24 J. E. Hobbie 



Deep mountain lakes were first investigated by Livingstone et al. 

 (1958) who pointed out that most of the thermal, chemical, and biological 

 events in these lakes were similar to those of oligotrophic temperate lakes. 

 They thought that the major effect of the arctic environment was on the 

 physiographic process affecting lake origins, sedimentation rates, and 

 input from the drainage basins. An intensive study of two other deep lakes 

 (Hobbie 1961, 1962, 1964) revealed that most of the yearly primary 

 productivity of the plankton occurred beneath the ice cover in late spring 

 and early summer. Later, both the light regime and the algal species and 

 biomass responsible for this early season bloom were investigated in detail 

 by Holmgren, Kalff, and Hobbie (reported in Hobbie 1973). It was found 

 that when the snow depth was less than 10 cm, great amounts of light 

 penetrated the ice. The light, plus the non-turbulent conditions beneath the 

 ice, allowed large numbers of flagellates and diatoms to develop. After the 

 ice left the lakes, conditions were poor for algal growth. 



Most of the research on shallow lakes has centered on the question of 

 the origin and development of the oriented lakes of the coastal plain. These 

 lakes originate when permafrost melts and the soil subsides (Rex 1961) 

 and receive their orientation from wind-driven currents which 

 differentially erode the ends of the elongated lakes (Carson and Hussey 

 1960). Scattered bits of information that exist on Ikroavik Lake, near 

 Barrow, show it to have low numbers of algae, nutrients (Prescott 1953), 

 and benthic animals (Livingstone et al. 1958). The whitefish population 

 has also been described (Wohlschlag 1953). 



Another well-studied shallow lake is Imikpuk, which is not an 

 oriented lake and which lies close to the Arctic Ocean. Chemistry of the 

 lake has been reported by Howard and Prescott (1973) and Boyd (1959); 

 the primary productivity by Howard and Prescott (1973) and Kalff 

 (1967b); the zooplankton by Comita (1956) and Edmondson (1955); and 

 the microbiology by Boyd and Boyd (1963). 



All of the pond limnology in northern Alaska has been done near 

 Barrow. The most extensive investigations were of the chemistry and 

 plankton productivity (Kalff 1965, 1967a, 1971). In these ponds, 

 phosphate, nitrate, ammonia, trace elements, and growth factors all 

 stimulated photosynthesis at various times. Kalff concluded that nutrient 

 deficiency did exist and that plankton productivity was extremely low 

 (around 1 g C m"^ yr~'). Another series of studies dealt with repro- 

 ductive cycles and controls of zooplankton (Stross and Kangas 1969). 



The only large rivers studied in northern Alaska have been the 

 Colville (Kinney et al. 1972) and the Sagavanirktok (Carlson et al. 1974). 

 These studies were mostly concerned with water chemistry but 

 zooplankton (Reed 1962), fish (McCart and Craig 1971), and discharge 

 (Arnborg et al. 1966) have also been looked at. The rivers contain little 

 plankton and a scanty bottom fauna. 



