Shellfish aquaculture and nutrient management science and policy

Transcription

1 Shellfish aquaculture and nutrient management science and policy NEFSC Milford Lab Julie M. Rose LISS STAC

2 Nitrogen management: TMDL Sediment Legacy Groundwater Point Nonpoint Agriculture Runoff Atmospheric Deposition Septic Systems Nitrogen Sources 15% Urban Runoff Lawn Runoff Point Nonpoint

3 Groundwater Septic Systems Lawn Runoff Nonpoint Urban Runoff Sediment Legacy Atmospheric Deposition Agriculture Runoff

4 What about shellfish? Because shellfish can remove nitrogen from the environment, states and municipalities would like to include shellfish in their plans to improve water quality Nitrogen Plankton Mussels Potential pathways of nutrient reduction: Assimilation into tissue & shell Enhanced sediment denitrification Burial in seafloor sediments U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 4

5 How could this work in practice? Case studies Mashpee MA: combination of oyster aquaculture and enhanced hard clam commercial harvest Town purchases clam seed, plants & maintains in locations that have good bottom substrate & need nitrogen reduction. When market size, open locations for commercial harvest & track harvest reports. N removal credit for N in tissue and shell. Cost-savings estimate = $140 million Data used in approval process: benthic surveys to ID good habitat; water quality classifications for harvest; local clam tissue and shell N content EPA Approved U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 5

6 How could this work in practice? Case studies Chesapeake Bay: Oyster BMP expert panel aquaculture Expert panel recommended and program approved nutrients in oyster tissue harvested by growers count towards required reductions. Default or site-specific nitrogen removal credits are possible. Separate estimates for triploid/diploid. Tracking through harvest reports of size and abundance. Data used in approval process: SH:DW relationship for Chesapeake oysters; tissue N&P content EPA Approved Shell, denitrification, burial, restoration, wild harvest are still being evaluated by the panel. U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 6

7 How could this work in practice? Case studies Falmouth, MA: oyster aquaculture development zones Town identifies locations that need nutrient reductions and also minimize user conflict. Town obtains all state and federal permits needed to grow oysters in these locations, then leases to farmers. Town tracks harvest reports to establish nitrogen removal. Not yet an approved part of Cape Cod s overall nitrogen management plan. Falmouth embayment-scale nitrogen reduction requirements established. U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 7

8 How could this work in practice? Case studies Pennsylvania: Pennsylvania Infrastructure Investment Authority invests $8 million of stormwater abatement money to build a freshwater mussel hatchery in Philadelphia. Seed will be used in restoration projects to address runoff from land. U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 8

9 Common implementation needs Nutrient content of tissue and shell: Species-specific Regional/local data preferred Shell height:dry weight useful Verification procedures: Assurance that reduction has occurred Harvest reports numbers and size Environmental monitoring Siting Identify locations that both require nutrient reduction and are suitable for shellfish growth U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 9

10 LIS municipal-scale shellfish nitrogen removal Partnership between NOAA, SBU, Greenwich Shellfish Commission Greenwich Shellfish Commission partners with CT DA/BA to manage commercial & recreational harvest Ideal shellfish conditions: productive waters with low bacterial counts

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12 Municipal leases Connecticut Shellfisheries Mapping Atlas, clear.uconn.edu

13 Municipal leases State leases Connecticut Shellfisheries Mapping Atlas, clear.uconn.edu

14 Municipal leases State leases Recreational Areas Connecticut Shellfisheries Mapping Atlas, clear.uconn.edu

15 Municipal leases State leases Recreational Areas Seed beds Connecticut Shellfisheries Mapping Atlas, clear.uconn.edu

16 60% of Greenwich seafloor used for shellfish activity Municipal leases State leases Recreational Areas Seed beds 955 acres oyster leases acres hard clam leases 900 acres rec. shellfish Connecticut Shellfisheries Mapping Atlas, clear.uconn.edu

17 Measuring & modeling seston removal and nitrogen absorption Hard clams: biodeposition method (Cranford & Hargrave 1994; Hawkins 1996; Galimany 2011) Eastern oysters: Farm Aquaculture Resource Management model (Ferreira 2007; Ferreira 2009) U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 17

18 Measuring clam feeding and nitrogen absorption (Hoellein et al. 2014) Water Egestion (feces) Ingestion Shellfish Filtration Absorption 2/8/2018 Rejection (pseudofeces) *Because inorganic matter isn t assimilated it is a neutral tracer TPM PIM/POM PN

19 Seston removal and nitrogen absorption rates across the growing season 8 Seston Filtration Rate (mg h -1 g -1 ) Nitrogen Absorption Rate (mg h -1 g -1 ) Jul-02 Jul-29 Aug-27 Oct-07 Jul-02 Jul-29 Aug mg seston h -1 g DW mg N h -1 g DW -1

20 Scaling clams to the municipal level Nitrogen absorption to nitrogen assimilation into tissue and shell how much N per gram DW? How many and what size clams are harvested annually in Greenwich? U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 20

21 Scaling clams to the municipal level: absorption to assimilation Tissue dry weight (g) Shell height (mm) Shell height to tissue dry weight from our data on Greenwich clams y = *x Assume constant filtration Assume feeding substantially reduced <10 o C (from our data, only active growth May-November) Average absorption rates per size class using our data standardization coefficient from Riisgard 1988 Assume 30% of nitrogen absorbed is lost to excretion based on Hibber 1977 in Kraeuter & Castagna 2001

22 Comparison to municipal nitrogen loads Vaudrey et al. (2016) modeled nitrogen loads to all Long Island Sound coastal subwatersheds 6 in Greenwich Total Greenwich annual N load: 98,383 kg U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 22

23 Total nitrogen load by source Atmospheric Deposition Nitrogen load (kg y-1) Sewer Septic Fertilizer 0 Byram River Greenwich Harbor Smith Cove Indian Harbor Mianus River Greenwich Cove U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 23

24 Acknowledgements Chesapeake Bay Expert Panel: J. Cornwell, J. Reichert, W. Slacum, L. Kellogg, M. Luckenbach, S. Bricker, K. Paynter, C. Moore, M. Parker, L. Sanford, B. Wolinski, A. Lacatell, L. Fegley, K. Hudson Mashpee: Rick York & Jeff Gregg Falmouth: Pete Chase PA: Danielle Kreeger EPA Long Island Sound Study: Mark Tedesco NOAA: Gary Wikfors & Office of Aquaculture VA Tech: Kurt Stephenson Town of Greenwich: Roger Bowgen, Sue Baker, Kim Bruce, William Gremp, Wilfred Cameron, Frank Cantelmo, Richard Kral, Sarah Crosby, Joan Seguin, Jonathan Stone, Jay Louden, Denise Savageau SBU: Anthony Dvarskas, John Bohorquez UNH: Kyla Kelly & Amy Carlile NOAA: Suzanne Bricker, Gary Wikfors, Mark Dixon, Judy Li, Shannon Meseck & Office of Aquaculture

25 Ingestion Egestion (feces) FTPM FPIM FPOM FNitrogen Water WTPM WPIM WPOM (f) WNitrogen Clearance Rate Filtration Rate Shellfish Filtration Assimilation Blue = directly measured Orange = mass balance calculation Rejection (pseudofeces) PTPM PPIM PPOM PNitrogen p = PPOM/PTPM *Because inorganic matter isn t assimilated it is a neutral tracer

26 U.S. Department of Commerce National Oceanic and Atmospheric Administration NOAA Fisheries Page 26