Graphics Library >> Food chain

Tag: Food chain

The bushmeat chain reaction
The illicit bushmeat trade involves a series of underlying socio-economic factors, but leads, with rising population densities, to local depletions of wildlife species, and increasingly inside protected areas.
03 Dec 2014 - by Riccardo Pravettoni, GRID Arendal
Ringed seal pupping lair, with the pup in the lair and the female approaching the haul-out hole from the water
Ringed seals are the 'classic' Arctic seal in many regards, being found as far north as the Pole because of their ability to keep breathing holes open in ice that can reach 2 metres in depth. This species is certainly on...
01 Nov 2007 - by Robert Barnes, UNEP/GRID-Arendal
Arctic pelagic food web
The marine animal food chain is very complex and multilayered as are most food chains. This is a quick reference to represent the complete food chain in regards to pelagic crustaceans and invertebrates.
28 Sep 2005 - by UNEP/GRID-Arendal
Coastal Arctic food web (drift ice)
The coastal Arctic food web is closely related to drift ice conditions and seasonal use of shorelines by both terrestrial and sea mammals. Numerous species depend upon each other and the transport of food to and from the...
28 Sep 2005 - by UNEP/GRID-Arendal
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...
17 May 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Comb-jelly (Mnemiopsis leidyi) spreading through the Caspian Sea (invasive species)
The comb jelly (Mnemiopsis leidyi) is well adapted to the habitat (salinity, temperature, and food range) and reproduces faster than endemic species. As it eats the same food as them, it has had a drastic effect on their...
04 Oct 2007 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Decline in trophic level of fisheries catch since 1950
A trophic level of an organism is its position in a food chain. Levels are numbered according to how far particular organisms are along the chain from the primary producers, to herbivores, to predators, to carnivores or ...
30 Nov 2007 - by Philippe Rekacewicz, Emmanuelle Bournay, UNEP/GRID-Arendal
Losses in the food chain – from field to household consumption
i.e., before conversion of food to feed. After discounting the losses, conversions and wastage at the various stages, roughly 2,800 kcal are available for supply (mixture of animal and vegetal foods) and, at the end ...
02 Feb 2009 - by Hugo Ahlenius, UNEP/GRID-Arendal
Ice coverage and primary production in the Arctic
Temperature changes may influence fish populations both directly, through shifts to areas with preferred temperature, and indirectly through the food supply and the occurrence of predators. The length of the ice-free per...
17 Mar 2010 - by Hugo Ahlenius, GRID-Arendal & CAFF
Comb-jelly (Mnemiopsis leidyi) spreading through the Caspian Sea (invasive species)
The comb jelly (Mnemiopsis leidyi) is well adapted to the habitat (salinity, temperature, and food range) and reproduces faster than endemic species. As it eats the same food as them, it has had a drastic effect on their...
21 May 2010 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Polar bear sub-populations and pollution
There are thought to be between 20,000 and 25,000 bears in the world, which occur in19 relatively discrete sub-populations, some of which are shared between nations. Topping the food chain in the Arctic, the polar bear i...
13 Oct 2010 - by Riccardo Pravettoni, UNEP/GRID-Arendal
Coastal Arctic food web (drift ice)
The coastal Arctic food web is closely related to drift ice conditions and seasonal use of shorelines by both terrestrial and sea mammals. Numerous species depend upon each other and the transport of food to and from the...
17 May 2005 - by 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 e...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006