At http://phys.org/print383921447.html … the subject is hydrothermal vents and methane seeps on the sea floor in various regions of the world. These have variously been treated as something of a geological and biological oddity – under the waves and out of sight. It is now emerging they are something special, an important force in the ecology of the marine system. They are also said to affect global climate but we can take that with a pinch of salt as climate has a habit of creeping into all manner of studies, with little real relevance. The article is in the journal 'Frontiers of Marine Science' (2016) and says that far from being an anomaly the vents pour out gases and minerals including nutrients essential in the growth of planktonic life forms. Marine life is attracted to vents – as they also release heat and energy from the interior of the Earth. They are in fact biological hot spots of diversity and host mussel and clam beds, mounds of shrimps and lots of crabs. They are also a prime fishing habitat. However, most importantly they contribute to the global food chain as they fertilise the oceans by creating zooplanktonic biomass. This leads to increased levels of planktonic life forms.
What would happen if sea floor vents suddenly became more active – possibly provoked by seismic activity? Would increased levels of gases and minerals, as well as methane, result in blooms of biomass? Could that have happened at some point in the past?