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Atmospheric concentrations of carbon dioxide (CO2) - Mauna Loa or Keeling curve Atmospheric concentrations of carbon dioxide (CO2) - Mauna Loa or Keeling curve
Atmospheric concentration of CO2 is steadily rising, and oceans directly assimilate CO2. As ocean concentration of CO2 increases, the oceans automatically become more acidic. This, in turn, may have severe impacts on coral reefs and other biocalcifying organisms. There is little debate on the effect as this is a straight-forward chemical process, but the implications for marine life, that may be severe due to many very pH-sensitive relationships...
01 Nov 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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shelfwater shelfwater
About shelfwater
29 Nov 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Major pathways and origins of invasive species infestations in the marine environment Major pathways and origins of invasive species infestations in the marine environment
All across the planet, the number and severity of outbreaks and infestations of invasive species (i.e. species purposefully or accidentally introduced in non-native environments) is growing, and invasions of marine habitats are now occurring at an alarming rate. Exotic and invasive species have been identified by scientists and policymakers as a major threat to marine ecosystems, with dramatic effects on biodiversity, biological productivity, hab...
01 Feb 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Tropical sea temperature rises and coral reefs - climate change scenarios Tropical sea temperature rises and coral reefs - climate change scenarios
The impacts of coral reefs from rising sea temperatures. When coral reefs become heat-exposed they die, leaving the white dead coral, also known as bleaching. With even moderate pollution, the coral are easily overgrown with algae, or broken down by wave activity or storms, leaving only “coral rubble” on the ocean bed.
01 Feb 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Invasive species in the marine environment - problem regions Invasive species in the marine environment - problem regions
The locations of major problem areas for invasive species infestations or occurrence of exotic species in the marine environment. The impacted areas are concurrent with the areas subjected to the worst pollution, the most intensive fisheries and bottom trawling, and major shipping routes. The areas in the figure have been highlighted based on an overview of literature, and the delineation of the areas are approximate.
01 Feb 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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scenarios scenarios
About scenarios
29 Nov 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Trends in fisheries and aquaculture production (2000-2005) Trends in fisheries and aquaculture production (2000-2005)
The world's marine fisheries have stagnated or slightly declined in the last decade, offset only by increases in aquaculture production. A major reason why the decline has not become more evident is likely because of advances in fishing efficiency, shift to previously discarded or avoided fish, and the fact that the fishing fleet is increasingly fishing in deeper waters
01 Feb 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Indications of structural changes in the marine ecosystem, catch ratios of predatory and plankton feeding fish Indications of structural changes in the marine ecosystem, catch ratios of predatory and plankton feeding fish
Three-quarters of fish stocks are currently exploited to the maximum extent, if not excessively. The Northeast Atlantic Ocean continues to exhibit declining catches, as well as a shift towards fish at lower levels in the food chain. This graphic illustrates the decline in the catch ratios of predatory and plankton-feeding fish in the Northeast Atlantic Ocean from 1950 to 1995.
17 May 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Trends in marine and freshwater populations Trends in marine and freshwater populations
The Marine Species Population Index provides an assessment of the average change over 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, which is attributed to the fact that major losses and degradation of marine ecosystems in the industrialised world took place prior to 1970. Marine sp...
17 May 2005 - by Delphine Digout, UNEP/GRID-Arendal
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River runoff by continent, 1921-1985 River runoff by continent, 1921-1985
River runoff represents the accumlated water, from preciptation and meltwater, that feeds into rivers that feeds into seas. The estimated annual figures in this graphic is what volume of water that ends up in the World Ocean. Factors influencing this volume is primarily the area that drains (e.g. area of continent), precipitation and evaporation. Tropical regions typically exhibit greater river runoff volumes. The Amazon carries 15% of all the wa...
17 May 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Human activities leading to coastal degradation Human activities leading to coastal degradation
Physical alteration and destruction of habitats are now considered one of the most important threats to coastal [and marine] areas. This graphic shows the extent to which twelve different human activities cause environmental degradation in estuaries, inter-tidal wetlands and the open ocean. The activities include the drainage of coastal ecosystems; the construction of dykes, dams and seawalls and the mining of wetlands.
17 May 2005 - by Delphine Digout, UNEP/GRID-Arendal
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Fiji, topographic map Fiji, topographic map
The Republic of Fiji is a small island country in the South Pacific Ocean. The country has a population of 850 000 people spread out over an archipelago of islands. The largest ones, Viti Levu and Vanua Leva houses the majority of the inhabitants.
04 Oct 2005 - by Hugo Ahlenius, UNEP/GRID-Arendal
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World ocean bathymetric map World ocean bathymetric map
The continental shelves, ridges and sea mounts are the most productive areas in terms of biodiversity, and is of highest importance for economic activities. It is also here that natural resources extraction - such as oil and gas - takes place. The largest expanses of ocean are vast plains of depths between 1500-5000 meters. The deepest areas are the trenches where the continental plates meet, such as the Marian Trench of the Pacific.
01 Feb 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Arctic, topography and bathymetry (topographic map) Arctic, topography and bathymetry (topographic map)
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 ...
01 Oct 2010 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Iceland, topographic map Iceland, topographic map
Iceland is located in Northern Europe, is an island between the Greenland Sea and the North Atlantic Ocean, northwest of the UK, comprising 103,000 sq km. It has an estimated population of 296,737 (2005). Major environmental concerns are: water pollution from fertilizer runoff; inadequate wastewater treatment.
04 Oct 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Aleutian and Pribilof Islands, reference map Aleutian and Pribilof Islands, reference map
This map locates two groups of islands, outside continental Alaska - the Pribiliof and Aleutian Islands. These islands are located in the Pacific Ocean and the south end of the Bering Sea in the Arctic, and are a part of the USA.
17 Mar 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Nenets Autonomous Okrug, reference map Nenets Autonomous Okrug, reference map
Nenets Autonomous Okrug is an administrative region in Arctic Northwest Russia, covering some 176000 sq km of tundra and marshland. The capital city of the region is Narian-Mar. Off the coast are parts of the Arctic ocean know as Barents and Kara seas, and the long island in the north west is Novaya Zemlya.
17 Mar 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Arctic sea routes - Northern sea route and Northwest passage Arctic sea routes - Northern sea route and Northwest passage
Sea routes along the edges of the Arctic ocean, or rather along the coasts of Northern Canada and Russia, holds potential for decreasing the number of days in shipping goods from the Pacific to Atlantic coasts in Europe and North America, and vice versa. In addition, this could provide a means to transport natural resources, such as oil and gas, extracted in the Arctic. Currently these routes have not been possible to use this, due to the ice con...
13 Feb 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
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Scenarios of sea level rise, now - 2100 Scenarios of sea level rise, now - 2100
Using the IS92 emission scenarios, projected global mean sea level increases relative to 1990 were calculated up to 2100. Taking into account the ranges in the estimate of climate sensitivity and ice melt parameters, and the full set of IS92 emission scenarios, the models project an increase in global mean sea level of between 13 and 94 cm. During the fist half of the next century, the choice of emission scenario has relatively little effect on ...
01 Oct 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Sea level rise due, past and scenarios due to global warming Sea level rise due, past and scenarios due to global warming
Over the last 100 years, the global sea level has risen by about 10 to 25 cm. Sea level change is difficult to measure. Relative sea level changes have been derived mainly from tide-gauge data. In the conventional tide-gauge system, the sea level is measured relative to a land-based tide-gauge benchmark. The major problem is that the land experiences vertical movements (e.g. from isostatic effects, neotectonism, and sedimentation), and these get ...
01 Oct 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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