Chlorophyll in Arctic Sea Ice

Abstract

Reviews investigations 1961-1963 into chlorophyll concentrations in sea ice in both arctic and antarctic regions. Results are compared with own researches off Devon Island, Canada, which are reported in detail. Chlorophyll a and c concentrations were obtained from underside of ice by a 7.5 cm diam ice corer and light penetration was measured by freezing a photometer into the ice; readings of both are tabulated. Chlorophyll values exceed concentrations in open sea water. The values were found to fall with increased light, and the high ratio of c to a is interpreted as a adaptation for maximum absorption of blue light through ice and snow. The algae are associated mainly with young ice peripheral to the Arctic Ocean. As a primary production resource, an estimated volume of 25 X 10*6 kg of chlorophyll a for a two-month for the arctic region is considered conservative.

Abundance and production of ice algae n Resolute Passage, Canadian Arctic

“…Alternatively, the efficiency of light use might differ from the values in the model; in particular, kchl, Ik and R~/ P~ might be larger. The remaining major possibility is that natural populations are subject to additional losses (Apollonio 1965, Grossi et al 1987 or to growth-limiting factors (Maestrini et al 1986, Smith et al 1987 other than light. In at least 2 cases, our results point to increased losses as important factors in addition to the available light in determining ice algal abundance.…”

“…1987). In the Arctic, both positive and negative correlations between algal abundance and light availability have been reported (Apollonio 1961, 1965, Clasby e t al. 1976, Horner 1985.…”

“…The availability of light influences ice algal abun-dance and production in the Arctic, Antarctic and Subarctic (Apollonio 1961, 1965, Gosselin et al 1985, Horner 1985, Grossi et al 1987, Smith et al 1988. In Hudson Bay, light was found limiting to algal photosynthesis in the first half of the growth season but increased to inhibitory levels in the later season (Gosselin et al 1985(Gosselin et al , 1986, while in McMurdo Sound, Antarctica, light was found limiting to algal production throughout the growth season (Grossi e t al.…”

Physical control of arctic ice algal production

“…Under conditions of low light (ca 2 to 25 pE m-2 S-') and temperature (-1.8"C) in the high Canadian Arctic ice algae, predominantly pennate diatoms, form dense populations (up to ca 100 to 300 mg chl m-2) in a thin layer (ca 1 cm) on the bottom of 1 to 2 m of annual sea ice (Apollonio 1961, 1965, Cota 1985, Smith et al 1987, 1988. In addition to augmenting total marine productivity, ice algae extend the brief summer open water season of phytoplankton production by about 2 mo in spring.…”

“…There is little doubt that light availability has a major influence on ice algal biomass and production in the Arctic, Subarctic and Antarctic (Apollonio 1961, 1965, Clasby et al 1976, Horner & Schrader 1982, Gosselin et al 1985, Horner 1985, Grossi et al 1987, Smith et al 1987, 1988, SooHoo et al 1987, especially during the winter-spring transition when incident irradiance increases dramatically. Growth irradiance (in situ light level) can also be manipulated and maintained fairly easily by stabilizing surface snow cover with a low profile snow fence (Cota 1985).…”