April 1951 CCMMERCIAL FISHERIES RE7IEW 9 



THE JOHN N.. COBB'S SHELLFISH EXPLORATIONS IN CERTAIN 

 SOUTHEASTERN ALASKAN WATERS, SPRING AND FALL OF 1950 



(A Preliminary Report) 

 By Edward A. Schaefers* 



INTRODUCTION 



The ccanmeroial shellfish potentialities in certain southeastern Alaskan waters 

 were surveyed by the John N. Cobb , an exploratory fishing vessel of the U. S. Fish 

 and Wildlife Service, in the spring and fall of 1950. Special emphasis was placed 

 on shrimp and crab fisheries. 



During the spring of 1950 a combined shakedown and shellfish survey cruise 

 was made by the vessel. Because of the limited amount of time between the vessel's 

 commissioning in February 1950 and the start of an extensive offshore exploration 

 for albacore , this first survey was a short one. Actual exploratory work was car- 

 ried on frcm March 24 to April 11 in the region near Ketchikan. 



A second survey was conducted fran October 30 to December 9. These five weeks 

 were spent in the waters adjacent to Baranof and Chichagof Islands. 



The cruises were made in the spring and fall because it was believed that the 

 findings might assist in the establishment of "off -season" fisheries in the area; 

 moreover, during these months work in the open ocean by an exploratory vessel tends 

 to be less practicable and productive because of time lost for adverse weather. 



This report is presented in two parts. The first part discusses the spring 

 survey trip while the second part discusses the fall operations. 



RESULTS OF SPRING OPERATIONS 



TYPES OF GEAR ; Three types of gear were used in the spring fishing operations — 

 traps, an otter trawl, and a dredge. 



The shrimp traps, made up of l^-inch stretched-mesh cotton webbing, were cubic 

 in shape with sides 34 inches square, containing 4 cone-shaped entrances (3 inches 

 in diameter) located in the center of each vertical side. 



The otter trawl, a small West Coast box-type trawl with a total length of 46O 

 meshes, had wings and body made of 21-thread, 2-inch stretched-mesh cotton webbing, 

 and a cod end of 24-thread, l^inch stretched-mesh cotton webbing. The net at the 

 throat was I5O meshes across and had a 75-niesh breast. 



The dredge used had a cast-iron frame and was spread with an 8-foot steel-pipe 

 beam. It was similar in most respects to a small Blake deejy-sea trawl, the chief 

 difference being the addition of two beams on the outer margin of the U-shaped 

 runneirs. The extra beams gave additional support to the frame and also seirved as 

 a place of attachment for the net. The net was a simple bag made of l|-inch 

 stretched-mesh, 24-thread cotton webbing. Although no sweep ropes were used, the 

 extra beams served in a similar manner. 

 ♦fishery engineer, north pacific exploratory fishery program, exploratory fishing and gear 



development section, branch of commercial fisheries, u. s. fish and wildlife service, 



seattle. washington. 



