about 10 pounds when they return to spawn and 

 die in their native stream. Most chum salmon are 

 taken in purse seines and are canned; hundreds of 

 thousands are caught in jrill nets and fish wheels 

 for human and dog food. This fishery is mostly in 

 the large rivers that run into the Bering and 

 Chukchi Seas of northern Alaska. Little biological 

 research has been done on chum salmon, so less 

 is known about them than any other Pacific salmon. 



633. Diversion and Collection of Juvenile Fish 

 with Traveling Screens. By Daniel W. Bates. 



March 1970, 6 pp., 6 figs. 



.ABSTR.ACT 



A horizontal traveling screen, suitable for screen- 

 ing fish or debris from powerplant water intakes 

 or irrigation diversions, was designed and operated 

 by the Bureau of Commercial F'isheries during 196.5- 

 69. The structure consisted of a vertically hung, 

 endless belt or wire-cloth screen panels, flush with 

 the face of the water intake structure or at an angle 

 to the direction of flow. 



Field tests in different water approach velocities, 

 with the screen traveling at various rates, proved 

 that such a facility can be operated efficiently. The 

 horizontal traveling screen, as described here, 

 should contribute materially to the development of 

 an efficient, relatively low-cost diversion facility 

 for fish and debris. 



Special Scientific Report — Fisheries 



586. The Trade Wind Zone Oceanography Pilot 

 Study Part VII: Observations of Sea Birds 

 March 1964 to June 1965. By Warren B. King. 

 June 1970. vi + 136 pp., 36 figs., 11 tables, 2 

 app. tables. 



ABSTRACT 



Sea birds were observed by scientists of the 

 Smithsonian Institution's Pacific Ocean Biological 

 Survey Program on a systematic basis in the central 

 Pacific Ocean for 1.5 months as part of the Trade 

 Wind Zone Oceanography Program of the Bureau 

 of Commercial Fisheries Biological Laboratory, 

 Honolulu. Hawaii. Two experienced observers al- 

 ternated watches each day from sunrise to sunset. 

 Every bird sighted was identified and logged, along 

 with the time and location of observation, the 

 number of birds in the sighting, and, when possible, 

 their age, sex, plumage, molt, behavior, direction of 

 flight, and any other information that might prove 

 pertinent. Twenty-five birds that were captured 

 alive were banded, and 18 birds were collected to 

 help verify sight records of species seldom or never 

 recorded previously in the central Pacific. In .'5,561.1 

 hours of observation, 1:5,080 sightings were made 

 of 65,707 birds along the replicate cioiise track 

 covering :34,:584 nautical miles {63,610 km.) 



The distribution and abundance of each of the 

 51 species or field-recognizable subspecies observed 

 within the study area were treated on a monthly and 



seasonal basis and discussed in the light of the 

 island of origin and breeding phenology of each 

 species. The abundance of sea birds was examined 

 in relation to environmental conditions to show the 

 extent of their association. 



The composition, distribution, and abundance of 

 flocks of sea birds were analyzed. 



587-590. Published in 1969. 



591. A Bibliography of the Lobsters, Genus 

 Homarus. By R. D. Lewis. January 1970, i + 

 47 pp. 



ABSTRACT 

 A total of 1,303 references are given. 



592. Passage of Adult Salmon and Trout 

 Through Pipes. By Emil Slatick. January 

 1970. iii + 18 pp.. 8 figs.. 12 tables. 



ABSTRACT 

 Pipes, which are relatively inexpensive and easily 

 installed, are an economical and efficient solution 

 to certain problems of fish passage at dams and at 

 other obstacles blocking migratory routes. The 

 purposes of this study (1963-64) were to determine: 

 (1) if adult salmon and trout at Bonneville Dam 

 on the Columbia River would use a pipe as a pas- 

 sageway and ("2) how the conditions at the entrance 

 and within the pipe, diameter and length, illumina- 

 tion, and flow would influence passage. The pipes 

 were 0.3, 0.6. and 0,9 m. in diameter and were "27.4 

 to 82.3 m. long. Chinook salmon (OtKorhytichiis 

 tshawytscha), sockeye salmon (O. nerka). coho 

 salmon (O. kisutch), and steelhead trout iSahno 

 gai)d)ieri) passed through unilluminated pipes up 

 to 82.3 m. long. Of the four species tested, only 

 steelhead trout appeared to benefit appreciably 

 from illumination. For distances up to 82.3 m., a 

 0.6-m. -diameter pipe was large enough to pass all 

 salmon and trout. The fish passed through a 0.6-m.- 

 diameter pipe when it was flooded or partly filled 

 with water, but did not readily enter a 0.3-m. pipe 

 until special conditions of water velocity and transi- 

 tion from pool to pipe were provided. 



593. Published in 1969. 



594. Seasonal and Areal Distribution of Zoo- 

 plankton in Coastal Waters of the Gulf of 

 Maine, 1967 and 1968. By Kenneth Sherman. 

 July 1970, iii + 8 pp., 6 figs.. 3 tables. 



ABSTRACT 

 The abundance, composition, and seasonal vari- 

 ations in the distribution of zooplankton are des- 

 cribed. Thirteen taxa were among the more abundant 

 zooplankters in the samples: 6 were holoplanktonic, 

 and 7 were meroplanktonic. Copepods were the 

 dominant zooplankters during all seasons in both 

 years. Zooplankton volumes were highest in the 

 western area (Cape Ann to Cape Elizabeth), inter- 



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