Richter, Maren E.

Diel vertical migration (DVM) of zooplankton at the Central Irminger Sea (CIS) Site (59.7°N-39.7°E) was studied using targetstrength calculated from ADCP echo intensity. Daily and seasonal patterns were interpreted using hydrographical data and vertical velocities of the scatterers from ADCP measurements were examined. Data obtained between summer 2004 and summer 2007 as well as during summer 2011 and summer 2012 was used. The data shows that the zooplankton at the CIS site perform normal vertical migration with ascent starting at dusk and descent one hour before dawn. Vertical velocities were between 1 and 4 cm=s with velocities being higher during the descent than during ascent. Two distinct deep scattering layers were visible throughout the time of the deployments one around 400m and one around 600m depth. There was some evidence of seasonal changes in DVM. In particular, the depth of the mixed layer had an influence on the strength of the backscatter signal and the vertical extent of the migration

Temporal Variability of Zooplankton from ADCP Backscatter Time Series Data at the Central Irminger Sea (CIS) Site

Abstract

Similar works

Full text

Available Versions

OceanRep