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Phosphate uptake along a coastal plain estuary
Author(s) -
Lebo Martin E.
Publication year - 1990
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1990.35.6.1279
Subject(s) - estuary , phytoplankton , salinity , bay , environmental science , sediment , productivity , environmental chemistry , oceanography , dry weight , phosphate , hydrology (agriculture) , zoology , chemistry , biology , ecology , nutrient , geology , botany , paleontology , geotechnical engineering , macroeconomics , economics , organic chemistry
Biotic PO 4 3− uptake rates were measured along the Delaware estuary to examine seasonal and spatial patterns of variation. Uptake was highest (40–90 nmol liter −1 h −1 ) in summer and lowest (<10 nmol liter −1 h −1 ) in winter. The highest rates of PO 4 3− uptake were measured in the tidal river and the lower bay (salinity > 15‰) where primary productivity is high. Between the river and the lower bay, the concentration of suspended sediment is high, and PO 4 3− uptake was reduced (<5 nmol liter −1 h −1 ) at all times of the year. Partitioning of uptake by size revealed that both bacteria and phytoplankton are important in the uptake of PO 4 3− throughout the estuary. The proportion of uptake by bacteria, however, changed spatially. In the tidal river where anthropogenic inputs are high, bacteria dominated PO 4 3− uptake and accounted for up to 70% of the total. Within the salinity gradient of the estuary, the proportion of bacterial uptake was much lower, with bacteria accounting for only 15–25% of PO 4 3− uptake. The competition between bacteria and phytoplankton for PO 4 3− was affected by anthropogenic inputs into the tidal river.