Operation and maintenance recommendations for a tropical marine fish hatchery

Aquacultural Engineering 57 (2013) 89–100

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Operation and maintenance recommendations for a tropical marine fish hatchery Luis Alvarez-Lajonchère a,∗ , Giancarlo Cittolin b,1 a b

Gr. Piscimar, Marine fish culture, Calle 41 No. 886 entre 24, Nuevo Vedado, Plaza, Ciudad de La Habana CP 10600, Cuba Aquaculture private consultant, Jl. Drupadi no. 23, Gg. Mertasari no. 1, Br. Basangkasa, Seminyak Kuta, 8361, Bali, Indonesia

a r t i c l e

i n f o

Article history: Received 20 January 2013 Accepted 6 August 2013 Keywords: Tropical marine fish hatchery Operational procedures Routine maintenance Preventive maintenance program

a b s t r a c t The most important operational maintenance, cleaning and disinfection routines are described on daily, weekly, per cycle and annual frequencies, considering facilities and equipment. Basic aspects of control, vigilance, automatic alarm systems, and preventive maintenance programs are briefly discussed. The importance, characteristic and functions of the plant maintenance manager and his assistants are highlighted, and the difficulties that can arise in some farms due to mistakes or when ignoring these aspects are analyzed. © 2013 Elsevier B.V. All rights reserved.

1. Introduction The design of tropical marine fish hatcheries are not commonly published, however, sharing details of their operation and maintenance is even more uncommon. Huguenin and Colt (2002) presented general guidelines for the design, operation and maintenance of aquaculture seawater systems. Examples of tropical marine fish hatcheries designs are those for striped mullet, Mugil cephalus (Nash and Shehadeh, 1980; Liu and Kelley, 1991; Tamaru et al., 1993), Asian sea bass or barramundi, Lates calcarifer (NICA, 1986; Parazo et al., 1998; Schipp et al., 2007), milkfish, Chanos chanos (Liu and Kelley, 1992), and multispecies facilities, as in Tucker (1998), and Alvarez-Lajonchère et al. (2007). In very few cases, the detailed operation and/or maintenance activities have been described in published hatchery manuals, as included in Moretti et al. (1999, 2005) for subtropical species and AlvarezLajonchère and Hernández Molejón (2001) for tropical species. There are other hatchery manuals in which operation and maintenance activities have been described along with the design of hatcheries, as for shrimps (FAO, 2007). Standard operating procedures and biosecurity rules must be considered since the design phase, to ensure efficiency and cost-effectiveness in order to maintain the productivity of large numbers of high quality seeds with optimum condition for their growth and survival, while minimizing the risks of disease outbreaks (FAO, 2007).

∗ Corresponding author. Tel.: +537 881 4985. E-mail addresses: [email protected], [email protected] (L. Alvarez-Lajonchère), [email protected] (G. Cittolin). 1 Tel.: +62 82144 457 951. 0144-8609/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.aquaeng.2013.08.005

The operation and maintenance of a fish hatchery are two key components in juvenile mass production technologies, yet they are frequently underestimated. An extreme example is the operation of pilot-scale or even commercial-scale hatcheries by unskilled personnel, a situation that occurs when standard, common aquaculture practices are not followed and/or operation costs are forcedly kept to a minimum. Under these circumstances, the ensuing problems would be more costly than paying an appropriate salary to trained and skilled technicians that could ensure the productive and financial efficiency required to achieve the objectives for which the hatchery was designed. Achieving production targets along with the highest levels of reliability and increased economic efficiency is translated into a successful hatchery. All these features make up the essential nature of a hatchery, it is therefore mandatory that the facilities and equipment be operated with maximum effectiveness. When a significant level of productive excellence is reached, it means that the qualitative and quantitative requisites defined in the design of a hatchery and the proper technology has been implemented. The operations in a hatchery can be subdivided into four main categories: (a) the bio-technological processes; (b) monitoring and control; (c) the level of hygiene, and (d) equipment maintenance. There is a significant lack of details sharing on operation of hatcheries, especially the practical procedures, which form an important part of the know-how and are delivered to a client as part of technology transfer. The object of this paper is to highlight and discuss some of the main aspects that are to be considered in the operation and maintenance of a hatchery. The aim is to provide an outline of procedures and their timing to assist the Hatchery Manager in defining their own organization. The procedures follow the concept of a

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hypothetical hatchery similar to that described by AlvarezLajonchère et al. (2007), based on the author’s own practical experience during several years in Mediterranean hatcheries and Latin American countries.

2. Hatchery operation, cleaning and maintenance: General guidelines Each hatchery should have its own General Operational Guidelines, also called Standard Operating Procedures (SOPs) (Moretti et al., 1999, 2005; Le Breton, 2001; FAO, 2007; Alvarez-Lajonchère et al., 2007). Their bio-technological protocols, on which production cycles in each sector and area are based, details the acceptable limits of measureable parameters to be controlled, the acceptable hygienic standards and the procedures to achieve them. A handy list of regularly implemented analyses and controls, of routine and indepth cleaning of preventive and on-request maintenance to allow proper equipment functioning, should be prepared. It is recommended that the approach for the preparation of operational guidelines be based on the hazard analysis and critical control point (HACCP) system adopted by the Codex Alimentarius Commission (WHO/FAO, 2010). In addition to the original objective regarding food safety, the HACCP can be also applied as a system to identify, assess and control (or prevent) hazards which could impair the well-functioning of any facility, equipment, procedure or technological development. It is important to carry out a hazard and risk analysis of all the hatchery facilities and equipment, and apply the HACCP principles: Identifying the critical control points and their adequate limits, monitoring requirements, corrective actions, record keeping procedures and the validity of all the established procedures. The bio-technological processes in which living organisms are involved (microalgae, zooplankton, broodstock, eggs, larvae, postlarvae and juveniles), are actually part of the SOPs, which are species-specific, but are not part of the scope of this study. SOPs should also identify the critical points of each operation, maintenance and control task divided by section, area, room, person in charge and responsibilities, and decision-making procedures for emergencies. SOPs must be known and extensively discussed by the Hatchery Manager and each Sector Manager together with all the staff during periodical briefings. The Hatchery Manager (HM) discusses with the Maintenance Manager (MM) the implementation of maintenance programs and the allocation of money and staff. The HM supervises the work performed by the MM and his personnel, who are responsible for keeping high standards of hygiene and performing careful repair and maintenance routines (see Section 4) inside the marine fish hatcheries, at both pilot and commercial level. This is one of the three areas on which R&D efforts focused on many European hatcheries during the 1980s (Sweetman, 1992), aiming to establish general and specific cleaning and disinfection routines expected at assuring optimal operational efficiency of a novel industry. New procedures were introduced, adopting well-established principles from animal husbandry and industry, dealing with thorough sanitary actions, standardization of procedures and monitoring and frequent equipment maintenance. Moretti et al. (1999) described with details these general rules, as well as routine daily, weekly, monthly and annually methods for monitoring, cleaning, disinfection and maintenance tasks in Mediterranean marine fish hatcheries. Some of these actions should be emphasized in case of tropical conditions, given higher temperatures and humidity, which, on the one hand, stimulates pathogen microorganism’s growth and, on the other hand, accelerates the life span of the equipment.

2.1. Hygiene and cleaning guidelines As a rule, all equipment must be cleaned thoroughly on a regular basis, before and after use, even in presence of living organisms (regular cleaning). Cleaning is repeated thoroughly at the end of a production cycle (in-depth cleaning) and again during the annual end of operations (sanitation). Of particular importance is the annual period in which the hatchery is almost emptied of living organisms (except for live food organism inocula and fish breeders), also called the sanitary stop, which should be carried out during the winter seasons in the tropics, usually characterized by lower reproduction activities. This measure is mandatory to prevent the dangerous accumulation of pathogens. Under a continuous production scheme, this could be replaced by a rotational design to allow thoroughly cleaning of each sector. It is highly recommended to program complete equipment maintenance in the entire facility at the same time. Many officials minimize the importance of annual maintenance and sanitary stop, or even worse, do not consider it at all. This period must be used to carry out many required activities that will eventually optimize the hatchery operational efficiency in terms of staff turnover, radical sanitation and in-depth maintenance. Each routine activity regarding the facilities and equipment for life support systems must be registered, including up-to-date records of work hours, maintenance carried out, possible malfunctions, operational problems, repairs, etc. The general cleaning of the hatchery’s dry laboratory, offices, bathrooms, warehouse, feed store, and other general support areas are just part of the routine work in every industrial premise and, therefore, have not been dealt with here. An operational and maintenance tasks sheet for staff guidance and record-keeping (Table 1 ) should be prepared for daily, weekly, rearing cycle and annual sanitary stop, on which major monitoring and control actions in each sector, area, system and equipment of the hatchery should be indicated. This sheet can be adjusted to particular hatchery design and situation and backed-up on a computer database with a calendar, where any incidence action, as well as important reminders, should also be recorded. The principal operational and maintenance actions that should be carried out according to a certain time frame are further detailed in four separate sheets. They are grouped according to their recommended frequencies, in daily (Table 2), weekly (Table 3), after every production cycle (Table 4) and during the hatchery maintenance and sanitary annual stop (Table 5). It is very important to carry out the sanitary procedures after each rearing cycle, as is emphasized by FAO (2007) with a minimum dry-period of a week. The sanitary and maintenance activities during the annual stop usually require about a month. 2.2. Relevant aspects on hatchery operation and maintenance 2.2.1. Seawater source, main delivery pipes and storage tanks It is a generally incorrect practice to minimize or even forget the importance of the primary pump station and its delivery system, once it has been installed and is operational. It is of sound importance to regularly check the pumps’ efficiency. Pump-tests should be carried out at the annual stop or after long rearing cycles. These tests are carried out over a 24-h period to determine the actual yield according to the original yield/drawdown relationship. First the static water level is checked; then water is pumped during 24 h until the water level does not go below the top of the screen (maximum pumping rate). Then the pumping rate is measured, running the pumps at about 50%, 75%, and 125% of the maximum rate, in each case continuing the test for at least 30 min. These measured values should be compared with the original ones obtained when the well was drilled. In addition, the pumps’

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operational efficiency should also be checked, measuring pumping rates and corresponding electric consumption at specific pumping heads, and comparing them with the original parameters identified when the pumps were installed. An equivalent procedure

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should be carried out in the case of sub-sand abstraction systems. Another related aspect, which is often neglected in fish hatcheries, is the maintenance of wells and sub-sand abstraction

Table 1 Control of operations in a tropical hatchery: example of task and record keeping sheet.

Sector/Facility

Inspection monitoring

turnover

Water quality T°C

Water sources and storage Well drawdown level Water flow SW pumps FW pumps SW Pump 1 pressure SW Pump 1 suction pressure drop SW Pump …… FW Pump …… Aqueduct water flow Level storage tank 1 Level storage tank 2 Level storage tank 3 Water effluent Effluent water flow Chlorination pond level Stabilisation pond level

…...…... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... …...…... ….…..... ….….....

…...…... ….…..... ….…..... ….….....

Water pre-treatment Chlorination Sand filters Sand filter pressure Sand filter backwash Activated carbon filter pressure UV steriliser radiation output Cartridge filters pressure Main water conditioning temperature

…...…... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... …...…...

Power supply Main power board Volt/Ampere reading Turn-on signals Switches and fuses Earthen circuits Power sockets Emergency Generator fuel level Emergency Generator test

…...…... ….…..... ….…..... ….…..... ….…..... ….…..... ….….....

General systems Alarm system Internal Lighting general system External lighting system Telephone and data network Documents and instructions for contingencies Cold storages

….…..... ….…..... ….…..... ….…..... ….…..... ….….....

Air/ oxygen supply Blowers Blowers air pressure Blowers suction pressure drop Blowers safety valve Liquid oxygen reservoir pressure Gaseous oxygen bottles pressure

…...…... ….…..... ….…..... ….…..... ….…..... …...…... ….….....

….…... ….…...

DO

pH

notes S‰

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Table 1 (Continued ).

Broodstock Tanks water renewal rate Sand filters Sand filter pressure Sand filter backwash Activated carbon filter pressure UV sterilisers radiation output Cartridge filters pressure Photoperiod timer settings Thermo-period timer setting

….…..... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... ….…..... ….….....

Live food Tanks water levels Tanks water temperatures Pure oxygen flow meter reading Photoperiod timer settings Cartridge filters pressure UV sterilisers radiation output CO2 supply pressure Ambient Conditioning temperature

…...…... …...…... ….…..... ….…..... ….…..... ….…..... ….…..... ….….....

Larval rearing Tanks water renewal rate Photoperiod timer settings Pure oxygen flow meter reading Recycling pumps Sand filters Sand filter pressure/ backwash Bio filter Bio filter pressure

….…..... ….…..... ….…..... ….…..... ….…..... …...…... ….…..... ….….....

Nursery Tanks water renewal rate Photoperiod timer settings Recycling pumps Sand filters Sand filter pressure/ backwash Bio filter Bio filter pressure Water heat pump settings Pure oxygen flow meter reading

….…..... ….…..... ….…..... ….…..... …...…... ….…..... ….…..... ….…..... ….….....

….…... ….…...

…...…... …...…...

…...…... …...…...

systems (see Section 4.2.2). Cansdale (1981) and New and Singholka (1982) described a sub-sand abstraction system and its maintenance. The control and maintenance of these systems is essential for the protection of a seawater source and the guarantee of a stable supply, adequate flow and water quality. Huguenin and Colt (2002) showed a typical pump installation (their Fig. 7.2) that offers the possibility to clean and backwash the intake system. Their installation was adapted by Alvarez-Lajonchère et al. (2007) and has been used successfully. Finally, even the maintenance of the main delivery and distribution pipe network system and of sedimentation and storage tanks is often underestimated and carried out without the required frequency (see Section 4.2.2). Huguenin and Colt (2002) analyzed several biofouling control methods used in seawater, especially for pipe cleaning and maintenance, also cited and applied by Alvarez-Lajonchère et al. (2007). These practices are unfortunately, seldom carried out in many hatcheries, especially in tropical regions, as has been personally confirmed by the authors. It is essential for hatchery efficiency and biosecurity to carry out these conservation activities at least once a year, with in-depth

controls at the end of each rearing cycle. A wise maintenance scheme should foresee more than one method at hand, to achieve maximum efficiency in a critical sector of the farm. Examples are: (a) a double main delivery pipe system; (b) a water velocity of 3–4 m/s to minimize bio fouling; (c) mechanical scrapers pushed under pressure (“pigs”), flexible and contractible, of greater diameter than the inside diameter of the pipe to be cleaned; d) disinfection with 500 ppm active chlorine solution (Huguenin and Colt, 2002). Alvarez-Lajonchère et al. (2007) included 12 inspection and cleaning points (Fig. 1) strategically located at each turn, and/or every 40 m along the 600 m length of the main delivery pipeline, to allow a strong cleaning and disinfection during the hatchery maintenance and sanitary annual stop. The storage tanks must be cleaned and disinfect regularly, at least by-monthly, cleaning and disinfecting one weekly or every fortnight. Tap water domestic storage tanks are usually recommended to be clean at least once every three or four months, however, there are tropical hatcheries which have never cleaned their storage tanks.

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Fig. 1. Hatchery intake pipe system: inspection and maintenance pits: (a) upper view; (b) lateral view. All dimensions are in m, except where otherwise indicated. Designed ˜ and M.A. Camacho Hernández. by the senior author, construction blueprints by M.A. Reina Canez

2.2.2. Disinfection practices in hatchery maintenance activities Sanitizing and targeted disinfecting are part of a broad approach to secure high hygienic standards for bio-technological processes in a hatchery. There are several disinfection techniques that could be applied during operation and maintenance, mostly using chemicals as chlorine (200 or 500 ppm), formalin (200 ppm), ethanol (50–70%), HCl (10%), hydrogen peroxide (20 ppm), chloramine T (1%), iodine (200–250 ppm), acriflavine (3–5 ppm), etc. The most applied is still the strong oxidizing property of active chlorine, from commercially available liquid bleach (sodium hypochlorite or NaOCl) or bleaching powder (calcium hypochlorite or Ca(OCl)2 ) at concentrations of 200–500 ppm (Kungvankij et al., 1985; Moretti et al., 1999, 2005; Wedemeyer, 2000; Huguenin and Colt, 2002; New, 2002; Alvarez-Lajonchère et al., 2007; FAO, 2007). The application of chlorine should be with carried out with caution given its toxicity to man mostly skin, eyes, and the respiratory tract) and to reared organisms, especially in their earlier stages. Chlorine is highly corrosive and could rise to several toxic and stable organic compounds, particularly in seawater and in water with high dissolved organic matter. These compounds can only be removed with activated carbon filters. Moretti et al. (1999) and Wedemeyer (2000) gave details of the analytical technique for determining the active chlorine content in commercial grade bleach, the residual active chlorine in water and the preparation of de-chlorination solution based on sodium thiosulfate (Na2 S2 O3 ) to neutralize residual chlorine (8 ppm/ppm of chlorine to be neutralized). In addition to sodium thiosulfate, any commercial de-chlorinator product, which can also neutralize chloramines, can be used. Equipment

disinfection is usually carried out with 200 ppm NaOCl for 1–3 h. Sanitation requires a 500 ppm hypochlorite solution either for three hours, overnight (Moretti et al., 1999, 2005; Liao et al., 2001; Huguenin and Colt, 2002; Alvarez-Lajonchère et al., 2007) or 24 h in case of seawater with high pH (Huguenin and Colt, 2002). Chlorine is applied usually in batches, sometimes sprayed onto the tank walls and bottoms, or to any device, as well as in a bath solution in separate disinfection containers, which should be present in almost every room (Alvarez-Lajonchère et al., 2007). Before using any disinfected equipment and device in the hatchery, a de-chlorination procedure is recommended, starting with a careful rinse using tap water to remove the remaining chlorine, then rinsing with treated seawater (for a through treatment when in presence of living organisms), and drying. If chlorine is used to disinfect water, determining residual chlorine and neutralizing with sodium thiosulfate before the introduction of the organisms is mandatory. Wedemeyer (2000) reported that a chlorine concentration of 0.1–0.3 ppm, as found in drinking water, will kill most commercially important aquatic species within minutes at any pH, and is therefore recommended that chlorine should not exceed 3–5 ␮g/L for chronic exposures. A maximum criterion for chlorine residual is 1 ␮g/L and existing test kits, are not reliable below 20–100 ␮g/L free chlorine (Huguenin and Colt, 2002). Filtration with activated carbon is very effective for de-chlorinating small volumes of water, assuring inactivation of both chlorine and chloramines, although the neutralization with sodium thiosulfate before filtration is recommended.

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Table 2 Scheduled control, cleaning and maintenance of a tropical marine hatchery: daily activities. Sector

Activity

Water sources and storage tanks

Check drawdown well level, pumps performance, water flow, working pressure and power consumption; check sand traps, remove excess sand; check and drain any accumulated water on pump sump; remove sediment in the pre-pumping chamber; check incoming flow of aqueduct supply, water levels and flows in the storage seawater and freshwater head tanks, performance of freshwater chlorination and de-chlorination systems; check water flow; monitor water environmental parameters; control for debris presence on storage tanks; check presence of fine particles in well pumped water Check every 4 h general performance of sand and activated carbon filters; check pressure gauge reading in sand filters, run a manual 10–20 min backwash at least twice daily (early in the morning and at night) and whenever required, according to the actual pressure; check pressure and water flow of main multi-cartridge filter, change the cartridge filter set, wash and disinfect the dirty one with 200-ppm NaOCl for an hour, rinse with tap water until no chlorine odor is detected, and sun dry; repeat for each sector’s cartridge filters early in the morning and every time the flow rate drops below a pre-set safe level; control UV-lamp radiation intensity output and working time; clean the quarts tube, the external walls of the irradiating chamber and purge its by-pass valve Check blower performances, air flow, working pressure and power consumption; check air filters and working pressure; monitor temperature of air output; check the pressure security valves performance Wash floor and walls with brushes and strong tap water jets at the end of each sector’s daily working activities Control tank water level and flows; monitor water quality parameters in tanks and recycling systems (RAS); check performance of RAS; inspect, clean, change and disinfect tank outlet screens; clean water and air hoses, siphon tank bottom and walls; clean the drainage channels; inspect, clean and disinfect egg collector systems, containers and handling devices; check lighting and photoperiod system performance; clean and disinfect hormone treatment tanks and fish handling devices after use; clean and disinfect food preparation equipment Control of water levels and water quality parameters in every tank; inspect air conditioners, check power consumption, air temperature, air filter; inspect and clean water traps on air distribution system, change air cartridge filter and clean vessels; clean water and air hoses; check pressure and water flow of cartridge filter, change the cartridge filter set, wash and disinfect the dirty one with 200-ppm NaOCl over an hour, rinse with tap water until no chlorine odor is detected, and sun dry; where possible back flush, autoclave and strongly disinfect cartridges with hydrogen peroxide solution; inspect both water flow-through and ambient UV-lamps for radiation intensity output and working time; clean the quartz tubes, the external walls of the irradiating chamber and purge its by-pass valve to eliminate stagnant water; clean glass ware with detergent and hot water, rinse with HCl and autoclave; check performance of lighting system, clean and disinfected lighted shelves with alcohol; inspect CO2 supply system; at the end of the day’s work, empty seawater pipes, wash floor and walls with brushes and strong tap water jets; inspect and clean autoclave, submersible heaters and water distiller, monitor power consumption

Water pre-treatment

Blowers

Floor, walls and metal parts Broodstock

Live food

Table 2 (Continued) Sector

Activity

Larval rearing and nursery

Control tank water level and flows; monitor water quality parameters in every tank and RAS; inspect, clean, change and disinfect tank outlet mesh filter; clean water and air hoses, siphon tank bottom and walls; clean the drainage channels; change line cartridge filters and clean and disinfect the dirty ones; inspect air supply system, avoiding stress to the larvae; inspect, adjust and clean surface “skimmers”, monitoring dead larvae, rotifers, etc.; check and clean lighting system; clean and disinfect larvae and juvenile sampling and handling tools; wash floor and walls with brushes and strong tap water jets; check, clean and disinfect storage tanks and tubes for live food delivery to larval tanks; check performance of RAS; clean and disinfect size graders and fish vacuum pressure pumps after their use; check feeders performance, remove food debris and clean them

2.2.3. Cartridge filter changes and cleaning procedures In many hatcheries, it is a common practice to leave cartridge filters unchanged for days or weeks, until water flow is extremely compromise. Sometimes they are just washed with tap water and installed back again or left to dry and another set installed. This practice does not take into consideration two main circumstances that affect the filtered water quality: (a) these cartridges are good substrates for bacteria and viruses, which build up considerably and, in poor cleaning conditions, can spread freely into hatchery water network; (b) inadequately cleaned cartridge show severe particle retention to a point where they become useless. It is important to change the filters with a clean and disinfected set at least once or even several times per day, according to the quality of the water that is filtered, and to clean and disinfect the filter carcass, and open the by-pass for a few seconds to eliminate stagnant water. In addition, it is very important to use new sets of cartridge at least each new rearing cycle. 2.2.4. Cleaning and disinfection of live food and larval rearing devices Airline hoses, diffusers, and water supply hoses on live culture and larval rearing tanks, as well as the mesh screens in larval tank outlets, are seldom cleaned and disinfected as they should be. These devices, as is the case with cartridge filters, are good substrates for pathogen organisms and can cause important hazards to live food plankton and fish larvae. The cleaning of these devices is one of the daily tasks that are to be carried out seven days a week during rearing cycles (see Table 2). The tank outlet mesh screen must be replaced at least twice daily, in the early morning and evening, and whenever it shows dangerous clogging. Additionally, replacing air and water hoses with clean and disinfected sets (dipping the removed ones in 10% HCl for a while) must be performed with each new rearing cycle. Inside these sectors, the UV sterilizer is targeted with two daily crucial cleaning procedures: The scrubbing of the quartz tube to allow full contact between UV rays and water, and the brief opening of the by-pass to eliminate the stagnant water, where dirt and bacteria could build up. 2.2.5. Cleaning and disinfection of the entire water and air distribution network At least once a year, but also after a disease outbreak, the complete water and air distribution network should undergo a full mechanical cleaning with scraping devices (such as the mentioned polyurethane or plastic “pigs” and the “snakes”). In addition, an indepth sanitation will follow by filling the pipes with a disinfection solution (500 ppm active chlorine or 200 ppm formalin), that will

L. Alvarez-Lajonchère, G. Cittolin / Aquacultural Engineering 57 (2013) 89–100 Table 3 Scheduled control, cleaning and maintenance of a tropical marine hatchery: weekly activities.

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Table 4 Scheduled control, cleaning and maintenance of a tropical marine hatchery: end of production cycle and sanitary annual stop.

Sector

Activity

Sector

Activity

Water sources and storage tanks

If the seawater is obtained through a submerged intake system, check the vacuum gauge on the pump suction and keep intake screen and piping free of fouling; seawater pump turnover; if there are dual main supply pipelines, shift the water flow to the pipe that has been let drying for a week, then divert during the first 15 min the pumped water to the effluent system to avoid that the dried fouling and debris could go into the hatchery pipework; clean at least one storage tank In-depth clean one sand filter with neutral detergent, hot water, soak one hour with 500-ppm NaOCl, then wash with tap water; clean UV-lamp quartz tubes and radiation meter Check air filters, clean and disinfect; blowers turnover Check EG performance (including fuel and lubrication circuits, cooling, control panel readings and indicators); check EG diesel tank level; run EG functional test (starting circuit and battery) during 20 min under normal load; check heat pumps performance; check water temperature in the hot water circuit; clean pump filter; heat-pumps turnover Monitor effluent water quality parameters as requested by regulatory agencies (different time intervals may be required); clean the drainage system channels; check performance of the continuous self-cleaning micro-screen filters, clean from debris, change and disinfect screen plates as needed; control of clarifiers, stabilization ponds, and sump levels (water and sludge) Check performance of the pure oxygen generator or the pure oxygen supply system and the dissolved oxygen level control system, following recommendations from Colt (2000); check for leaks on the distribution network and the performance of the flowmeters; substitute with new flow meter whenever required; check actual oxygen availability and switch to a new oxygen tank or set of bottles before the old one is finished Floor, walls and metal parts should be cleaned and disinfected with 500-ppm NaOCl, leaving them soaking during one hour and then washed with tap water jets and brushes Recycling pump turnover; monitor levels of metabolic wastes and bacteria on the recycling system and remove if required; general cleaning of RAS components (sumps, pumps, mechanical and biological filters, foam fractionators, thermal conditioning system, UV sterilizer); replace water inlet and air hoses with clean and disinfected sets; renovate NaOCl solution in disinfection tubs General cleaning and disinfection, especially seawater supply pipeline; replace water inlet, water delivery and air hoses with clean and disinfected sets, clean the used ones and keep them in 10% HCl; replace flexible tubing with a clean and disinfected set; clean drainage channel system; inspect and clean refrigerator, monitor temperature and power consumption; inspect electric control panel and test safety switches; renovate chemicals in disinfecting tubs Check water and air supply systems performance; replace water and air tubing with a clean set, clean the used set and keep them in 10% HCl; empty, clean and disinfect substrate in degassing columns; strong cleaning and disinfection of size graders and feeders; inspect electric control panel and test safety switches; renovate chemicals in disinfecting tubs

Water sources

Clean and disinfect main delivery pipes with 500-ppm active chlorine solution (see Section 2.2.2). As an alternative use 200-ppm formaldehyde or 10% HCl. Leave pipes filled with the disinfectant solution for 48 h, then flush with clean water and finally let to dry; backwash intake pipes with 500-ppm active chlorine or 10% HCl solutions into the well or sub-sand system; run a test pump of the well and check pump operational efficiency Substitute the cartridge filter sets for new sets and strong clean filter vessels; dismantle sand and activated carbon filters and change filter media; dismantle UV-lamps and in-depth clean radiation chamber and quartz tubes, substitute expired UV-lamp bulbs according to their working hours Disinfect air pipelines with 200-ppm formalin (see Water sources above) Make-up or change fluids (lubricant, cooling); change air, lubricant and fuel filters; inspect battery electrolyte and clean connections; check generator diesel tank level (in case of sediment drain the fuel and clean the tank) Compare the trend of main water quality parameters with the established standards and apply the required solutions; remove and dispose the sludge; clean at least one unit of the effluent system Strong cleaning and disinfection of floor and walls, leaving them soaking during 48 h with 500-ppm NaOCl and washing with tap water jets afterwards; metal parts must be subject to a general maintenance, including a protective anticorrosive paint Check the performance of the RAS, dismantle and clean those components much in need; drain and clean the pump sumps and the mechanical filters; as per the bio-filters, consider the need of its re-activation for a new production cycle before cleaning it Strong cleaning and disinfection of the complete sector, including the water and air distribution pipe lines; change air filters, and clean and disinfect the used ones; inspect the pure oxygen circuit; dismantle UV-lamps and in-depth clean radiation chamber and quartz tubes, substitute expired UV-lamp bulbs according to their working hours Complete and strong cleaning and disinfection of the whole sector; check pure oxygen circuit performance; cleaning larval tanks and degassing packed columns; check the performance of the RAS, dismantle and clean those components much in need; drain and clean the pump sumps and the mechanical filters; as per the bio-filters, consider the need of its re-activation for a new production cycle before cleaning it

Water pre-treatment

Blowers Emergency generator (EG) and main water conditioning system

Effluent treatment system

Pure oxygen system

Floor, walls and metal parts

Broodstock

Live food

Water pre-treatment

Blowers Emergency generator

Effluent treatment system

Floor, walls and metal parts

Broodstock

Live food

Larval rearing and nursery

remain inside for 48 h. This is followed by washing with treated seawater or hot freshwater.

they have the tendency to fill up with sediments, debris, uneaten food and feces, which reduce the flow and represent a source of contamination. These characteristics demand frequent monitoring as well as conscientious cleaning and disinfection actions. Personnel with low level of “hatchery culture” and experience usually do not even look at the draining channels, which often are not easily accessible because they are usually covered with concrete slabs, wooden boards, reinforced fiberglass slabs, etc. It is thus wise to frequent inspect, clean and disinfect the discharge channel network and sedimentation facilities network (clarifiers, sedimentation basins, stabilizing ponds, etc.), as well as any treatment equipment such as rotatory drum filters, and the sludge removal and disposal system of the hatchery to prevent possible disease outbreaks and serious environmental contamination.

2.2.6. Effluent treatment system Sludge and effluents are discharged by gravity via a drainage/gutter system. Since these drains are not self-cleaning,

2.2.7. Quarantine sector (for juveniles and broodstock) The quarantine sector is completely isolated from the rest of the hatchery. Particular care should be taken with its waste disposal

Larval rearing and nursery

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Table 5 Scheduled control, cleaning and maintenance of a tropical marine hatchery: indepth maintenance and sanitary annual stop. Sector

Activity

Water sources and storage tanks

General maintenance and strong cleaning and disinfection: seawater intake facility (well, sub-sand system, etc., see Section 4.2.1), including shock chlorination to control bacteria; dismantle, repair and clean all pumps and motors; pipelines strong cleaning first with diluted hydrochloric acid (commercial 33% HCl) flushed into the pipes to eliminate calcareous residues. Afterwards, mechanical cleaning methods should be applied employing polyurethane or plastic “pigs” to remove fouling organisms and debris, then disinfection using 500-ppm NaOCl; brush-clean all storage tanks with neutral detergent and tap water, then spray walls and bottoms with 500-ppm NaOCl, leaving them soaked with it for 48 h, at the end wash with tap water Dismantle and strong cleaning and disinfection of all equipment and change the line cartridge filter sets for new sets; change sand and activated carbon filter media; change UV-lamp bulbs Dismantle air blowers for full mechanical maintenance; complete disinfection of air distribution system with 10% formalin solution or 500-ppm potassium permanganate in 100% formalin (37–39% aqueous solution) during 48 h Make an in-depth mechanical/electrical maintenance; run a full test through the Automatic Transfer Switch. Dismantle and in-depth clean the pump filter, the heat exchange coil, fan and cover Strong cleaning and disinfection of all components; complete maintenance of the micro-screen filter; remove and dispose the sludge from all effluent network General and complete maintenance and disinfection, including valves and flow meters Strong cleaning and disinfection of floor and walls; metal parts must be subject to a general maintenance, including a protective anticorrosive paint Strong cleaning and disinfection of all components, especially the RAS systems, during which breeders must be kept under flow-through A complete dismantling, strong cleaning and disinfection of all sector components, including the water, air and oxygen distribution lines, tanks, RAS, etc.; fluorescent light tubes should be substituted

Water pre-treatment

Blowers

Emergency generator and main water conditioning Effluent treatment system

Pure oxygen system Floor, walls and metal parts Broodstock sector

Live food, larval rearing and nursery sectors

and effluent treatment. Staff working in this area should not be permitted to enter other hatchery sectors and should follow strict hygienic and sanitary protocols at all times. This sector should have the following characteristics: • There should be means provided for disinfection of feet and hands upon entering and exiting the unit. • The quarantine facility should have an independent supply of water and air with separate treatment and disinfection systems and a system for the treatment of effluents to prevent the potential escape of pathogens into the environment. • The seawater supply must enter a storage tank where it will be treated with hypochlorite solution, subsequently inactivated with sodium thiosulfate (7 ppm for every 1 ppm of residual chlorine) and strong aeration for at least 10 min. Finally, possible chorine residues should be detected with the appropriate test kit. • The NaOCl treated water could be treated by means of activated carbon filters to eliminate chlorine by-products. • Wastewater must be collected into another reservoir for further chlorination (10–50 ppm active chlorine concentration for 0.5–1 h) and de-chlorination before being released. • All dead, moribund, or infected fish must be incinerated and buried far from the hatchery. If an infection disease is found, all

• • • •

the fish from the same group should be sacrificed, incinerated and buried. Used plastic containers and hoses must be washed and disinfected with 200-ppm hypochlorite solution before and after use. All tools used in the quarantine sector must be clearly marked, be kept in the same area and be disinfected at the end of the day. Prophylactic treatment for juveniles and broodstock must be established and applied. Behavior of quarantined fish and research of possible pathogens should be carried out during and at the end of the quarantine period.

3. Monitoring and biosecurity measures Monitoring includes all the control actions, checking visual and sounds changes in the system, which shall be performed by trained personnel to assure all system’s proper functioning, in accordance with the facility design and the protocols applied in every sector. The sensitiveness of the biological cycles reproduced in a hatchery calls for a mandatory safety approach to hygiene by establishing strict standardization of operations and prophylactic measures. 3.1. The hazard analysis critical control point The hazard analysis critical control point (HCCP) approach is very useful to prepare and implement biosecurity protocols (FAO, 2007). It is a preventive risk management system based on hazard analyses and it has been widely applied on many human activity fields. It should establish, for every critical control point, the actual value of main parameter to be checked and actions to be taken so that it remains within acceptable limits. Biosecurity protocols are important for hatchery safety regarding disease-causing organisms (FAO, 2007). The World Organization for Animal Health standards are good guides for prevention and disease control (OIE, 2003). Prevention is better than medication, especially for pilot and commercial scale facilities. Biosecurity is based on three main components: Prevention, monitoring, and control actions to be taken in each case (treatments, restrictions and elimination), referring to horizontal and vertical introduction and transfer of pathogens. To implement biosecurity protocols, the main steps are: (a) use of high quality water, free of disease organisms; (b) use of diseasefree fish and control of incoming fish before their entrance to the hatchery; (c) establishment of quarantine areas with their SOP; (d) maintenance of good environmental parameters (optimum is best), to avoid stress (acute and chronic stress factors) to organisms being reared; (e) strict treatment procedures of incoming seawater and fresh water; (f) use of uninfected feedstuff; (g) strict hygiene procedures (cleaning, disinfection, and sterilization, as required); (h) personal hygiene procedures; (i) use of immune enhancers and probiotics to increase disease resistance in the organism being reared. 3.2. General hygiene rules • Living organisms entering the hatchery should be from a certified source; fish should also be quarantined for four weeks to identify a cure for any disease they might be carrying. • In case of potential viral infections, polymerase chain reaction (PCR) diagnostic techniques are recommended. • In general, visitors should not be allowed to enter sensible parts of hatcheries. If so, they should go through footbath, wear disposable shoe or boot covers, and wash hands with a disinfecting soap or solution. • All vehicles must pass through a wheel bath. The wheel bath must be regularly filled with 200 ppm NaOCl or 200 ppm formaldehyde

L. Alvarez-Lajonchère, G. Cittolin / Aquacultural Engineering 57 (2013) 89–100

•

•

•

• • •

•

•

•

•

• • • •

• • •

• • •

solution, which should be changed to maintain the desired level of disinfecting activity. Transport vehicles and boats should be cleaned with pressurized tap water, sprayed with 500–1500 ppm NaOCl, and let to soak for 48 h in the parking lot for their disinfection, rinsed with pressurized tap water and let to dry for a week. Steam at ≥100 ◦ C for 5 min can also be applied. Conscientious attention should be given to the cleaning and disinfection of all equipment and devices used in fish capture, handling, transportation, and feed preparation. All equipment, instruments, devices, etc., that could be restricted to certain sectors or areas should be labeled and their use prohibited in another hatchery sector or area. Cleaning and disinfection SOPs should be implemented and strictly followed in each sector. Only authorized personnel from one sector should enter other sectors. Staff personal hygiene: (a) hands must be washed before starting to work; this should be done with disinfection solutions (i.e. 70% alcohol) before entering most sensitive sectors, like live food culture and larval rearing; (b) shoes and boots must be disinfected (usually with 500 ppm NaOCl or 200 ppm formalin solutions) in large flat tanks filled with the disinfecting solutions before entering and when leaving each sector, area, or room; (c) disinfection solutions should be changed once a week; (d) when handling fish, cotton or surgical gloves should be always used; (e) smoking must not be allowed. Entry of potential disease vectors should be minimized through the use of physical barriers such as fencing. Wire net and covering mesh can be used to exclude birds and insects as well as to keep outside tanks and drainage system screened and covered. Each tank should have its own tool set (hand net, instruments, beaker, pipette, etc.) required to check broodstock, live food, larvae, or juveniles. These devices should be used exclusively for the pertinent tank. Prophylactic treatments should be applied to all fish eggs before their incubation. A formalin (100 ppm) bath for 1 min, followed by iodophor (0.1 ppm iodine) for 1 min has been recommended for shrimp eggs (OIE, 2003), acriflavine (5 ppm) for 1 min for fish eggs (Tiensongrusmee et al., 1989; IbarraCastro et al., 2012), while ozone treatment has been recommended in some European and Australian hatcheries (see Schipp et al., 2007). Microalgae strains should be systematically subjected to purifying procedures (agar plate cultures, progressive dilution sub-culture, and replication). No air diffusers should be used for microalgae culture. Air hoses should have an open end, secured to a weight. Rotifer and copepod strains should be thoroughly disinfected systematically. Microalgae should be filtered with a fine mesh before their introduction in larval rearing tanks. Rotifers, copepods and Artemia nauplii and meta-nauplii must be treated (fresh water, ozone, NaOCl, etc.) to reduce microorganism loads before supplied to the larvae. Artemia cysts must be at least disinfected if not decapsulated. There should be an outdoor area for tank and other equipment strong cleaning and disinfection purposes. Whole fish, squids and shrimps to be processed as moist feed, should be bought fresh, instantly frozen and stored at −20 to −30 ◦ C for at least two or three weeks before use. Pelleted feed should be stored at 20 ◦ C or at least in an air conditioned room. Fish should be reared in high quality water and optimum environmental conditions to avoid stress. Fish nutrition, especially larvae, should be kept at optimum levels.

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3.3. Prophylactic and disinfection actions to avoid contaminations Live food production starts with pure strain microalgae culture in borosilicate glassware (test tubes, Erlenmeyer flasks, bottles, etc.). Any actions that will ensure the axenic condition are imperative (cleaning and disinfection of all glassware, culture handling with flaming procedures in laboratory or laminar flow chambers, sterilized water, ambient UV sterilizer, etc.). This should be continued with cleaning and hygiene measures all through each of the production lines (Moretti et al., 2005). Pathogen microorganisms are usually present everywhere in the rearing environment. Juvenile stages show higher resistance to the stress associated to culture procedures (Tucker, 1998). Once the stress level surpasses certain limits, fish become more susceptible to disease, especially to infectious diseases (Le Breton, 2001). To avoid going beyond such limits, it must be ensured that environmental parameters are within the best range for each developmental phase of each species, that handling procedures are suitable and that nutritional requirements are adequately fulfilled. Other stress factors as mechanical vibrations, noises, etc., should be prevented, and cleaning and hygiene routines fully implemented, avoiding the usage of antibiotics as part of the prophylactic treatments as much as possible (Moretti et al., 1999; Le Breton, 2001; Alvarez-Lajonchère et al., 2007). Large rooms with many larval tanks are prone to increase the risk of spreading an infection from tank to tank, which could be minimized with smaller rearing rooms for a limited number of tanks. Recently, the use of probiotic microorganisms has been useful to decrease pathogen bacteria levels on live foods and larval tanks (FAO, 2007). In addition, there are evidences that fish species rotation can reduce the bacteria infectious risks at larval stage (Sweetman, 1992). 3.4. General controls 3.4.1. Water quality monitoring Monitoring water quality parameters (temperature, salinity, dissolved oxygen, pH and NH3 –N) is essential on all marine hatchery sectors. In some, this should be carried out 2–6 times per day manually or continuously if automated monitoring devices are used. This can avoid stress and assure the best rearing performance (in terms of growth and survival), and is important for hatchery efficiency. The effectiveness of UV-lamps should be regularly checked by running microbiological analyses of inlet and outlet water. It is mandatory to monitor also the main chemical parameters of the effluents, particularly those required by regulatory agencies, at least at the end of each rearing cycle. 3.5. Alarm systems Marine fish hatcheries require shift work patterns, i.e. they need the constant presence of workers 24 h a day, given that any mechanical, chemical or electric failure can damage all the season’s results in a very short period. Many hatcheries opt for two “daylight” shifts linked to the feeding habits of reared organisms, and a third shift that takes place at evening/night, often called night watch. The alarm system should be completely reliable and should be backed-up by batteries connected to continuous recharging systems. A recommended layout could be audible and visual alarms at each sector’s electric panel plus a general control panel, where all the alarm signals are sent, located in the vigilance office, with people working 24 h 7 days a week. Most common alarm systems protect motors from failure, dangerous water level and pressure levels, and protect the rearing environment from dangerous water parameter values. They may be grouped as follows:

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(a) Main intake, continuous supply to filters and recycling pumps: audible and visible alarms on safety switch and float switch. (b) Blowers: audible and visible alarm on safety switch, temperature and pressure switches. (c) UV sterilizers: acoustic and visual alarm on safety switch and radiation intensity probe. (d) Sedimentation, pre-treatment and pressure-head tanks, storage tanks, recycling system (RAS) pump sumps: acoustic and visual alarm on water level switch. (e) Fish rearing tanks, mass culture/enrichment of rotifers and Artemia: acoustic and visual alarm on dissolved oxygen and temperature probes (with automatic supply of pure oxygen through solenoid valves, if required). (f) Building: acoustic and visual fire alarm.

Table 6 Night watchman tasks: indicative general work plan. Reading of monitoring instruments, water levels and water flow must be as prescribed. Motors must run as prescribed (turnover if needed). Air and gaseous oxygen must flow as prescribed (adjust if needed). Call the person in charge in case of major water/energy/oxygen blackout. Sector/facility

Check if settings/running as prescribed

Water intake

Actual water flow; water levels; aqueduct pressure head; intake pipes for leaking Actual water flow; ponds water levels Pumps operation (turnover if needed); power board failure; pipework leaks, damage, disconnected hoses, water in the sump Actual water level and flows Filter operation; filters pressure/level reading (backwash if needed); sterilizers output reading; water leaking Main power board: volt/ampere reading, safety switches. GE correct running and volt/ampere output, fuel (run test start). In case, call the person in charge Blower operation; pressure reading (turnover if needed); if the emergency blower is operational; air leaking. Pure oxygen reservoir pressure, leaks. Gaseous oxygen op/manometers: reading (adjust if needed). Diffusers, bubble size Tank water levels and water flows; aeration in each tank; illumination and photoperiod; thermo-period and heating/cooling system; freezers and cool room always working and note temperature reading; air/water leaking. Handling tools disinfected and ready to use. Power supply: safety switches Tank/container/vessel water levels; cartridge filters pressure reading; ambient temperature (adjust if needed); illumination and photoperiod; aeration/oxygenation; heating equipment; UV sterilizer reading; CO2 supply; air/water/oxygen leaking. Power supply: safety switches Tank water levels and water flows; tank aeration/oxygenation supplies; illumination and photoperiod; tank drainage filter clogging (change and clean if necessary); skimmer actual operation (change and clean if necessary); tank packed column operation; air/water/oxygen leaking. Handling tools disinfected and ready to use. Power supply: safety switches Tank water levels and water flows; aeration/oxygenation; illumination and photoperiod; tank drainage filter clogging (change and clean if necessary); skimmer actual operation (change and clean if necessary); air/water/oxygen leaking. Handling tools disinfected and ready to use. Power supply: safety switches Water levels and water flows. Actual operation of each equipment (pumps, foam fractionator, drum filter, mechanical and biological filters, water thermal conditioning, water sterilizer, degassing columns)

Water effluent Pumping station

Storage tanks Water treatment

Power supply

3.6. Night watchman duties and monitoring The night watchman shift is based on an overall control scheme carried out during frequent checking itineraries of the whole facility by trained and conscientious personnel. During daytime, hatchery processes are followed by the workers of each sector, while during the night, weekends and holidays, fewer dedicated personnel, in charge of specific duties, do the work. The night watchman controls and adjustments are listed in Table 6 and examples of special bio-technological duties carried out by them are shown in Table 7. Before leaving, the night watchman must prepare a report of the work done during the night, hand it in, and discussed it with the designated person, if required. Any pending assignment or problem should be made known, too.

Air/oxygen supply

Broodstock

Live food

Larval rearing

4. Preventive maintenance program Several key facilities and equipment should be part of a Preventive Maintenance Program (PMP). Huguenin and Colt (2002) have stated that the same philosophy for the installed backup equipment (in stand-by position), should be applied to the PMP. There are cases when serious consequences may arise if equipment malfunction cannot be solved quickly. Equipment that did not receive timely preventive maintenance will show malfunctions eventually. The implementation of a serious PMP implies a full commitment of dedicated staff, with the necessary discipline and without delays in programmed actions. The PMP is a key backup of the hatchery efficiency. However, it is not uncommon to see seawater hatcheries boing operated without any PMP or under unsound allocation of resources, which mean that a series of harmless malfunctions can lead to a critical stop of operations. This is a good example of technical ignorance and absence of essential aquaculture knowledge. In those cases, there are very few options left and the costs and consequences of that lack of dedicated management are of great magnitude. Another incorrect strategy is to delay these preventive maintenances in times of crisis and limited budgets, not considering that disastrous failures are at any time. The hatchery MM is the person in charge for preparing the purchase lists of spare parts and tools for the maintenance tasks and simple repairs. The MM shall be responsible for all the maintenance to be carried out by the hatchery staff or specialized technician. He should also be responsible for the specialized repair any equipment by external services contractors. When any equipment failure occurs, it is essential to determine the cause, given that if it was due to external circumstances, it is quite possible that the problem could occur again if the unfavorable conditions are not solved.

Nursery

RAS

4.1. Equipment preventive maintenance program The equipment subject to continuous work needs attentive care, costly spare parts and even replacement of entire apparatus if is prone to repeated failure at the end of its useful life. This PMP, spare part substitution, etc., should take place while devices are in normal operation and present no problems, so that a high level of flexibility is reached and serious difficulties are avoided. Important hatchery equipment, such as water pumps, emergency generators (EG), sand and carbon filters, multiple cartridge filters, UV-sterilizers, blowers, water distiller, scales, microscopes, air conditioners, heat pumps, etc., require PMP run by specialized technicians. Usually, these preventive maintenances should be carried out according to the manufacturer recommendations, or after a certain amount of work hours. This is one of the reasons for recording device operating hours, maintenance that has been carried out, procedures that have been implemented and

L. Alvarez-Lajonchère, G. Cittolin / Aquacultural Engineering 57 (2013) 89–100 Table 7 Special duties to be carried out by the night watchman: hourly work plan. Time

Task

20:00

Clean and prepare the rotifers enrichment tanks as prescribed Prepare and distribute Culture Selco® a to the rotifers mass cultures and measure dissolved oxygen (DO) and temperature (T) in each tank Prepare and distribute Protein Selco® a to the rotifers enrichment tanks and measure DO and T in each tank Purge rotifers mass cultures and measure DO and T in each tank Clean emptied tanks, instruments and devices, dipping them in the disinfecting tub; fill the new rotifers culture tanks with seawater and fresh water as prescribed; harvest rotifers from the culture tanks where prescribed and pour them into the prepared enrichment tanks Harvest Artemia nauplii from the incubation tanks and pour them into to the prepared enrichment tanks; control DO and T in each rotifer and Artemia tank and, if needed, adjust the gaseous oxygen supply; harvest enriched rotifers and Artemia meta-nauplii and pour into the low temperature stocking tanks In-depth cleaning of the emptied incubation/culture/enrichment tanks; inoculate Artemia cysts in the incubation tanks; disconnect the water distiller when the containers are completely full; clean and disinfect all vessels, instruments and devices, hang them to dry. Change water cartridges or filter bags if needed Clean each larval rearing tank bottom and walls with proper siphon; clean their upper off-water inner wall with a wet sponge; clean the water and air tubing, air diffusers, surface cleaners. Fill the automatic belt feeder of larval with proper artificial feed

21:00–02:00

02:00–03:00 3:00–03:30 03:30–4:00

4:00

5:00

6:00

NB: timing could vary according to different cyst and enrichment type. a Or any other similar product.

spare parts that have been changed, along with any performance deficiencies. 4.2. Facility preventive maintenance program 4.2.1. Wells and sub-sand abstraction systems The maintenance operations of wells and sub-sand abstraction systems are similar and simple but need to be systematic. A combination of good preventive maintenance and good management practice, e.g. limiting water pumping rates with longer pumping intervals, can minimize the effect of mineral incrustation of screens and perforated liners. Experiences on water wells have shown that preventative maintenance should be applied before a bio-fouled well has lost about 20% of its original specific capacity. Sometimes the water flow is reduced by fine sediment accumulation within the gravel pack. This will need backflushing for several minutes each hour, repeating part of the well development procedures, preferably increasing the pumping rate until the pumped water is free of fine sediment and the flow has been increasing until there is no friction head loss. During this maintenance operation, the pumped water should be diverted to the hatchery effluent system, due to its sediment content. A very effective method is the one used also for well development, jetting with high-pressure water through the well screen to loosen the fine sediments, moving the water outlet system up and down and rotating it inside the screen portion, while at the same time pumping the well water. 4.2.2. Seawater piping system It is indispensable that the fouling in the seawater distribution circuits be included in the PMP. Biofouling organisms and potential pathological microorganisms constitute one of the most important factors that could affect system performance, and their control

99

is one of the most difficult tasks for operation and maintenance, in close relationship with the specificity of the site. Biofouling increases inner surface roughness, reduces diameter and flow, by which water velocity and friction (pressure) increase. Control actions must be planned from the design phase be included within the PMP procedures and carried out systematically. As the extent of fouling increases, its consequences are aggravated at such level that control methods become more costly and complex and sometimes the whole pipe system must be replaced. It is recommended that at least two different maintenance options for piping systems are available for each system section. There are some preventive approaches and treatments, which could lower the biofouling problems. Site selection is the first one, e.g. choosing an area were biofouling organisms are not abundant. Among others, the followings: (a) water velocity of 3–4 m/s to prevent biofouling; (b) filtration, particularly in those hatchery sectors where requirement of the cleanest water is required (up to 1 ␮m absolute retention) gives the advantage of supplying almost fouling-free water to block the fouling before entering the circuit; (c) UV-sterilization is also effective in removing undesired organisms from the water network. The use of ozone disinfection of the incoming water is part of the general treatments applied in some hatcheries. It is very effective, not only to reducing pathogen organisms, but also for potential biofouling organisms. This treatment has to be applied with extreme caution, due to ozone toxicity, as well as to toxic by-products in seawater, as bromamine and others (Colt and Cryer, 2000), which must be removed before using the ozonated water, usually with activated carbon filters. A common approach is to have two complete parallel piping systems, at least at the main intake pipeline, usually cross-connected for maximum flexibility (Huguenin and Colt, 2002). This strategy, although with an initial high cost, is very efficient for seawater distribution as well as for the care of the piping system. The standard operation is to use one of the two pipes at a time, while the other is kept dry in anaerobic conditions, killing the fouling organisms on the inner surfaces. Another option is working with one circuit while the other is under maintenance or repair. The systems are systematically alternated every two weeks. The seawater pumped during the first 10–15 min through the system should be diverted to the effluent, to avoid the detached organisms and debris entering the system. Moreover, a strong cleaning procedure should be carried out during the hatchery general maintenance and sanitary annual stop, commencing with diluted hydrochloric acid (commercial 33% HCl) flushed into the pipes to eliminate calcareous residues. Afterwards, mechanical cleaning methods should be applied employing polyurethane or plastic “pigs” (usually bullet-shaped devices, contractile or flexible, with a diameter slightly greater than the pipe to be cleaned), providing entrance and extraction points at the ends of long pipe runs and assuring high pressure water flow to move the “pig” inside the pipe. In addition, the use of tap water to fill and wash the seawater pipes is also useful.

Acknowledgments We wish to express thanks to many persons that shared invaluable information on hatchery design and operation principles, especially to R. Guidastri, D. Pérez Franco, N.Y. Rodríguez and F. Alonso. It is acknowledged the application in June 2009 of an earlier version of the present procedure during a project carried out in Nicaraguan Caribbean coast for the Instituto Nicaragüense de la Pesca y la Acuicultura (INPESCA), as part of an assistance project provided by the Centre for Development Cooperation in Fisheries (Institute of Marine Research, Norway) and funded by the

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Norwegian Agency for Development Cooperation (Norad). The author is indebted to Grisel Padrón for reviewing the English version of the manuscript. References Alvarez-Lajonchère, L., Hernández Molejón, O.G., 2001. Producción de juveniles de ˜ operación y tecnologías. peces estuarinos para un Centro en y el Caribe: diseno, The World Aquaculture Society, Baton Rouge. ˜ Alvarez-Lajonchère, L., Reina Cánez, M.A., Camacho-Hernández, M.A., Kraul, S., 2007. Design of a pilot-scale tropical marine finfish hatchery for a research center at Mazatlán, México. Aquacult. Eng. 36, 81–96. Cansdale, G., 1981. Sea water abstraction. In: Hawkins, A.D. (Ed.), Aquarium Systems. Academic Press, London, pp. 48–61. Colt, J., 2000. Pure oxygen systems. In: Stickney, R.R. (Ed.), Encyclopedia of Aquaculture. John Wiley and Sons, Inc, New York, pp. 705–712. Colt, J., Cryer, E., 2000. Ozone. In: Stickney, R.R. (Ed.), Encyclopedia of Aquaculture. John Wiley and Sons, Inc, New York, pp. 622–628. FAO, 2007. Improving Penaeus monodon Hatchery Practices: Manual Based on Experience in India. In: FAO Fisheries Technical Paper. No. 446. FAO, Rome. Huguenin, J.E., Colt, J., 2002. Design and Operating Guide for Aquaculture Seawater Systems, second ed. Elsevier, Amsterdam. Ibarra-Castro, L., Lizarraga-Osuna, C.R., Gómez-Gil, B., Alvarez-Lajonchère, L., 2012. Prophylactic treatments for surface disinfection of spotted rose snapper Lutjanus guttatus eggs. Rev. Biol. Mar. Oceanogr. 47, 155–160. Kungvankij, P., Tiro Jr., L.B., Pudadera Jr., B.J., Borlongan, E., Tech, E.T., Chua, T.E., Technology Series No. 2 1985. A Prototype Warm Water Shrimp Hatchery. Network of Aquaculture Centres in Asia, Bangkok, Thailand, pp. 1–22. Le Breton, A., 2001. Prevention of Diseases, Deformities and Stress in Marine Hatcheries. Larview, Ghent, Belgium, http://www.inv.com/larview. Liao, I.C., Su, H.N., Chang, E.Y., 2001. Techniques in finfish larviculture in Taiwan. Aquaculture 200, 1–31. Liu, K.K.M., Kelley, C.D., 1991. Striped Mullet (Mugil cephalus). The Oceanic Institute Hatchery Manual Series, The Oceanic Institute, Hawaii. Liu, K.M., Kelley, C.D., 1992. Milkfish (Chanos chanos). The Oceanic Institute Hatchery Manual Series, The Oceanic Institute, Hawaii.

Moretti, A., Pedini Fernandez-Criado, M., Cittolin, G., Guidastri, R., 1999. Manual on Hatchery Production of Seabass and Gilthead Seabream, vol. 1. FAO, Rome. Moretti, A., Pedini Fernandez-Criado, M., Vetillart, R., 2005. Manual on Hatchery Production of Seabass and Gilthead Seabream, vol. 2. FAO, Rome. Nash, C.E., Shehadeh, Z.H., 1980. Review of breeding and propagation techniques for grey mullet, Mugil cephalus L. ICLARM Stud. Rev. 13, 1–87. National Institute of Coastal Aquaculture (NICA), 1986. Technical Manual for Seed Production of Seabass. National Institute of Coastal Aquaculture, Songkhla. New, M.B., FAO Fisheries Technical Paper 428 2002. Farming Freshwater Prawn. A Manual for the Culture of the Giant River Prawn (Macrobrachium rosembergii)., pp. 1–212. New, M.B., Singholka, S., FAO Fisheries Technical Paper 225 1982. Freshwater Prawn Farming. A Manual for the Culture of Macrobrachium rosenbergii., pp. 116. Office International des Épizooties (OIE), 2003. Manual of Diagnostic Tests for Aquatic Animals, fourth ed. Office International des Épizooties, Paris, pp. 358. Parazo, M.M., Garcia, L.Ma.B., Ayson, F.G., Fermin, A.C., Almendras, J.M.E., Reyes Jr., D.M., Avila, E.M., Toledo, J.D., 1998. Sea Bass Hatchery Operations, 18. Aquaculture extension manual, Southeast Asian Fisheries Development Center, Tigbauan, Lloilo, Philippines, pp. 1–42. Schipp, G., Bosmans, J., Humphrey, J., 2007. Northern Territory Barramundi Farming Handbook. Northern Territory Department of Primary Industry, Fisheries and Mines, Northern Territory, Australia, Technical Publication. Sweetman, J.W., 1992. Larviculture of Mediterranean marine fish species: current status and future trends. J. World Aquacult. Soc. 23, 330–337. Tamaru, C.S., FitzGerald Jr., W.J., Sato, V., 1993. Hatchery Manual for the Artificial Propagation of Striped Mullet (Mugil cephalus L.). Guam Aquaculture Development and Training Center and The Oceanic Institute, Guam. Tiensongrusmee, B., Budilenksono, S., Cjhanstarasri, S., Yuwono, S.K.Y., Santoso, H., UNDP/FAO/INS/81/008/MANUA/15 1989. Propagation of Seabass, Lates calcarifer in Captivity. Seafarming Development Project. Tucker Jr., J.W., 1998. Marine Fish Culture. Kluwer Academic Publishers, Boston. Wedemeyer, G.A., 2000. Chlorination/dechlorination. In: Stickney, R.R. (Ed.), Encyclopedia of Aquaculture. John Wiley and Sons, Inc, New York, pp. 172–174. World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO) Standards Programme, 2010. Codex Alimentarius Commission Procedural Manual, ninth ed. World Health Organization/Food and Agriculture Organization of the United Nations, Rome, pp. 191.