|
1000
|
Abstract/Summary
|
-
In Tayrona National Natural Park (Colombian Caribbean), abiotic factors such as light intensity, water temperature, and nutrient availability are subjected to high temporal variability due to seasonal coastal upwelling. These factors are major drivers controlling coral reef primary production. This offers the opportunity to assess the effects of abiotic factors on key coral reef ecosystem services in terms of productivity. We therefore quantified primary net (Pn) and gross production (Pg) of the dominant local primary producers (scleractinian corals, macroalgae, algal turfs, crustose coralline algae, and microphytobenthos) at a water current/wave-exposed (EXP) and -sheltered (SHE) site in an exemplary bay of Tayrona National Natural Park. A series of short-term incubations was conducted to quantify O2 fluxes of the different primary producers before and at the end of the upwelling event 2011/2012. At the level of the organism, scleractinian corals showed highest Pn and Pg rates before upwelling (16 and 19 mmol O2 m-2 specimen area h-1), and corals and algal turfs dominated the primary production at the end of upwelling (12 and 19 mmol O2 m-2 specimen area h-1, respectively). At the ecosystem level, corals contributed most to total Pn (EXP: 81 %; SHE: 65 %) and Pg (EXP: 78 %; SHE: 55 %) before the upwelling, while at the end of the upwelling, corals contributed most to Pn and Pg only at EXP (73 and 75 %) and macroalgae at SHE (52 and 46 %, respectively). Despite the significant spatial and temporal differences in individual productivity of investigated groups and their different contribution to reef productivity, no spatial or temporal differences in daily ecosystem Pn and Pg were detected (194 – 218 and 311 – 409 mmol O2 m-2 seafloor area d-1). Our findings therefore indicate that local autotrophic benthic reef communities are well adapted to pronounced fluctuations of environmental key parameters. This might lead to a higher resilience against climate change consequences and anthropogenic disturbances.
|
