Ecological Dynamics in the Subarctic Pacific, a Possibly Iron-Limited Ecosystem

• Published in: Limnology and oceanography Vol. 36; no. 8; pp. 1600 - 1615
• Main Authors: Miller, Charles B., Frost, Bruce W., Wheeler, Patricia A., Landry, Michael R., Welschmeyer, Nicholas, Powell, Thomas M.
• Format: Journal Article
• Language: English
• Published: Waco, TX American Society of Limnology and Oceanography 01-12-1991
• Subjects: 290301 - Energy Planning & Policy- Environment, Health, & Safety- Regional & Global Environmental Aspects- (1992-); 540320 - Environment, Aquatic- Chemicals Monitoring & Transport- (1990-); AMMONIUM COMPOUNDS; Animal and plant ecology; Animal, plant and microbial ecology; AQUATIC ECOSYSTEMS; AQUATIC ORGANISMS; BIOGEOCHEMISTRY; Biological and medical sciences; BIOLOGICAL AVAILABILITY; CARBON SINKS; CHEMISTRY; Diatoms; ECOSYSTEMS; ELEMENTS; ENERGY PLANNING, POLICY AND ECONOMY; ENVIRONMENTAL SCIENCES; Fundamental and applied biological sciences. Psychology; GEOCHEMISTRY; Grazing Control; IRON; Marine; Marine ecology; Marine ecosystems; METALS; NITRATES; NITROGEN COMPOUNDS; NUTRIENTS; Oceans; OXYGEN COMPOUNDS; PACIFIC OCEAN; PHYTOPLANKTON; PLANKTON; PLANTS; POPULATION DYNAMICS; PRODUCTIVITY; Sea water; Sea water ecosystems; SEAS; SINKS; Subarctic regions; SURFACE WATERS; Synecology; TRANSITION ELEMENTS; Tropical regions; Pacific Ocean; North Pacific; IN, North Pacific; INE, Subarctic Pacific; Marine environment; Primary productivity; Iron; Biogeochemical cycle; Ecosystem
• ISSN: 0024-3590; 1939-5590
• DOI: 10.4319/lo.1991.36.8.1600

It has been suggested that production in offshore waters of the subarctic Pacific is limited by availability of dissolved Fe. Although that is not yet adequately established, the functional consequences of the limitation (if it exists) can be characterized from the results of the SUbarctic Pacific Ecosystem Research (SUPER) program. Fe limitation, or something like it, establishes a phytoplankton community dominated by very small cells. These plants are not limited by Fe availability. Rather, their production is limited by their stock and available illumination. Stock is set by microzooplankton grazers with rapid population growth rates and, thus, rapid response to increases in phytoplankton abundance. Micrograzers provide efficient recycling of nitrogen as $NH_4$, and the ready availability of $NH_4$ sharply limits the annual utilization of $NO_3$. Persistently high $NO_3$ concentrations result. Other possibly Fe-limited, oceanic ecosystems with persistently high, near-surface nutrients require similar, detailed analysis of ecosystem function.