| Ocean Nutrients Concentration levels of
ocean nutrients vary with time (the time of year or season) and space (where they are in
the ocean). By knowing when and where nutrient concentrations occur in ocean waters, we
can predict a subsequent phytoplankton bloom, since phytoplankton need certain nutrients
to live and reproduce. We conducted a survey of nutrient levels across lower Cook Inlet
(see map for transect details). The graph
below depicts concentrations of nitrogen, silica, and phytoplankton in late June 1997.
Note that decreases in both nitrogen and silicon concentrations in the eastern portion of
the cross-inlet transect are inversely correlated with phytoplankton abundance. While
a drop in nitrogen concentrations is typical of use by any phytoplankton, the utilization
of large portions of available silicon suggests that that diatoms, which require silicon
as a structural nutrient, were common at this time. |
