CHAPTER 11 Processing at Sea and Factory Ships MOGENS JUL Danish Meat Products Laboratory, Copenhagen, Denmark and Danish Meat Research Institute, Roskilde, Denmark I. Introduction 437 A. Perishability of Seafoods 437 B. Triple Purpose of Fishing Craft 439 II. Preserving and Processing the Catch on Board 440 III. Technical Considerations 441 A. Working Space 441 B. Carrying Capacity 441 C. Fishing Factory Ships 443 D. Capacity of the Processing Equipment 443 E. Water Supply 444 F. Ice Supply 444 G. Operating in a Rough Sea 444 H. Transfer of Catch on the High Sea 445 I. Unloading 447 J. Maintenance 447 K. Quality of Product 447 L. Speed 449 IV. Some Economic and Social Considerations 449 A. Wages and Accommodations 449 B. Working Conditions 450 C. Future Operations 450 D. Factory Ships or Shore Bases 451 V. Experience in Preservation and Processing at Sea 451 A. Salting Aboard 451 B. Floating Canneries 453 C. Freezing at Sea 456 D. Utilization of Waste Fish and By-products Aboard 466 VI. Summary 467 References 470 I. Introduction A. PERISHABILITY OF SEAFOODS As was pointed out by A. W. Anderson at the first Interna­ tional Fishing Gear Congress (Kristjonsson, 1959), fish and other sea­ foods are among the most perishable of all foodstuffs. This is a matter of minor concern to the fishermen in inshore fisheries, when the fish is 437 438 MOGENS JUL kept aboard for only a few hours or, at the utmost, for a few days and where the catch may be preserved in ice until the craft has returned to port. Efforts to improve this means of preservation, by the use of chilled sea water, nitrite, antibiotics, etc., have not succeeded in bringing about any substantial extension of the keeping time of fresh fish aboard ships, and there are today several types of fishery where this system of preserva­ tion aboard is insufficient. Some are listed below. 1. No Shore Facilities In many parts of the world, e.g., the Antarctic, Greenland, and the North Pacific, fishing may be carried out close to shores where no process­ ing facilities exist. Even where they exist, they may be far away from population centers and the processed product must be carried long distances to consuming centers. 2. Short Seasons Many types of fishery, e.g., the Alaskan salmon industry and herring fishing in the North Atlantic, are so highly seasonal that it is difficult to make a shore installation profitable because of the short period of each year in which it can be kept in operation. 3. Operations on the High Seas A fishery may often be conducted far from any shore and therefore necessitate transport over considerable distances. This is the case, for instance, in the traditional British distant-water trawling industry. Here trips may be up to 2400 miles to and from the fishing grounds and the trawlers spend about 9 days running back and forth and only 9 days fishing. 4. Depleted Stocks, etc. Fishing communities in England, New England, and Japan experience difficulties because stocks in nearby waters have become depleted, so fishing can be extended only by exploiting grounds far from the home ports. Some countries, such as Greece, Italy, Japan, Spain, the Soviet Union, the United Kingdom, and the United States, have a need for fish that greatly exceeds even the maximum supply from nearby waters. Fish, then, must be obtained by imports or by fishing operations far from the home ports. In all these instances, there is considerable interest in means of pre­ serving the catch in a nonperishable form aboard. One other solution exists, of course, in that the fish may be kept aboard alive. In most fisheries, this is not possible because the fish are 11. PROCESSING AT SEA AND FACTORY SHIPS 439 dead when taken aboard or have been fished at such depths that they cannot survive the change in pressure. Besides, live tank storage is space- consuming and may affect the stability of the craft. Yet France in 1960 had a total of 83 boats with live tanks (FAO, 1961). In recent years, further interest in processing aboard has existed be­ cause an increasing share of the world's catch is being processed anyway. FAO (1963) indicates that direct consumption of fresh fish increased from 12.2 million tons in 1955 to 16.0 million tons in 1962. In the same period, the amount of fresh fish used for preservation or other processing increased from 14.1 million tons to 28.7 million tons. If the fish is to be processed anyway, this might as well, in many instances, take place on the fishing grounds. B. TRIPLE PURPOSE OF FISHING CRAFT In traditional fishing operations, the fishing craft serves three pur­ poses, (1) catching fish, (2) carrying the crew and the catching equip­ ment to and from the fishing grounds, and (3) transporting the catch to port. This means that the craft must have substantial fish-carrying capacity and, even though ice is generally used for preserving the catch, must be fast in order to bring the fish back to port in a reasonably fresh condition. This implies that the design of the craft is a compromise between these functions, which often results in considerable adjustments. The need for a quick return to port with the catch has greatly influenced the design of craft, especially trawlers; for example, some of the latter are equipped with double the power needed to handle the trawl. Even then, a return to port may often be necessary before the holds are full in order that the catch may be delivered while still in good condition. There is, therefore, in some fisheries a considerable interest in separat­ ing these functions, i.e., making fishing craft that will be efficient catch­ ing craft and fish-transport vessels to carry the catch and supplies be­ tween the fishing grounds and the port. Another solution lies in preserving the catch at sea in order that fishing may continue until the holds are full. The former solution was employed when, many years ago, use was made in England of a fish-transport service to and from trawlers operat­ ing in the North Sea. The vessel transported supplies to the trawlers and fish from them. This method, referred to as "fleeting," was standard use for trawlers fishing out of Hull, England, up to about 1930. (See also Volume II, Chapter 1, pp. 21-22.) Similarly, the Japanese sometimes use three vessels in pair trawling operations. They are rotated in such a fashion that two are constantly fishing while the third is on its way to and from port. 440 MOGENS JUL Complete separation of functions occurs in Antarctic whaling expedi­ tions where the whalers are catching ships exclusively, while a mother- ship, i.e., the whale factory ship, supplies the whalers and does all the processing and most of the transporting of the catch. Besides, commercial freighters carry fuel and other supplies to the factory ship and whale oil and meal back to port, while the factory ship remains on the whaling grounds for the full season. II. Preserving and Processing the Catch on Board The above indicates that in many fisheries there exists a great need for preserving or processing the catch aboard. Traditionally, this has been done for centuries in the North Atlantic ground fishing and the Icelandic herring fisheries. Ships from France, Portugal, and Spain have salted the catch of cod-like species obtained off Newfoundland and Greenland FIG. 1. Diagram of the various arrangements for fishing and fish processing. 1: Fishing vessels. 2: Long-distance trawlers equipped for freezing the catch. 3: Motherships operating under their own power on the high seas. 4: Motherships installed on scows, etc., not able to navigate on the high seas. 5: Transport vessels equipped for serving a fishing fleet by taking the iced catch to a not too distant harbor. 6: Transport vessel for taking a processed catch from a mothership to a port. 7: Ordinary transport vessel. 8: Shore bases. 9: Fishing ports. 10: Rail cars (may be refrigerated). 11: Trucks. (After Pavlov, 1956.) 11. PROCESSING AT SEA AND FACTORY SHIPS 441 aboard. Today, further development has taken place in this field and large-scale long-distance fishing may soon rely entirely on processing the catch aboard. Several approaches to the problem have been outlined by Pavlov (1956). The various arrangements for fishing and handling are illustrated in Fig. 1. All of the above mentioned solutions are used. It appears that the main possibilities lie in the fields of self-contained fish-processing ships and in motherships operating with a fleet of fishing boats, both at times supported by transport vessels. Over the years, much interest has been shown in schemes for process­ ing the catch at sea. Yet, until recently, few fisheries were based on processing at sea. This is due to the fact that such processes generally are difficult to operate, especially when they require a large processing crew and expensive processing installations. Therefore, much experi­ mentation and experience are needed before such an operation can become efficient. In the years following World War II, much progress has been made in some of these fields, and referred to at the Second World Fishing Gear Congress, London, 1963. Considerable information on the subject is also given in Volume II, Chapter 19, Section VI. Problems in factory ship operations have been discussed by Anderson (1951), Birkhoff (1956), Hardy (1947), Jul (1954), Kuprianoff (1956), Nickum (1955), Pavlov (1956), Ranken (1961), and Traung (1955, 1960). Considerable information on the subject has been assembled by the Food and Agriculture Organization of the United Nations and pre­ sented at the First and Second International Fishing Boat Congresses, Paris and Miami, 1953, and Rome, 1959.