Bayraktarov, E. and Wild, C. (2013) Spatiotemporal variability of sedimentary organic matter supply and recycling processes in coral reefs of Tayrona National Natural Park, Colombian Caribbean. Biogeosciences Discussions, 10 (12). pp. 2977-2990. DOI https://doi.org/10.5194/bgd-10-19895-2013.

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Abstract

Sediments are fundamental for the function ofoligotrophic coral reef ecosystems because they are majorplaces for organic matter recycling. The Tayrona NationalNatural Park (TNNP, Colombian Caribbean) is located be-tween the population center Santa Marta (>455 000 inhabi-tants) in the southwest and several river mouths in the east.Here, coral reef sediments experience pronounced changes inenvironmental conditions due to seasonal coastal upwelling,but knowledge of relevant spatiotemporal effects on organicmatter supply to the sediments and recycling processes is notavailable. Therefore, sediment traps were deployed monthlyover 14 months complemented by assessment of sedimentaryproperties (e.g., porosity, grain size, content of particulateorganic matter and pigments) and sedimentary O2demand(SOD) at water-current-exposed and sheltered sites alongdistance gradients (12–20 km) to Santa Marta and the easternriver mouths (17–27 km). Findings revealed that seasonal up-welling delivered strong (75–79 % of annual supply) pulsesof labile organic matter mainly composed of fresh phyto-plankton detritus (C : N ratio 6–8) to the seafloor. Sedimen-tary chlorophyllacontents and SOD increased significantlywith decreasing distance to the eastern rivers, but only duringupwelling. This suggests sedimentary organic matter supplycontrolled by nutrient-enriched upwelling waters and river-ine runoff rather than by the countercurrent-located city ofSanta Marta. Organic matter pulses led to significantly higherSOD (more than 30 %) at the water-current-sheltered sites ascompared to the exposed sites, ensuing a rapid recycling ofthe supplied labile organic matter in the permeable silicatereef sands.

Document Type:	Article
Programme Area:	UNSPECIFIED
Research affiliation:	Ecology
Refereed:	Yes
Open Access Journal?:	Yes
DOI:	https://doi.org/10.5194/bgd-10-19895-2013
ISSN:	1810-6285
Date Deposited:	14 Aug 2019 16:53
Last Modified:	01 Oct 2020 12:59
URI:	http://cris.leibniz-zmt.de/id/eprint/2622

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