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Thomas Landry and J.F. Mallet DFO, Moncton NB
Fisheries and Oceans Pêches et Océans Canada Canada Exploring the potential of enhancing oyster spat collection activities through high density reproductive sanctuaries in Caraquet Bay, New-Brunswick. Thomas Landry and J.F. Mallet DFO, Moncton NB
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Fisheries and Oceans Pêches et Océans
Canada Canada
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Oyster Population 1958 – Malpèque 1974 – 2574 t 1979 – 1282 t
Fisheries and Oceans Pêches et Océans Canada Canada Oyster Population 1958 – Malpèque 1974 – 2574 t 1979 – 1282 t 1987 – 808 t 1991 – 696 t 1999 – 553 t During the first phase of this project, we evaluated the structure of the main oyster bed in Caraquet Bay, using a geostatistical method. We found that the bed was (216/290*100) % smaller than it was 2 decades ago. Despite the reduction in size, the total biomass was (51.6/31.5*100) larger than it was in However, the highest biomass ever recorded for this bed was (63.5*240). It is important to note that this peak was recorded following a major restoration exercise. Total Surface: m2 Total Population: 112 x 106
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Restoration Options Habitat Approach Shelling Desilting
Fisheries and Oceans Pêches et Océans Canada Canada Restoration Options Habitat Approach Shelling Desilting
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Restoration Options Population Approach Reproductive Sanctuaries
Fisheries and Oceans Pêches et Océans Canada Canada Restoration Options Population Approach Reproductive Sanctuaries Predator Management Seeding
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Synergy = Healthy Ecosystem
Fisheries and Oceans Pêches et Océans Canada Canada Community Government Industry Synergy = Healthy Ecosystem
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Oyster Industry: Caraquet NB Commercial Fisheries Spat Collection
Fisheries and Oceans Pêches et Océans Canada Canada Oyster Industry: Caraquet NB Commercial Fisheries Spat Collection
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Reproductive Biomass (Oysters > 35 mm)
Fisheries and Oceans Pêches et Océans Canada Canada Reproductive Biomass (Oysters > 35 mm) Main Public Bed Population: Total Surface = 1.9 km2 Total Biomass = 73 x 106 AVG Size = mm Density = 37.7/ m2 Coastal Beds Populations: Total Surface = 2.1 km2 Total Biomass = 8 x 106 AVG Size = mm Density = 3.9/ m2
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Fisheries and Oceans Pêches et Océans
Canada Canada Fecundity FECUNDITY Fc = * ( * L )2.36 * N (Drew, 2002) Where: Fc = total fecundity (number of egg produced) L = mean shell length (mm) N = population size
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Fertilization FERTILIZATION EFFICIENTY
Fisheries and Oceans Pêches et Océans Canada Canada Fertilization FERTILIZATION EFFICIENTY Fe = * D0.72 (Drew, 2002) Where: D = N/A Where: Fe = fertilization efficiency of oysters D = oyster density (oysters/m2) N = population size, A = area (m2) 20 40 60 80 100 1 3 5 Gamete age (hrs) Concentration [10^6] [10^4] [10^2] Rate of fertilization (%) [10^0]
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Present Status Coastal Beds Population: Main Public Bed Population:
Fisheries and Oceans Pêches et Océans Canada Canada Present Status Coastal Beds Population: Total Biomass = 8 x 106 Fecundity = 2.2 x 1011 Fertilization Efficiency = 0.01 Main Public Bed Population: Total Biomass = 73 x 106 Fecundity = 2 x 1012 Fertilization Efficiency = 0.07% 2006: 50 million seed production
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Fisheries and Oceans Pêches et Océans Canada Canada
16 14 12 10 8 Total Growth (mm) 6 4 2 Banc public P. aux H. Maisonnette St-Anne B. P. aux R. Site 3.5 B C B B B BC 3 B B B B B B B B B AB 2.5 01/06/01* A AB A A A 05/07/01 2 A A A A 01/08/01 Condition Index (%) 1.5 27/08/01 1 30/10/01 0.5 Banc Public P. aux H. Maisonnette St-Anne B. P. aux R. (P. 0,000) (P. 0,000) (P. 0,000) (P. 0,000) (P. 0,000) Site
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Restoration Scenario: Optimizing the picking activity
Fisheries and Oceans Pêches et Océans Canada Canada Restoration Scenario: Optimizing the picking activity Population (≥ 35 mm) Participants Individual quota (kg) Landing (oysters) 30% Tax 15 500
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Restoration Scenario: Optimizing the picking activity
Fisheries and Oceans Pêches et Océans Canada Canada Restoration Scenario: Optimizing the picking activity Year Density (oysters/m2) Sanctuary (m2) Fecundity (egg production) Fertilization efficiency (%) Fertilized eggs 1 221.5 225 1.32 x 109 0.24 3.16 x 108 2 450 2.64 x 109 6.32 x 108 3 675 3.96 x 109 9.48 x 108 4 900 5.29 x 109 1.26 x 109 5 1 125 6.61 x 109 1.58 x 109 6 1 350 7.93 x 109 1.90 x 109 7 1 575 9.25 x 109 2.21 x 109 8 1 800 1.06 x 1010 2.53 x 109 9 2 025 1.19 x 1010 2.85 x 109 10 2 250 1.32 x 1010 3.16 x 109
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Fisheries and Oceans Pêches et Océans
Canada Canada Benefits
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THANK YOU MERCI Questions ? Fisheries and Oceans Pêches et Océans
Canada Canada THANK YOU MERCI Questions ?
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