THE SARDINE, MACKEREL, AND HERRING FISHERIES 139 



The Maine Sardine Industry. The raw material for the IVIaine sardine 

 industry is, as already stated, the small sea herring {Clupea harengus) 

 which is found in commercial quantities in the shallow waters along the 

 Maine coast. Although the Maine sardine has been utilized industrially 

 since 1875, the canned product in past years has not enjoyed the public 

 favor to the extent that sardines from other localities or lands enjoyed. 

 This situation has recently been changed by a very efficient research and 

 advertising program initiated cooperatively by the twenty-five or more 

 canners of the Maine sardine. The program, financed by a per-case tax 

 and aided by a technological research laboratory and an organization to 

 grade the entire sardine pack, has been highly successful and rewarding. 



Fishing and Processing Methods. The methods formerly used for the 

 harvesting of the Maine sardine were either to trap the fish in weirs or 

 to trap and isolate the fish in coves with stop nets. Today the principal 

 method of fishing for Maine sardine is purse seining. By leaving the fish 

 in the net for roughly 24 hours, the digestive tract of the fish will have 

 been cleared. The fish is transferred by means of suction pumps from the 

 seine to the fishing boat or to the carrier boat. As the hold is filled with 

 fish, salt is added, usually at the rate of 4 pounds per bushel of fish. At 

 the dock-side, the fish is again pumped from the boats into flumes that 

 lead to holding tanks in the cannery where the fish is resalted to replace 

 salt lost during unloading and to get a suitable salt level in the canned 

 product. 



The importance of the addition of salt to fish in transit, as well as in 

 the holding tanks at the cannery, has been the subject of much work 

 at the Maine Research Laboratory and elsewhere. The work at Maine 

 has shown that the addition of salt in proper quantities will protect the 

 fish against bacterial decomposition long enough, under the conditions 

 of the Maine fisheries, to provide a reasonable time for transporting and 

 processing in the plant. The strong influence of temperature upon the 

 protein nitrogen losses into the brine was thoroughly studied by the 

 Maine workers, and this probably is one of the more important reasons 

 why in-plant refrigeration, as well as carrier-boat refrigeration, is gradu- 

 ally gaining a foothold. The fishing boats seldom operate more than some 

 few hours run from the cannery so no ice or refrigeration is used. 



From the holding (brining) tanks, the fish are taken on a conveyor 

 to the processing room where the sardines are placed on wire racks 

 called ''flakes." After they are stacked in layers on a special cart, the 

 sardines are rolled into a steam box for precooking. Some canners pre- 

 cook the fish in steam, others bake them or fry them in oil, still others 

 put the sardine into the cans raw and do the entire cooking process in 

 the can. The dressing and trimming of the fish are usually done in a 



