Hatchery-Based Aquaculture of the Sea Cucumber Holothuria scabra in the Federated States of Micronesia Masahiro Ito *, M. Hagilmai, B. Halverson, C. Maluwelgiye and J. Smith Aquaculture Research and Development, College of Micronesia Land Grant Program, P.O. Box 1179, Kolonia, Pohnpei, FM96941, Federated States of Micronesia Saipan Guam Yap Chuuk Pohnpei Kosrae Papua New Guinea 1
Pohnpei Island Nett Point Hatchery & Pearl Farm Sokehs Harbor Dekehtihk Is. (Airport) Lenger Is. Parem Is. Kehpahra Is. Pehniou Is. Pearl Farm Man Madol Madolenihmw Objectives Objective 1. Search and collect sandfish broodstock (years 1 ~ 2) Objective 2. Conduct broodstock conditioning, spawning induction and larval rearing for training Micronesians (years 1 ~ 2) Objective 3. Develop methods for juvenile production and grow-out in both tank and lagoon conditions (years 3 ~ 4) > Objective 4. Continue restocking operation of sandfish (years 4 ~ ) 2
Wild Stock Survey & Broodstock Collection 10 Holothurian species were found around the hatchery site The sea cucumber species found near-shore in the Northern Pohnpei Lagoon October, 2008 December, 2009. Common Name Scientific Name Habitat Sandfish Holothuria scabra mangrove shore, tidal flat, deep muddy soft sand, sea grass (eelgrass) bed Lollyfish Curryfish Brown Sandfish Snakefish Blackfish Pinkfish Stonefish Red Surffish Greenfish Holothuria atra Stichopus variegates Bohadschia marmorata Holothuria coluber Actinopyga miliaris Holothuria edulis Actinopyga lecanora Actinopyga mauritiana Stichopus chloronotus - mangrove shore, - tidal flat ~ inter-tidal - shallow mud/sandy - sea grass ~ seaweed -coral gravel ~ boulder 3
Daytime sandfish stock survey preliminary results by CPUE method Zone Location Survey Area CPUE Sandfish/Staff-hr. NEPL (S1) Nett Point 9 sites S1-1(a-m) 2.20 NEPL (S1) SW Parem Is. S1-2 1.30 NEPL (S1) SE Lenger Is. S1-3 0.00 NEPL (S1) SW Dekehtihk Is. S1-4 1.10 EPL (S2) U S2 NA SEPL (S3) Madolenihmw S3-1 28.80 SPL (S4) SE Kitti Pweniou Is. S4-1 5.00 W-SWPL (S5) SW Kitti Keipahla Is. S5-1 0.00 W-NWPL (S6) Palikir S6-2 NA NWPL (S6) W Sokehs S6-1 14.00 Daytime Sandfish stock survey preliminary results by LT method Survey Zone and Area Sandfish per ha.(10,000 sqm) Nett Point (S1-1) 122.20 SW Parem Is. (S2-2) 40.00 SE Lenger Is. (S1-3) 0.00 SW Dekehtihk Is. (S1-4) 400.00 Sokehs Harbor (S6-1,,,S6-5) 400.00 Palikir (S5 & S6) U (S2) Madolenihmw (S3) Kitti (S4 & S5) Not Completed Not Completed Not Completed Not Completed 4
Natural Habitat and Simulated Tank System Sandfish Holding Tank for Broodstock & Juveniles combined partial flow-through and closed re-circulating seawater system H I J F D C B A E G 5
Setting up semi-closed recirculating seawater system Long Term Broodstock Holding at Day & Night in the raceway tanks (simulating natural habitat) at Night at Daytime 6
Sandfish (Holothuria scabra) color morphs Hatchery 7
Spawning Induction Dry treatment Inducing spawning by thermal shock Spawning tank maintenance (siphoning out droppings) Fertilized eggs Rearing Larvae and Juveniles Newly settled postlarva (pentactula) & juveniles Microalgae culture Larval rearing tank Settlement tank & postlarval rearing plates 8
Juvenile Grow-out System Juvenile grow-out tank (2 weeks ~ 1 months) Long-term juvenile culture tank simulating natural habitat (1 month ~) Cultivating naturally occurring algae on the plates for feeding Frequency 70 60 50 40 30 20 10 0 10-15 Growth Body Length Histogram of Juveniles (n = 421) 24 weeks after fertilization (24 weeks 32.0 ± 11.5 after mm (mean fertilization) ± SD) 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55 56-60 61-65 66-70 71-75 Body Length Range 76-80 81-85 86-90 91-96 - 95 100 9
Body Weight -LR2 Group (n = 421) 24 weeks after fertilization 50 45 40 35 Frequency 30 25 20 15 10 5 0 Wet Weight Range mean ±SD (2.7 ± 2.9 g), Max. 18.7 g, Min. 0.2 g, Ave. 3.6 g Sandfish Juvenile Length vs. Weight in LR2 Group (n = 421, 24 weeks after fertilization) Body Length (mm) 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 y = 21.958x 0.392 R 2 = 0.866 0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Body Wet Weight (g) 10
Juveniles 6-month-old Growth rate varied widely from individuals without giving additional food Body Weight -LR2 Group (n = 98) 54 weeks after fertilization 12 10 Frequency 8 6 4 2 0 Wet Weight Range mean ±SD (5.5 ± 6.8 g), Max. 36.7 g, Min. 0.5 g, Ave. 8.1 g 11
Burrowing at Daytime and Coming out of sand at night (feeding associated nocturnal behavior) at night (juveniles everywhere) at daytime (no juvenile visible) Comparisons of day & night survey results at Nett Pt. CPUE method (same site at day & night) approx. 100 m 2 area (1 ha) Nett Point H. scabra CPUE Total Staff-Time (NEPL S1-1) Found Sandfish/Staff-hr. (hr.) Total 253 3.00 85.0 Day (9 sites) 117 2.20 53.0 Night (7 sites) 136 4.30 32.0 LT method (same site at day & night) duplicate of 25 m long by 2 m wide Nett Point (NEPL S1-1) H. scabra Found (average/lt) estimated density per h.a no. of duplicated LT (50 sq.m) Day (3 sites) 11 122.2 9 Night (3 sites) 8 88.9 9 12
Training Micronesian Technicians Outdoor Grow-out Tanks (~18 months) 13
Feeding Protocols 3 microalgae species (C.mulleri P. lutheri, N.oculata) Day 1 = 0 cells/ml (Gastrula) Day 2 = 8,000 (early Auricularia) Day 3 5 = 20,000 ~ 25,000 (mid Auricularia) Day 6 9 = 30,000 ~ 45,000 (late Auricularia) Day 10 11 = 30,000 ~ 20,000 (Doliolaria& Pentactula) Day 12 13 = 20,000 ~ 8,000 + naturally grown epiphytes (Pentactula) *introducing seagrass for juveniles Day 13 30 = 100g eelgrass/1000l + naturally grown epiphytes (Juvenile) *tank culture system Day 1 ~ 6 = static batch culture Day 7 ~ 10 = partial flow-through culture(100% per 16 hrs) Day 11 ~ 24 = full time flow-through culture (100% per 24 hrs) Day 25 ~ = semi-closed recircilating seawater system in the raceways. Thank you! 14