http://www.hcn.org These are the search results for the query, showing results 1 to 2. http://www.hcn.org/issues/346/17018 In Unnatural Landscapes, Ceiridwin Terrill travels to four arid sites to show how scientists fight to protect indigenous organisms from invasive species No publisher Aaron Gilbreath feral pig Unnatural Landscapes Phil Service biologists Pister weeds invasive exotic species endangered species Owens pupfish Louisiana crawfish Concordia University National Park thistle Invasive species Russian scientists iceplant species Ceiridwin Terrill 2010-08-06T20:59:10Z News Article http://www.hcn.org/issues/341/16868 Congress has tried to regulate ballast water in ships in order to stop the spread of zebra mussels, but so far loopholes in the law and tussles over policy have made the effort ineffective. No publisher Michelle Nijhuis Great Lakes Ontario Congress International ballast water exotic species Scientists Hugh MacIsaac Union of Concerned Zebra mussels Phyllis Windle Invasive National Invasive Species Act Politics Coast Guard Maritime Organ invasive species University of Windsor in 2010-08-17T23:31:43Z News Article