Measuring and evaluating nitrogen removal services in oyster reefs - PowerPoint PPT Presentation

Measuring and evaluating nitrogen removal services in oyster reefs M F Piehler, A R Smyth, J H Grabowski and SP Thompson

Consequences of oyster habitat degradation Filtration Stabilization Habitat Loss of ecosystem goods and services

Habitat degradation tends to reduce habitat complexity Simple Habitats Complex Habitats

Grabowski et al. (2012) Bioscience

Oyster reefs may help resist eutrophication

Illustration by AR Joyner and HW Paerl

Piehler and Smyth 2011, Ecosphere

“Indeed, a man would have to eat sixteen dozen of these acephalous molluscs in order to gain the 315 grammes of nitrogen he requires daily.” Jules Verne, 'Twenty Thousand Leagues Under the Sea’

Oyster Reef Denitrification and Landscape Position How does landscape setting affect oyster reef denitrification? Control Oyster reefs Mudflat Mudflat + Reef Marsh Marsh + Reef Seagrass + Marsh+ Seagrass + Marsh Reef

Oyster Reef Landscape Position And Denitrification Control + Reef 250 200 ( μmol N-N 2 m -2 hr -1 ) Denitrification 150 * 100 50 0 Mudflat Marsh SAV + Marsh Seagrass + Habitat Setting Marsh

Oyster Reef Landscape Position And Denitrification Response to increased nutrient loading 600 Control Control + Nitrate + Reef + Reef + Nitrate 500 * ( μmol N-N 2 m -2 hr -1 ) 400 * * Denitrification 300 200 100 0 Mudflat Marsh SAV + Marsh Seagrass + Marsh Habitat Setting

Biotic and Abiotic Denitrification Results from sediment flux experiment 350 No difference in rates between weeks C 300 Average Percent Increase Shell: 24% ( μmol N-N 2 m -2 hr -1 ) Live: 61% 250 Denitrification B Rates similar to 200 other oyster reefs A and mud flats in 150 area during summer. 100 50 0 Control Shell Live Treatment N=8, Wilcoxon

Evaluating estuarine N processing • Rigorous measurements of processes • Net contributions to N processing • Transferable data $1300 $1600 $800 $200 All values are dollars per hectare per year $1600

What does estuarine N removal cost?

Where to next?

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