There are two basic transport systems for live fish - the closed

system and the open system. The closed system is a sealed

container in which all the requirements for survival are selfcontained.

The simplest of these is a sealed plastic bag partly

filled with water and oxygen. The open system consists of waterfilled

containers in which the requirements for survival are

supplied continuously from outside sources. The simplest of these

is a small tank with an aerator stone

Loka, Jayasree

Philipose, K K

CMFRI Digital Repository

Handbook on Open Sea Cage Culture77TRANSPORTATION OFFINGERLINGS AND JUVENILESOF MARINE FINFISHJayasree Loka and K.K. PhiliposeO pen seacage farming has become a viable marine systemto grow the marine finfishes in large scale from fingerlingstage to marketable size in a commercial way. Major advantageof marine cage culture systems is, unlimited supply of highquality seawater and large carrying capacity for a substantialaquaculture production. In order to stock large scale fingerlingsor juveniles collected either from natural waters or hatcheriesit is essential to transport them to cage site in live and healthycondition.There are two basic transport systems for live fish - the closedsystem and the open system. The closed system is a sealedcontainer in which all the requirements for survival are self-contained. The simplest of these is a sealed plastic bag partlyfilled with water and oxygen. The open system consists of water-filled containers in which the requirements for survival aresupplied continuously from outside sources. The simplest of theseis a small tank with an aerator stone.IX78Handbook on Open Sea Cage CultureThe basic factors and principles associated with any live fishtransport systems are evaluated before the actual ways of fishtransport are commented on. The transportation of live fishinvolves the transfer of large numbers (or biomass) of fish in asmall volume of water. During transportation, fish are subjectedto handling stress and may die, if survive, growth of fish may beaffected. The principles governing packaging, handling andtransportation of live fish are essential to minimise stress.Major stress factors influence transportationQuality of fish: The quality of fish transported is a decisivecriterion. The fish to be transported must be healthy and ingood condition. Weakened individuals should be eliminated fromthe consignment, particularly when the temperature duringshipment is high. When the fish are of poor quality, even a greatreduction of fish density in the transport container fails to preventfish losses. If the transport time is much longer, weak fish arekilled at a much higher rate than fish in good condition. Thefishes should be acclimatized to a lower water temperature beforetransport to avoid stress factors. To reduce the temperature forcooling the water natural ice should be used and usage of ice ofcarbonic acid should be avoided. As a guide ratio, 25 kg of icewill cool 1 000 litres of water by 2°C. If the water contains fishduring the cooling process, the temperature drop should not befaster than 5°C per hour. Direct contact of fish with ice shouldbe prevented at the same time. The total temperature differenceshould not be greater than 12–15°C, with respect to the speciesand age of the fish.The fish to be transported, except for the larval stages shouldbe left to starve for at least a day. The fish with full digestivetracts need more oxygen, are more susceptible to stress, andproduce excrements which take up much of the oxygen of thewater. The transport time of the larvae of herbivorous fishesshould not last longer than 20 hours and that of many aquariumspecies should be shorter than 12 hours.Handbook on Open Sea Cage Culture79Dissolved oxygen (DO): The presence of dissolved oxygen doesnot presuppose an absence of stress as other adverse factors canstill exist with high DO, eg. high water temperature, pH changes.Fish demand for dissolved oxygen as fish depends on watertemperature, fish density (numbers and size), time of last feeding(level of starvation) and transportation time. It is thereforeimportant to keep the transport water cool and fish biomass atan optimum, with due consideration for possible delays intransportation and the need for additional oxygen by the fish.Starving the fish prior to packing would also slow down ammoniaaccumulation and minimise unnecessary uptake of dissolvedoxygen.Ammonia (NH3): Ammonia is excreted by fish and is reportedto be toxic at low concentrations of 0.6 ppm. Ammonia excretionby fish decreases as its concentration in water increases, resultingin high blood ammonia. High blood ammonia elevates bloodpH which affects enzyme-catalysed reactions affectingmetabolism. Starvation and lowered temperatures reduceammonia excretion.Carbon dioxide: Fish become distressed when carbon dioxide(from respiration) accumulates rapidly in water since the bloodis unable to carry oxygen under these conditions. Low levels ofcarbon dioxide (3–6 ppm) may be beneficial since it preventsthe buildup of unionised ammonia. Carbon dioxide is also amild anaesthetic and may be considered in alleviating stressduring transportation.Handling: Stress during handling and packing may be so severeas to cause chronic and acute mortalities. Poor handling andpacking procedure may also cause osmoregulatory and metabolicdisfunctions. Therefore it is important to proceed gently andquickly.Water temperature (heat and cold): Water temperaturesgreater than 28°C accompanied by declining dissolved oxygenand increasing ammonia, create a hostile environment. This is80Handbook on Open Sea Cage Culturethe likely situation if fish are over-packed or transportation isdelayed under tropical conditions. Temperatures that are toolow (<18°C) can cause thermal shock, especially in young fish.Stressed fish usually succumb to diseases after 1–2 weeks, if notalready dead on arrival.Methods of alleviating stressReducing transport water temperature : This prevents thermalstress and improves oxygen stability. Ice should be used in thecorrect quantities and this depends on fish species and size andalso the transportation period. Alternatively, cooled water (18°C)can also be used by lightly sedating the fish in 18°C water priorto packing, and then using water at the same temperature fortransport. Under air freighting conditions, this temperatureincreases by about 1–4°C after 12–14 hours, and fish are usuallyalive.Insulation: The use of insulated containers like styrofoam boxes,newspaper lagging helps to maintain the temperature of transportwater, being poor heat conductors. They also reduce vibration.Anaesthesia: Anaesthesia prevents fish hyperactivity. The oxygenconsumption of newly-packed fish elevates for 30–60 minutesand declines as fish acclimate to the new environment. The first30–60 minutes after packing is therefore important. Someanaesthetics used are MS-222, carbonic acid, benzocaine andphenoxyethanol. However the use of certain chemicals foranaesthetising food fish is not to be recommended.Transportation of live fish : Fish are transported live as live fishare transported by air, road or overseas source to the local farmsite for culture. Transportation can be made by using cheapmaterials and equipment like plastic bags, rubber bands,compressed oxygen, cardboard or styrofoam boxes. Food fishfingerlings are packed at about 500 per bag at two bags per carton.It can be generally observed that as fish size increases, the numbersHandbook on Open Sea Cage Culture81packed per bag decreases (Table 1). However, a higher biomassis tolerated by larger fish.Table 1: Food fish fingerling packing conditions bythe ‘plastic bag’ method and transportation timeranging from 8–12 hoursPacking Fish mean No./beg Biomass g/L   Transport waterconditions wt (g)  temp. (°C)Fish speciesGrouper 8–11 100 89–100 7–9 28–2911–14 50 102–128 4–5 28–2911–17 50 147 4–5 28–29Seabass 4.5–5 70–100 50–100 11–20 27–28>5–10 60–100 93–148 14–35 25–28>10–15 50–100 94–180 8–16 27–28>15–20 50 133 8 27–28>20–30 35–60 200–300 7–10 27–28>30–40 35–40 222–267 6–7 27–28>40–50 35 292 6 27–28>50–70 25 267 4 27–28105 20–25 525 5 27–28Transportation of larger-sized fish (Regional / Local)Transfer of live market size fish from farm to landing point (byboat in tanks).a. Transportation of live market - size fish from landing pointto Landing Centre (in tanks on lorries).b. Transfer of live fish from farm to farm (by boat, in tanks).82Handbook on Open Sea Cage CultureSeabass Fingerling Packing :Packing in oxygenated plastic bagsMethod Iy Measure about 3 times the fish weight of filtered seawater(eg. if fish is 600g, measure about 1.8 litres of seawater) andpour into a plastic bag.y Transfer the fish gently into the bag.y Measure the height of water in the bag.y Insert the delivery tube from the oxygen cylinder well intothe water and oxygenate slowly, twisting the plastic bag roundthe tube to prevent oxygen loss.y Gradually inflate the bag so that oxygen occupies about 4times the water volume.y Secure the bag with rubber bands, leaving the outer bag free.Make sure the bag is firmly inflated and not flaccid.y Secure the outer bag with more rubber bands.y Place the packed bag of fish into a styrofoam box lined withnewspaper (lagging to prevent rapid temperature change).y Store the box in an air-conditioned room (19–22°C) for 12hours to simulate our cargo temperatures and transport.Method IIy Measure about 3 times the fish weight of filtered seawater(eg. if fish is 600 g, measure about 1.8 litres of seawater) andpour into a plastic bag.y Transfer the fish gently into the bag.y Calculate the volume of cooled (18°C) filtered seawater requiredto cover the fish (weight of seawater = 3 × wt. of fish).y Pour the water into the plastic bag.Handbook on Open Sea Cage Culture83y Calculate the weight of ice required (25g ice/l seawater)and weigh the ice out in a small plastic bag. Secure the bagof ice and place it in the plastic bag of water.y Transfer the fish gently into the bag.y Measure the height of water in the bag.y Insert the delivery tube from the oxygen cylinder well intothe water and oxygenate slowly, twisting the plastic baground the tube to prevent oxygen loss.y Gradually inflate the bag so that oxygen occupies about 4times the water volume.y Secure the bag with rubber bands, leaving the outer bagfree. Make sure the bag is firmly inflated and not flaccid.y Secure the outer bag with more rubber bands.Source:Berka, R., 1986.The transport of live fish.A review. EIFAC Tech.Pap.,(48):52 p.FAO. Training Manual on Marine Finfish Netcage Culture in SingaporeRegional seafarming project RAS/86/024

Transportation of fingerlings and juveniles of marine finfish

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Transportation of fingerlings and juveniles of marine finfish

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