By Wendy Barnaby
Climate change and other catastrophes may affect the islands of life on the ocean floor, according to Dr Jon Copley of the University of Southampton.
"There may be nowhere for life to hide," he says.
"Hot vents and cold seeps on the ocean floor are like islands. Carpets of mussels and swarms of shrimps thrive around them. Scientists used to think these islands acted as air-raid shelters for some species during global catastrophes, like an asteroid colliding with Earth.
"However, the vents and seeps are ephemeral, and may be hundreds of miles apart," says Copley. "Life needs to be able to move from one to another.
"It is the larvae which do the island-hopping. The adults time their reproduction to produce their young when there will be most food to sustain their travels."
Dr Copley and his team have studied the sex-lives of the shrimp at one of the cold seeps in the Gulf of Mexico. They have discovered that their reproduction follows the seasonal cycles of the sunlit world above. They breed in late autumn and hatch their offspring in early spring.
"The animals time the release of their offspring to coincide with a spring bloom in microscopic plant life growing at the surface," he says. "The larvae feed on material that sinks from the sunlit top 200m of the ocean."
Volcanic vents are hot, and occur where mineral-rich fluids erupt from the seabed. Seeps are not volcanic. They are caused by geological processes squeezing chemicals out of the seabed.
The minerals sustain rich colonies of life around them all year round. Scientists used to think that their food source was independent of the world above.
Other researchers have found the same seasonal pattern in mussel species at volcanic vents and cold seeps.
"This link suggests that changes in patterns of life in surface water could be communicated to patterns of life in these remote corners of the ocean floor", says Dr Copley. "So if an asteroid slams in to the Earth and blocks out the sun, these environments won’t be perfect air raid shelters for all the species that live there.
"Similarly, if climate change were to alter patterns of life in surface waters, our work suggests that these changes could potentially be communicated to the ocean floor."
Dr Copley says researchers have as yet no evidence of impacts of climate change on the ocean floor.
In the next two years, he and his team plan to mount three expeditions to Antarctica. "The Antarctic is particularly interesting," he says, "because we know what lives at vents in the north Atlantic and the eastern Pacific – is the Antarctic the missing link? The two oceans might be connected via the Antarctic, through ocean currents or geological history."
Read more news coverage online at BBC News, the Guardian, and the Times. Watch the video highlights at BBC News.
Dr Copley will be presenting the Charles Lyell Award Lecture at the BA Festival of Science on Monday. This year is the 30th anniversary of the discovery of volcanic vents on the ocean floor.
This year's BA Festival of Science is organised by the BA (British Association for the Advancement of Science) in partnership with the University of York, Science City York and the City of York council. It is supported by the Department for Innovation, Universities and Skills, BP and Yorkshire Forward.