| I've been looking at ocean biodiversity, |
| that's the diversity of species that live in the world's oceans. |
| About 20 years ago, |
| biologists developed the idea of what they called 'biodiversity hotspots'. |
| These are the areas which have the greatest mixture of species, |
| so one example is Madagascar. |
| These hotspots are significant |
| because they allow us to locate key areas for focusing efforts at conservation. |
| Biologists can identify hotspots on land, fairly easily, |
| but until recently, very little was known about species distribution and diversity in the oceans, |
| and no one even knew if hotspots existed there. |
| Then a Canadian biologist called Boris Worm |
| did some research in 2005 on data on ocean species that he got from the fishing industry. |
| Worm located five hotspots for large ocean predators like sharks, |
| and looked at what they had in common. |
| The main thing he'd expected to find was that they had very high concentrations of food, |
| but to his surprise that was only true for four of the hotspots - |
| the remaining hotspot was quite badly off in that regard. |
| But what he did find was that in all cases, |
| the water at the surface of the ocean had relatively high temperatures, |
| even when it was cool at greater depths, |
| so this seemed to be a factor in supporting a diverse range of these large predators. |
| However, this wasn't enough on its own, |
| because he also found that the water needed to have enough oxygen in it - |
| so these two factors seemed necessary to support the high metabolic rate of these large fish. |
| A couple of years later, in 2007, |
| a researcher called Lisa Balance, who was working in California, |
| also started looking for ocean hotspots, but not for fish - |
| what she was interested in was marine mammals, things like seals. |
| And she found three places in the oceans which were hotspots, |
| and what these had in common was that these hotspots were all located at boundaries between ocean currents, |
| and this seems to be the sort of place that has lots of the plankton that some of these species feed on. |
| So now people who want to protect the species that are endangered need to get as much information as possible. |
| For example, there's an international project called the Census of Marine Life. |
| They've been surveying oceans all over the world, including the Arctic. |
| One thing they found there which stunned other researchers |
| was that there were large numbers of species which live below the ice - |
| sometimes under a layer up to 20 metres thick. |
| Some of these species had never been seen before. |
| They've even found species of octopus living in these conditions. |
| And other scientists working on the same project, |
| but researching very different habitats on the ocean floor, |
| have found large numbers of species congregating around volcanoes, |
| attracted to them by the warmth and nutrients there. |
| However, biologists still don't know how serious the threat to their survival is for each individual species. |
| So a body called the Global Marine Species Assessment is now creating a list of endangered species on land, |
| so they consider things like the size of the population - |
| how many members of one species there are in a particular place - |
| and then they look at their distribution in geographical terms, |
| although this is quite difficult when you're looking at fish, because they're so mobile, |
| and then thirdly they calculate the rate at which the decline of the species is happening. |
| So far only 1,500 species have been assessed, |
| but they want to increase this figure to 20,000. |
| For each one they assess, |
| they use the data they collect on that species to produce a map showing its distribution. |
| Ultimately they will be able to use these to figure out not only where most species are located |
| but also where they are most threatened. |
| So finally, what can be done to retain the diversity of species in the world's oceans? |
| Firstly, we need to set up more reserves in our oceans, |
| places where marine species are protected. |
| We have some, but not enough. |
| In addition, to preserve species such as leatherback turtles, |
| which live out in the high seas but have their nesting sites on the American coast, |
| we need to create corridors for migration, |
| so they can get from one area to another safely. |
| As well as this, action needs to be taken to lower the levels of fishing quotas |
| to prevent overfishing of endangered species. |
| And finally, there's the problem of 'by-catch'. |
| This refers to the catching of unwanted fish by fishing boats - |
| they're returned to the sea, but they're often dead or dying. |
| If these commercial fishing boats used equipment which was more selective, |
| so that only the fish wanted for consumption were caught, |
| this problem could be overcome. |
| OK. So does anyone have any... |