Tasmanian Slope Trophodynamics Study 1991-1993: Primary Productivity Data

This record describes the primary productivity data collected as part of the 1991-1993 Tasmanian Slope Trophodynamics Study undertaken by CSIRO Division of Fisheries. Primary productivity measurements were taken on 4 cruises of FRV "Southern Surveyor" on three 60 km transects across the continental shelf to the south and south-east of Tasmania in July 1991 (cruise SS 02/91), February 1992 (cruise SS 01/92), November 1992 (cruise SS 04/92) and April 1993 (cruise SS 03/93). There were typically 5-6 primary productivity stations per transect per cruise. At each station, water samples were collected in Niskin bottles from 3 depths and primary productivity was determined using 14C incubation experiments at a range of 4 light intensities. An additional, mmore intensive experiment was conducted over a 24 hour period at one site using samples from 6 depths incubated at seven light intensities. From these data, P vs I (photosynthesis versus irradiance) parameters were calculated, in particular alpha (the slope of the P vs I curve) and P-max, the light-saturated rate of carbon fixation. These values were then used to model primary production in the water column on a diel, seasonal, and spatially varying basis.