Distribution and spawning areas of four fish species
Distribution and spawning areas of arctic cod, polar cod, herring and capelin in the Barents Sea region. The Barents region is in the Arctic and covers the area of Western Russia and the northern areas of Finland, Sweden and Norway.
04 Oct 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Fish yield and fish sanctuaries, MACH sites
Continous monitoring of fish yields have increased since the MACH project start in 1998, with a more than doubled yield in 2004 compared to 1999. Part of the project has been for the communities to establish fish sanctuaries to enable re-spawning and over-wintering of fish.
11 Jul 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
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
Tigris and Euphrates rivers fragmentation
It has been predicted that access to water will create conflict between countries. In Africa, central Asia, west Asia and the Americas, some countries are already arguing fiercely over access to rivers and inland seas, and confrontations could arise as water shortages grow (Gleick, 2000). Countries currently or potentially involved in international disputes over access to river water and aquifers include:
- Turkey, Syria and Iraq (the Tigris and...
26 Jan 2009 - by Philippe Rekacewicz
Fish diversity in freshwater systems
Although freshwater ecosystems such as rivers, lakes and wetlands occupy less than 2% of the earth’s total land surface, they provide a wide range of habitats for a significant proportion of the world’s plant and animal species. Many are yet to be discovered, but the number of freshwater species worldwide is estimated at between 9,000 and 25,000 (Cosgrove and Rijsberman, 2000). However, this number is rapidly decreasing due to human interference....
26 Jan 2009 - by Philippe Rekacewicz
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
Fish protein world consumption
Consumption of proteins from fish in % of total consumption of animal protein.
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
Biological oxygen demand - BOD: 1976-2008
The availability of oxygen is one of the most important indicators of the condition of a water body, because dissolved oxygen, or DO, (the amount of oxygen dissolved in water) is necessary for most aquatic organisms, including fish and invertebrates. Some species have very defined lower limits of DO that they can tolerate. Increases in DO can indicate improvements in water quality, such as has occurred in many parts of the world in the last 30 ye...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
The WWF living planet index for freshwater
'The over-exploitation and mismanagement of fisheries, particularly when combined with other man-made stresses, can lead to the collapse of regional fish faunas. In many countries, aquaculture is rapidly increasing in response to declining natural fisheries, often exacerbating the degradation of inland and coastal ecosystems through habitat alteration, pollution and the introduction of alien species' (Revenga et al., 1998).
The Freshwater Specie...
26 Jan 2009 - by GRID-Arendal
Damming the world
The construction of large dams - defined as those with walls at least 15 metres high - has increased significantly over the past 50 years. The average height of new dams, estimated at 30-34 m from 1940-1990, increased to about 45 m in the 1990s, due largely to construction trends in Asia. The average area and volume of freshwater reservoirs have also steadily increased, rising to about 50 km2 between 1945 and1970, declining through the 1980s to 1...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
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
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