1I've been looking at ocean biodiversity,
2that's the diversity of species that live in the world's oceans.
3About 20 years ago,
4biologists developed the idea of what they called 'biodiversity hotspots'.
5These are the areas which have the greatest mixture of species,
6so one example is Madagascar.
7These hotspots are significant
8because they allow us to locate key areas for focusing efforts at conservation.
9Biologists can identify hotspots on land, fairly easily,
10but until recently, very little was known about species distribution and diversity in the oceans,
11and no one even knew if hotspots existed there.
12Then a Canadian biologist called Boris Worm
13did some research in 2005 on data on ocean species that he got from the fishing industry.
14Worm located five hotspots for large ocean predators like sharks,
15and looked at what they had in common.
16The main thing he'd expected to find was that they had very high concentrations of food,
17but to his surprise that was only true for four of the hotspots -
18the remaining hotspot was quite badly off in that regard.
19But what he did find was that in all cases,
20the water at the surface of the ocean had relatively high temperatures,
21even when it was cool at greater depths,
22so this seemed to be a factor in supporting a diverse range of these large predators.
23However, this wasn't enough on its own,
24because he also found that the water needed to have enough oxygen in it -
25so these two factors seemed necessary to support the high metabolic rate of these large fish.
26A couple of years later, in 2007,
27a researcher called Lisa Balance, who was working in California,
28also started looking for ocean hotspots, but not for fish -
29what she was interested in was marine mammals, things like seals.
30And she found three places in the oceans which were hotspots,
31and what these had in common was that these hotspots were all located at boundaries between ocean currents,
32and this seems to be the sort of place that has lots of the plankton that some of these species feed on.
33So now people who want to protect the species that are endangered need to get as much information as possible.
34For example, there's an international project called the Census of Marine Life.
35They've been surveying oceans all over the world, including the Arctic.
36One thing they found there which stunned other researchers
37was that there were large numbers of species which live below the ice -
38sometimes under a layer up to 20 metres thick.
39Some of these species had never been seen before.
40They've even found species of octopus living in these conditions.
41And other scientists working on the same project,
42but researching very different habitats on the ocean floor,
43have found large numbers of species congregating around volcanoes,
44attracted to them by the warmth and nutrients there.
45However, biologists still don't know how serious the threat to their survival is for each individual species.
46So a body called the Global Marine Species Assessment is now creating a list of endangered species on land,
47so they consider things like the size of the population -
48how many members of one species there are in a particular place -
49and then they look at their distribution in geographical terms,
50although this is quite difficult when you're looking at fish, because they're so mobile,
51and then thirdly they calculate the rate at which the decline of the species is happening.
52So far only 1,500 species have been assessed,
53but they want to increase this figure to 20,000.
54For each one they assess,
55they use the data they collect on that species to produce a map showing its distribution.
56Ultimately they will be able to use these to figure out not only where most species are located
57but also where they are most threatened.
58So finally, what can be done to retain the diversity of species in the world's oceans?
59Firstly, we need to set up more reserves in our oceans,
60places where marine species are protected.
61We have some, but not enough.
62In addition, to preserve species such as leatherback turtles,
63which live out in the high seas but have their nesting sites on the American coast,
64we need to create corridors for migration,
65so they can get from one area to another safely.
66As well as this, action needs to be taken to lower the levels of fishing quotas
67to prevent overfishing of endangered species.
68And finally, there's the problem of 'by-catch'.
69This refers to the catching of unwanted fish by fishing boats -
70they're returned to the sea, but they're often dead or dying.
71If these commercial fishing boats used equipment which was more selective,
72so that only the fish wanted for consumption were caught,
73this problem could be overcome.
74OK. So does anyone have any...