for the fourth consecutive year and provided 5 per- 

 cent of the catch in the Chesapeake Bay Area and 

 36 percent of the catch in the North Carolina fall 

 fishery. On the liasis of its contribution to the fish- 

 ery in the Chesapeake Bay and Middle Atlantic 

 Areas, the incoming year class (1961) appeared to 

 be less than average in abundance. Except for age-0 

 fish, the mean lengths and weights in the South At- 

 lantic Area in 1962 were less than the means for the 

 previous 7-year period. The means for age-4 fi.sh 

 were less than the 7-year means in the Middle and 

 North Atlantic Areas, but slightly greater in the 

 Chesapeake Bay Area. With few exceptions, the 

 mean lengths and weights of other age groups in 

 the Chesapeake Bay, Middle Atlantic, and North 

 .Atlantic .Areas were greater than the 7-year means. 



528. U.S. Federal research on fisheries and lim- 

 nolog'y in the Great Lakes throii.srh 1964: An 

 annotated bibliography. By Ralph Hile. 

 March 1966, iii + 53 pp., 2 tables. 



ABSTRACT 

 The annotated bibliography is preceded by a brief 

 account of the Federal research program in fisheries 

 and limnology in the Great Lakes in 1957-64. The 

 bibliography covers 314 papers by staff members 

 of the Bureau of Commercial Fi.sheries Biological 

 Laboratory in Ann Arbor, Mich., and 35 by asso- 

 ciated scientists with whom the Laboratory had 

 contractual or other cooperative arrangements; in- 

 cluded also are patents issued to Laboratory person- 

 nel. A roster of Laboratory scientists as of Decem- 

 ber 31, 1964, is appended. 



529. The Bureau of Commercial Fisheries Type 

 IV electrofishing shocker — Its characteristics 

 and operation. Bv Beniamin G. Patten and 

 Charles C. Gillaspie. April 1966, iii + 15 pp., 

 10 figs. 



ABSTRACT 



A fish .shocker which is efl^ective, dependable, light 

 weight, and economical to purchase and operate is 

 described. The output energy of this shocker is 450 

 volts direct current at 150 milliamperes, pulsed into 

 square waves at frequencies controllable from 20 to 

 100 per second with a fixed duration of 6 millisec- 

 onds. 



This output energy produces a good galvanotaxis 

 reaction in fish in the field. Our experimentation 

 and information from the literature indicates the 

 output energy of the described shocker to be of a 

 favorable range. 



Methods of operation of electric shockers are 

 given. The recommended sizes of the electrodes are 

 about 40 cm. square for the anode and 2.3 m. square 

 for the cathode. The electrodes should be operated 

 close together, especially in resistive waters. In 

 suitable waters a wading technique is used, but a 

 floating electrofi.shing operation is necessary if 

 waters are deep or swift. 



The effectiveness of a shocker is often reduced 

 by environmental factors, but in most situations 

 little can be done to compensate for this. The effects 

 of water resistivity, variations in fish size or species, 

 temperature, and fish mortality factors are discussed 

 in relation to the success of eleetrofishing operations. 



530. Seasonal and areal distribution of zoo- 

 plankton in coastal waters of the Gulf of 

 Maine. 1964. By Kenneth Sherman. May 

 1966, 11 pp., 10 figs., 4 tables. 



ABSTRACT 

 A description is given of the composition and sea- 

 sonal variations of zooplankton in coastal waters of 

 the Gulf of Maine during 1964, and comparisons 

 are made between 1963 and 1964. Twelve zooplank- 

 ton groups (major taxa) were represented in the 

 samples. Five occurred as holoplanktonic forms and 

 seven were meroplanktonic. Copepods were the dom- 

 inant zooplankters during all seasons. Zooplankton 

 volumes for both years followed similar areal trends. 

 Mean annual volumes were highest in the western 

 area (Cape Ann, Mass., to Cape Elizabeth, Maine) ; 

 moderate in the central area (Cape Elizabeth to Mt. 

 Desert Island, Maine) ; and low in the eastern sector 

 (Mt. Desert Island to Machias Bay, Maine). Zoo- 

 plankton volumes were generally lower in 1964 than 

 in 19G3. Seasonal and annual variations in abun- 

 dance of zooplankters ai-e discussed in relation to hy- 

 drography. Local hydrography appears to influence 

 the abundance and distribution of coastal zooplank- 

 ters more directly than does the cyclonic-eddy system 

 of the Gulf proper. 



531. Length-weight relation of the summer 

 flounder Paralichthys dentatns (Linnaeus). 

 By Fred E. Lux and L. R. Porter, Jr. June 

 1966, iii + 5 pp., 1 fi.g., 3 tables, 1 app. table. 



ABSTRACT 

 Length-weight equations of the form W r= c L'' 

 in which W is weight, L is length, and c and b are 

 constants are given for summer flounder for each 

 calendar quarter. Weight for a given length varied 

 seasonally. Males were slightly heavier than fe- 

 males of the same length. 



532. Growth and survival of sockeye salmon in- 

 troduced into Ruth Lake after removal of 

 resident fish populations. By William R. 

 Meehan. July 1966, iii + 18 pp., 12 figs., 14 

 tables. 



ABSTRACT 

 Sockeye salmon (Oncorhynchus nerka) in three 

 lakes on Afognak Island, Alaska, were studied. Ruth 

 Lake was treated with rotenone to remove resident 

 fish. Midarm Lake, which had no salmon, and Little 

 Kitoi Lake, which has a small run of sockeye, were 

 used as controls to compare survival and growth of 

 introduced fry and natural fry with survival and 



