Dams are believed to be one of the biggest threats to freshwater organisms worldwide: They disrupt normal patterns of water and sediment flow, impede migration, and alter the character of spawning and feeding grounds. A shortage of data has until now prevented a thorough global assessment of the threat dams pose to fish species, but a study described in the June issue of BioScience attempts just that.
“In reserves off Spain and Italy, we found the largest fish biomass in the Mediterranean. Unfortunately, around Turkey and Greece, the waters were bare” – Enric Sala, National Geographic Society.
75% of cut-the-fin-dump-the-dying-shark fishery is illegal. Many sharks also die as by-catch of conventional fishing. These sharks never reach the shore either – and their deaths are also not documented.
Certain types of plankton have adapted themselves to living in water with low oxygen content, so they can hide away from fish when digesting [through anaerobic glycolysis] and meanwhile suppressing their metabolism. Only at night, when in search for food, … Continue reading