Diatom abundance and fatty acid composition of ice algae and of Calanus glacialis in samples obtained in 2008 in the eastern Beaufort Sea

The copepod Calanus glacialis plays a key role in the lipid-based energy flux in Arctic shelf seas. By utilizing both ice algae and phytoplankton, this species is able to extend its growth season considerably in these seasonally ice-covered seas. This study investigated the impacts of the variability in timing and extent of the ice algal bloom on the reproduction and population success of C. glacialis. The vertical distribution, reproduction, amount of storage lipids, stable isotopes, fatty acid and fatty alcohol composition of C. glacialis were assessed during the Circumpolar Flaw Lead System Study. Data were collected in the Amundsen Gulf, south-eastern Beaufort Sea, from January to July 2008 with the core-sampling from March to April. The reduction in sea ice thickness and coverage observed in the Amundsen Gulf in 2007 and 2008 affected the life strategy and reproduction of C. glacialis. Developmental stages CIII and CIV dominated the overwintering population, which resulted in the presence of very few CV and females during spring 2008. Spawning began at the peak of the ice algal bloom that preceded the precocious May ice break-up. Although the main recruitment may have occurred later in the season, low abundance of females combined with a potential mismatch between egg production/development to the first feeding stage and phytoplankton bloom resulted in low recruitment of C. glacialis in the early summer of 2008.

Physical characteristics and bacterial production and respiration at stations sampled during 2008 in the eastern Beaufort Sea

Bacterial carbon demand, an important component of ecosystem dynamics in polar waters and sea ice, is a function of both bacterial production (BP) and respiration (BR). BP has been found to be generally higher in sea ice than underlying waters, but rates of BR and bacterial growth efficiency (BGE) are poorly characterized in sea ice. Using melted ice core incubations, community respiration (CR), BP, and bacterial abundance (BA) were studied in sea ice and at the ice-water interface (IWI) in the Western Canadian Arctic during the spring and summer 2008. CR was converted to BR empirically. BP increased over the season and was on average 22 times higher in sea ice as compared with the IWI. Rates in ice samples were highly variable ranging from 0.2 to 18.3 µg C/l/d. BR was also higher in ice and on average ~10 times higher than BP but was less variable ranging from 2.39 to 22.5 µg C/l/d. Given the high variability in BP and the relatively more stable rates of BR, BP was the main driver of estimated BGE (r**2 = 0.97, P < 0.0001). We conclude that microbial respiration can consume a significant proportion of primary production in sea ice and may play an important role in biogenic CO2 fluxes between the sea ice and atmosphere.

List of monuments in Belgium and Luxembourg /

At head of title: American Defense--Harvard group, Committee on the Protection of Monuments.

Notice des peintures, sculptures et dessins moderne exposés dans les galeries du Musée National du Luxembourg.

Mode of access: Internet.

Le Musée national du Luxembourg : catalogue raisonné et illustré des peintures, sculptures, dessins, gravures en médailles et sur pierres fines, et objets d'art divers des écoles contemporaines /

Includes index.

Notice des peintures, sculptures et dessins, de l'école moderne exposés dans les galeries du Musée national du Luxembourg.

Includes bibliographical references (p. [xvii]-xxiii) and index.

Comparison of behavior of bowhead whales of the Davis Strait and Bering/Beaufort stocks /

Mode of access: Internet.

Les premières violations du droit des gens par l'Allemagne: Luxembourg et Belgique,

At head of title: Pour la défense du droit international.

Belgium and Holland including the grand-duchy of Luxembourg; handbook for travellers

Maps on end papers.

Luxembourg, 1994 post report.

Mode of access: Internet.

Banque du peuple : suivie du rapport de la Commission des délégués du Luxembourg /

Mode of access: Internet.