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Fishing yield Fishing yield
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...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
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The water cycle The water cycle
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...
01 Feb 2008 - by Philippe Rekacewicz , UNEP/GRID-Arendal
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Benefits of marine and coastal ecosystems to human wellbeing Benefits of marine and coastal ecosystems to human wellbeing
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...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
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Planet index 2007 for marine species population Planet index 2007 for marine species population
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 ...
26 Jan 2009 - by GRID-Arendal
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Coral reefs at risks Coral reefs at risks
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. ...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
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Industrial areas and seasonal zones of oxygen depleted waters Industrial areas and seasonal zones of oxygen depleted waters
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...
26 Jan 2009 - by Phillipe Rekacewicz, (Le Monde diplomatique) February 2008
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Thermohaline Circulation Thermohaline Circulation
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).
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Southern Ocean Carbon Sink Change Southern Ocean Carbon Sink Change
The Southern Oceans are recognised as an important carbon sink currently taking up approximately 15% of anthropogenic CO2. Models predict that as the atmospheric concentration of CO2 increases, so should the ocean’s absorbtive capacity. This seems to be happening in most areas, but not so in the Southern Ocean, which is observed to have a declining ability to absorb CO2.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Blue Carbon Sink Burial Rates a) Blue Carbon Sink Burial Rates a)
The capacity of ocean's blue carbon sinks (tons of carbon per hectare per year).
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Oceans Carbon Fluxes Oceans Carbon Fluxes
An important role played by the ocean is the storage and exchange of CO2 with the atmosphere, and its diffusion toward deeper layers. At high latitudes, dense waters sink, transferring carbon to the deep ocean. Warming of the ocean surface inhibits this sinking process and therefore reduces the efficiency of CO2 transport and storage. Furthermore, as water warms up, the solubility of CO2 declines, therefore less gas can be stored in the sea water...
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Blue Carbon Sinks Blue Carbon Sinks
The carbon captured by living organisms in oceans is stored in the form of sediments from mangroves, salt marshes and seagrasses. Benefiting from the excellent conditions available to support plant growth, vegetated coastal habitats rank amongst the most productive habitats in the world, comparable in production to the most productive agricultural crops. Blue carbon sinks are strongly autotrophic, which means that these ecosystems fix CO2 as orga...
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Green Carbon Green Carbon
45% of green carbon stored in natural terrestrial ecosystems and the remaining 55% is captured by living organisms in oceans and ocean's blue carbon sinks.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Fish Catch Fish Catch
The worlds most productive fishing grounds are confined to major hotspots in around 7.5% of the ocean surface, where over half of the fish are caught.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Blue Carbon Sink Burial Rates b) Blue Carbon Sink Burial Rates b)
The capacity of ocean's blue carbon sinks (total annual blue carbon sink burial rates).
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Atmospheric Circulation Patterns Atmospheric Circulation Patterns
Carbon cycling in the world’s oceans. The flow of carbon dioxide across the air-sea interface is a function of CO2 solubility in sea water (Solubility Pump). The amount of CO2 dissolved in sea water is mainly influenced by physico-chemical conditions (sea water temperature, salinity, total alkalinity) and biological processes, e.g. primary production. The solubility pump and the biological pump enhance the uptake of CO2 by the surface ocean influ...
06 Oct 2009 - by Giulio Frigieri
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Sea Ice Anomaly in Northern Hemisphere Sea Ice Anomaly in Northern Hemisphere
Arctic sea-ice reductions have significant impacts on climate, wildlife and communities. The opening of open water across the Arctic ocean will have unknown consequences in terms of changes in water circulation and redistribution of species from the Atlantic and Pacific oceans. As sea ice coverage declines, albedo diminishes and more radiation is absorbed by the sea water, in a feed-back process that enhances warming and melting sea ice.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Sea Level Anomalies Sea Level Anomalies
Melting and warming will have consequences on ocean circulation. Additionally melting of inland glaciers and continental ice sheets on Greenland and Antarctica, and the thermal expansion of ocean waters are causing sea level rise.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Annual rainfall Annual rainfall
Sumatran orangutans live in lowland tropical rainforests, with precipitation normally between 1,680 mm and 4,070 mm annually. Western regions receive much more rain than those in the east, as prevailing winds from the Indonesian ocean are forced upwards, cooling rapidly and condensing water vapour, which then falls as precipitation.
13 Sep 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Humpback Whale movements within the South Pacific Humpback Whale movements within the South Pacific
Mortality due to entanglement and collisions with ships has been reported within the Southern Hemisphere. To varying degrees these threats are all present in both the Oceania region and the Southern Ocean. The International Whaling Commission’s Southern Ocean Whale Sanctuary and temporary moratorium against commercial whaling offers limited protection to Humpback Whales from commercial whaling, but scientific whaling remains a threat. There is...
15 Nov 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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The long migration of the Humpback Whale The long migration of the Humpback Whale
Humpback annual migrations between feeding grounds in polar waters to mating and calving grounds in tropical waters are amongst the longest of any mammal. Following heavy exploitation during much of the 19th and 20th centuries, Humpback Whales have been legally protected from commercial whaling since 1966, except for aboriginal and subsistence take, and in most areas their populations are showing signs of recovery. However, there is little evid...
15 Nov 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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