Kahala Broodstock Management: Final Report

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Kahala Broodstock Management Project CTSA Progress Report to the Public June 3, 2011:

Kahala Broodstock Management Project CTSA Progress Report to the Public June 3, 2011 Charles W. Laidley, Ken Liu, Chad Callan, Eric Martinson Finfish Department, Oceanic Institute Waimanalo, Hawaii Neil Anthony Sims, Jennica Lowell Kona Blue Water Farms, Kailua-Kona, Hawaii

Background:

Background Amberjacks ( Seriola ) are emerging as premier aquaculture candidate species worldwide : Fast growth rates Excellent product quality High-market value Wild fishery in Hawaii is plagued by high incidence of ciguatera and worms Japan has been leader in Seriola culture utilizing wild-collected yellowtail and greater amberjack fingerlings to stock surface net pens. Natural stocks of fingerlings are not readily available in Hawaii, … and wild stocks are fully exploited in Asia and Europe Therefore … goal of this project is to develop a captive broodstock program as part of a larger effort in Hawaii utilizing hatchery-generated fingerlings for commercial growout

Two species of Kahala in Hawaiian waters:

Two species of Kahala in Hawaiian waters Longfin amberjack ( Seriola rivoliana ) Greater amberjack ( Seriola dumerili )

Kahala culture development:

Kahala culture development In late 90’s OI brought in both two kahala species, Seriola dumerili and Seriola rivoliana Although both spawned in captivity, only Seriola rivolian a spawned well in captivity (warmer water/smaller size) S. rivoliana eggs proved relatively easy to rear using standard rotifer/Artemia-based hatchery protocols with hatchery survival rates of 7 to 11% in initial runs Captive reared juveniles grew extremely well in captivity on standard marine fish growout diets 2.2kg at 1 yr 4.8kg at 2 yrs 6.2kg at 3.5 yrs

Kahala growth (onshore):

Kahala growth (onshore) Fed standard Skretting marine grower diet Growth to 2.2 kg at 1 yr of age Growth 4.8 kg at 2 yrs of age Growth 6.2 kg at 3.5 yrs of age

Kahala culture development (cont’d):

Kahala culture development (cont’d) Captive reared stocks reached sexually maturity at just under two years of age, and began spawning in captivity Captive broodstock spawn year-round, with increased spawn frequency in summer months Spawn size is variable … typically 100,000 to 600,000 (mean ~300,000) for a tank of 20 broodstock (1:1 ratio of male to female) Egg fertility and viability rates were lower than from wild-collected stocks … suggesting need for improved broodstock diets. New salmon broodstock diet ( Vitalis SA, Skretting ) appeared to resolve egg quality issues

Reproductive Development:

Reproductive Development Monthly sampling to track reproductive development in F1 (domesticated) population Males mature at 21 months of age Females mature at 24 months of age Spawning began at 24 months of age

Tank Spawning of F1’s:

Tank Spawning of F1’s Kahala spawn year-round in captivity with reduced egg output in the winter months (despite constant temps between 25 and 27ºC) A tank of 20 newly matured broodstock generated an average of 287,885 eggs per spawn with a fertility rate of 51%

Project Objectives:

Project Objectives Objective 1: Design and commission a two-tank recirculating aquaculture system (RAS) for holding kahala broodstock Objective 2: Establish an expanded kahala broodstock population for study of broodstock holding systems Objective 3: Compare broodstock health and performance in flow-through versus water reuse broodstock holding systems Objective 4: Evaluate long-term effects of a formulated commercial diet on broodstock health and reproductive performance at both OI and KBWF Objective 5: Disseminate project findings on kahala broodstock holding conditions

Objective 1: Design and commissioning a two-tank recirculating aquaculture system (RAS) for holding kahala broodstock at OI:

Objective 1: Design and commissioning a two-tank recirculating aquaculture system (RAS) for holding kahala broodstock at OI Adult kahala stocked into four 12 ft. dia. X 6 ft. deep fiberglass tanks Indoor tanks maintained under photoperiod and temperature control Tanks had submerged multiport water inlets built into sides and dual drainage from bottom for feed and feces and side for eggs Two tanks maintained under flow-through and two tanks maintained using RAS

Objective 1: OI water treatment systems continued:

Objective 1: OI water treatment systems continued Flow-through water treatment systems: Vacuum degassing Mechanical filtration Recirculating aquaculture system: Sump Pressurized glass filter Fluidized sand bed Protein skimmer High-output UV unit

Objective 1: KBWF water treatment systems:

Objective 1: KBWF water treatment systems Broodstock holding systems 45m³ broodstock tanks (8’ deep x 50’ diameter) HDPE liner surrounded by steel structure with a center drain Oxygen levels controlled by Point Four System Tanks covered by 95% shade-cloth KBWF Flow-through water treatment systems: Surface seawater provided by the Natural Energy Lab Filtration: a series of sand-filters containing multiple layers of media allowing filtration down to 20µm Cartridge filtration to 5µm KBWF Recirculating aquaculture system: sand filter utilizing crush glass media protein fractionator 450L biofilter containing bioballs UV sterilizer 8 turnovers/day with approx. 10% new water/day

Objective 2: Establish an expanded kahala broodstock population for study of broodstock holding systems:

Objective 2: Establish an expanded kahala broodstock population for study of broodstock holding systems OI kahala stocks: sourced with F1 fish from KBWF open ocean cage operations in Kona Juvenile kahala (~2kg) were shipped by air from KBWF to OI New stocks were quarantined and matured in outdoor 25m 3 broodstock tanks In May 2009 (following system commissioning) stocks of 6 to 12kg kahala were allocated into four indoor broodstock tanks (6’deep x 12’ dia.) for planned holding trials KBWF kahala stocks: Flow through system was stocked with wild-collected stocks fed sardines and squid RAS system was stocked with F1 stocks sources from KBWF open ocean cages and fed pelleted Vitalis broodstock diet from Skretting

Objective 3: Compare broodstock health and performance in flow-through versus water reuse broodstock holding systems:

Objective 3: Compare broodstock health and performance in flow-through versus water reuse broodstock holding systems OI kahala broodstock adapted quickly to indoor tank systems at with the initiation of spawning soon after stocking in May 2009 KBWF broodstock also appeared to adapt well to both flow-through and RAS systems Overall reproductive performance appeared better in the flow-through systems at both locations

Table 1: Effects of water treatment (flow-through vs. recirculating) on reproductive performance of OI captive kahala broodstock over the project period.:

Table 1: Effects of water treatment (flow-through vs. recirculating) on reproductive performance of OI captive kahala broodstock over the project period. Stocks maintained in flow-through systems generated almost double the eggs of stocks maintained in the RAS In addition to improved egg output … there was also an increase in fertility rates (63% vs. 73%) and egg viability rates (20% vs. 42%) in fish maintained in flow-through system compared with fish maintained under the RAS treatment Eggs Spawned Fertility Rate Viability Rate Month FT RAS FT RAS FT RAS June 2009 766,332 2,669,216 37 90 28 78 July 2009 1,489,279 1,533,544 85 83 85 57 Aug 2009 1,849,307 1,202,531 79 73 79 15 Sept 2009 761,961 370,889 64 68 22 7 Oct 2009 734,500 221,500 91 71 10 0 Nov 2009 754,833 128,500 39 39 23 2 Dec 2009 1,561,600 317,550 59 41 42 12 Jan 2010 1,354,017 125,334 76 22 42 5 Feb 2010 2,976,150 453,983 86 59 49 13 March 2010 1,654,799 1,318,683 92 72 55 17 April 2010 1,421,583 321,142 94 71 27 18 TOTAL 15,324,358 8,662,871 802 688 461 222 MEAN 1,393,123 787,534 73 63 42 20

Table 2: Effects of water treatment (flow-through vs. recirculating) on reproductive performance of KBWF captive kahala broodstock over the project period.:

Table 2: Effects of water treatment (flow-through vs. recirculating) on reproductive performance of KBWF captive kahala broodstock over the project period. Due to differences in fish origin, age, size, and diet it is not possible to directly compare the treatment groups … however, both systems supported broodstock egg production Overall egg viability rates remained low throughout the study period under both broodstock systems … however, the large numbers of eggs obtained from these very large broodstock holding systems afforded sufficient numbers of eggs to meet hatchery supplies Eggs Spawned Viability Rate Month FT RAS FT RAS Nov 2006 3,284,000 0 20% Dec 2006 9,470,000 0 37% Jan 2007 10,327,000 0 40% Feb 2007 9,167,000 0 35% Mar 2007 9,140,000 0 29% Apr 2007 8,152,000 813,000 34% 17% May 2007 7,676,000 2,376,000 21% 17% June 2007 8,203,000 3,358,000 15% 2% July 2007 7,190,000 5,648,000 24% 13% Aug 2007 6,479,000 6,049,000 15% 12% Sept 2007 8,241,000 5,964,000 17% 4% Oct 2007 1,049,000 3,702,000 1% 7% Nov 2007 7,001,000 4,842,000 28% 11% Dec 2007 7,188,000 2,577,000 31% 20% TOTAL 102,567,000 35,329 MEAN 7,326,200 3,925,400 24.8% 11.4%

Objective 4: Evaluate long-term effects of a formulated commercial diet on broodstock health and reproductive performance:

Objective 4: Evaluate long-term effects of a formulated commercial diet on broodstock health and reproductive performance Broodstock were maintained on Vitalis SA (Skretting) broodstock diet from June to November 2009 Diet supported year-round egg production Egg quality in terms of viability, hatch and early larval development remained poor Therefore switched half of stocks to new Vitalis CAL formulation for remaining 5 months Initially the calamari meal supplemented diet improved egg production and egg viability rates … but by end of trial reproductive performance did not differ between dietary treatments Mean Spawn Size Fertility Rate Viability Rate Month Vitalis Vitalis CAL Vitalis Vitalis CAL Vitalis Vitalis CAL June 2009 147,400 151,172 46 54 10 43 July 2009 160,707 174,671 82 86 67 56 Aug 2009 143,506 162,087 69 84 18 13 Sept 2009 74,583 94,885 61 70 8 20 Oct 2009 168,000 105,188 89 73 3 7 Nov 2009 104,750 73,278 13 65 5 20 mean before 133,158 126,880 60 72 18 27 Dec 2009 147,400 151,172 46 54 10 43 Jan 2010 66,685 146,435 38 60 11 35 Feb 2010 86,906 187,101 67 78 24 38 March 2010 151,627 139,280 87 77 35 37 April 2010 162,715 141,250 81 98 33 6 mean after 123,067 153,047 64 73 23 32

Objective 4: Evaluate long-term effects of a formulated commercial diet on broodstock health and reproductive performance:

Objective 4: Evaluate long-term effects of a formulated commercial diet on broodstock health and reproductive performance Conducted a series of egg quality trials at end of project (April 2010) Egg fertility rates were excellent with mean values greater than 90% Egg viability (completion of egg development) were much lower and appears to be an issue with amberjacks Hatch rates were very low and highly variable Vitalis : 3% hatch rate Vitalis CAL 22% hatch rate Note that wild-collected amberjack do not take readily to pelleted diets, and therefore are provide raw diets

Earlier Kahala broodstock diet results:

Previous kahala diet studies showing inferior egg quality for fish fed on raw (smelt, squid, shrimp) and pelleted growout diets. Conversion to high-lipid broodstock diet (Vitalis SA) led to marked improvement in egg production and egg quality. Earlier Kahala broodstock diet results

Necropsy Results:

Females were slightly smaller than males (i.e., energy input into egg production vs. growth) Female liver hepatosomatic index was larger than males … consistent with increased hepatic vitellogenin production. Water treatment (RAS vs. flow through) had no effect growth, liver or gonad development. Calamari enriched diet yielded an increase in ovarian weight and increased fecundity Necropsy Results

Project Summary: :

Project Summary: Of the two local amberjack species, the longfin amberjack ( Seriola rivoliana ) appears the most suited to captive culture in Hawaii Both wild-collected and domesticated stocks can be used as broodstock Broodstock are prone to ectoparasiste infections, and thus wild stocks require rigorous quarantine protocols … giving special attention to Cryptocaryon . Domesticated stocks provide better protection from ectoparasite introductions, but appear more prone to egg quality issues. Broodstock will spawn year-round under ambient conditions in Hawaii, although spawn frequency and egg output slows during the winter months. Broodstock can be maintained in either flow through or recirculating aquaculture systems, although reproductive performance was better in the flow-through systems Fish history and diet appear have significant effects on egg quality, with domesticated stocks often yielding poor performing eggs. Therefore, there is a need for additional research on broodstock dietary requirements.

Special thanks to …:

Special thanks to … Center for Tropical & Subtropical Aquaculture National Oceanic & Atmospheric Association

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