Application of this method during the spring bloom period (9 May to 26 June) provided the first non-invasive time series dataset used to monitor changes in bottom ice chi a concentration, an index of algal biomass, at a single point location.
Furthermore, the presence of phytoplankton under sea ice during late spring (e.g., Fortier et ah, 2002; Mundy et ah, 2009; Arrigo et ah, 2012), as well as the observed aggregates of ice algae sloughed from the ice between the sensor and ice interface, would falsely increase biomass estimates of the bottom ice chl a.
Nevertheless, values of bottom ice chi a concentration and all environmental variables except [E.sub.d](0, PAR) changed significantly following the spring storm, an observation supported by the field observations discussed under "Site Conditions" above.
Warming of the bottom ice can negatively affect ice algae biomass by causing a) ice ablation, resulting in the sloughing of algae from the ice into the water column (Lavoie et al., 2005) or b) brine drainage, which causes algal sloughing following erosion of the ice habitat, particularly where liquid brine drains from the ice (Lavoie et al., 2005; Mundy et al., 2005; Juhl and Krembs, 2010).
The influence of bottom ice melt on removal of algal cells, particularly the influence of changes in thickness to the bottom skeletal layer, could not be assessed in this study.
The decline in the bottom ice salinity over time (r = 0.855, p < 0.05) shows that gravity-driven drainage of brine from the ice (i.e., brine drainage) and replacement by less saline meltwater likely occurred (Fig.
In addition, under higher light conditions, the relative production of proteins of the bottom ice algae decreased, whereas the lipid proportion increased.
To evaluate the changes in the photosynthetic carbon allocation of the ice algae community under different light conditions, we analyzed relative rates of production of different macromolecules from the ice algal productivity experiment on 28 April 2003, when the bottom ice algal biomass was sufficiently large to conduct the experiment.
Physical parameters and chlorophyll-a concentrations in the bottom ice (3 cm) at the sampling sites on the land fast-sea ice at Barrow in 2003.
(2005) showed with a model that nutrient levels in the bottom ice may fluctuate greatly during a diurnal cycle.
As expected, the carbon uptake rates of bottom ice algae and underlying phytoplankton increased as the incubation depth through the ice hole decreased and consequently light intensity increased (Fig.