H-11 

 RESEARCH PROGRAMMES 



1. Describe the physical/chemical factors governing the distribution, abundance, 

 productivity and behaviour of the marine organisms. 



2. Describe the short and long term environmental fluctuations governing the biology of 

 Antarctic marine flora and fauna. 



3. Identify and measure, for the purpose of ecosystem modelling, the main physical and 

 chemical driving forces in oceanic and coastal areas of the Southern Ocean. 



2.3.3 Research programmes 



1. Factors affecting primary production. 



Current estimates of primary production vary widely and our estimates are largely based on 

 station data taken by oceanographic ships at different times and often in different years. If we 

 are to provide reUable estimates of productivity and rates of energy flow, we must achieve 

 geographic coverage using standardized methods and techniques. 



The primary production component of the BIOMASS programme will focus on a detailed 

 documentation of the geographic variability in rates of primary productivity and on the factors 

 which control production in the Southern Ocean. Although the productivity in polar seas with 

 intermittent ice cover has been thought to be Umited primarily by the seasonal deficiency of 

 available light and lack of permanent thermocUne formation, recent evidence from the 

 Arctic/sub-Arctic regions (Apollonio, 1961; McRoy and Goering, 1974) and the Antarctic 

 (Bunt and Lee, 1970; Meguro, 1962) indicates that the ice cover in these regions provides 

 oceanographic conditions which in fact support high primary productivity on the under-surface 

 of the ice during periods of the year when the water column itself is not productive. This ice 

 mantle must, therefore, play a major role in organic production in the polar seas; and the fact 

 that photosynthesis takes place beneath ice at low light intensities becomes of special interest. 



Because wind-induced turbulence carries phytoplankton down as far as the pycnocline, the 

 amount of light available for photosynthesis varies wdth the depth of the mixed layer. Thus, a 

 considerable amount of work will have to be devoted to the study of the factors that govern 

 primary production in the Southern Ocean. Such study should include measurement of solar 

 radiation, light penetration in the water column, vertical stability of the surface layer, and a 

 suite of physical, chemical and biological parameters which influence these major variables 

 (cloud type and cover, wind velocity and direction, transparency, organic and inorganic 

 suspended matter, trace elements, vitamins, etc). 



The broad features of the phytoplankton programme are outUned below: 



(a) Study of the geographic and seasonal distribution of phytoplankton and estimate of 

 primary productivity within and below the euphotic zone. Special attention needs to 

 be given to measurements of photosynthetic activity of the micro-algae beneath the 

 pack ice. Contributions of the various primary producer communities (pelagic, 

 seasonal pack ice, and near -shore benthic communities— including macro-algae) should 

 be obtained on a seasonal basis. 



(b) Study of the distribution and abundance of the phytoplankton in relation to 

 physical/chemical and biological characteristics of the water masses. 



(c) Study of the effect of low temperature on metabolic rates of phytoplankton, and 

 determination of their specific growth rates. 



(d) Study of rate Umiting processes, uptake kinetics of nitrogen and silica by organisms, 

 and the specific role of zooplankton and in situ microbial regeneration. 



(e) Study of the species composition of phytoplankton. 



(f) Study of the grazing and dispersion loss rates (including loss rates to the benthos). 



