|Fish Handling, Preservation and Processing in the Tropics: Part 2 (NRI)|
Suitability of site Unloading systems
Fish landings of all sizes tend to be by their very nature focal points of the fishery industry. On the one hand, catching vessels from different fishing areas focus on the centre for landing their fish and for obtaining essential supplies and, on the other hand, traders, processors, marketeers etc. from different inland areas focus on the landing for their supplies of raw material (see Figures 16 and 17).
Suitability of site
Due to the multiplicity of different functions that a fishing harbour, therefore, has to perform, it is extremely important that the site is selected with care. In many cases, the final decision as to the site for a new fishing harbour will be a political one but the technical requirements must be made clear at the planning stages. The following list of requirements gives some idea of the many factors which must be taken into account during the planning stages:
1. It must be at a convenient distance from the fishing grounds.
2. It must be in a convenient location with regard to existing or planned fish markets and must have good communication with such markets.
3. There must be adequate and suitable space both on the sea and landward sides for development of an efficient fishing station. This should include areas for fish processing and auxiliary industries, shipbuilding and repair, offices, shops, space for the parking of lorries and cars etc.
4. It must be remembered that the fishing industry depends on people and there must be sufficient attractive residential accommodation for fishermen, traders and workers in the fishing industry and their families.
5. There should be safe access from the open sea in all weathers and all states of tide.
6. The site should provide safe shelter for vessels likely to use it.
7. There must be adequate depth of water in the harbour and approaches for the sizes of vessel contemplated. This depth must be able to be obtained and maintained at reasonable cost.
8. There must be suitable ground conditions for building of harbour walls, quays, breakwaters etc., and for the land-based factories and infrastructure.
The suitability of a particular site depends on the type, size and number of fishing vessels; the type of fish to be caught and landed; the processing that may be done in the immediate vicinity of the harbour; the neighbouring communications network which may serve the site etc.
Once a site which meets the necessary requirements has been chosen, then the actual facilities required must be detailed and the following points are worth considering:
(a) A safe and easily identified approach from the open sea with adequate depth at all tides should be marked.
(b) A safe well-defined entrance and approach channel of adequate depth at all tides should be constructed.
(c) There must be a sufficiently large, deep and protected basin to cater for all types of vessel. This must take into account turning and manoeuvring of vessels within the harbour area and anchorage of the vessels awaiting landing space. There should also be permanent anchorage for vessels unable to use the berthing quays, and also servicing facilities for dredgers and other maintenance vessels etc.
(d) There must be, within the complex, provision of all necessary navigational beacons and visual and electronic aids to assist vessels in the safe use of the port.
(e) Where necessary, protective breakwaters of adequate structural design and suitable layout should be provided to reduce wave or storm effects within the approach channel and port facilities.
(f) There must be adequate landing, servicing and provisioning, berthing and repair quays or jetties to cater for the number and types of vessels using, or likely to use, the facility in the foreseeable future. This particular point brings out the necessity for forward planning. A well-designed and adequate harbour facility will attract more fishing business. It is necessary to plan ahead to make sure that there are going to be adequate services for future expansion.
(9) All necessary utility services must be planned and provided: for instance, fuel oil loading points and storage; water, ice-making plants and ice storage for the supply of vessels and the shore-based activities; electricity supply for public, industrial and domestic use; surface water drainage and sewerage systems; fire precaution services for vessel and shore use.
(h) Consideration must be given to the buildings required for: display, auction and sales; sorting; agents' and wholesalers' activities; harbour and fishery administration offices; storage accommodation for containers, gear and equipment; workshops and maintenance stores; possibly, training centres and laboratories; wholesale and retail suppliers for ships supplies; sheds or other buildings for repair of nets and vessel maintenance at the berthing quays; storage for repairing items such as ropes, nets, fish boxes, lobster pots; accommodation sheds for port transportation machines, for instance, fork-lift trucks, mobile cranes, tractors, waggons.
(i) There must be adequate space for the development of the necessary processing industries. It may be decided that public cold stores and freezing facilities are required from the start and these should be planned and built at the same time as the rest of the fishing harbour. If private industry is likely to need to build its own factories for fish processing, then there should be adequate areas made available for them at reasonable cost.
(j) If the harbour complex is not already on a main road or rail head, there should be connections made to the main trunk road or rail head for the movement of fish to and from the harbour area. These roads and rail connections should also include any connections that need to be made within the harbour area itself for taking provisions from one part to another.
(k) Provision of parking space for industrial and private vehicles must be made; adequate space around halls and industries, for loading and unloading vehicles, which does not upset the free flow of through traffic, must be provided.
(1) There must be provision of vessel, engine and gear repair facilities in the vicinity of the harbour, and the inclusion of a boatbuilding establishment where the fleet is rapidly expanding or replacing itself from local resources.
One of the most important functions that a fishing port must perform is that of unloading fish from vessels returning from sea. The type of unloading system adopted obviously depends on a number of factors, for instance:
1. The type of fish being landed, e.g., fresh, frozen etc.
2. The use to which the fish are to be put, e.g., for human consumption or for industrial processing.
3. The types of vessel landing fish and the stowage methods used on the vessels themselves, e.g., box, bulked, shelved etc.
4. The tidal rise and fall in the harbour.
5. The number of vessels being unloaded.
6. The cost and availability of labour as opposed to the cost and availability of energy.
7. The ambient temperatures.
It must be remembered that, whichever system is chosen, it should be as efficient as possible, especially in terms of the time taken to get the fish from the hold of the vessel to cold storage, the auction floor or to transport because it is at this stage that unacceptable rises in temperature of cooled fish can occur. In addition, crews of vessels returning from long voyages may be anxious to return to their families for leave or to return to sea as soon as possible.
Unloading fresh fish
There are many ways of unloading fresh fish.
1. Bulked fish are often put into boxes on board the vessel and handed up on to the dockside.
Comments: This method is labour-intensive, it may be slow and can cause physical damage to the fish.
2. Bulked fish may be put into baskets which are swung on to the dockside using either the ships derrick or shore-based cranes.
Comments: This Is a reasonably fast method of unloading with experienced labour. Derricks can be powered and are, therefore, subject to failure; hand powered derricks are sometimes used. Fish are handled twice (i.e. into the baskets and then out again into a second container at the dockside); therefore, physical damage can be a problem.
3. Lifting boxes of fish directly from the hold to dock with a
Comments: This means that there is minimal handling of the fish. Boxes can be used for further transportation of the fish. Any ice left will remain in the boxes, thereby helping to keep the fish cool.
4. Mechanical elevators and conveyors are used in some fisheries.
Comments: This method can be fast but it often separates the fish from the ice and, therefore, unacceptable rises in temperature can occur. It enables direct transport of fish to the auction hall along conveyors. Fish can be sorted and/or re-iced from the conveyors. If well-designed, these methods cause no physical damage to the fish.
Unloading frozen fish
1. When uniform blocks of frozen fish, for instance from freezer trawlers, are to be unloaded, a mechanical tailor-made system is often used.
2. Frozen bulk stowed fish, such as tuna, are often unloaded using swinging derricks, baskets, nets or boxes. These methods can cause physical damage to the fish.
Unloading industrial fish
Vessels catching pelagic fish, such as anchovy, menhaden, capelin, herring etc., for conversion into fish meal often catch large quantities of fish of fairly uniform size. The care needed in handling fish for the domestic market is not as necessary with these fish although they must be unloaded quickly. Industrial fish can obviously be unloaded in the same way as other fresh fish but, to speed up the operation and save on manpower, various pumps and mechanical unloading devices have been produced for this purpose.