trip (at which time after-cod-end meshes are still elongating) through 3 trips, or the average life of a manila cod end under reasonable loads. After-use data gathered through the years 1955, 1956, and 1957 revealed that cod ends made of 50yard, four-ply manila twines were practically all within the specifications after use. Unmodified cod ends, identified by F. W. S. tags, used on 1 through 4 trips showed oversize meshes. OBSERVATIONS The consensus of those engaged primarily in the haddock fishery is that the regulation is beneficial. Those engaged in the catching of other species including haddock are critical of the regulation. Their mar 3.750 3.875 4.000 4.125 4.250 4.375 4.500 4.625 4.750 4.8755.000 5.125 5.250 5.375 5.500 BETWEEN KNOT MEASURE IN INCHES Fig. 10 Dispersion about the mean of 4.500 inches of after-use measurements of 15 50-yard, 4-ply double manila twine cod ends. ketable catch is composed of all sizes and species, such as whiting and ocean perch, which either escape or gill in regulation-size haddock meshes. The mesh regulation is recognized by all who work with the fishery as a requirement for the use of an average mesh size designed to accomplish the primary objective of releasing haddock of a size sufficient to allow the maximum utilization of the resource. BIBLIOGRAPHY BEDFORD, B. C. AND BEVERTON, J. H. BOEREMA, L. K. 1956. Some Experiments on Factors Influencing Mesh BRANDT, A. Von 1956. Measurement of Meshes of Trawl Nets. International Commission for the Northwest Atlantic Fisheries, Symposium Biarritz, France, Circular Series No. 353 B-42. CLARK, J. R. 1952. Experiments on the Escapement of Undersize Haddock through Otter Trawls. Commercial Fisheries Review, vol. 14, no. 9 (September). (Also Sep. No. 321.) 1952. Further Experiments on the Escape of Under- ELLIS, R. W. GRAHAM, H. W. 1952. Minimum Net-Mesh Size for the New England Haddock Fishery, Commercial Fisheries Review, vol. 14, no. 12 (December). (Also Sep. No. 334.) 1954. United States Research in Convention Sub-Area 5 During 1953. International Commission for the Northwest Atlantic Fisheries, Ann. Proc. 4. and PREMETZ, E. D. 1955. First Year of Mesh Regulation in the Georges Bank Haddock Fishery. U. S. Department of the Interior, Fish and Wildlife Service, Special Scientific Report--Fisheries No. 142. KLUST, G. MARGETTS, A. R. 1956. Definitions and Testing of Light Trawls. International Commission for the Northwest Atlantic, Symposium Biarritz, France, Circular Series No. 353 B-45. PARRISH, B. B. 1950. Experiments on the Shrinkage of Trawl CodEnd Meshes. Paper presented to Comparative Fishing Sub-Committee, International Council for the Exploration of the Sea. COOLING FISH FILLETS The fishing industry has false ideas about the cooling ability of crushed ice; also too many believe that a little ice will do a lot. The general idea seems to be that once a fish, a can, or a plastic bag of fillets has been surrounded, even lightly, with crushed ice, irrespective of the thickness of the fish itself or the container of fillets, that rapid chilling and no further spoilage is assured. More often than not, such is not the case. If the lot of fillets happens to be thick and their temperature warm, say 60° F., it may take hours for the temperature to drop to where bacterial activity is effectively slowed down. Meantime, spoilage is taking place at a rapid rate. The answer to this situation is to ice heavily and use thin lots of fillets. The effectiveness of icing thin layers is vividly shown by the following data taken from an English report (J. Science Food and Agriculture 9(2) 78-82, 1958): "When the packages of fillets were cooled with plenty of ice on both top and bottom, a 3-inch layer starting at 40° F. cooled to 38 F. in 2 hours; a 6-inch layer took 10 hours. A 3-inch layer starting at 60° F. cooled to 33° F. in 4 hours; while a 6-inch layer was cooled from 60° F to 36° F. in 10 hours and several more hours would be needed to reach 33° F." Thus the thickness of the layer is of very great importance. BOTTOM TRAWLING EXPLORATIONS OFF By Melvin R. Greenwood* SUMMARY 1300 125° Explorations to determine quantities and species of bottom fish available to commercial trawling gear in the offshore waters of Southeastern Alaska between Dixon Entrance and Hazy Islands were conducted by the U. S. Bureau of Commercial Fisheries during the fall of 1956 and spring of 1957. The fall investigation was made by the Bureau's exploratory fishing vessel John N. Cobb, and the spring investigation was made by the Tordenskjold, a Seattle commercial trawler chartered by the Bureau for this work with SaltonstallKennedy Act funds. A considerable amount of clear trawling bottom was found throughout the area investigated at depths ranging from 50 to 200 fathoms. Alaska coral growths were encountered on much of otherwise clear bottom, but did not pose a serious problem to fishing efficiency and gear damage was usually slight. In some areas, however, the bottom topography precluded any possibility of trawling. Pacific ocean perch was the most abundant food species caught, and many catches of more than 1,000 pounds per hour were made during the spring operations. Arrow-toothed flounder and Alaska pollock dominated catches during the fall exploration, and together they comprised 60 percent of the aggregate catches made by the John N. Cobb. A limited number of shrimp-trawl drags made by the Tordenskjold revealed good signs of pink shrimp and sidestripe shrimp; however, additional work is necessary to accurately determine the offshore shrimp potential in this area. Weather conditions during the fall exploration were adverse, 550 500 450 ALASKA LEGEND: AREAS PRESENTLY FISHED BY COMMERCIAL TRAWLERS. AREA EXPLORED BY JOHN N. COBB AND TORDENSKJOLD. Fig. 1 General chart of waters off Pacific Northwest showing present commercial bottom-fishing areas and the area explored by the John N. Cobb and Tordenskjold. with strong winds and large swells predominating. The weather was generally favorable during the spring exploration. *Fishery Methods and Equipment Specialist, Branch of Exploratory Fishing and Gear Research, U. S. Bureau of Commercial Fisheries, Seattle, Wash. BACKGROUND Exploratory fishing to determine quantities and species of bottom fish available to commercial-type trawls in ocean waters off Southeastern Alaska between Dixon Entrance and Hazy Islands was conducted by the U. S. Bureau of Commercial Fisheries in 1956 and 1957. The exploratory activities were carried out from October 7 to List of Common and Scientific Names of Fish and Shrimp Caught During November 7, 1956, and from May 23 to June 30, 1957. The Bureau's exploratory fishing vessel John N. Cobb was used for the earlier cruise and a chartered commercial trawler, the Tordenskjold, was used to carry out the work in 1957. Funds for the charter were provided by the Saltonstall-Kennedy Act of 1954. The otter-trawl fishery of the Pacific Northwest began in the early 1920's in the waters within Puget Sound. Since its inception, the fishery has expanded to include grounds from off southern Oregon to northern Hecate Strait, British Columbia (fig. 1). The expansion of fishing grounds followed increased market demands for bottom fish and the inability of the original areas exploited to produce the quantities required. In 1951 and 1952 exploratory trawl fishing was carried out aboard the John N. Cobb in deep water (mostly over 100 fathoms) off the Oregon and Washington coasts (Alverson 1951 and 1953). Commercial quantities of Dover sole, sablefish, and Pacific ocean perch were found outside the areas then being utilized by the fishery. These grounds are currently being fished by the Washington and Oregon trawl fleets. The need for the expansion of trawling grounds is ever-present because of the steadily increasing demand for bottom fish. Investigations to determine the commercial potential of bottom fish resources off Southeastern Alaska were suggested by Pacific Northwest fishermen. The area explored was chosen because of its proximity to grounds presently being fished in northern Hecate Strait and because of the possibility of future markets developing in nearby Alaskan cities. Fishing operations were carried out between latitudes 54°20' N. and 55°48' N. (Dixon Entrance to Hazy Islands) and from approximately 5 to 35 miles offshore at various depths from 56 to 208 fathoms. A total of 30 drags was made by the John N. Cobb in the fall and 85 drags by the Tordenskjold in the spring. VESSELS USED The general design of the John N. Cobb is that of a West Coast purse seiner, as are most vessels of the Pacific Northwest trawl fleet. The vessel has an over-all length of 93 feet with a beam of 25 feet and a mean-load draft of 9 feet (Ellson 1950). On a seine-type trawler, the net is set and towed from the stern and hauled over the starboard side. Fig. 3 The chartered vessel, Tordenskjold, a schoonertype trawler. The Tordenskjold, a schooner-type vessel, was designed and built for halibut fishing (Sundstrom 1957), but was rigged for trawling in 1942. This vessel has an over-all length of 75 feet, a beam of 18 feet, and a mean-load draft of 9 feet. The net is set and hauled over the starboard side on this type of schooner-trawler and, as in the case of seine-type trawlers, is towed from the stern. FISHING GEAR A standard 400-mesh western otter trawl, similar to that described by Alverson (1951), with a 41-inch mesh1/ cod end and a 400-mesh eastern otter trawl (fig. 4) with a 3-inch mesh cod end were used for the bottom-fish investigations. During the 1957 exploration, the last 6 feet of the cod end of the otter-trawl were lined with 1-inch mesh netting. The purpose of the liner was to retain shrimp encountered during otter-trawl drags. Areas which yielded significant quantites of shrimp when the cod end with the liner was used were subsequently fished with a 43-foot flat Gulf of Mexico-type shrimp trawl. This trawl had a 1-inch mesh cod end and was towed from a single cable using a 25-fathom bridle arrangement ahead of the doors (Schaefers & Johnson 1957). A Dietz-LaFond type bottom sampler was used near the end of each drag. The subsequent bottom sample, in conjunction with the contents of the net and/or the type of gear damage sustained, was the basis for determining the type of bottom recorded for each drag. TRAWLING BOTTOM SUITABLE TRAWLING BOTTOM: A considerable amount of clear trawling bottom was located between the 50- and 200-fathom depth contours (fig. 5). Abundant 1/All mesh sizes referred to in this report are stretched measure, including one knot. |