Quahog Larval Dispersal and Settlement in Narragansett Bay

Additional Contributions From: RWU:! Pandora Wadsworth (Senior Thesis)! Susanna Keilig (Senior Thesis)! Brad Bourque, Matt Griffin, John Amaral (Drifters) URI/GSO:! Kevin Rosa!

The Fishery ~$5 million ~500 shell fishers supported East Passage! 12% Greenwich Bay 5% West Passage! 19% Coastal Ponds 3% 2013-2016 a Conditional B! 18% Conditional A! 41% 2013-2016 Landings Gre East Conimic Condi0on CoastalP Condi0onalA M ACCSP

Management Areas Closed Conditionally Closed! (CSO Abatement) Closed Spawner! Sanctuary

Some Questions 1) What are the main larval source/settlement connections?! 2) Might closed or conditionally closed areas be important larval source areas?! 3) How effective is the established Spawner Sanctuary?! 4) How many larvae are lost to RI sound?! 5) What impacts might climate change produce?! 6) How can we use larval transport information for management?

Spatial Distribution DEM Hydraulic Dredge Data! Gridded areas well sampled. Non-gridded poorly sampled! High densities correspond to productive fishing grounds! Closed Areas highest densities

Spatial Distribution- Depends on: Larval source area adult density/fecundity! Transport currents larval behavior! Settlement location at metamorphosis substrate condition/habitat preference! Mortality fishing pressure predation adverse conditions (e.g. hypoxia/anoxia)

Life Cycle Planktonic Larvae (8-12 days) Sessile Adults MaineClammers.org

Tracking Currents Depths of: 1 meter 3 meters 6 meters 1 meter

1-meter (diamond) 3-meter (triangles) Drifters Ohio Ledge 2014 6 release sites darker symbols are western 59 drifters export from Ohio Ledge to East/West Passages

Drifters Ohio Ledge 2014 6 release sites darker symbols are western 3-Meter Drifters Only

Drifters 12 Hours After Release 1 Meter 3 Meter 4 central release sites

Drifters 24 Hours After Release 1 Meter 3 Meter 4 central release sites

Drifters Full time 1 Meter 3 Meter 4 central release sites

Depth Matters! Model Results West Passage a RWU" drifter designed and teste N a S East Passage a RWU" drifter designed and teste a S N Rogers, 2008

Tracking Currents Acoustic Doppler Current Profiler (ADCP) Wind Surface Bottom

Tracking Currents-Drifters 1 Meter 3 Meter 6 Meter

Drifters 1 Meter 3 Meter

Wind Speed (m/s) 14 12 10 8 6 4 2 0 14 12 10 8 6 4 W W N June/July Wind at Conimicut Light 0% S N 2.6% 5.2% 7.8% June/July Wind at Quonset 0% 1.8% 3.6% 5.4% 10.4% 7.2% 13% 9% Gyre Flux (m 3 /s) Gyre Flux (m 3 /s) 1500 1000 500 0-500 -1000-1500 1500 1000 500-500 0-1000 -1500 E -2000 Circulation Model Upper Bay Ohio Ledge Area CW CCW -6-3 0 3 6 9 12 Northward Wind (m/s) Mid Bay Conanicut Point CW CCW -6-3 0 3 6 9 12 Northward Wind (m/s) 2 0 NOAA S Rogers, 2008

Circulation Model ROMS Model Domains: Low resolution Nested high resolution Configuration: Low resolution model provides boundary conditions for highresolution Bay model. 50-100m resolution in upper Bay. 15 vertical levels! Forcing: measured river inflows tides from ADCIRC (NOAA). observed meteorology

Circulation Model ROMS Model-Data Comparison Temperature! Obs. Surface Model Surface Obs. Bottom Model Bottom Salinity

Timing is Everything Trajectory simulation: Clusters of 65 passive particles released every hour for 6 hours.

Larval TRANSport (LTRANS) SW and LW Radiation Swimming Direction (z) ROMS Velocities (x,y,z) Tides Boundary LTRANS Input Wind Rivers Release Time and Swimming Location (x,y,z,t) Speed

Larval TRANSport (LTRANS) 1km 2 grid = 428 boxes!! 1,000 larvae /gridbox released randomly May 15-June 15!! larvae released 1m from bottom

LTRANS Active Behavior Days 2-6 51% up Days 6-10 50% up Days 0-2 90% up Days 10+ Increasing Down Swimming Speed Linearly Decreases 1.43 mm/s at day 1 0.2 mm/s at day 11

The Whole Bay 71 30' 71 25' 71 20' 71 15' 71 10' 71 30' 71 25' 71 20' 71 15' 71 10' 41 45' Passive 62% lost Active 51% lost 41 40' 41 35' 41 30' 0.0050 0.0045 0.0040 0.0035 0.0030 0.0025 0.0020 0.0015 0.0010 0.0005 0.0000

Providence River closed 71 30' 71 25' 71 20' 71 15' 71 10' Passive Active 30% lost 14% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Conditional A conditionally closed 71 30' 71 25' 71 20' 71 15' 71 10' Passive Active 34% lost 20% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Conditional B conditionally closed 71 30' 71 25' 71 20' 71 15' 71 10' 71 30' 71 25' 71 20' 71 15' 71 10' Passive Active 38% lost 25% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Spawner Sanctuary closed 71 30' 71 25' 71 20' 71 15' 71 30' 71 10' 71 25' 71 20' 71 15' 71 10' Passive Active 52% lost 37% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Spawner Sanctuary closed 71 30' 71 25' 71 20' 71 15' 71 10' Passive Drifters 41 45' 41 40' 41 35' 41 30' 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Greenwich Bay and Coves seasonal closed 71 30' 71 25' 71 20' 71 15' 71 30' 71 10' 71 25' 71 20' 71 15' 71 10' Passive Active 35% lost 21% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

Greenwich Coves closed 71 30' 71 25' 71 20' 71 15' 71 10' Passive Active 24% lost 13% lost ' ' ' 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000 '

Investigating Climate Impacts -1 day 51% up -1 day 50% up -12hrs 90% up -1 day Increasing Down Spawning Compressed into May 15 June 1

Investigating Climate Impacts Spawner Sanctuary 71 30' 71 25' 71 20' 71 15' 71 10' Current Warmer 35% lost 26% lost 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.002 0.000

An on-line version of the document is available at: www.dem.ri.gov/maps/mapfile/shellfsh.pdf 4A 4A West Passage Harvest Area Upper Narragansett Bay / East Passage 1C Kickemuit River Management Area 5K 1A 5B Co 5A 2A 2B 2C 1M 1B 4A 5K 4B 3B 3C 3A 5A Sakonnet River Management Area Spa 3H Greenwich Bay / West Passage 4A 5B 5B 3W 5A 5B Sakonnet River Harvest Area 4A ves 5C Sakonnet River 3W Where from? East Passage Harvest Area wne 2013-2016 Landings 15% 60 % r 10% r e n Bissel Cove / Fox Island 3F 8% 3W 5B MH B 20% Quonchontaug Pond Spawner Sanctuary Winnapaug Pond Spawner Sanctuary 4A 6N Ninigret Pond Spawner Sanctuary 6Q 6W Quonochontaug Pond Spawner Sanctuary 58% Coastal Ponds Greenwich Bay Management Sub Area 1 2A 1B 2C 3B Potowomut Management Area A 3C Potowomut Management Area C 3H 6B 3W High Banks Management Area Potters Pond Spawner Sanctuary 6P Jenny's Creek Bissel Cove / Fox Island 6P Bissel Cove /Fox Island Management Area 6P Block Island Great Salt Pond Harvest Areas Area 1A - Conditional Area "A" tp as 12 sag e! % 5% 3A s s Pa % t 9 s e 1 W Bay 2B reenwich Bay Management Sub Area 2 Potowomut Spawner Sanctuary Area B Area 1M - Mill Gut Area 2A - Greenwich Bay Sub Area 1 Area 2B - Greenwich Bay Sub Area 2 Area 2C - Greenwich Bay Sub Area 3 Area 3A - Potowomut Management Area A 3F 3W Cond. A Point Judith Pond & Potter Pond Area 3F - Bissel Cove / Fox Island Management Area 11% Shellfishing Prohibited Area 3H - High Banks Management Area Not Assessed - Shellfishing Prohibited Area 3W - West Passage Upper Narragansett Bay Conditional Area - A Area 4A - East Passage Upper Narragansett Bay Conditional Area - B Area 4B - Bristol Harbor Shellfish Transplant Area Area 5B - Sakonnet River Area 5C - Sakonnet River Management Area Area 5K - Kickemuit River Management Area Area 6B - Block Island - Great Salt Pond Area 6N - Ninigret Pond Area 6P - Pt. Judith and Potters Pond Area 6Q - Quonochontaug Pond Area 6W - Winnapaug Pond 3% **Shellfishing Classifications Area 3C - Potowomut Management Area C Area 5A - Mt. Hope Bay s ond lp C Area 3B - Potowomut Spawner Sanctuary Area B **Shellfish Closure Areas are shown on this map for reference only. Refer to the current document "Notice of Polluted Shellfishing Grounds" for detailed descriptions of classified waters Conditional B! 18% Shellfishing Prohibited until June 28 2010 Conditional Closure!!!!!!!!!!!!!!!!!!!! Seasonal Closure Block Island Seasonal Closure A,C Block Island Seasonal Closure B ver i R. P This symbol indicates the location of a marina facility that has an associated seasonal closure. Refer to the current document "Notice of Polluted Shellfish Grounds" for more information. 12% % s e ov C ta oas Area 1B - Conditional Area "B" Area 1C - Conimicut Triangle % 47! e ag ch Ea s 1A Greenwich Bay Management Sub Area 3 S e rag ave 016 3-2 201 Conditional Area "A" eenwich Bay and West Passage w a p 2 i enw Gre 3W 5C 0% 16% Conditional A! 41% 1 P. 6% Riv er 10 P stal land ckis s ond Blo Coa a nala i0o d Con n i0o u c imi M t Eas e Gre 1) What are the main larval source/settlement connections?! d Con Cond. B Con 12% W 11%.R iv er

1) What are the main larval source/settlement connections?! Answers 2) Might closed or conditionally closed areas be important larval source areas?! 3) How effective is the established Spawner Sanctuary?! 4) How many larvae are lost to RI sound?! 5) What impacts might climate change produce?! 6) How can we use larval transport information for management? Closed areas are important larval sources. Greenwich Bay Coves to Greenwich Bay Providence River to upper bay Conditional Areas A and B to upper bay and West Passage (and East Passage).! The current Spawner Sanctuary is well located to distribute larvae throughout the West Passage and into Greenwich Bay.! ~50% of larvae bay-wide are lost to RI sound, but highly variable! A warmer bay should lead to faster larval development and increased larval retention! And

Quahog Larval Transport: Information Use in Management Larval transport result can be used by DEM in future evaluations of coastal development and operations (e.g. aquaculture permitting, dredging)

Quahog Larval Transport: Information Use in Management Larval transport result can be used by DEM in future evaluations of coastal development and operations (e.g. aquaculture permitting, dredging)!! These results provide us better, quantifiable information on the value of polluted and conditionally closed areas in supporting Narragansett Bay larval production.

Quahog Larval Transport: Information Use in Management Mean # Quahogs m -2 Larval transport result can be used by DEM in future evaluations of coastal development and operations (e.g. aquaculture permitting, dredging)!! These results provide us better, quantifiable information on the value of polluted and conditionally closed areas in supporting Narragansett Bay larval production.! Source/sink information for quahog larvae can provide insight into larval mortality and the stocks spatial recruitment dynamics, which will be incorporated into the future stock assessment.