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Department of Fisheries and Aquatic Resources (DFAR) Sri Lanka. National Aquatic Resources Research and Development Agency (NARA) Sri Lanka. United Nations University Fisheries Training Programme (UNU-FTP) Iceland. Icelandic International Development Agency (ICEIDA) Iceland.
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Department of Fisheries and Aquatic Resources (DFAR) Sri Lanka National Aquatic Resources Research and Development Agency (NARA) Sri Lanka United Nations University Fisheries Training Programme (UNU-FTP) Iceland Icelandic International Development Agency (ICEIDA) Iceland Handling of fish on-board Quality and safety issues in fish handling ----- A course in quality and safety management in fishery harbours in Sri Lanka NARA, DFAR, ICEIDA and UNU-FTP
Content • Video about handling on-board • Current practices and improvements • Handling of tuna on-board
Learning objectives • After this lecture the participants will have: • an overview of the situation in Sri Lanka regarding handling on board • ideas on how to improve the situation
Video Handling of fish on-board - UK -
Current practices • Fish is put in hold at sea temperature • Fish is stored loose in hold (pressure on fish in lower layers) • Fish is cooled with crushed block ice or flake ice • Handling time on deck is long (in heat) • Gutting and bleeding usually not practised
Video Storing fish in the hold
Possible improvements • Put fish into ice slurry in an insulated tub after catch • for cooling down fast • for bleeding • Put cold fish into boxes in hold • easier handling • less pressure on lower layers • possible to use day markings
Manual transport equipment Sack or case truck Hand-drawn truck Hand pallet truck
Flake ice Ice slurry Cooling rates in the center of cod - comparison of flake ice and liquid ice Temp. (°C) Time (hours)
Cooling /keeping cool • Ice slurry is good for cooling fish down quickly • compleatly surrounds the fish • good heat transfer • Flake ice is good for keeping fish cool • keeps fish moist while melting • blood water and slime is washed off • This may require less ice than the current practices and give much better quality fish
Video Small boat in Reykjavik harbour
Content of this lecture • The importance of handling and storage of ocean tuna • Diagram of handling and storage of raw material
COMMON SPECIES OF OCEAN TUNA IN SRI LANKA Big eye tuna Yellow fin tuna
The importance of pre-handling and holding of ocean tuna • Assure good quality of raw material • Prevention of histamine formation
Maintain quality of raw ocean tuna If catching, pre-handling and holding is not done properly Appearance will be changed Colour and flavour of flesh can be changed
The importance of handling and holding of ocean tuna (Continued) Histamine Histidine Histamine Histidine decacboxylaza
Diagram of HANDLING and holding of OCEAN TUNA Catching, gaffing and landing Killing Bleeding Gutting Cleaning On-board storage
CATCHING, GAFFING AND LANDING THE FISH • Always gaff the fish through the head. • Use two gaffs for big fish, the second through the mouth • It is advisable to lift the fish tail to help haul it on-board • Carry out all subsequent handling on a foam pad
KILLING THE NEWLY- LANDED TUNA Once aboard, the fish should be killed immediately
Bleeding Bleeding the tuna by making a cut in the side of the fish with a knife, five to ten centimeters behind the base of pectoral fin recess, on both sides of the fish. Blood should flow freely from these cuts.
GUTTING OF FISH • The gutting of fish can bring about the following advantages: • Make subsequent chilling more effective • Remove undesirable digestive enzymes • Prevent undesirable bacteria in the fish intestine from spreading • Avoid the penetration of parasites such as nematodes from the gut into the flesh
Cleaning of fish Scrub the inside of the abdominal cavity without removing the white membrane which covers the backbone. Carefully rinse the fish, inside and outside. The fish is now ready to be placed in brine or ice.
ON-BOARD STORAGE It is recommended to use the two following staged procedure to obtain a top-quality fish (like in pre-handling of raw materials). Lower the internal temperature of the fish by placing it in chilled brine (a slurry of crushed ice and seawater). After the core temperature reaches 0°C, put the fish in ice and keep it there until arrival at port. Alternatively, the tuna can be iced directly to reduce temperature. However this method takes longer time
UNLOADING of fish The following rules are important during loading: Do not twist the fish when removing them from the ice. They should be held by the head rather than the tail. Handling the fish gently. Do not leave the fish too long in the open air or sunlight.
References Training materials on catching and on-board handling of ocean tuna. Pacific Ocean Organisation. INFOFISH (1999) Hall, G.M (1997). Fish Processing Technology Scombroid Poisoning. FDA (1999) FDA (2003)