Dissolved inorganic nutrients including 5 macro nutrients: silicate, phosphate, nitrate, nitrite, and ammonium from water column bottle samples collected between October and April at Palmer Station, 1991 - 2025.

The inorganic plant macronutrients dissolved phosphate, silicate, nitrate, nitrite and ammonium are the major sources of nutrition for phytoplankton growth in seawater (with sunlight and inorganic carbon). Macronutrient distributions reflect the large-scale circulation patterns in the oceans and are useful properties to delineate water masses. Dissolved inorganic nutrients samples are typically collected in every Niskin bottle sample collected at and near Palmer Station, Anvers Island, Antarctica on the Western Antarctic Peninsula. Water samples are collected throughout the water column at stations within the Palmer LTER region (primarily B and E, to 50m and 65m respectively). Beginning in the 2020-2021 season, Station B is no longer sampled. In Antarctic waters, dissolved inorganic macronutrients are seldom depleted to limiting concentrations except during heavy prolonged phytoplankton blooms. This is due to the fact that phytoplankton growth is more often limited by light or iron, and to the short growing season. Water samples are analyzed for dissolved nutrients with recognized standard oceanographic protocols for nutrient autoanalyzers (continuous flow analyzers).