tation of phytodetritus to the benthos. The Northeast Water Polynya pr
ovides an ideal system in which to test whether a compressed season of
pelagic productivity corresponds to recruitment patterns in benthic o
rganisms. We took sediment cores at a station nine times between 30 Ma
y and 11 August 1993 and assessed seasonal patterns in recruitment and
benthic pigment concentration. Two distinct, but compositionally diff
erent, peaks in benthic pigment concentration were observed during thi
s period. While total polychaete recruitment showed a broad mid-summer
peak in intensity, at the taxonomic level of family and below, peaks
were sharper and suggested seasonal recruitment events. No support, ho
wever, was identified for synchrony of reproduction with pulses of sed
imenting food from the water column, indicating that food limitation d
oes not explain reproductive patterns in this region. Trophic dynamics
, including differential feeding, predation, and survival patterns amo
ng recruits, may provide a mechanism for the observed lag time between
pulses of food and recruitment, but additional study is required to r
esolve the determining factors.