Biodiversity misses the point

A smart environmental policy must look at the big picture

“Dad, look, it’s a bald eagle!” I exclaimed, pointing up through the car window to track the enormous bird in flight. My father, who has a sad history of disregarding his daughter’s birding prowess (“Holly, there’s no way you saw a hummingbird in New Jersey” and “That can’t be a kingfisher”), was at least curious enough to turn the car around, if only to prove me wrong.

And there, perched on a telephone pole on Christmas Day in the Florida Keys, was a magnificent specimen of our nation’s symbol. Dad had to eat crow.

My feelings about bald eagles have been mixed ever since I spent a summer in Juneau, Alaska, watching them steal food from other birds and squabble gracelessly amongst themselves. Still, symbolic species like the eagle have reminded Americans of the importance of the natural world and motivated us to conserve the last vestiges of wilderness in our country.

This year, the United Nations wants us to move beyond iconic and charismatic species (like the World Wildlife Fund’s panda) and recognize the importance of all life on Earth — that is, our world’s biodiversity. 2010 has been declared the International Year of Biodiversity, and speeches, celebrations, and media programming have been set up to promote this new conservation ideal. As extinction rates rise and threats from climate change and habitat loss expand, the U.N. hopes to inspire equal protection for all life forms.

But is a deep-sea microbe really as important as a smiling dolphin?

Biodiversity metrics don’t discriminate. Beyond a sense of moral obligation to protect our fellow life forms — a calling that is undoubtedly stronger towards the personable dolphin than an invisible bacterium — lies a slew of potential benefits for humanity. Scientists constantly screen marine compounds for antibiotic and chemotherapeutic activity. What unknown microbe will provide the next medical breakthrough? What nature-inspired technology will underpin the next Fortune 500 company? Here at MIT, we recognize the significance of natural inspiration in our research, even when the heartlands of biodiversity — tropical jungles, coral reefs, and the like — couldn’t seem farther away.

Preserving biodiversity is another matter altogether.

Millions of species remain undiscovered, their potential importance to humanity unexplored. And, with human activity driving species extinctions at 100 to 1,000 times the normal background rate, we could lose the cure for cancer or the clue to new photovoltaic technology without ever knowing it existed. Simultaneously, conservation dollars are limited. Could biodiversity help us set priorities?

Non-profit groups measure biodiversity when choosing the best land parcels to purchase for conservation. Scientists catalog life forms and store their DNA in test tubes. The U.N. identifies “biodiversity hotspots” and argues for their international priority. Seed banks store samples of numerous plant varieties to safeguard the genetic potential of our crops.

Unfortunately, while biodiversity preservation may have broadened conservation efforts, it is not always most useful metric.

Imagine two hundred-acre forests. Plot A is home to 50 species, Plot B to only 40. It would cost the same dollar amount to preserve either plot. The biodiversity argument would compel you to protect the 50-species forest, and without further investigation you might readily agree. However, upon closer inspection you find that Plot A is missing five critical species, and the food web is in the process of collapsing. Conservation efforts would be futile, so you should prioritize the acreage you have the best chance of saving.

One could imagine many other reasons to choose the less diverse Plot B: Less political opposition, more immediate threats, greater productivity that supports larger animal populations. Clearly, it’s important to think of biological systems as an interacting whole, not just as a sum of numerous equivalent parts.

Now, consider ex situ conservation efforts — collecting DNA in test tubes, storing frozen eggs, and banking seeds in Svalbard. Remember that this is not a Noah’s Ark process. Preserving a species’ full complement of genetic diversity requires more samples than “two of every kind.” It can cost tens of thousands of dollars to collect and store the seeds of a single variety of plant; it’s even more expensive to store viable embryos or DNA in a Jurassic Park-esque creation scheme.

In the end, though, what does it mean to have a black rhino egg in your freezer when the animal no longer roams the Earth? What does it mean to store the genetic code of a dozen phytoplankton species on your hard drive if the oceans are too polluted for the organisms to survive?

There will always be a time to draw a line in the sand, to refuse to allow the last members of a species to slip away. The trick is knowing which battles are worth fighting, and which species can be saved. When does conserving biodiversity no longer reflect the greater good?

I currently work with climate change projections for South Florida, home to nearly 40 threatened or endangered species. As sea levels rise and temperatures increase, the habitats of some of these species will simply vanish. Do we carve out a little enclosure to the north and airlift the species to managed safety? In so doing, we separate an animal from its native environment and commit it to relying on man. We also displace existing species when we create the new enclosure. And we expend money and resources perhaps better allocated elsewhere.

Yet how does one stand by and watch the last few Key Deer — adorable miniaturized browsers whose habitat will soon be underwater — meet their salty fate?

We live in a world of impossible choices and irreversible change. Preserving biodiversity is one call for action that can motivate us to conserve a broader and more egalitarian swath of nature. But biodiversity cannot be the only metric by which we operate.

It’s time to get a bit more ruthless with our priorities and more creative with our pocketbooks. We must plan to preserve today’s world, but also anticipate tomorrow’s needs and limitations. That means not just tallying the genes, but also seeing the bigger picture.

Holly Moeller is a graduate student in the MIT/WHOI Joint Program in Biological Oceanography. She welcomes reader feedback at hollyvm@mit.edu. “Seeing Green” runs on alternate Tuesdays.