Seabirds in the Greenland, Barents and Norwegian Seas, February-April 1982

Seabirds in the Greenland, Barents and Norwegian Seas, February-April 1982

Seabirds in the Greenland, Barents and Norwegian Seas, February-April 1982 R. G. B. BROWN Brown, R. G. B. 1984: Seabirds in the Greenland, Barents and Norwegian Seas, February-April 1982. Polar Research 2 n.s., 1-18. The pelagic distributions of seabirds in the Greenland, Norwegian and western Barents Seas are poorly known, especially in winter. This paper describes quantitative observations made in the course of an oceanographic cruise between 60"-79"13'N and 15"W-l8"30'E from 25 February to 4 April 1982. Seabirds were generally scarce: the principal species were Fulmarus glacialis, Rissa nidacryla, Pagophila eburnea, Uria spp. and Alle alle. Numbers were greatest in the south and east, where the sea surface temperatures were warmest. Pagophila eburnea and Cepphus gtylle were most commonly seen near the edge of the pack-ice in the Greenland Sea. In the pack-ice zone Fulmam glacialis and Alle alle were commonest where the sea surface was 4040% covered with ice. These late-winter observations are compared with published accounts of summer distributions. Preliminary quantitative comparisons also suggest that the size of the population of Uria spp. wintering in the survey area, and especially in the western Barents Sea, is significantly larger than that which winters off Nova Scotia, eastern Canada; the reverse is true of Alle alle. R. G. B. Brown, Canadian Wildlife Service. Bedford Institute of Oceanography, P. 0.Box 1006, Dartmouth, Nova Scotia, Canada, B2Y 4A2. Introduction haug et al. 1977; Brun 1979; Einarsson 1979; The Greenland, Norwegian, and Barents Seas Petersen 1982.) form the northeast corner of the North Atlantic By contrast there is surprisingly little infor- Ocean. Their northern boundary is at ca. 80"N, mation about the birds' distributions at sea. Up from northeast Greenland through northern Sval- to a point these can be inferred from analyses of bard to Frans Josef Land, at the southern limit the recoveries of birds ringed at colonies in Sval- of permanent pack-ice - the boundary between bard, Novaya Zemlya, northern Norway and the the North Atlantic and Arctic Oceans. They are adjacent coasts of Russia; for example, Holgersen bounded on the west by Greenland, on the east (1961), Bianki (1967), Norderhaug (1967), Sal- by Novaya Zemlya, and on the south by Norway, omonsen (1967, 1971, 1979b), and Tuck (1971). Faeroe and the north coast of Iceland (Figs. 1- What is lacking, however, is direct observation 6). of seabird distributions at sea in this area, com- This area supports a very large population of parable with that done off eastern Canada (e.g. breeding seabirds; the distributions, and to a Brown et al. 1975; Renaud et al. 1982). The pub- lesser extent the numbers, of these are fairly well lished literature is sparse: Quennerstedt (1868), known. There are between 1 and 5 million pairs Belopol'skii (1933), Menzies (1965), Meltofte of seabirds breeding in Svalbard, 1 million on (1972), Grafe (1973), Byrkjedal et al. (1976), Novaya Zemlya, 1.75 million along the coast Joiris (1976), Hansen (1978), Blomqvist & Elan- between the Kola peninsula in northwest Russia der (1981) and Meltofte et al. (1981), and the and the Lofoten Islands in northwest Norway, records in the more general reviews of Fisher and ca. 5 million in Faeroe and northern Iceland (1952) and L~venskiold(1964). Virtually all of combined. There are also large, uncensused col- these pelagic observations have been made during onies in Frans Josef Land, Jan Mayen, and east the summertime. Quennerstedt's (1868) summary and northeast Greenland. (Data from Bird & of seabirds seen during a spring sealing voyage Bird 1935; Seligman & Willcox 1940; Salomonsen to the pack-ice east of Jan Mayen is the principal 1950, 1979a, 1981; Fisher 1952; Fisher & Lockley exception. 1954; L0venskiold 1964; Joensen 1966; Norder- The present paper contributes observations 2 R. G. B. Brown which I made in this area on the Bedford Institute northernmost point of the cruise, on 12 March. of Oceanography cruise 82-001 in early spring We visited Tromsa on 23-25 March, passed Jan 1982. The CSS 'Hudson' left Reykjavik on 24 Mayen on 30 March, and arrived in Glasgow on February, sailed north around Iceland to the 6 April. Most of our work was done in the deep Greenland Sea and reached 79"13'N,01.16'E, the waters between the east Greenland pack-ice, Jan Fig. 1. Average numbers of Fulmars Fulmurus gluciulis per kilometre in the Greenland, Norwegian and Western Barents Seas, 25 Febmary-4 April 1982. Averages refer to 1"N x 2"W 'squares'; 'n' indicates the number of lominute watches on which each was based. The 'unreliable' counts (in parentheses) were made during a period of strong gales, during which observation was difficult. The approximate position of the pack-ice is based on a map derived from satellite imagery and issued on 9 March 1982 by Deutscbes Wetterdienst/Seewatter Amt, Deutsches Hydrographisches Institut, Hamburg. The pack-ice margin was east of the positions shown during the last half of March 1982. For further details, see the text. Seabirds in Greenland, Barents and Norwegian Seas 3 Mayen and Svalbard; the extent of the ornitho- which entered the 90" arc while they were circling logical coverage is shown in the species maps or following the ship were ignored. No attempt (Figs. 1-6). was made to fix an outer limit to the census area. The survey area is dominated by two circulation Tests with a range-finder (Heinemann 1981) on patterns (e.g. Norderhaug etal. 1977: Fig. 2). The a subsequent cruise on the 'Hudson' suggest that East Greenland Current, the principal outflow on average I recorded large white birds like Ful- from the Arctic Ocean, brings cold water and mars Fulmarus glacialis and Kittiwakes Rissa tri- pack-ice southwest along the whole of the east dactyla at distances of up to 400m, but small, coast of Greenland. On the east, by contrast, the dark ones like Little Auks Alle alle only up to relatively warm Norwegian Current, a contin- 200m, though the latter were visible at greater uation of the Gulf Stream/North Atlantic Drift distances under good conditions. Only counts system, flows northeast up the coast of Norway. made in good visibility are included in Table 1 Its influence in the northeast Atlantic, made and Figs. 1-6, for all Regions except North Ice- apparent by the virtual absence of pack-ice, land. All counts were made while the ship was extends north to western Svalbard and east to moving, though the speeds were variable, espe- Novaya Zemlya, and another branch of the Drift cially when we were manoeuvring in pack-ice. brings warm water to the south coast of Iceland. The birds were therefore counted in 10-minute For the purposes of this paper it is convenient periods corrected for the ship's speed, and the to divide our survey area into eight Regions, results expressed as the number of birddkm. based on this oceanographic zonation (Figs. 1-6; Table 1). The area north of 72"N is divided into the North-West Greenland Sea (NWGS: 16"W- 6"E); North-East Greenland Sea (NEGS: 6"- Distributions 16"E) and the Western Barents Sea (WBS: 16"- Fulmar Fulmarus glacialis - (Fig. I; Tables 1, 2) 19"E). The regions south of 72"N are Jan Mayen (JM: 68"-72"N, 16"-6"W), the North-West Nor- Fulmars were commonest in the Norwegian and wegian Sea (NWNS: 65"-72"N, 6OW-6"E); Barents Seas, and close to their colony on Jan North-East Norwegian Sea (NENS: 68"-72"N, Mayen. In the Greenland Sea they usually 6"-19"E) and South-West Norwegian Sea (SWNS: occurred at the edge of the pack-ice, in the zone 60"-65"N, 6OW-6"E). A region off Northern Ice- where 1040% of the sea was covered by ice land (NI) has been added for the purposes of (Table 3). Quennerstedt (1868) found a similar some of the discussions, but the weather was too association near Jan Mayen in spring, as did stormy for reliable quantitative observations dur- McLaren (1982) in Baffin Bay. Fulmars were also ing our passage through it. Figs. 1-6 and Table common off Northern Iceland, where they breed 1 show the extent of pack-ice cover in the various in large numbers (Fisher 1952; Petersen 1982). Regions during our cruise. Table 1 also shows the The majority of the birds in the Norwegian Sea average sea surface temperatures (measured by and off Jan Mayen were in the Light plumage standard meteorological bucket); with the excep- morph ('LL' in Fisher's (1952) classification); the tion of WBS (n = S), each average is based on Dark morph (Fisher's classes 'L', 'D' and 'DD') over 20 samples. predominated elsewhere. The percentages of 'LL' birds in the various Regions (based on counts of 'joining' birds only, see above) were: SWNS 96.0% (n = 177); NENS92.4% (n = 185); NWNS Methods 96.1% (n = 155); WBS 8.8% (n = 113); NEGS Birds were counted by a modification of the tech- 10.6% (n = 142); JM 99.5% (n = 220); NWGS nique described by Brown et al. (1975). The 26.1% (n = 203). 'LL' birds were commoner close observer stood on the ship's bridge, eye height to the Norwegian coast than Fisher (1952: ca. 13.4m above sea level (giving a horizon of Fig. 41a) shows for January-April, but the per- ca. 13.5 km), and counted all birds seen in a 90" centages elsewhere were very similar. arc extending from the bows to one side of the ship.

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