20 J. E. Hobbie 



The Tundra Aquatic Project 



In 1970, a modest, pre-IBP grant from NSF allowed the pond studies 

 to begin. The goal of this grant was to follow the effects of oil and nutrient 

 fertilization on ponds. Two projects, that of V. Alexander on phyto- 

 plankton responses and that of R. Barsdate on nutrient and water 

 chemistry, were started and the ponds chosen for whole-pond 

 experimentation and for controls. One whole pond and several small 

 subponds (plastic enclosures) were fertilized with P and N and one whole 

 pond was treated with crude oil. 



In 1971, the IBP funding began and a complete range of aquatic 

 projects was started. The emphasis during this year was on obtaining the 

 most complete data possible for carbon, nitrogen, and phosphorus flow for 

 both a pond and a lake (Ikroavik). The projects of Alexander and Barsdate 

 were continued and additional projects added that dealt with zooplankton 

 (R. Stross), bacteria, decomposition, and benthic algae (J. Hobbie), fish 

 (J. Cameron), dissolved carbon, particulate carbon, and benthic 

 respiration (M. Miller), macrobenthos (D. Bierle), protozoa (R. Dillon), 

 and macrophytes (P. McRoy). Observations on the manipulated ponds 

 were continued throughout the entire project. 



In 1972, the first modeling efforts began and a preliminary plankton 

 model was developed. The field work at Barrow was oriented towards sub- 

 pond experiments; treatments of nutrients (two concentrations), of added 

 light, of darkness, and of higher temperatures were used. Because the 

 outdated tracked vehicle continually broke down, travel to Ikroavik Lake 

 became impossible and no more samples were taken. 



During 1973, emphasis was shifted to modeling, and simulation 

 models of benthic, planktonic, and zooplankton systems were developed. 

 The field work was devoted mostly to developing the constants and rates 

 needed for the models. Several specialists were brought in for the summer 

 to work on areas of research that were still poorly-understood: (T. 

 Fenchel, protozoan ecology; D. Kangas, zooplankton respiration; S. 

 Dodson, invertebrate predation.) The summer of 1974 was spent in 

 preparing reports. 



Modus Operandi 



To reach the goals of the project we first used traditional limnological 

 techniques to identify and measure the important pathways of carbon and 

 energy flow in the tundra ponds. Next, the modeling was begun and used 

 both to plan future experimental research on the processes and to evaluate 

 the importance of proposed research. The philosophy we have followed in 

 modeling is as follows: 



