Nitrogen isotopes of organic nitrogen in reef coral skeletons as a proxy of tropical nutrient dynamics

Primary consumer stable nitrogen isotopes as indicators of nutrient source.

Non-point source loading of nitrogen and phosphorus is a primary cause of eutrophication of inland waters, although the diffuse and variable nature of nutrient inputs makes it difficult to trace and identify nutrient pathways. Stable nitrogen isotope values (delta15N) in aquatic biota are thought to reflect anthropogenic nutrient inputs, and they may be a promising tool fortracing nutrient sour...

Microbial nitrogen transformations in unconsolidated coral reef sediments

Major nitrogen (N) pools and bacterial transformations of N were examined in carbonate sediments of 3 reefs in the central area of the Great Barrier Reef, Australia. Depth distributions of nitrate (NO3-) and ammonium (NH,+) and rates of NH4+ production, N2 fixation (nitrogenase activity by CzHz reduction) and denitrification were measured in muddy sediments of an inshore reef and in fine-. medi...

Sponges and ascidians control removal of particulate organic nitrogen from coral reef water

We studied removal rates of plankton and total particulate organic nitrogen (PON) by benthic reef communities from the overlying water in a large experimental flume. The flume was filled with mixtures of coral and coral rubble, and biomass of plankton was measured as water was recirculated over the experimental benthic community. All planktonic particle types, picoplankton, nanoplankton, microp...

Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse

Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand ...

Nitrogen Isotopes in Paleoclimate Research