Kongsfjorden is a glacial fjord in the Arctic (Svalbard) that is influenced by both Atlantic and Arctic water masses and harbours a mixture of boreal and Arctic flora and fauna. Inputs from large tidal glaciers create steep environmental gradients in sedimentation and salinity along the length of this fjord. The glacial inputs cause reduced biomass and diversity in the benthic community in the inner fjord. Zooplankton suffers direct mortality from the glacial outflow and primary production is reduced because of limited light levels in the turbid, mixed inner waters. The magnitude of the glacial effects diminishes towards the outer fjord. Kongsfjorden is an important feeding ground for marine mammals and seabirds. Even though the fjord contains some boreal fauna, the prey consumed by upper trophic levels is mainly Arctic organisms. Marine mammals constitute the largest top‐predator biomass, but seabirds have the largest energy intake and also export nutrients and energy out of the marine environment. Kongsfjorden has received a lot of research attention in the recent past. The current interest in the fjord is primarily based on the fact that Kongsfjorden is particularly suitable as a site for exploring the impacts of possible climate changes, with Atlantic water influx and melting of tidal glaciers both being linked to climate variability. The pelagic ecosystem is likely to be most sensitive to the Atlantic versus Arctic influence, whereas the benthic ecosystem is more affected by long‐term changes in hydrography as well as changes in glacial runoff and sedimentation. Kongsfjorden will be an important Arctic monitoring site over the coming decades and a review of the current knowledge, and a gap analysis, are therefore warranted. Important knowledge gaps include a lack of quantitative data on production, abundance of key prey species, and the role of advection on the biological communities in the fjord.

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Abstract:The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (, the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment.

Alone among piscine taxa, the antarctic icefishes (family Channichthyidae, suborder Notothenioidei) have evolved compensatory adaptations that maintain normal metabolic functions in the absence of erythrocytes and the respiratory oxygen transporter hemoglobin. Although the uniquely "colorless" or "white" condition of the blood of icefishes has been recognized since the early 20th century, the status of globin genes in the icefish genomes has, surprisingly, remained unexplored. Using a-and f-globin cDNAs from the antarctic rockcod Notothenia coriiceps (family Nototheniidae, suborder Notothenioidei), we have probed the genomes of three white-blooded icefishes and four red-blooded notothenioid relatives (three antarctic, one temperate) for globinrelated DNA sequences. We detect specific, high-stringency hybridization of the a-globin probe to genomic DNAs of both white-and red-blooded species, whereas the 8-globin cDNA hybridizes only to the genomes of the red-blooded fishes. Our results suggest that icefishes retain inactive genomic remnants of a-globin genes but have lost, either through deletion or through rapid mutation, the gene that encodes p-globin. We propose that the hemoglobinless phenotype of extant icefishes is the result of deletion of the single adult ,3-globin locus prior to the diversification of the clade.In 1954 Ruud (1) published the first systematic analysis of the "white" blood of an antarctic icefish, Chaenocephalus aceratus. He reported that fresh blood was nearly transparent, contained leukocytes at 1% by volume, but lacked erythrocytes and the respiratory transport pigment hemoglobin. Furthermore, the oxygen-carrying capacity of C. aceratus blood was approximately 10% that of two red-blooded notothenioids. Subsequent investigations extended these observations to other icefish species and revealed that icefish blood contains small numbers of "erythrocyte-like" cells that, nevertheless, are devoid of hemoglobin (2, 3). Thus, limited to oxygen physically dissolved in their blood, the icefishes have evolved compensatory physiological and circulatory adaptations-e.g., modest suppression of metabolic rates, enhanced gas exchange by large, well-perfused gills and cutaneous respiration, and large increases in cardiac output and blood volume-that ensure adequate oxygenation of their tissues (4, 5).We have initiated studies to determine the status of globin genes in channichthyid genomes and to evaluate potential evolutionary mechanisms leading to the hemoglobinless phenotype. Icefishes evolved from the red-blooded Notothenioidei (6, 7), which, in contrast to temperate fishes, are characterized by a paucity of hemoglobin forms (7-10). Adults of the family Nototheniidae (antarctic rockcods) generally possess a major hemoglobin, Hb 1 (-95% of the total), and a second, minor hemoglobin, Hb 2, that differ in their a chains (al and a2, respectively) (11-13). The more phyletically derived harpagiferids and bathydraconids have a single hemoglobin. The trend toward reduced hemoglobin multiplicity in t...