 |
| Titel |
Spatiotemporal variability of sedimentary organic matter supply and recycling processes in coral reefs of Tayrona National Natural Park, Colombian Caribbean |
| VerfasserIn |
E. Bayraktarov, C. Wild |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 11 ; Nr. 11, no. 11 (2014-06-06), S.2977-2990 |
| Datensatznummer |
250117448
|
| Publikation (Nr.) |
 copernicus.org/bg-11-2977-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Sediments are fundamental for the function of oligotrophic coral reef
ecosystems because they are major places for organic matter recycling.
The Tayrona National Natural Park (TNNP, Colombian Caribbean) is located between
the population center Santa Marta (>455 000 inhabitants) in the
southwest and several river mouths in the east. Here, coral reef sediments
experience pronounced changes in environmental conditions due to seasonal
coastal upwelling, but knowledge of relevant spatiotemporal effects on
organic matter supply to the sediments and recycling processes is not available.
Therefore, sediment traps were deployed monthly over 14 months complemented
by assessment of sedimentary properties (e.g., porosity, grain size, content
of particulate organic matter and pigments) and sedimentary O2 demand
(SOD) at water-current-exposed and sheltered sites along distance gradients
(12–20 km) to Santa Marta and the eastern river mouths (17–27 km).
Findings revealed that seasonal upwelling delivered strong (75–79% of
annual supply) pulses of labile organic matter mainly composed of fresh
phytoplankton detritus (C : N ratio 6–8) to the seafloor. Sedimentary
chlorophyll a contents and SOD increased significantly with decreasing
distance to the eastern rivers, but only during upwelling. This suggests
sedimentary organic matter supply controlled by nutrient-enriched upwelling
waters and riverine runoff rather than by the countercurrent-located city of
Santa Marta. Organic matter pulses led to significantly higher SOD (more than
30%) at the water-current-sheltered sites as compared to the exposed
sites,
ensuing a rapid recycling of the supplied labile organic matter in the
permeable silicate reef sands. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|