Desain palka kapal pengangkut ikan ditinjau dari aspek teknis, mitigasi risiko dan ketahanan hidup ikan

Abstract

The continuity of humpback grouper (Cromileptes altivelis) culture activity is influenced by availability of juvenile in lot of number in the right time, right size, and right quality. A certain method and transportation moda is needed due to a long distance between location of hatchery and rearing (growing) location in order to maintain high survival ratio. Nowadays, closed system method is applied for transporting juvenile of hunchback grouper with total length of less than 8 cm. In this method, the juveniles are put into the plastic bag with sea water and oxygen of certain composition before transported by land, sea or air transportation moda. By using this method some limitations appear such as, amount of fish juveniles and time needed for transportation. The objectives of this research are: 1) to determine the risk level of life fish carrier with ‘opened system’ to mortality ratio of fish juvenile with total length (TL) 5 – 7 cm and its risk source, 2) to determine the risk mitigation steps that can reduce level of fish juveniles mortality and 3) to determine the design of life fish carrier that can transport fish juveniles, especially the design related to existence of fish juveniles in the fish hold during transportation. Literatures review, laboratory experiments simulations, and numerical analysis methods have been applied in this research. An asessment to open system life fish carrier transporting juvenile with 5 – 7 cm TL was carried out. In general, this kind of carrier was used to transport juvenile of minimum 16 cm TL. Transporting juvenile with 5 – 7 cm TL by using open system carrier indicates high risk. A risk mitigation attempt was done by designing a fish hold equipped with resirculation water system and optimizing the amount of juveniles that could be transported in the fish hold. The result of this mitigation process showed that fish hold with keel damper constructed at the inner wall was able to reduce free surface effect during ship rolling and to maintain the ship stability toward free surface effect occured during rolling. Besides, keel damper gives positive effect in increasing oxygen concentration in the fish hold during rolling event. Another result showed that the use of combination between recirculation and aeration shows a good perfomance to maintain sea water quality in the fish hold. A certain amount of juveniles that were put in the fish hold model for simulation of the designed system resulted in the stability of seawater quality in the fish hold during the experiment and 100% survival ratio of juvenile at the end of 48 hours experiment. Based on the above result, recomended transportation moda for fish juvenile with 5 – 7 cm TL in large amount with long sailing time and high survival ratio is closed system of life fish carrier equipped with keel damper and combination system of resirculation and aeration in the fish hold with fish juvenile density depend on the oxygen consumption rate for each individual fish juvenile.