Mangroves (Photo: Diego M. Rossi/Getty)
My latest for TakePart:
There’s a tendency in our flat screen-fixated society to treat the preservation of nature and wildlife as a boutique issue. I mean “boutique” in the sense that it’s become a ladies-who-lunch sort of thing. Nice, but it doesn’t really matter.
Our own experience also reinforces the subliminal impression that destroying nature—or at least pushing it back away from civilized life—actually makes us healthier. Turning forests into fields has made it easier for us to get food, for instance, and building dams provides the electricity to power those flat screens, build products, and create jobs.
But a new study in Proceedings of the National Academy of Sciences argues that the continued loss of habitat is in fact increasingly a matter of life and death. Let’s skip the subtleties and go straight to a list of the study’s dozen deadly effects:
1. In Asia, Africa, and South America, those seemingly beneficial dams and irrigation projects have created new homes for the aquatic snail species that transmits schistosomiasis. It now afflicts more than 200 million people worldwide with symptoms including coughing, abdominal pain, diarrhea, fever and fatigue. The altered habitat also provides breeding places for mosquitoes and other disease-carrying organisms, increasing the incidence of malaria, filariasis, encephalitis, and other dreadful diseases.
2. Our increasing incursions into remote wilderness areas are bringing epidemic diseases out of the jungle and into our backyards. Roughly 75 percent of emerging diseases—think HIV, Ebola, West Nile virus, SARS, and the new coronavirus in the Middle East—spill over from the animal world.
3. When we reduce the variety of species living in an area, we make it more likely that new diseases will spill over to humans. The “dilution effect” theory suggests that when you have many species in a habitat, some of them will be ineffective, or even dead ends, at transmitting a particular disease pathogen. So they dilute the effect of the pathogen and keep it from building up and spilling over to humans. Studies have correlated reduced species diversity with increases in West Nile virus, Chagas disease, Lyme disease, and hantavirus.
4. When we destroy coastal mangrove swamps in Sri Lanka, or dune vegetation on the beach in New Jersey, we lose vital protection against deadly storms. In the Asian tsunami of 2004 one village in Sri Lanka that had cut down its mangrove swamps to create shrimp farms suffered 6,000 deaths. In a comparable Sri Lankan village that left its mangroves intact, only two people died.
5. By providing nursing grounds for young fish and for the prey species they will eventually eat, those mangrove swamps are responsible for about 80 percent Read the rest of this entry »