terbury in Christchurch, New Zealand, as part ofcontinuing cooperative project with the laboratoryProfessor George Knox. The dried lipid extracts Wreturned to California, where final determinationsthe pollutant concentrations in these wildlife sanipare proceeding, at the Bodega Marine Laboratory.

I am grateful for the assistance of Mr. Seddon Bnington of the University of Canterbury, expeditileader Mr. Brian D. Bell, and the other New Zca!aWildlife Branch personnel who assisted with the olections. This work was supported by National Sence Foundation grant GV-36080.

References

Alexander, W. B. 1955. Birds of tie Occ,i,i.c. New York, Put-nanis Sons. 306 r

George, J. L.. and D. E. H. Frear. 1966. Pesticides in theAntarctic. Journal of Applied Ecology. 3 ( suppi ) : 155 61/.

Risebrough, R. W., and G. M. Carmignani. 1972. Chlorinatedhydrocarbons in antarctic birds. In Con rerlaiwn Problem rin Anta,'ci,ci (13. C. Parker. ed) . p. 6380.

Risebrough, R. W., P. Reiche, D. B. Peakall, S. U. Herman,and M. N. Kirven. 1968. Polychlorinated hiphenvls in theglobal ecosystem. Ni/ore. 220: 1098-1102.

Siaden, W. J . L., C. M. Menzie, and W. L. Reichel 1966.DDT residues in Adélie penguins and a crabeater seat fromAntantica. Nature, 210: 670.3,

Tatton, J. 0'G., and j. H. A. Ruzu.ka. 1067. (.)rganochiorinepesticides in Antarctica. Nature, 215: 346-8.

Census of pelagic seals off theOates and George V Coasts, Antarctica

ALBERT W. ERICKSON, J . R. GILBERT and J . Otis

College of Lorestry, ll'ildlife and Range SciencesUnitei-stiy of Idaho

From January 16 to 26, 1973, a census was taken ofthe seals extant in the residual summer Pack ice offthe Oates and George V Coasts, Antarctica, employingUSCGC Burton Island and two 1414-52A helicopterson consignment to Burton Island from the Coast GuardAviation Training Command, Mobile, Alabama. Sup-plemental to this prime endeavor, a complete censusof the seals inhabiting the Ballcny Islands was per-formed, a general reconnaissance of Campbell Island ofthe Auckland Island group was made, and portions ofthe inshore areas along the western coast of the RossSea were censused for Weddell seals.

Results of the census of the Oates and George VCoasts are presented in the table. The census consistedof a 1.33 percent area sample of the outer pack icearid a 0.68 percent area sample of the total pack iceextant between 145°F. and 170°E. (fig.). The sample

effort was spread over ii randomly selected transectsextending from the pack ice edge to an average distanceof 49.7 nautical miles south toward the continent. Theprocedure followed in taking the census was for BurtonIs/and to penetrate the ice pack for distances up to 60miles along a given transect. A census was then madeby flying the census transect up to 60 miles farther southinto the pack and back out to the ice edge. The censuseswere conducted during the midday (1100-1400 local)haulout period for crabeater (Lobodon carcinophagus)seals (Erickson ci al.. 1971), and navigation along thetransect was by radar monitoring of the helicopters fromBurton Li/and. The surveys were flown at an elevationof 500 feet. The width of the transects was 1/1 nauticalmile on either side of the survey helicopter.

A total of 604.7 square nautical miles was includedin the census. This effort yielded 2,405 seals, or 3.98seals per square nautical mile. Projection of this densityestimate to the . 0,500 nautical square miles of areasampled (fig.) gives a minimal population estimate of1,131,000 seals for this area. This tentative estimate isexpected to he adjusted upward once the census data arefully analy zed and corrected for seals missed owing totime and weather effects (Siniff ci al., 1970; Erickson eta/.. 1971 ) . This estimate also does not include the areaof the ice pack l y ing south of the southern termini ofthe survey transects.

These data suggest lesser abundances of seals in thepack ice of the Oates and George V Coasts on a compari-son with siuiiilarly developed data for the Amundsenand Bellingshausen seas (Erickson ci al., 1972), wherea mean density of 6.09 seals per square nautical mile wasobserved. Both values are well below the densities (10to 20 per square nautical mile) determined for the Wed-dell Sea (Siniff ci al., 1970: Erickson ci al., 1971), butthe data for the Weddell Sea were developed differently,and thus direct comparisons with the data for the otherareas is difficult.

The species composition of the seals observed in theOates-George V Coast ice pack was 88.4 percent crab-eater (Lohodon ca'cinophapu.r), 6.1 percent leopard(H)di-urt,'a /(-ion)'x), 3.0 percent Weddell (Leptony-chotes uc'dde/iu), and 2.5 percent Ross (Oinniatophocaros.ri) . This compositional makeup is in very close agree-ment with that observed in the Amundsen and Belling-shausen seas (Erickson, 1972), where slightly greaterproportions of crabeater and leopard seals (92 and 4percent, respe( itvely) and slightly lower Proportions ofWeddell and Ross (2.5 and 1.5 percent) seals wereobserved. In all likelihood the agreement between thecompositional data of the two areas would have beengreater had not the census for the Oates and George VCoasts area included a slightly greater amount of interiorpack ice, which Weddell and Ross seals favor.

Tallies also were made of penguins and whalesduring the census. Totals included 47 Adélie (Pygoscelis

aof

e reofles

onridol-ci-

July-August 1973 191

GEORGE V-OATES COAST PACK ICE ZONE CENSUSED FOR PELAGIC SEALS IN 1973

adeliae) penguins, 29 emperor (Aptenodytes forsteri)penguins and 14 whales (Balaenoptera sp.). The rela-tively low numbers of penguins observed in the packice off the Oates and George V coasts corresponds withthe findings determined in the Bellingshausen andAmundsen seas (Erickson et al., 1972). This is under-standable in view of the fact that the adult birds areashore on rookeries during the austral summer. Nonethe-less, low penguin densities are indicated for these seasas contrasted to the much greater numbers of Adélieand emperor penguins that were observed in the WeddellSea (Erickson et al., 1969).

Of particular interest was the very few whales ob-served off the Oates and George V coasts. This is inmarked contrast to the large numbers of baleen whalesobserved in the Amundsen and Bellingshausen seas(Erickson et al., 1970). Explanations for this difference

are not obvious. It may reflect differences in the produc-tivity of the waters between the two areas, but data onthis point are lacking.

Concommitant with the pack ice censuses, blood speci-mens were obtained from 24 crabeater, 5 leopard, 27Weddell, and 4 Ross seals for use in studies of thepopulation affinities of antarctic seals. The samples weretaken from live seals following capture and anestetizationprocedures described by Cline et al. (1969).

Leucocyte cultures and chromosome spreads were pre-pared aboard Burton Island for later reading. Significantto this effort during 1973 was the high success achievedin preparing cultures employing the new trypsin bandingstaining technique (Seabright, 1971). Successful cultureswere obtained for each of the 60 seals attempted. Speci-mens of blood sera also were taken for analysis of theblood proteins and enzymes. The studies will be per-

192 ANTARCTIC JOURNAL

formed employing gel electrophoretic procedures (Sealet al., 1970, 1971) and microcomplement fixation tech-niques (Seal et al., 1970).

The survey of seals on Campbell Island of the Auck-land Islands group was attempted on January 11, 1973,and was conducted between 1713 and 1802 hours localtime. The procedure followed in taking the survey wassimply to fly the beach edge at approximately 500 feetelevation and enumerate all seals observed. Unfortunate-ly, many seals were in the water at the time of thesurvey and thus were not readily observed. Also, highwinds prevailed at the time of the survey, thus furtherlimiting its thoroughness. Despite these limitations, 122Hooker sea lions (Neophoea phocartos) and 66 ele-phant seals (Mirounga leonina) were observed. Sixty-nine of the sea lions were observed in two groupsat Northwest Bay. Another group of 27 was observed atSouth Point. The largest group of elephant seals observedwas 27, in the vicinity of Shoal Point. Another group of23 was observed at the base of Northwest Bay.

The survey of the Balleny Islands was conducted onJanuary 23, 1973. Conditions were ideal for taking thesurvey, the weather being bright and the wind calmthroughout. Consequently, a very thorough census wasachieved. Young Island, the most northerly of the BallenyIslands and located just north of the Antarctic Circle at67 0 5., was flown in the morning and was found devoidof seals except for 29 Weddell and 3 elephant sealsthat were observed on 2 small islets at the south end ofYoung Island. The shores of Young Island drop pre-cipitously to the ocean and afford almost no haulout areasfor seals. Buckle Island, just south of the AntarcticCircle, was censused at midday, and it, too, was devoidof seals. However, several Adélie penguin rookeries werenoted on the island together with small numbers ofchinstrap penguins (Pygoscelis antarctica). Sabrina Is-land, an islet at the south end of Buckle, was foundto harbor two small groups of seals numbering nineteenWeddell and five elephants. It also supported a mixed

colony of about 1,500 Adélie and chinstrap penguins.Sturge Island, the most southerly of the Balleny Islands,was surveyed during the evening hours. One group of 73Weddell and 3 elephant seals was located on a spitat the southern end of the island. Except for this smallspit, the entire island is ringed by glaciers or precipitouscliffs and is generally not suitable as a seal habitat.

The inshore areas of the Victoria Land coast thatwere surveyed included portions of Edisto and GerlacheInlets, Nova Bay, Tucker Inlet, and Coulman Island.Approximately 3,000 Weddell seals were observed alongthese coast regions. Of particular interest in these sur-veys was the finding of groups of Weddell seals number-ing up to 200 in glacier splits several miles inland fromthe ocean. The only way the seals could have reachedthese locations was by swimming under the glaciers.

References

Cline, D. R., D. B. Siniff, and A. W. Erickson. 1969. Im-mobilizing and collecting blood from antarctic seals. Journalof Wildlife Management, 33(1): 138-144.

Erickson, A. W., D. R. Cline, and R. J . Hofman. 1969. Popula-tion study of seals in the Weddell Sea. Antarctic Journal ofthe U.S., IV(4): 99-100.

Erickson, A. W., J . R. Gilbert, G. A. Petrides, R. J . Oehlen-schiager, A. Sinha, and J . Otis. 1972. Populations of seals,whales, and birds in the Bellingshausen and Amundsen Seas.Antarctic Journal of the U.S., VI1(4): 70-72.

Erickson, A. W., D. B. Siniff, D. R. Cline, and R. J . Hofman.1971. Distributional ecology of antarctic seals. In: Symposiumon Antarctic ice and Water Masses (G. Deacon, ed.). Cam-bridge, England, W. Heifer & Sons Ltd. p. 55-76.

Seabright, M. 1971. A rapid banding technique for humanchromosone. Lancet, 2(2): 971-972.

Seal, U. S., A. W. Erickson, D. B. Siniff, and D. R. Cline.1971. Blood chemistry and protein polymorphisms in threespecies of antarctic seals (Lobodon carcinophagus, Leptony-chotes weddelli, and Mirounga leonina). Antarctic ResearchSeries, 18. p. 181-192.

Seal, U. S., A. W. Erickson, D. B. Siniff, and R. J. Hofman.1970. Biochemical, population genetic, phylogenetic, andcytological studies of antarctic seal species. In: Symposium

Results of the seal census conducted in 1973 off the Oatesand George V Coasts of Antarctica.

Censustransectnumber

210

34567

1189

Totals

Longitude(E.)

1450 30'147° 57'147024'150000'153 009'156042'158°45'163°51'164° 15'167002'169° 36'

Latitude(S.)

65032165°45'65045164"32'64057f65003'66033169° 17'69° 17'70° 15'71003'

Crabeater

81335168495

57161205

4037

349198

2,126

Leopard

523

329

2724

54

197

73

Weddell

026

3402045

245

147

RossArea (nm°)

226.2

1150.0

12

40.8

7

56.3

3

44.8

5

107.7

5

126.9

4

35.7

4

32.4

5

63.320.6

59

604.7

Date

16 Jan17 Jan17 Jan19 Jan20 Jan21 Jan22 Jan24 Jan24 Jan25 Jan26 Jan

July-August 1973 193

on Antarctic Ice and W—ater Masses (E. Deacon, ed.). Cam-bridge, England, W. Heifer & Sons Ltd. p. 77-9.

Siniff, D. B., D. R. Cline. and A. W. Erickson. 1970, Popula-tion densities of seals in the Weddell Sea, Antarctica. in1968. In: Antarctic Ecology, Vol. 1 (M. W. Hoidgate, ed).London, Academic Press. p. 377-39-L

Population dynamics of Weddell sealsin McMurdo Sound, Antarctica

D. B. SINIFF, V. B. KUECHLE, and L. E. EIIERHARDT

Department of Ecology and Behavorial Biology(Jniz'ers/ty of illiiinesota

During October and November 1972, this project con-centrated on two areas of investigation: (1) work wascarried out at Hutton Cliffs using sonic tags to determinethe size of the underwater territory of male Weddellseals, and (2) the nonproductive female segment ofthe population was estimated using marked recapturemethods.

At the Hutton Cliffs colony, all male Weddell seals

were tagged and the total colony censused every otherday to try to determine which males were likely to beterritorial animals. When a suspected territorial malewas identified, this animal was instrumented with a sonictag broadcasting at about 60 kHz, and this instrumenta-tion was used to determine the position of the animalunder the sea ice. Three hydrophones were arranged in atriangle along one side of the tide crack. An electroniccounter allowed us to determine the difference in arrivaltime (in milliseconds) of pulses at the three hydro-phones. This information was taken to the Universityof Minnesota, where we are delineating the underwaterterritories of some of our study animals. This method oftinder-ice location had several limitations, but we ob-tained adequate data on about five animals and plan to domore work of this nature.

For the last three seasons, we have been estimating themagnitude of the nonproductive female segment of theMcMurdo Sound population. This work entails the tag-ging of approximately 1 20 nonproductive females atthree different times throughout the field season. Betweenmarking periods we move about the McMurdo Soundarea and tally all seals, including tag numbers when

- -

ve

Ito

• .

"I

141 J^

AL

(S. NavyA Weddell seal surfaces at an ice hole near Hutton Cliffs, Ross Island.

194 ANTARCTIC JOURNAL