| dc.description.abstract | Data on first feeding Arcto-norwegim cod larvae in Lofoten, northern
Norway, sampled during the period 1974 - 1984, are examined to verify
the theory on the influence of small-scale turbulence on the contact
rate between predator and prey (Rothschild and Osborn, 1988). The number
of prey per cod larval gut are compared to the concentration of
prey, Galanus finmarchicus nauplii, and to data on wind speed and
static stability of the upper layer. The data indicate that the contact rate
increases by a factor of 2,8, when the average wind speed
increases from 2 m s-1 to 6 m s - 1 . Independent data on cod larval
cruising speed, the velocity and concentration of prey organisms,
inserted into the model of Rothsehild and Osborn (1988) show a comparable
average increase in contact rate of 2,2 times for the same
increase in wind speed. The data indicate that the turbulent velocity
has a greater contribution to contact rate than the Larval swimming
speed, when wind speed exceeds 4 m s-1 . The larval period of Arctonorwegian
cod is an important period for the formation of the year
class. Larval stages are confined to the mixed layer, and therefore
the variable contact rate induced by wind mixing aust be an important
regulatory mechanism for the formation of year class strength. | en |
