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The Lay of the Land: Understanding Quahog Management in Rhode Island

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The Lay of the Land: Understanding Quahog Management in Rhode Island presented by Jeff Mercer of the RI DEM at May 19th, 2014 Rhode Island Shellfish Management Plan Stakeholder meeting

The Lay of the Land: Understanding Quahog Management in Rhode Island presented by Jeff Mercer of the RI DEM at May 19th, 2014 Rhode Island Shellfish Management Plan Stakeholder meeting

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  • 1. The Lay of the Land: Understanding Quahog Management in Rhode Island Jeff Mercer RI DEM, Principal Biologist May 19, 2014
  • 2. 39.1 Million Clams 6.96 Million Pounds $5.15 million Dollars 534 Fishermen Quahogs by The Numbers 2012 Landings 1. Squid $19 Million 2. Lobster $12 Million 3. Sea Scallop $9 Million 4. Summer Flounder $7 Million 5. Quahog $5 Million CHERRY 3% CHOWDER 10% LITTLE NECK 64% TOP NECK 23%
  • 3. • Management Goals – What do we hope to accomplish through management? • Management Tools – What are the specific ways which we manage the resource and fishery? • Assessment Methods – How do we go about assessing existing strategies and potential modifications to management? Outline
  • 4. Management Philosophy The marine fishery resources belonging to, allocated to, and of interest to Rhode Island need to be preserved and protected, at healthy, sustainable levels- – Because of their ecological value, and – Because they are renewable natural resources that provide food, recreation, income, employment, and other economic, social, and cultural benefits.
  • 5. • Maintain the health of the State’s marine ecosystem • In accordance with sustainable harvest levels, manage harvest in ways that – Make full and effective use of available harvest opportunities, while minimizing discards, ecological impacts, habitat degradation, and other wasteful practices – Balance the interests of different user groups and stakeholders Management Goals
  • 6. • Recreational Harvesters – Provide fair, open, and equitable access and harvest opportunities with certain preferences to residents of the State • Commercial Industry – Maintain an economically strong viable and diverse industry – Support the business interest of fishermen and economic interest of the industry – Support safe fishing operations – Support enhanced marketing opportunities • Prospective Fishermen – Provide meaningful access opportunities without unduly impacting the interests of those currently engaged in the industry • General Public – Maintain the health of the State’s marine ecosystem – Provide a stable supply of safe, fresh, locally caught seafood Management Goals
  • 7. – Minimum Size – Harvest Methods – Licensing – Daily Catch Limits – Area Based Management • Limited Access Time • Reduced Daily Limits • Rotational Harvest • Spawner Sanctuaries – Transplants – Harvesting and Handling Requirements (OWR &DOH) Management Tools
  • 8. – Fishery Dependent • Landings Data - SAFIS • Catch Per Unit Effort (CPUE) – Fishery Independent • Dredge Survey • Other field surveys – Life History Studies • Age and Growth • Maturity schedule • Fecundity • Natural Mortality Models Bay-Wide Population Modeling Area-Specific Depletion Modeling Computer Simulations Assessment Methods
  • 9. Harvesting and Handling – OWR & DOH Density 8-20 X Greater than Avg • Pollution closures act as de facto marine reserves • 50% of nitrogen in quahog has origin from waste water • More tolerant to hypoxia than predators = predation refuge
  • 10. Harvesting and Handling – OWR & DOH • Pollution closures act as de facto marine reserves • 50% of nitrogen in quahog has origin from waste water • More tolerant to hypoxia than predators = predation refuge 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) # of Licenses Meat Weight (MT)
  • 11. Minimum Size 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 ShellWidth(mm) Age (yrs) Legal Size Growth Curve Sexual Maturity *1987 moved from 1.5” length to 1” width
  • 12. 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data Harvest Methods 31,000,000 lbs
  • 13. 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data Harvest Methods 31,000,000 lbs = 3,500 Elephants
  • 14. 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data Harvest Methods
  • 15. 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data Harvest Methods
  • 16. TITLE 20 § 20-6-7 Use of dredges …no person shall take any oysters, bay quahaugs, or soft-shell clams from the waters of this state by dredges, rakes, or other apparatus operated by mechanical power or hauled by power boats. Harvest Methods
  • 17. 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data Harvest Methods
  • 18. Licensing 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data
  • 19. • Open Access (through mid 1990s) • 1st Moratorium (1995 – 1998) • Open Access (1999) • 2nd Moratorium (2000-2002) • New Licensing Program (2003) Licensing
  • 20. • Use of License Endorsements to limit access to certain species • Use of Exit/Entry Ratios to control effort levels – Currently 2:1 for Quahog Endorsement • Annual process of regulatory review and modification, based on input from industry and advice from RI Marine Fisheries Council Licensing
  • 21. Licensing 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) * NMFS Landings Data
  • 22. 1984 1985 1986 1987 19881989 1990 1991 1992 1993 1994 1995 1996 1997 19981999 2000 20012002 20032004 20052006 2007 2008 2009 2010 2011 2012 0 100 200 300 400 500 600 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 AbundanceinMillions(t) F Rate (t-1) Licensing – Stock Assessment model
  • 23. License Type 2003 Total 2013 Total Net Change MPL 1191 829 -362 PEL w/QH 924 376 -548 CFL w/QH 271 420 +149 Student SF 107 48 -59 65 & ↑ SF 50 268 +218 TOTALS 2,543 1,941 -602 Licensing
  • 24. 0 200 400 600 800 1000 1200 1400 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 #ofLicenses Year MPURP PEL CFL SFO65 STUD MPURP Active PEL Active CFL Active SFO65 Active STUD Active Licensing - # of Active Licenses
  • 25. 0 20 40 60 80 100 120 140 1-5 6-10 11-25 26-50 51-100 101-150 151-200 201-250 251-306 #ofFishermen Days Fished PEL MPURP CFL SF065 Stud Licensing - 834 Total Active ~ 150 Fishermen
  • 26. 0 20 40 60 80 100 120 #ofActiveFishermen Age PEL MPURP CFL SFO65 STUD 93 fishermen under 40 years old Licensing – Age of Fishermen
  • 27. 0 20 40 60 80 100 120 #ofActiveFishermen Age PEL MPURP CFL SFO65 STUD Only 19 full-time fishermen under 40 years old (100+ days) Licensing – Age of Fishermen
  • 28. 0 2 4 6 8 10 12 0 500 1000 1500 2000 2500 3000 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 UnemploymentRate(%) Landings(MT)&Licenses(#) Year # of Licenses Meat Weight (MT) Unemployment Rate * NMFS Landings Data Licensing – & unemployment
  • 29. Daily Catch Limits License Type Endorsements Limits Cost Full Harvest Principal Effort (PEL) Quahog Soft Shell Whelk Other 12 bu/day (3 in MAs) $150 License No Fee for 1st Endorsement $75 each add’l Multipurpose (MPL) N/A 12 bu/day (3 in MAs) $300 Limited Harvest Commercial Fishing (CFL) Quahog Soft Shell Whelk Other 3 bu/day $50 License $25 for each Endorsement Student *Quahog only 3 bu/day $50 Over 65 *Quahog only 3 bu/day No Fee Recreational (Resident) N/A ½ bu/day (1 peck in MA) No license Recreational (Non-res) N/A 1 peck/day (1/2 peck in MA) $200 / $25/ $11
  • 30. 𝑁𝑖𝑗 = 𝑁𝑖𝑗−1 ∗ 1 − 𝑝 ∗ 𝑒− 𝐹 𝑖𝑗−1+𝑀 + 𝑁𝑖−1𝑗−1 ∗ 𝑝 ∗ 𝑒− 𝐹 𝑖−1𝑗−1+𝑀 N = population size F = fishing mortality rate P = promotion probability governed by von Bertalanffy growth equation derived from Henry & Nixon (2008) M = natural mortality rate i = size class j = year Inputs to Model 1. Landings 2. Fisheries Independent Abundance Index 3. Fishing Effort Index Daily Catch Limits – Size-structured Stock Assessment Model
  • 31. 0 20 40 60 80 100 120 140 160 #ofQuahogs(millions) Year Landings Size Structured Stock Assessment Model Gibson, 2010
  • 32. 0 100 200 300 400 500 600 #ofQuahogs(millions) Year Abundance Landings Gibson, 2010 Daily Catch Limits – Size-structured Stock Assessment Model
  • 33. Polynomial Logarithmic Stock-Recruitment Models Great South Bay, NY How Many Quahogs do We Need? Kraeuter et al, 2005 Density Dependence 0.75 Adults/m2 = Recruitment Failure Daily Catch Limits
  • 34. 0 100 200 300 400 500 600 #ofQuahogs(millions) Year Abundance Landings Recruitment Failure 0.75 Adults/m2 X 125km2 Fishable Area Daily Catch Limits – Size-structured Stock Assessment Model
  • 35. Kraeuter et al, 2005 Daily Catch Limits – Spawning Stock & Recruitment
  • 36. 0 100 200 300 400 500 600 #ofQuahogs(millions) Year Abundance Landings Reduced Recruitment 1.5 Adults/m2 X 125km2 Fishable Area Daily Catch Limits – Size-structured Stock Assessment Model
  • 37. West Passage Conditional B Conditional A Greenwich East Passage ma ma ma ma West Passage 25.9% Conditional A 23.6% Conditional B 20.9% Greenwich Bay 14.4% East Passage 11.9% Management Areas 0.9% Coastal Ponds 0.8% Not Identified 0.7% Sakonnet 0.6% Mt Hope Bay 0.3% Block Island 0.0% • No info on Closed Waters • Tagging Areas are Large Area Based Management
  • 38. • 1993-2013 • Use hydraulic dredge to sample adult populations • Stratified Random Sampling Design • 2368 tows of 30 m • 26,000+ clams Area Based Management – Dredge Survey
  • 39. • Not corrected for dredge efficiency • High densities correspond to productive fishing grounds • Shallow areas poorly assessed • Closed Areas highest densities Area Based Management – Dredge Survey
  • 40. Adapted from Gaylord, et al., 2005 Habitat Area Habitat Area Protected Fished P F Protected P Area Based Management
  • 41. Habitat Area Habitat Area Protected Fished P F 49% of Studies Fisheries Yield Higher with Traditional Management 51% of Studies Fisheries Yield Higher with MPAs Gaines, et al., 2010 Area Based Management
  • 42. Habitat Area Habitat Area Protected Fished P F Protected P Area Based Management
  • 43. Habitat Area Habitat Area Protected F P F P PPP P P PP P P F FF Area Based Management Rhode Island Management
  • 44. Habitat Area Habitat Area Protected P F P P f • Management = 67.8km2 • Est. Fishable Area ~ 125km2 F P F F P F Pp f p p f P P Area Based Management Rhode Island Management Management Areas = 67.8km2 Estimated Fishable Area ~ 125km2
  • 45. Area Based Management – Greenwich Bay
  • 46. Area Based Management – Greenwich Bay DEC JAN FEB MARCH APRIL GB Sub Area 1 & 2 CLOSED OWR 8-12 Jan 2 and starting Jan 6 8-12 MWF 8-12 MWF 8-12 MWF 8-12 MWF High Banks & Pot C Open Open Open Open Open Bristol CLOSED 8-12 MWF beginning Jan 3 Open Open Open Bissel/Fox Opens 2nd Wed* Open* Open* Open* Open* Mill Gut Opens 2nd Wed Open Open Open Open
  • 47. • LESLIE'S METHOD • Assume • Nt= No - Ct • Kt = Ct = cumulative catch • Nt = No-Kt • but, “N" is not an observable variable in most studies,so after multiplying through by q (the catchability coefficient) • qNt = qNo - q(Ct) • CPUE= a + b (Kt) • Fit a regression then – a) the slope of the line is an estimate of q – b) the intercept is qNo = CPUEo – c) the initial population can be estimated by Intercept a/ slope b Area Based Management – Leslie Depletion Model
  • 48. Area Based Management – Leslie Depletion Model 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows)
  • 49. Area Based Management – Leslie Depletion Model 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows)
  • 50. Area Based Management – Leslie Depletion Model 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows)
  • 51. Area Based Management – Leslie Depletion Model 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows)
  • 52. Area Based Management – Leslie Depletion Model 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows) 240 Total Marshmallows
  • 53. Area Based Management – Leslie Depletion Model y = -0.1519x + 38.173 R² = 0.9817 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows) Starting N Catch exp rate Volume Start Dens. End Dens. F Rate End N 251 240 0.955 12 20.9 0.94 3.1 11
  • 54. Area Based Management – Leslie Depletion Model y = -0.1162x + 34.888 R² = 0.9657 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(marshmallows/handful) Cumulative Catch (Total # of Marshmallows) Estimated 262 Total Marshmallows Starting N Catch exp rate Volume Start Dens. End Dens. F Rate End N 262 207 0.791 12 21.8 4.56 1.56 55
  • 55. Area Based Management – Leslie Depletion Model y = -0.1162x + 34.888 R² = 0.9657 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 MeanCPUE(quahogs/fisher/day) Cumulative Catch (Total # of Quahogs) Starting N Catch exp rate Area Start Dens. End Dens. F Rate End N 262 207 0.791 12 21.8 4.56 1.56 55
  • 56. Area Based Management – Leslie Depletion Model December 2009 – March 2010 y = -0.0002x + 1362.9 R² = 0.2653 0 200 400 600 800 1000 1200 1400 1600 0 500,000 1,000,000 1,500,000 MeanCPUE(quahogs/fishermen/day) Cumulative Catch (# of quahogs) Starting # Start #/m2 Catch End # End #/m2 5,963,116 2.82 1,458,649 4,504,467 2.13 2002-May 2010 Area = 2,109,619 m2 F Rate = 0.281
  • 57. Area Based Management – Leslie Depletion Model • May 2010 pollution line changes
  • 58. Area Based Management – Leslie Depletion Model • May 2010 pollution line changes • Summer 2010 DEM conducts dredge survey • Densities as high as 26 quahogs/ m2 when adjusted for efficiency • SAP & RIMFC decide to open only Area A (north side)
  • 59. Area Based Management – Leslie Depletion Model Dec. 2010- March 2011 y = -5E-05x + 1901.2 R² = 0.6006 0 500 1000 1500 2000 2500 0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 MeanCPUE(quahogs/fishermen/day) Cumulative Catch (# of quahogs) Starting # Start #/m2 Catch End # End #/m2 40,983,314 27.09 5,866,505 35,116,809 23.21 Area = 1,512,589 m2 F Rate = 0.154
  • 60. Area Based Management – Leslie Depletion Model Dec. 2011- March 2012 y = -8E-05x + 1728.2 R² = 0.5128 0 500 1000 1500 2000 2500 0 2,000,000 4,000,000 6,000,000 MeanCPUE(quahogs/fishermen/day) Cumulative Catch (# of quahogs) Starting # Start #/m2 Catch End # End #/m2 20,765,498 6.51 6,588,476 6,588,478 4.45 Area = 3,189,110 m2 F Rate = 0.382
  • 61. Area Based Management – Leslie Depletion Model • May 2012 pollution lines extended • Dredge Survey results from Summer 2012 • Densities reduced from ~ 9/m2 to < 1/m2
  • 62. Area Based Management – Leslie Depletion Model Jan 2013- March 2013 y = -0.0003x + 1471.7 R² = 0.4798 0 200 400 600 800 1000 1200 1400 1600 1800 2000 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 MeanCPUE(quahogs/fishermen/day) Cumulative Catch (# of quahogs) Starting # Start #/m2 Catch End # End #/m2 4,872,719 1.79 2,012,279 2,860,440 1.05 Area = 2,727,668m2 F Rate = 0.533
  • 63. Area Based Management – Leslie Depletion Model Jan 2014 - March 2014 y = -0.0004x + 1522.1 R² = 0.4154 0 200 400 600 800 1000 1200 1400 1600 1800 2000 0 500,000 1,000,000 1,500,000 MeanCPUE(quahogs/fishermen/day) Cumulative Catch (# of quahogs) Starting # Start #/m2 Catch End # End #/m2 3,544,222 1.30 1,482,124 2,062,099 0.76 Area = 2,727,668m2 F Rate = 0.542
  • 64. Habitat Area Habitat Area Protected P F P P f • Management = 67.8km2 • Est. Fishable Area ~ 125km2 F P F F P F Pp f p p f P P Area Based Management Rhode Island Management
  • 65. Habitat Area Habitat Area Protected P F P P f • Management = 67.8km2 • Est. Fishable Area ~ 125km2 F P F F P F Pp f p p f P P Area Based Management Rhode Island Management
  • 66. Habitat Area Habitat Area Protected Fished P F Protected P SOURCE SINK For reserves to be effective they must also increase populations beyond reserve borders through: 1. Larval Export 2. Adult Spillover (Transplants?) Area Based Management - Spawner Sanctuaries
  • 67. • Larvae released randomly over 30 day period • Released in top 2 meters • Passive for 11 days • Swim towards bottom for 24 hours – randomness added • Site Specific Settlement – OFF LTRANS Area Based Management
  • 68. Greenwich Cove Prohibited Area Based Management
  • 69. • ~100 million eggs/m2 • Larval Duration 8-12 days • Large potential reproductive output Area Based Management
  • 70. Marroquin-Mora & Rice (2008) • Too Dense? • Crowding may lead to poor condition and low reproductive output • CI = dry soft tissue wt X 1000/ (total wt - shell wt) Area Based Management Matt Griffin RWU/URI
  • 71. Area Based Management - Transplants Since 1977 ~ 9 million lbs of quahogs transplanted
  • 72. High Banks Potowomut Sanctuary Greenwich Cove Area Based Management – Transplants
  • 73. Potowomut Spawner Sanctuary Approved-Closed High Banks Management Area Approved Area Based Management - Transplants
  • 74. Area Based Management - Spawner Sanctuaries Data from TNC
  • 75. Questions?