Part II: PELAGIC FUR SEAL INVESTIGATIONS, 1966 



Pelagic fur seal research in 1966 was 

 carried out from 21 January to 25 March off 

 the coast of central and southern California, 

 one of the major fur seal wintering grounds 

 in the eastern North Pacific. Primary objec- 

 tives of the research were to study the dis- 

 tribution of fur seals by nnaking a systennatic 

 survey of the area at a time of maximunn 

 abundance and to collect a representative 

 sample of fur seals for studies of food habits, 

 age, sex, size, and reproductive condition. The 

 survey and collections of fur seals extended 

 our coverage of the area south to lat. 32° N. 



and offshore in most places to a distance of at 

 least 185 km. (100 miles). This was the 9th 

 year of research under the terms of the In- 

 terim Convention on Conservation of North 

 Pacific Fur Seals. 



This part of the report summarizes re- 

 search data obtained at sea in 1966 and relates 

 it to information collected in other years. The 

 distribution of fur seals in 1965 and 1966 are 

 compared. Also given are the results of 

 food habits studies for several years and 

 observed changes in the feeding habits of fur 

 seals. 



EQUIPMENT, METHODS, AND PERSONNEL 



In the past, 21 - to 24-m. (70- to 80-foot) 

 fishing vessels (purse seiner type) have been 

 satisfactory for collecting the large numbers 

 of seals needed to fulfill requirements of the 

 Convention. Since 1963 the Commission has put 

 less emphasis on collecting a large number of 

 seals but requires that research effort beheld 

 at about the same level. This requirement has 

 caused studies of distribution to be expanded. 

 The distribution studies require larger vessels. 



Two relatively large vessels were used for 

 pelagic research in 1966. The M/V Pribilof •■■ "^ 

 was used primarily for survey work and 

 secondarily for collecting seals. The height of 

 the bridge above the water was an advantage 

 for observing seals during studies of distribu- 

 tion, and the large size of the Pribilof allowed 

 her to work safely far offshore and to remain 

 there during storms. A vessel's usefulness for 

 collecting seals, however, decreases as its 

 size increases. The Pribilof, for exannple, 

 could not be used to chase seals, because most 

 would easily escape if not collected on the first 

 pa ss. A smaller but more naaneuverable vessel, 

 the M/V Lynnann,"""^ a whale catcher, was char- 

 tered primarily for collecting seals in 1966. 



The Pribilof and the Lynnann were satis- 

 factory for the work in 1966. Dories launched 

 from these vessels (when weather permitted) 

 were useful supplements for hunting seals. 



M/V Pribilof : Bureau of Comrnsrcial Fisheries Pri- 

 bilof Islands supply vessel; registered length 64 m. (210 

 feet), 3,398 m.^ (1,200 gross tons), 14,000 horsepower, 

 cruising speed 22.2 km. per hour (12 knots), 



■"■^M/V Lynnann ; registered length 38.3 m. (125.5 feet), 

 736 m.-' (260 gross tons),l, 000 horsepower, cruising speed 

 18.5 km. (10 knots). 



Equipment and methods, now standardized, 

 have been described by Fiscus, Baines, and 

 Wilke (1964), and by Fiscus and Kajimura 

 (1967). Twoobservers equipped with binoculars 

 were continuously on duty while the vessel 

 cruised transects for studies of distribution. 

 From their respective stations on either side 

 of the bridge, the observers recorded all seals 

 sighted, time observed, estimated distance 

 from the vessel when abeam of the seal, and 

 behavior of each (i.e., sleeping, resting, swim- 

 ming, feeding, etc.). The position of the vessel 

 was plotted hourly on a chart by the mate of 

 the watch. The location of each seal observed 

 was also plotted. 



Seals were shot with 12-gauge shotguns 

 loaded with 00 buckshot, weighed, measured, 

 and examined for tags, marks, scars, general 

 condition, barnacles, and algae. Stomachs, 

 reproductive tracts, and upper canine teeth 

 were collected and taken to our laboratory in 

 Seattle at the end of the season. Here, stomach 

 contents were identified, reproductive con- 

 ditions were recorded, and teeth were sec- 

 tioned for determining age. The data were 

 recorded on punch cards and processed. 



Because records for eight seals were in- 

 complete, these animals are represented only 

 in the sections on distribution of seals by date 

 and locality, and relative abundance and size 

 of groups. 



Biologists aboard the vessels and in the 

 Seattle laboratory were: Richard K. Stroud-- 

 M/V Lynnann ; Clifford H. Fiscus and Hiroshi 

 Kajimura-- M/V Pribilof . Assistants aboard 

 the vessels and in the laboratory were David 

 Harcombe, Roger E. Paul, and Donald E. Ross. 

 Milton E. Timmes assisted in the laboratory. 



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