I think the newspaper somewhat exaggerates the anthropogenicity of "dead Zones". There's a river of scientific research on the subject but not an awful lot of rigorous, year-round, detailed mapping of river outflows. Even so, that's a pretty well-written article.

The major river's estuaries that flow from developed farmland and urban areas certainly have more frequently observed plumes of anoxia. My favorite is the Mississippi River, whil has a year-round dead zone that varies in size from a few cubic miles to larger than several New England states.

Once I was on a beach in LA during a "jubilee". This occurs when the anoxic water squeezes large fish closer and closer to shore until they actually get in the surf for oxygen. On a stretch of beach perhaps 2 miles long I saw several hundred redfish, flounder, shark, mackeral, rays, cobia, and rafts of shrimp. The fish were often on the 20# to 50# range. A man with a bat and a big sack wouldv'e cleaned-up.