Polar cod (Boreogadus saida) was found to be sensitive to the warming scenarios and the model predicted that it would be extirpated in most of its range even under the milder warming scenario. This is due to its occurrence in the Arctic Ocean, which largely precludes it from moving northwards. Polar cod was predicted to be extirpated around Greenland and its abundance was largely reduced in other parts of the Arctic Ocean after 30 years of hypot...

Scientists are just beginning to learn about the many species in the remote, deep waters of the polar oceans. Corals, for example, are not limited to the warm, shallow waters of the tropics. They also exist in many cold, deep waters all over the world, including Arctic and sub-Antarctic waters. Coral reefs are marine ridges or mounds, which have formed over millennia as a result of the deposition of calcium carbonate by living organisms, predomin...

The red king crab is native to the Okhotsk and Japan Seas, the Bering Sea, and the northern Pacific Ocean, where it is an important economic resource. In Alaskan waters, red king crabs have historically been the second most valuable species to fishermen after salmon, although since the 1980s overharvesting has led to the closure of some areas to fishing. The king crab also has an invasive distribution in the Barents Sea. Since its introduction in...

The land mass in the Arctic - Greenland and parts of Canada, Alaska, Russia and the Nordic countries - surrounds the Arctic Ocean. In the low Arctic, down to the temperate regions, the taiga coniferous forests represents a vast band of deep forests. North of the taiga, the tundra of the Arctic - with low vegetation, shrubs and various degrees of permafrosts spreads out. Beyond the tundra, there might be barren regions with only rock and few plant...

The Arctic represents the northermost area of the World, the Arctic Ocean and the land areas that surrounds it. The region is characterized but cold temperatures, and ice and snow. The summers are short, but with long periods of daylight (midnight sun). The winters are long and cold and with periods with no sun (polar night). The Arctic Ocean is one basin that is mostly covered by sea ice, and is connected to the Pacific and Atlantic Oceans. The ...

Another process that results in rising sea levels is the addition of water mass from land ice. Melting glaciers and ice caps, as well as the vast ice sheets of Greenland and Antarctica, raise sea-levels if their water mass enters the ocean as melted water or icebergs (Pritchard et al. 2009, Steig et al. 2009, Velicogna 2009). Furthermore, it is estimated that melting of tropical glaciers (most of them are considered small) could cause an increas...

Changes in sea levels resulting exclusively from changes in ocean density and circulation patterns, results of atmosphere-ocean general circulation models (AOGCM) for climate change scenario A1B (this scenario assumes future rapid demographic and economic growth, introduction of new and more efficient technologies, accompanied by a balanced use of all types of energy sources) show that there will be significant spatial variability, i.e., changes ...

It is expected that by 2050 there will be threats to ecosystem services in the Andes and Mexico, in the Central American and Caribbean sub-regions, and in southeastern Brazil, while there will be negative effects on fishing in the Pacific coastal areas of Peru and Chile. The decrease in precipitation will have adverse effects on agricultural yields in several regions and countries throughout the continent. Particularly noteworthy within Latin Ame...

El Niño Southern Oscillation (ENSO) is a natural phenomenon that has occurred for centuries. Ocean and atmospheric conditions in the Pacific tend to fluctuate between El Niño (warming) and a drop in temperature in the tropical Pacific known as La Niña. The fluctuations are rather irregular, but tend to appear every three to six years. A more intensive phase of each event may last for about a year. A warming climate may contribute to an increase i...

During a period between May 1994 to September 1995 the profile of the beach dramatically changed. A rising sea level combined with more storms, washed away vulnerable beaches. With the sand gone, the coast is more vulnerable to waves going further inland, threatening fresh water wells with salinisation, leading to land erosion, and making the areas less attractive for tourism. When a beach starts to deteriorate, the process can be amazingly quick...

El Niño describes 'the warm phase of a naturally occurring sea surface temperature oscillation in the tropical Pacific Ocean', and southern oscillation refers to 'a seesaw shift in surface air pressure at Darwin, Australia and the South Pacific Island of Tahiti'. This graphic explains the El Niño-Southern Oscillation Phenomenon, showing the differences between a normal year and an El Niño year.

El Niño describes 'the warm phase of a naturally occurring sea surface temperature oscillation in the tropical Pacific Ocean', southern oscillation refers to 'a seesaw shift in surface air pressure at Darwin, Australia and the South Pacific Island of Tahiti' amd La Nina refers to the cooling phase of the same temperature oscillation that causes El Nino. This graphic shows how the El Nino phenomenon changed weather conditions in southern Africa in...

Overview of the geopolitical situation in the European sector of the Arctic. Despite ongoing discussions, Russia and Norway continue to dispute their maritime limits in the Barent's Sea. The sea is relevant for shipping, mineral resources (oil) and fisheries.

Three-quarters of the world’s fish stocks are currently exploited to the maximum extent, if not in excess (FAO, 2000). This exploitation has had the following impacts: - A growing variety of fishery products are being exploited. Commercial fishermen are targeting progressively smaller species at lower levels of the food chain because the main predator species are being depleted. - Most of the world’s main fishing areas are close to full exploit...

Environment water transport system. The water cycle consists of precipitation, vapour transport, evaporation, evapo-transpiration, infiltration, groundwater flow and runoff. Figure 1 explains the global water cycle, illustrating how nearly 577,000 km3 of water circulates through the cycle each year. A table of estimated residence times shows the approximate times that water resources exist as biospheric water, atmospheric water and so on. The w...

Besides the well-known economic value of fisheries, there are several other activities generating significant revenues in coastal and marine areas. Tourism has become one of the world’s fastest growing industries, providing a significant proportion of the GDPs of many developing countries. Small island states are particularly reliant on coastal and marine tourism. In the Caribbean, for example, the industry accounts for a quarter of the total eco...

The Marine Species Population Index provides an assessment of the average changeover time in the populations of 217 species of marine mammals, birds, reptiles, and fish. The index represents the average value of six regional ocean indices. More pronounced declines are seen in the southern oceans, attributed to the fact that major losses and degradation of marine ecosystems in the industrialized world took place prior to 1970. Marine species are ...

There are two distinct regions in which coral reefs are primarily distributed: the Wider Caribbean (Atlantic Ocean) and the Indo-Pacific (from East Africa and the Red Sea to the Central Pacific Ocean). - The diversity of coral is far greater in the Indo-Pacific, particularly around Indonesia, the Philippines, and Papua New Guinea. Many other groups of marine fauna show similar patterns, with a much greater diversity in the Indo-Pacific region. ...

This graphic illustrates the strong link between areas with high densities of industrial activity and zones of seasonally oxygen-depleted waters. There is a strong link between areas with high densities of industrial activity and zones of seasonal oxygen-depleted waters. In recent years there has been an increasing focus on treating and reducing municipal and industrial waste, and on reducing nitrogen levels in agricultural runoff. However, less...

Thermohaline circulation is a 3-dimensional flow involving surface and deep ocean waters, which is driven by differences in water temperature and salinity. (Image source: NOAA/NCDC).