Se. Lochmann et al., ABUNDANCE AND CONDITION OF LARVAL COD (GADUS-MORHUA) AT A CONVERGENT FRONT ON WESTERN BANK, SCOTIAN SHELF, Canadian journal of fisheries and aquatic sciences, 54(7), 1997, pp. 1461-1479
In November and December 1992, Atlantic cod (Gadus morhua) larvae were
most abundant at a convergent front located at the periphery of a wel
l-mixed gyrelike water mass rotating near the crest of Western Bank (o
uter Scotian Shelf). Zooplankton wet biomass and plankton abundance (2
72 and 529 mu m size-classes) were also higher in the frontal region r
elative to the adjacent water masses. We used the frontal feature to t
est the hypothesis that larvae in frontal regions are in better condit
ion than larvae elsewhere. No significant differences in triacylglycer
ol content (an index of nutritional condition), Fulton's K condition i
ndex, nor in the daylight feeding ratio were found between larvae in t
he frontal region and those in the adjacent waters. The convergent fro
nt acted as a larval collector, but exchange with other water masses e
liminated measurable differences in larval condition. Our observations
indicate that physically driven retention, not differential mortality
(approximated by condition), was responsible for high abundances of c
od larvae at this front.