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This report is a summary of observations and collections made by P.O.B.S.P. personnel in the eastern Pacific Ocean from 11-24 March,1967. Participating personnel included Brian Harrington (biologist-in-charge), David Burckhalter, and James Lewis. Superior cooperation was received from the officers and crew of the U.S.N.S. SHEARWATER (T-AG 177). The grid track was followed as closely as circumstances would allow, but due to equipment failure and weather conditions a few deviations will be noted. First, on the night of 14-15 March a departure from the grid was made at point "D" in order to go to Port Hueneme for repair of the ship's steering. After two days in port, we returned to point "D" on the night of 17-18 March. The biologist in charge does not feel that this interrup- tion had any significant effect on grid observation data. Other deviations from the nominal track will be noted between points "G" and "H", and can be accounted for by the fact that the LORAN was inoperative, and due to cloudy weather there were no accurate fixes. Although not shown on map one, it is quite possible that the track between points "M" and "O" was also inaccurate for the same reason. Diurnal positions in this section of the grid should be considered accurate only to the nearest ten miles, and within five miles over the remainder of the grid cruise. All nocturnal positions are probably within ten miles. Eastern Grid Survey Number 4 The eastern grid survey was conducted from 1200 hours 12 March until 2345 hours 22 March, 1967 with an interruption of three days from 14-17 March. A total of 89.6 hours of diurnal observation were conducted over 826 linear miles. A summary may
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be found in table 1. An additional 14.5 of nocturnal survey were conducted (see table 5.) Weather data during this survey were recorded on appropriate forms and ADP sheets. In general, light winds and seas predom- inated; a high pressure system in the area was a major influence. Thus, in general, observation conditions were quite similar to those on the last EAC cruise, and hence the two can be reasonably compared. Also diurnal survey was conducted in approximately the same areas on both cruises thus allowing further compara- bility. But, as will be discussed later, there were major differ- ences in the populations found. Thirty bathothermographs were taken over about 3/5 of the grid track at four hour intervals; a damaged cable prevented drops over the last portion. Flocking With the exception of a few groups of storm petrels and Red phalaropes, flocking activity was not observed during this survey. Flocking in the above species will be discussed in the species accounts. Food Sources Over previous EAC cruises only one school of feed-fish has been noted. During this survey numerous schools of small fish were frequently noted at night over the western extreme of the southern two thirds of the grid. None were seen during daylight hours. It would seem likely that such an abundance would attract fish-feeding birds; but such did not seem to be the case. In fact, fewer fish- feeding species were noted than on any of the previous surveys, little doubt due to the fact that they have migrated northward.
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all the black storm petrels noted this cruise were probably Leach's. Density distribution was noticeably different in the north section where on previous cruises it has not exceeded .032 birds per square mile. This survey a density of .113 (N=28) was noted in the north. A brief review of regional density suggests that the Leach's petrel probably moves around a great deal in the winter range. Besides the fluctuations noted above, the central area has varied from .106 to .199 b/sq.mi. and the south from .153 to .308. East- west densities have also varied considerably. As noted in previous reports, some of this variation may be accounted for by differences in observation conditions. Six Leach's Petrels were collected in the grid; of four males two were recorded as having enlarged gonads, and one of two females had slightly enlarged ova. Fork-tailed Petrel (Oceanodroma furcata) 2 Both sightings were in the north section. In view of previous survey results it does not seem reasonable to assume that the apparent population decline is significant. Pterodroma sp. (Unidentified) 7 Of seven sightings, six (two birds each in three sightings) were noted in the western half of the grid. Only two were seen reasonably well, and these were believed to have been White-winged Petrels (P. leucoptera), but a positive field identification was not made. Red Phalarope (Phalaropus fulicarius) 291 + 4 nocturnal Red Phalarope were the most abundant species in the grid during this cruise. Most were in flocks, but many were also recorded
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as single birds.Both males and females were collected. Most had some red feathers of the nuptial plumage present, but none were noted to have significantly enlarged gonads. But the heavy fat condition on most specimens as well as the apparently increasing flocking tendency suggests that a migratory movement may be under way or imminent. Density distribution on this cruise was different from that recorded last month when the north and south sections were favored. This cruise no birds were seen in the north section, about 65% were in the central section, and the remainder were in the south. East-west distribution was also different from last month when the western section was highly favored. This cruise the western area still had the most dense population, but the east had fifteen times as many birds as last month. These changes when combined with the fact that the population has been steadily increasing suggests that, if not migrating, the population density is quite static. Pomarine Jaeger (Stercorarius pomarinus) 2 Jaeger sp. (Unidentified) 1 The reduction of numbers suggests that the higher numbers noted last month were indicative of a migration peak. As in past cruises, all sightings were in the eastern portion of the grid. Glaucous-winged Gull (Larus glaucescens) 4 Three of the four sightings were in the north section, and the other was in the central section. All were immature birds. The sharp overall reduction of numbers indicates that this species has probably migrated to the north. Herring Gull (Larus argentatus) 119 The sharp change of distribution since previous cruises is
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Grid Mammals Changes in mammal populations since previous cruises would seem quite significant. In the north section mammals were conspicuous by their absence. Where on previous cruises we would normally see up to thirty Fur Seals (Callorhinus ursinus) only four were identified. Two additional seals were unidentified. No other mammals were seen in the north section. The central section was heavily populated with mammals. Seals were represented by one bull Elephant Seal (Mirounga angustirostris), an unidentified sea lion, and two unidentified Otarids. Whales were numerous and included what was believed to have been a Baird's Beaked Whale (Berardius bairdii). Twenty-nine Sperm Whale (Physter catodon) and 28 Pilot Whales (Globi- cephala scammonii) were also identified. All the Sperm Whales were travelling in a northward direction. Porpoise in the central section were of two identified species. Fourteen Bottle-nosed Dolphin (Tursiops truncatus) were seen in two groups, each time in company with another species( Pilot whale and Risso's Dolphin). Five Risso's Dolphin ( Grampus griseus) were tentatively identified and photographed. In addition to those photographed, five unidentified porpoise were seen. The south section also had a good number of mammals. Otarids were represented by two unidentified sea lions. Twenty five Pilot Whales and five Sperm Whaleswere also seen. Porpoise were numerous, but most were unidentified. Those which were well seen included Bottle-nosed Dolphin,(3), Risso's Dolphin (5), 12 Striped Dolphin (Lagenorhynhus obliquidens) and two Baird's Dolphin (Delphinus delphis). The latter two species were in the same school, as were the Risso's and Bottle-nosed Dolphin. Of the 53 unidentified por-
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Non-Grid Survey No.5 Once again the non-grid survey includes observations made while proceeding to (northern section) and returning from (southern section) the grid area. In addition, due to ship troubles which necessitated return to port, an extra day of non-grid observations was made in the northern section. For the days of March 11, 12, and 17 observations were carried on for 13.4 hours over a distance of 143 linear miles. On March 23 sightings were conducted for 11.9 hours over a distance of 66 linear miles. A total of 25.3 daylight hours of observation was conducted over 209 linear miles (see map). All non-grid observations are summarized in Table 7. Schedule time distance begin observations cease observations Mar. 11 2.6 hrs. 35 mi. 1515 Pt. Fermin 1800 33°55'N 118°51'W Mar. 12 5.7 hrs. 50 mi. 0620 34°38'N 121°03'W 1200 34°57'N 121°59'W Mar. 17 5.1 hrs. 58 mi. 1300 34°09'N 119°23'W 1810 34°10'N 120°24'W Mar. 23 11.9 hrs. 66 mi. 0620 31°41'N 120°06'W 1810 32°44'N 118°51'W Activity in the two non-grid sections appeared to be much the same, with birds usually engaged singly in their daily activities. In the northern section, however, there was some evidence of flocking activity. Several large flocks of gulls were observed off shore* and they accounted for more than one-half of the northern non-grid birds logged. Also a few large flocks of alcids and a few small flocks of Kittiwakes were observed a few miles off shore in the Santa Barbara channel. Since no flocking activity was noticed in the southern non-grid section, where observations were conducted as close to 50 miles near land, birds were apparently grouping only in off shore waters. * Off shore refers to coastal waters just off shore.
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Jaegers Jaegers were seen occasionally (9) in both non-grid sections. Five were recorded as Pomarine Jaegers, while four were recorded as Jaeger sp. One Pomarine Jaeger was observed one mile off shore in the northern section. Red Phalarope Red Phalaropes (13) were commonly seen in the southern portion of the non- grid area. All occurred singly or in pairs. Once again none were sighted in the northern section. Gulls As in the previous cruises Herring Gulls were infrequently observed near land; only close to the grid area were they commonly sighted. On this cruise 37 were logged (9 adults: 1 immature), 34 in the northern section and 3 in the southern section. Herring Gulls in the southern section were greatly reduced in numbers from previous cruises. As far as other kinds of gulls were concerned, great numbers of them (est. 1200), mostly California Gulls (156 positively identified), were aggregated close to shore along the Santa Barbara channel, some of which briefly followed the ship. No California Gulls were sighted in the southern non-grid section. In the northern section also observed were 11 Western gulls (adults), 3 Glaucous-winged Gulls (immatures), 1 Ring-billed Gull (immature), and 48 Black-legged Kittiwakes (1 adult : 3 immature). In the southern section, on the other hand, Western Gulls were more commonly sighted (21, 1 adult; 1 immature, 1 collected), while only one adult Black-legged Kittiwake was seen (collected). Contrasting this survey to the one before it, Black-legged Kittiwakes were extremely abundant in the prior one (1109 birds) in the same southern area where observations were made. In the previous report, I stated that an exceptional feeding area was responsible for the large aggregation of birds. I also ruled
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Date 12/MARCH Ship SHEARWATER (LAG 77) Cruise No. 17747-4 Organization________________ Recorder_________________ Sunrise: Time 0621 Position: Lat.34°38'N, Long.121°02'W Sunset: Time 0615 1815 Position: Lat. 35°03'N, Long. 122-52W Miles travelled from 0000 hours to sunrise = 63 Miles travelled from sunrise to sunset = 97 45 mi in gulf Miles travelled from sunset to 2400 hours = 56 TIME OF FIX TYPE OF FIX LATITUDE LONGITUDE 1. 2. miles Sunrise to noon : 59 3. noon to sunset: 38 4. 97 5. Hourly Positions: Time Latitude Longitude Wind Dir. Wind Sp. Wave Dir. Wave Hgt. 0100 34°15.5'N 120° 01'W 225 5 345 2 0200 34° 21.2'N 120° 11.2 240 7 345 3 0300 34° 23.3'N 120° 24'W 250 9 350 3 0400 34° 26.5'N 120° 38.5 250 9 350 3 0500 34° 31'N 120° 55'W 180 17 270 8 0600 34° 36'N 120° 59'W 150 17 270 8 0700 34° 41'N 121° 11'W 150 17 270 8 0800 34° 46'N 121° 24' W 150 15 225 7 0900 34° 48'N 121° 30'W 150 21 210 9 1000 34° 50'N 121-38W 180 21 210 9 1100 34° 52'N 121-48W 150 21 210 9 1200 34° 58'N 122-00' 180 21 210 9 1300 34° 58'N 122-04 205 15 245 9 1400 34° 58'N 122-11'W 205 15 245 9 1500 34° 58'N 122.92W 205 15 250 10 1600 34° 58'N 122-34W 200 15 250 12 1700 35-06'N 122-42W 220 15 290 14 1800 35-02'N 122-52'W 220 15 225 15 1900 35-05'N 122-55'W 240 15 225 15 2000 35-07 123-07 W 220 10 225 16 2100 35-07 123-18W 220 13 230 10 2200 35-06 123-30W 230 13 230 10 2300 35-06 123-40'W 250 13 230 10 2400 35-06N 123° 52'W 250 13 230 10 958b-SI-MNH Rev. 9/28/66
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Date 19 MARCH 67 Ship SHERWATER (FAG+71) Cruise No. 77-67-4 Organization P.O.R.S.P. Recorder Sunrise: Time 0630 Position: Lat. 32°59'N, Long. 126°26'W Sunset: Time 1830 Position: Lat. 32°34'N, Long. 124°44'W Miles travelled from 0000 hours to sunrise = 67 Miles travelled from sunrise to sunset = 110 Miles travelled from sunset to 2400 hours = 55 TIME OF FIX TYPE OF FIX LATITUDE LONGITUDE 1. 1900 STAKS 32°34'N 124°38'W 2. Hourly Sun Lines & L.A.W. for 1200 posn. 3. 4. 5. Hourly Positions: Time Latitude Longitude Wind Dir. Wind Sp. Wave Dir. Wave Hgt. 0100 33°18'N 125°34'W 345 12 300 6 0200 33°18'N 125°44'W 345 12 320 8 0300 33°18'N 126°02'W 345 12 320 8 0400 33°18'N 126°14'W 300 14 320 10 0500 33°18'N 126°25'W 300 10 310 8 0600 33°05'N 126°26'W 300 8 320 4 0700 32°54'N 126°27'W 300 8 290 4 0800 32°47'N 126°35'W 320 14 290 6 0900 32°33'N 126°22'W AIRS 4 270 3 Reach PTG+100 1000 32°34'N 126°12'W AIRS 3 CALM CL TO +90 1100 32°35'N 126°03'W AIRS — CALM SKIP IN 1200 32°35'N 125°54'W AIRS — CALM water today 1300 32°35'N 125°44'W AIRS — CALM 1400 32°35'N 125°34'W AIRS — CALM 1500 32°35'N 125°21'W 285 8 330 3 1600 32°37'N 125°11'W 25 5 300 4 1700 32°34'N 125°02'W 275 10 330 5 1800 32°34'N 124°49'W 275 10 350 5 1900 32°34'N 124°38'W 275 10 330 5 2000 32°34'N 124°28'W 275 10 330 5 2100 32°33'N 124°14'W 270 10 270 1 2200 32°32'N 124°02'W 270 10 270 1 2300 32°32'N 123°50'W 270 10 270 1 2400 32°31'N 123°36'W 270 10 270 2 958b-SI-MNH Rev. 9/28/66
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Date 20 MARCH Ship SHEARWATER (FAG-17) Cruise No. 177-L7-4 Organization____________________ Recorder______________________ Sunrise: Time 0614 Position: Lat. 32°29'N, Long. 121°20'W Sunset: Time 1817 Position: Lat. 31°46'N, Long. 121°28'W Miles travelled from 0000 hours to sunrise = 64 Miles travelled from sunrise to sunset = 130 Miles travelled from sunset to 2400 hours = 63 TIME OF FIX TYPE OF FIX LATITUDE LONGITUDE 1. 0600 STAR 32°24'N 122°22'W 2. 1830 STARS 31°46'N 121°-31'W 3. 4. 5. Hourly Positions: Time Latitude Longitude Wind Dir. Wind Sp. Wave Dir. Wave Hgt. 0100 32° 31'N 123°25'W 300 10 310 1 0200 32° 30'N 123°13'W 300 10 310 1 0300 32° 30'N 123°01'W 300 9 310 2 0400 32° 30'N 122°49'W 300 10 310 3 0500 32° 30'N 122°37'W 300 10 300 3 0600 32° 24'N 122°25'W 300 10 300 3 0700 32° 24'N 122°18'W 300 10 310 5 0800 32° 24'N 121°58'W 300 8 310 5 0900 32° 22'N 121° 44 330 13 320 5 1000 32° 22'N 121° 33'W 330 13 320 6 1100 32° 22'N 121° 19'W 330 13 330 6 1200 32° 22'N 121° 07'W 330 13 300 6 1300 32°07'N 121°00'W 320 14 330 5 1400 31°57'N 121°00'W 320 14 320 5 1500 31°51'N 121°00'W 320 15 320 6 1600 31°42'N 121°05'W 320 14 320 7 1700 31° 43'N 121° 10'W 320 14 320 6 1800 31° 46'N 121° 27'W 330 13 320 6 1900 31° 46'N 121° 39'W 330 15 320 6 2000 31° 45'N 121° 49'W 320 15 330 6 2100 31° 43'N 122° 02 330 11 330 4 2200 31° 42'N 122° 15'W 330 11 340 4 2300 31° 41'N 122° 27'W 345 14 340 4 2400 31° 40'N 122° 40'W 345 14 340 4 1300-1700 - Maneuvering to Fix STG-Gear. 958b-SI-MNH Rev. 9/28/66
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Date 21 MARCH 67 Ship SHEARWATER (TAG-17) Cruise No. 177-67-04 Organization ________________ Recorder _______________ Sunrise: Time 0620 Position: Lat. 31°09'N, Long. 123°57'W Sunset: Time 1833 Position: Lat. 31°46'N, Long. 126°06'W Miles travelled from 0000 hours to sunrise = 66 Miles travelled from sunrise to sunset = 99 <Note see chart. Lots of maneuvering - ENG Miles travelled from sunset to 2400 hours = 65- TIME OF FIX TYPE OF FIX LATITUDE LONGITUDE 1. 1200 By L.A.N. Hourly Sun Lines from 0900-1500 hrs. 2. all other D.R. Positions ECRS 3. 4. 5. Hourly Positions: Time Latitude Longitude Wind Dir. Wind Sp. Wave Dir. Wave Hgt. 0100 31°46'N 122°51'W 305 11 301 2 0200 31°34'N 123°04'W 320 12 315 5 0300 31°33'N 123°14'W 320 14 320 9 0400 31°39'N 123°25'W 320 14 310 9 0500 31°39'N 123°40'W 320 14 310 9 0600 31°39'N 123°52'W 320 14 310 9 0700 31°38'N 124°05'W 310 11 310 8 0800 31°38'N 124°18'W 310 11 310 8 0900 31°39'N 124°26'W 310 11 290 8 1000 31°40'N 124°36'W 30 06 296 8 1100 31°41'N 124°47'W HAFRS - CALM 1200 31°44'N 125°00'W HAFRS - CALM 1300 31°44'N 125°09'W HAFRS - 250 17 1400 31°48'N 125°19'W HAFRS - 250 4 1500 31°45'N 125°29'W 315 10 270 3 1600 31°44'N 125°37'W 315 10 270 3 1700 31°42'N 125°47'W 300 5 270 3 1800 31°41'N 125°59'W 270 5 270 3 1900 31°40'N 126°13'W 285 9 270 3 2000 31°33'N 126°23'W 285 9 270 3 2100 31°22'N 126°24'W CALM - CALM -- 2200 31°16'N 126°24'W CALM - CALM -- 2300 30°58'N 126°25'W CALM - CALM -- 2400 30°56'N 126°20'W CALM - CALM -- 958b-SI-MNH Rev. 9/28/66