Mark Luckenbach Virginia Institute of Marine Science College of - PowerPoint PPT Presentation

Mark Luckenbach Virginia Institute of Marine Science College of William and Mary

Oysters are filter-feeders. They filter stuff out of the water. The stuff that most TMDLs seek to reduce is nitrogen (N). Oysters don’t filter N, they filter phytoplankton that contain N. So, what happens to the N when they filter phytoplankton? www.dnr.sc.gov

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point TMDLs focus Gas Transfer of materials sources, runoff from on reducing (N 2 ) Diffusion of materials the watershed and N input Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Phytoplankton Gas Transfer of materials sources, runoff from (N 2 ) require dissolved Diffusion of materials the watershed and N for growth Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Oysters filter phytoplankton from the water Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Some of the N is incorporated into tissues. Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Some of the N is released into the water Water Column Dissolved Inorganic where it supports Nitrogen further phytoplankton growth. Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Some of the N is deposited Water Column Dissolved Inorganic on the Nitrogen sediment surface and can be buried. Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Under the right conditions, some of the N is converted to other forms by microbes Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials If the sediments the watershed and Microbial mediated reactions contain O 2 and the deposition from the right microbes, airshed nitrification can occur. Phytoplankton Water Column Dissolved Inorganic Nitrogen Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Nitrogen Cycling on Oyster Reefs Atmosphere Nitrogen Legend Nitrogen from point Gas Transfer of materials sources, runoff from (N 2 ) Diffusion of materials the watershed and Microbial mediated reactions deposition from the airshed Phytoplankton Water Column Dissolved Inorganic Nitrogen Denitrification can occur in anoxic zones, producing N 2 gas, which diffuses to the atmosphere. Oysters Sediments Biodeposits Aerobic Ammonium Nitrite Nitrate + ) - ) - ) (NH 4 (NO 2 (NO 3 Organic Nitrogen Sediments Anaerobic Nitrogen Buried Ammonium Nitrate Nitrite Gas + ) - ) - ) Nitrogen (NH 4 (NO 3 (NO 2 (N 2 ) Adapted from: Newell RIE, Fisher TR, Holyoke RR, Cornwell JC (2005) Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA. In: Dame RF, Olenin S, (eds). The comparative roles of suspension feeders in ecosystems, NATO ASI Sci Ser 4 Earth Environ Sci, Springer-Verlag, Berlin, p 93–120.

Kellogg et al. (2013) studied a restored oyster reef in the Choptank River, MD and found 251 kg N per acre were stored in the tissues and shells of oysters, but this included high densities of oysters up to 7 years old. 225 kg N per acre per year is lost through denitrification. At this rate, if 23% of the suitable bottom in the Choptank River were restored with comparably healthy oyster reefs, it would equal the entire nutrient reduction target for that tributary.

a. How much reduction could we gain from harvest? b. How much from denitrification? NOAA Chesapeake Bay Office (NCBO)-Sponsor Workshop Review by the Scientific and Technical Advisory Committee (STAC) for the Chesapeake Bay Program