Wednesday, January 29, 2020
10:00 - 11:00, 60 min. -
Environmental Science:
Trophic Cascades -
Rory and I watched several short videos showing what happens to ecosystems when changes happen at the top of a trophic pyramid. In one case the re-introduction of wolves to Yellowstone National Park resulted in the increase in biodiversity, stabilization of riverbanks, and the return of lost forested areas. The second cascade describes how whales, returning after the devastation of whaling, have increased the fish population, by significantly driving phytoplankton to the surface to photosynthesize and reproduce, which also sequesters millions of tons of carbon dioxide from the atmosphere. In both of these cases we studied the return of a species that humans had hunted out of ecosystems. In the first, humans brought the wolves back into the mix, in the second, the end of whaling has allowed for the natural return of the apex species. Rory and I discussed how cascades work and how far humans can influence trophic systems for positive results.