UCSB scientists have come out with a list of what they say are the most at-risk coastal spots in the world. These hot spots are mostly in Asia and the Mediterranean, save for the worst offender: the mouth of the United States’ own Mississippi River.
The study, published in the Journal of Conservation Letters, is described by its authors as the first to examine each of the following four components: nutrient input from agriculture in urban settings, organic pollutants derived from pesticides, inorganic pollutants from urban runoff, and direct impact of human populations on coastal marine habitats. “One of the great challenges is to decide where and how much to allocate limited resources to tackling these problems,” said Benjamin Halpern, of UCSB’s National Center for Ecological Analysis and Synthesis, in a press release. “Our results identify where it is absolutely imperative that land-based threats are addressed - so-called hot spots of land-based impact - and where these land-based sources of impact are minimal or can be ignored.”
The study found that the damage to the Mississippi River mouth results from nutrient runoff from farms farther upstream. This causes algae to grow in such abundance that it uses nearly all available oxygen, creating what researches call a “dead zone.”
Halpern also noted that because rivers empty into the ocean in only a certain number of spots around the world, much of the ocean is spared from the worst of riparian pollution. The rest of the ocean, he said, would benefit from a focus on other threats, including fishing, climate change, invasive species, and commercial shipping.