In recent years, reports of havoc caused by swarms of jellyfish have inspired speculation that these simple, otherworldly creatures are capitalizing on changes we have brought to ocean ecosystems.
Scientists are finding we could be jellyfish's potential benefactors. Overfishing relieves them of competition and predators. Nutrient-rich pollution can cause phytoplankton blooms, providing feasts for some jellies and reducing the water's oxygen content, which could favor their high tolerance for low oxygen. The warmth of climate change could foster expansion among some species. We transport invasive species to new environments, where they thrive. And coastal development provides new shelter for the jellies' stationary life stage, called a polyp.
An article called "The Jellyfish Joyride," published in 2009 in the journal Trends in Ecology and Evolution, discusses the theory that, without a change on our part, these pressures could push ecosystems topped by fish and marine mammals to devolve into ones dominated by jellyfish, as they may have been 500 million years ago.
It is exactly the type of summary Steven Haddock dislikes.
Too easily villainized?