Thursday, June 01, 2006

Species Census

I was taking a look at IUCN's list of threatened species and wondering to myself, what about the species that aren't threatened with extinction but their populations are declining drastically?

For example, I was reading in the NYTimes:

"Elkhorn and staghorn used to be the dominant species on the Caribbean reef as recently as the early 80's," said Jennifer Moore, a natural resource specialist for the protected resources division of the National Marine Fisheries Service, which placed coral on the threatened list after prompting from the Center for Biological Diversity, based in Arizona. "But the species has declined 97 percent since the late 70's."
Wouldn't it be better to know about this issue when the population has only declined by 10 or 15%? Then you could make changes before the dramatic population decrease, and possible extinction. Better to invest early on in trying to maintain populations then to put in a ton of effort when the population is already on the verge of extinction. And yet, as far as I know there is no list similar to IUCN's for species that are losing the largest amount of their population.

This BBC article talks about how deep sea fish stocks are being plundered. Once again, no species is on the verge of extinction, but the populations are decreasing.

So then I was thinking, what I really want to know is the populations of all the species that are out there. What I really want a is species census to count up every living being on the planet.

I am sure that scientists have a good feel for the populations of some species. It would be valuable to collect data and estimate the populations for the rest. Once we have species populations, we could put the values on a site like WikiSpecies for all to view. This data would give you a good feel for the state of life on earth. Which species are most populous? Where do they live? Which mammals have the largest populations? I have no idea. Are humans at the top, or do rats, bats or cows have us beat? Which species are growing in population? Which are losing? This would give environmentalists a better picture of the world and might change how they try and protect the environment.

I am also curious, what does the distribution of species populations look like? Are there a few with huge populations and then tapering off to a long tail of species with a small population? Or maybe it is a bell curve distribution with a few huge populations, many with moderate populations and a few with very small populations. I don't know, but the species census would easily answer this.

Instead of comparing by populations, it might make more sense to compare by total biomass, which could be easily calculated by multiplying population by average weight. Otherwise it would look like mice and flys were the most important species on th planet.

One issue that they will run into is that not all species have been found. There are approximately 1.8 million known species, and another 13 million or more that have yet to be discovered.

I found this graphic (click for larger version) over at GreenFacts, which shows that we have found most of the vertebrates and plants species, and that most of the unknown ones are insects and fungi.

I would guess that the unknown species have low populations. If they had large populations, wouldn't you think someone would have run into them by now? I don't know how important the unknown species are if they are mainly insects and fungi and they have low populations. I would rather have lots of these species go extinct than have a couple of species with extremely large populations go to the verge of extinction.

Having this data would allow us to look at the population of all species and see how it changes from year to year. It would let us understand the impact of climate and land changes. If you cut down a forest to turn it into farm land, some species are net losers while others are winners. If you had a good estimates of species counts, you could see the impact of those changes. How many additional cows and crows and insects are now alive vs. how many wild animals are now gone? Or if the climate warms, what happens to various species? I am sure we will hear about those species that are close to extinction, but what about those who are losing large amounts of their population? Or looking at the glass half full side, what about those species that see their populations increase due to global warming? You never seem to hear about them on the news, but I am sure there will be some winners. This species census will allow us to see that.

As the human population grows, there is a trade off between supporting our population and the population of other species. It would be nice to be able to quantify this, and the species census will help to do this. For every additional human that lives, how many fewer animals can the earth support?

Right now environmentalists focus on endangered species and how to protect them. It might make more sense to try and stabilize populations of species, then try and rescue them once their populations are very low. But, currently there is no good source for animal populations to see what is happening. The species census would collect that data and make it available. It would allow us to see the impact, both positive and negative, to various species due to larger human populations and climate change. It would give us a better feel for the state of life on earth than just focusing on the few species that are close to extinction.

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