Human activities degrade ecosystems. This has been obvious for millennia in terrestrial and fresh-water systems, but it became obvious only recently in marine systems. Examples of degraded marine ecosystems are numerous, but the causes of these changes are uncertain because of inherent difficulties in studying marine systems. One theme of questions focuses on distinguishing degrees to which various physical...
Bottom trawls are large nets which are used to catch groundfish and other commercially targeted fish and crustacean species. Bottom trawls are one of the most destructive fishing gear types because they directly threaten species richness and biodiversity, and they catch a variety of non-target, undesirable or unmarketable species. The non-target species, or bycatch, is discarded overboard often either...
Millions of global citizens live in areas where toxins shorten lives. Here are perhaps ten of the most polluted cities in the world. The primary pollutant in each city is noted in parentheses:
10. Sumgayit, Azerbaijan (petrochemicals)
This is another city that suffered from generations of environmental neglect in the former Soviet Union. The indiscriminate discharge of industrial pollutants into the...