Nutrient Limitation of Net Primary Production in Marine Ecosystems

TLDR: There is a feeling among many limnologists and environmental engineers who study lakes that marine ecosystems also probably are phosphorus limited, and environmental management agencies often assume that phosphorus limitation in marine ecosystems is the rule.

Abstract: The question of nutrient limitation of primary production in estuaries and other marine ecosystems has engendered a great deal of debate. Although nitrogen is often named as the primary limiting nutrient in seawater (3, 17-19, 50, 52, 55, 61, 76, 80), this is by no means universally accepted. Many workers have argued that phosphorus is limiting (58, 71), that both nitrogen and phosphorus can simultaneously be limiting (9), or that primary production can switch seasonally from being nitrogen-limited to phosphorus-limited (6, 46). Others argue that nutrients are not limiting at all in many marine ecosystems, including highly oligotrophic waters (15). To some extent these disagreements result from poor communication due to different definitions of nutrient limitation. Considerable argument also occurs over the various methods and approaches used to estimate nutrient limitation. Limnologists in particular have tended to be critical of the methods often used to study nutrient limitation in marine ecosystems (23). Nutrient limitation in lakes has historically received more study than that in estuaries, and most mesotrophic and eutrophic north-temperate lakes are phosphorus limited (8, 62, 63, 66, 81). Thus, there is a feeling among many limnologists and environmental engineers who study lakes that marine ecosystems also probably are phosphorus limited. Lacking strong mechanistic arguments to explain why nutrient limitation might be different in estuaries than in lakes, environmental management agencies often assume that phosphorus limitation in marine ecosystems is the rule.