Abstract: Pack ice is a layer of frozen seawater on the top of the polar oceans, varying in thickness from a few centimetres to tens of metres. It is an ephemeral feature, not just of polar regions but also of seas such as the Baltic, Caspian and Sea of Okhotsk. At its maximum extent it covers 13% of the Earth's surface area, making it one of the major biomes on the planet.For many years seen as an obstacle to trade and a threat to human life, the ice itself is now perceived to be vulnerable as we come to realize the dangers posed by global warming. Sea ice not only dominates polar regions but is also central to global ocean circulation as well as global climate patterns. Every year the formation, consolidation and subsequent melt of millions of square kilometres of ice influence the whole of the ocean's ecosystems.This is the first book to offer the general reader access to a remote frozen habitat which has for so long fascinated explorers, writers and scientists. During the harsh polar winter the surface of the ocean freezes up, forming a temporary ice layer called pack ice, or sea ice. This gives rise to a spectacular floating world which for a number of months each year becomes home to a wealth of plant and animal life. The wonderful colour photographs of life on, in and under the ice help draw the reader into this superb account of an extreme environment. Guaranteed to capture the imagination.The author is a veteran of six expeditions to the Arctic and Antarctic, and this book is packed with photographs taken in the course of his journeys. His lively and readable text conveys his excitement at the dangers and possibilities of life on the ice. He provides an in-depth background to the whole ecosystem of sea ice, its living communities and the structure of the ice itself. The level of accurate scientific detail will satisfy anyone looking for a reliable, up-to-date overview of this topic.

Abstract: Various abiotic and biotic parameters, including phytoplankton distribution, were studied to investigate seasonal changes within the fast-ice cover in Chupa Inlet, a freshwater-influenced Arctic-like fjord in Kandalaksha Bay (White Sea). Sea ice and under-ice water were collected along transects in the inlet in February and April 2002. Ice-texture analysis, salinity and δ¹⁸O values indicated that the complete ice sheet had transformed within 2 months. This resulted from an upward growth of snow ice and subsequent melting at the underside of the ice, which makes a comparison between the two sampling periods difficult in terms of defining temporal developments within the ice. Nutrients, DOC and DON concentrations in the under-ice water were typical for Russian Arctic rivers. Concentrations of nitrate, silicate and DOC in the ice were lower, which is attributed to a loss as the ice forms. The concentrations were also modified by biological activity. In February, there was a strong correspondence between the distribution of biological parameters, including particulate and dissolved organic carbon and nitrogen (POC and PON, DOC and DON) and inorganic nutrients (nitrate, nitrite, phosphate and silicate), which was not the case in April. The correlation between both DOC and DON with ammonium indicates heterotrophic activity within the winter ice collected in February. Sea-ice organisms were distributed throughout the ice, and several assemblages were found in surface layers of the ice. In April, a more typical distribution of biomass in the ice was measured, with low values in the upper part and high algal concentrations in the lower sections of the ice, characteristic of a spring ice-algal bloom. In contrast to the February sampling, there was evidence that the ice-algal assemblage in April was nitrogen-limited, with total inorganic nitrogen concentrations being <1 µ mand a mean inorganic nitrogen to phosphorus ratio of 2.8. The ice assemblages were dominated by diatoms (in particular, Nitzschia spp.). There were temporal shifts in the assemblage composition: in February, diatoms accounted for 40% and in April for >98% of all organisms counted.

Abstract: Sea ice, which covers up to 7% of the planets surface, is a major component of the worlds oceans, partly driving ocean circulation and global climate patterns...