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| the Colombian hippo population. Four individuals were present at the time of Pablo Escobar’s death in 1993, and the population is presently estimated to number between 65 and 80.
in Shurin, Riaño, Negro, et al., 2020.
DOI: 10.1002/ecy.2991
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Abstract
The keystone roles of mega‐fauna in many terrestrial ecosystems have been lost to defaunation. Large predators and herbivores often play keystone roles in their native ranges, and some have established invasive populations in new biogeographic regions. However, few empirical examples are available to guide expectations about how mega‐fauna affect ecosystems in novel environmental and evolutionary contexts. We examined the impacts on aquatic ecosystems of an emerging population of hippopotamus (Hippopotamus amphibus) that has been growing in Colombia over the last 25 years. Hippos in Africa fertilize lakes and rivers by grazing on land and excreting wastes in the water. Stable isotopes indicate that terrestrial sources contribute more carbon in Colombian lakes containing hippo populations, and daily dissolved oxygen cycles suggest that their presence stimulates ecosystem metabolism. Phytoplankton communities were more dominated by cyanobacteria in lakes with hippos, while bacteria, zooplankton and benthic invertebrate communities were similar regardless of hippo presence. Our results suggest that hippos recapitulate their role as ecosystem engineers in Colombia, importing terrestrial organic matter and nutrients with detectable impacts on ecosystem metabolism and community structure in the early stages of invasion. Ongoing range expansion may pose a threat to water resources.
Keywords: hippopotamus, lakes, productivity, water resources, exotic species, eutrophication
Jonathan B. Shurin, Nelson Aranguren Riaño, Daniel Duque Negro, David Echeverri Lopez, Natalie T. Jones, Oscar Laverde‐R, Alexander Neu and Adriana Pedroza Ramos. 2020. Ecosystem Effects of the World’s Largest Invasive Animal. Ecology. DOI: 10.1002/ecy.2991
UC San Diego scientists and their colleagues have published the first scientific assessment of the impact that an invasive hippo population, imported by infamous drug lord Pablo Escobar, is having on Colombian aquatic ecosystems. The study revealed that the hippos are changing the area's water quality by importing large amounts of nutrients and organic material from the surrounding landscape.
A Drug Lord and the World’s Largest Invasive Animal ucsdnews.UCSD.edu/feature/a-drug-lord-and-the-worlds-largest-invasive-animal
