The Census of Marine Life

Sarah -  This week saw the first report of the Census of Marine Life.  This has been a worldwide project spanning in the last 10 years, aiming to catalogue the diversity, distribution and abundance of life in the oceans.  I went along to launch of the census report in London and spoke to Marine Ecologist Enric Sala...

Enric Sala -   Well today was a celebration of 10 years of great work and 2700 people from 8 different countries who have worked their *beep* off for 10 years.  This project has completely transformed our vision of the ocean.  So right now, we know that there are far more species than we thought, that the ocean life is more connected than we thought, but also, that it's more impacted by human activities than we thought 10 years ago.

Sarah -   That was Enric Sala who acted as compere for all the talks and discussions throughout the day of the launch, and was also involved in looking back at fish populations of the past for the survey.  As Enric said, this was a global effort.  Researchers went out and collected samples, took photographs and measurements from all types of marine ecosystem.  From tropical mangroves to under the sea ice in Antarctica, to abyssal planes and ocean trenches out to the open ocean, to try and get an idea of what species were living in each area.  During the census, they found 6,000 potential new species and have pushed up the estimate for total marine species to over 250,000.  One of the methods pioneered by the census was DNA barcoding which allows you to take a sample from an ecosystem and identify all the animals present.  Ann Bucklin is from the University of Connecticut...

Ann Bucklin -   The way the census has started bar coding is what we called "gold standard barcoding".  We work from an identified specimen and we determine the sequence.  And so now, we have a gold standard.  We have a DNA sequence with a name on it.  Overall, 35,000 species of marine organisms, marine animals have been barcoded.  Now, what we're starting to do is to take that scoop of animals; whether it's a net sample of plankton, a scoop of sediment, any kind of habitat you could name, and we're doing deep sequencing with the new high throughput sequencing, to tell us how many species we think are in that sample.  Some of those will match our library of gold standard barcodes, some will not, but some will be close enough so that we can classify them.  So we say, we don't know what copepod that is, but we know it's a copepod.  That's the power of what we call environmental barcoding.

Sarah -   Ann Bucklin there.  In terms of the distribution of species, researchers used a range of tracking methods including satellites and acoustic techniques to find out where, when and how far species travel.  The tracking studies, as well as looking at the genetics in different areas, led the census to conclude that ecosystems and marine species are much more interconnected than we thought, which really has important implications for conservation.  Looking at abundance, this is where it becomes a much less positive story.  The census estimates that 90% of top marine predators like tuna, marlin and sharks have been lost in the last 50 years alone, due to over-exploitation and habitat loss.  And looking much further back, they found that humans have been impacting fish populations for much longer than we previously thought, certainly back at least 2,000 years.  But the census isn't just an interesting piece of zoological and ecological information.  It could also act as a guide to inform conservation efforts and as a guide to policy makers.  As Maritime Lawyer turned Ocean Conservation Adviser, Kristina Gjerde explains...

Kristina Gjerde -   Bringing the high seas, the oceans into the living room will help to stir some concern about what is the state of the ocean these days and if that concern can be translated to our policy makers that're in our capitals, in our hometowns then we would start to see some action.

Sarah -   That was Kristina Gjerde, talking to me at the Royal Institution in London.