Contrasting assemblages of seabirds in the subglacial meltwater plume and oceanic water of Bowdoin Fjord, northwestern Greenland

• Published in: ICES Journal of Marine Science
• Main Authors: Nishizawa, Bungo, Kanna, Naoya, Abe, Yoshiyuki, Ohashi, Yoshihiko, Sakakibara, Daiki, Asaji, Izumi, Sugiyama, Shin, Yamaguchi, Atsushi, Watanuki, Yutaka
• Other Authors: Votier, Stephen, MEXT, Japanese Ministry of Education, Culture, Sports, Science and Technology
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2019
• Subjects: Ecology; Aquatic Science; Ecology, Evolution, Behavior and Systematics; Oceanography; Greenland; Fulmar; Bowdoin; Bowdoin Fjord; Alle alle; Black guillemot; Black-legged Kittiwake; Calanus hyperboreus; Cepphus grylle; Fulmarus glacialis; glacier; Glaucous Gull; Larus hyperboreus; little auk; Northern Fulmar; rissa tridactyla; thick-billed murre; Tidewater; Uria lomvia; Copepods; uria
• Online Access: http://dx.doi.org/10.1093/icesjms/fsz213; http://academic.oup.com/icesjms/article-pdf/77/2/711/32881925/fsz213.pdf

Abstract In Greenland, tidewater glaciers discharge turbid subglacial freshwater into fjords, forming plumes near the calving fronts, and these areas serve as an important foraging habitat for seabirds. To investigate the effect of subglacial discharge on the foraging assemblages of surface feeders and divers in a glacial fjord, we conducted boat-based seabird surveys, near-surface zooplankton samplings, and hydrographic measurements at Bowdoin Fjord, northwestern Greenland in July. Foraging surface feeders (black-legged kittiwake Rissa tridactyla, glaucous gull Larus hyperboreus, and northern fulmar Fulmarus glacialis) aggregated within a plume-affected area in front of Bowdoin Glacier. This area was characterized by highly turbid subglacial meltwater and abundant large-sized zooplankton including Calanus hyperboreus, chaetognaths, and ctenophores near the surface. Surface feeders fed on these aggregated prey presumably transported to the surface by strong upwelling of subglacial meltwater. In contrast, divers (little auk Alle alle, thick-billed murre Uria lomvia, and black guillemot Cepphus grylle) foraged outside the fjord, where turbidity was low and jellyfish and Calanus copepods dominated under the influence of Atlantic water. Our study indicates spatial segregation between surface feeders and divers in a glacial fjord; surface feeders are not hindered by turbidity if taking prey at the surface, whereas divers need clear water.