H-12 



RESEARCH PROGRAMMES 



2. Detrital regime. 



There is danger in any resource-oriented research in which studies are weighted more 

 toward the mechanisms of production than toward the equally important mechanisms of 

 recycling the organic material produced. The main source of detritus in the open ocean is dead 

 plankton, faecal material, and organisms embedded in the ice. It is likely that the flux of energy 

 through these pathways is considerable. The routine detrital programme consists of 

 measurements of particulate organic carbon which, in combination with measures of 

 chlorophyll a (for phytobiomass) and adenosine triphosphate ATP (for living matter), allow the 

 concentration of detritus to be determined. More complex studies include measurements of 

 transfer rates, such as rates of release of ice detritus (by melting), rates of advection from 

 regions of high and low detritus, rates of detrital fall out, and so on. Research on associated 

 transfer rates, such as decomposition and mineralization, was mentioned in (1) above. 



3. Factors affecting secondary production. 



The secondary production component of BIOMASS is focused on those elements and 

 processes within the krill ecosystem which control or modify the flux of energy to krill. For 

 example, part of the detrital flux may sustain significant secondary production by bacteria; 

 other zooplankton herbivores may compete with krill for algal food; zooplankton carnivores 

 may take developmental stages of krill in significant numbers; other zooplankton may provide 

 alternative or supplementary forage for typical krill feeders such as some birds, seals and baleen 

 whales. The programme should include: 



(a) Study of the distribution and abundance of the zooplankton species in relation to 

 environmental gradients and to seasonal variabilities. 



(b) Study of the vertical distribution of the zooplankton in relation to the water masses 

 and to the polar front. 



(c) Study of the role of the zooplankton in the dynamics of the pelagic food webs, 

 including the pack ice where possible. 



(d) Study of the life history of key species of zooplankton with particular emphasis on 

 their feeding biology. 



So far as possible, the secondary production programme will have a size specific basis, eg, 

 size specific distribution of biomass, size specific grazing and size specific respiration rates. The 

 role of zooplankton as forage organisms for fishes, cephalopods, birds and mammals could best 

 be studied on board those trawlers associated with BIOMASS and at shore laboratories. Recent 

 developments in radioactive tracer technique have made it possible to investigate food 

 relationships within the zooplankton more effectively than in the past and such studies could 

 well constitute a major part of research programmes on ships with well equipped biological 

 laboratories. 



Because the distribution of krill corresponds, in general, with the area that is seasonally 

 covered by pack ice, this ice-mantle is of considerable significance in the study of krill. Thus, an 

 effective biological study of the Southern Ocean will require a fresh look at the secondary 

 production within the pack ice ecosystem. 



4. Distribution and significance of surface currents and fronts. 



Because of previously established macro-scale correlation between the biology of the 

 Southern Ocean and its major frontal zones and because the distribution of krill is so patchy, 

 the research programme on surface physical discontinuities is an important part of the 

 BIOMASS programme. Such studies have an advantage in that they may be carried out not only 

 by research vessels with station time at their disposal but also by supply vessels and by remote 

 sensing from satellites. The shipboard programme mainly includes measurements of 



