Archive for the 'biodiversity' Category

Meet Three Endangered Animals

Saturday, April 28th, 2018

Ajo Middle School Citizen Scientists  NPS photo

I learned about two sea creatures while vacationing this spring near Puerto Peñasco in Mexico. By coincidence, we were close to the home of these two endangered animals, at the north end of the Sea of Cortez.

The totoaba is a large fish that only lives in a very small area, and only spawns in the Colorado River delta. Most notable, however, are its swim bladders, which are prized delicacies in China. These organs make the fish valuable, so that it is often captured even though it is protected by law. Locals fish with gill nets which allow small fish to pass through, but the holes are sized to catch the totoaba.

Totoabas reproduce slowly. They don’t become fertile until they are 6 or 7 years old, but they live to be 15 at most and only spawn just once a year. The young are picky—they require brackish water. Totoaba eggs are laid in the Colorado River delta where the river mixes with the ocean. Indeed, their whole population is confined to the area near the Colorado’s mouth.

Unfortunately, the Colorado River has so much water diverted for human needs that most of the time no fresh water reaches the Sea of Cortez. With no fresh water to mix with the ocean, there is no brackish water for spawning—one of the reasons the totoaba is going extinct.

The second species, the vaquita, is the world’s smallest porpoise and shares in the same small habitat with totoabas. Vaquitas are smaller but plumper than their neighbors causing them to also get caught in gill nets. Since they are mammals, they drown unless they can get to air every few minutes.

These two neighbors are both critically endangered because of habitat destruction and “overharvesting”. Both species are likely to become extinct in the near future. Although the Mexican government has passed laws forbidding the use of gill nets, that hasn’t prevented destruction of the two creatures. Unfortunately the prospect of a large payout from selling a totaba is too large an incentive for many poor fishermen to resist.

Vaquitas are also protected by Mexican law, but they apparently are only killed by accident. Their population, which was never large, is now estimated to be as few as a dozen. These animals are secretive and difficult to see, but scientists can listen to their high frequency sound, which vaquitas use to communicate. These calls allow scientists to estimate the animals’ numbers.

In an effort to save vaquitas, scientists from 9 countries banded together to organize VaquitaCPR. After months of planning they captured one of these little animals, with the hope of keeping it safe in an enclosed area of ocean. The specimen showed signs of severe stress, however, so they released her. The second animal didn’t fare as well—it died shortly after capture. 

I first read about vaquitas and totoabas in a Scientific American article, “Goodbye, Vaquita: How Corruption and Poverty Doom Endangered Species”. It is sad to learn that our human needs and carelessness are destroying these beautiful animals.

Driving home from Puerto Peñasco we entered Organ Pipe Cactus National Monument right after we crossed the border. We stopped at the visitor center to get oriented to the Monument and eat a picnic lunch. The nature trail offered a great way for all 3 of us (our dog traveled with us) to stretch our legs. At its end we were surprised to find a small oasis with shady trees, luxuriant plants, a pond and a sign with the unpronouncable title: “Quitobaquito Pupfish”. This is the name of another endemic species—meaning its entire geographic range is tiny, like the totaba and vacquito. This species of pupfish only occurs naturally in 2 places in the world. In the USA the only habitat is in the Monument’s Quitobaquito Spring, which forms a small pool. The second location in the Rio Sonoyta, just over the border in Mexico.

A few years ago the Spring appeared to be drying up. In an attempt to preserve these small, rare fish, the Monument enlisted the help of 160 young citizen scientists—students at the nearby Ajo middle school! They collaborated to design and to build the pupfish refuge. The kids continue to monitor the condition of the oasis, water quality and number of fish.

This story of endangered species started out sadly with the totaba and vaquito, but has a happy ending with the pupfish. Unfortunately, many more species are lost to our expanding human population than can be saved.

© Richard Grossman MD, 2018

Consider Human Inhabitants When Creating Nature Reserves

Sunday, April 24th, 2016

tiger closeup 4

Last summer a big game hunter from Minnesota shot Cecil, a famous male lion, in Zimbabwe. The Zimbabwean officials didn’t press charges against Cecil’s killer.

Many people in this country were outraged that such a rare and beautiful beast had been murdered. The response in Africa was different, however. For us a lion—especially a noble and handsome male—symbolizes freedom and wildness. In Africa, however, a lion means danger.

We live in a protected bubble from which most predators have been excluded. It is true that occasionally a mountain lion will injure or kill a human, but fortunately that is a very rare, newsworthy incident. Black bears are also responsible for a few injuries and rare deaths here in Colorado. The real killer is not a predator but the sweet, innocent herbivore—deer.

Biologist E. O. Wilson has recently written a book advocating that half of the planet become a nature reserve. He wrote: “…I propose that only by committing half of the planet’s surface to nature can we hope to save the immensity of life-forms that compose it.”

I grieve for the loss of biological diversity (biodiversity). Although we cannot know exactly, it is estimated that species of plants and animals are going extinct at 1000 times the normal rate; we are in the 6th mass extinction. There have been five prior mass extinctions, the last one being about 65 million years ago when a huge meteor hit off the coast of Mexico. The resulting explosion changed the climate for centuries, killing off dinosaurs. What is different about the current mass extinction is that it is caused by a single species—ours.

Each species has evolved strategies to maximize reproduction, to gather nutrients efficiently and to ward off other species that imperil it. We are no different, except we have been so amazingly successful. Sadly, our success endangers nonhuman species—and probably ourselves, since our livelihood depends on the web of life.

I have a problem with those who are “prolife”. Our human success is causing the extinction of other animals and plants. By preventing women from access to family planning and safe abortion services, the people who claim to be “prolife” are actually destroying the biodiversity that makes our planet habitable.

Although I haven’t read Wilson’s “Half-Earth: Our Planet’s Fight for Life”, its premise troubles me. Yes, it is important to do what we can to protect other species. Yes, the major cause of loss of species is loss of habitat. Yes, preserves (both terrestrial and marine) have shown their value in preserving biodiversity. The Center for Biological Diversity has a brilliant record of protecting endangered species by preserving habitat.

Turning half the Earth into preserves would slow the loss of biodiversity. But what about the people who currently live on that land—many of whom live in overcrowded, developing countries? what would happen to them?

We had the good fortune to visit the Ranthambhore preserve in India where we observed a Bengal tiger in the wild. We also heard about people who were forced off that land and repatriated to a nearby village. They now make their living by making and selling souvenirs to tourists. This model would not work for half of Earth’s surface, however. Where could all those people settle?

This conundrum is one of the plotlines of “The Hungry Tide” by Amitav Ghosh. This wonderful novel takes place in the Sundarbans, the deltas of four major rivers where they empty into the Bay of Bengal. Thousands of squatters settled on Marichjhanpi Island, an Indian animal refuge, in1979. Piya, a protagonist, biologist and protector of animals, is distressed when settlers kill a man-eating tiger. Forest Guards moved in and destroyed the settlement—and the settlers. Thousands of people were killed in this genocide. Although this sounds incredible, it is based on history.

Thanks to the foresight of Americans a century ago, we have the National Park Service, one of the agencies that take care of our public lands. We should be proud that 14% of our land is currently protected. Costa Rica may have the highest percentage of land preserved for nonhuman use at 25%. It is important to preserve what we have and to continue to protect more wilderness, parks, forests and roadless areas for our enjoyment, and especially for the benefit of other species. However, it is important to keep human rights in mind when considering making new protected areas. Voluntary family planning will help achieve that goal by decreasing population pressure.

© Richard Grossman MD, 2016

Woodman, Spare that Tree

Monday, December 28th, 2015

Autumn-Lake-Reflection-800px

 

                       Woodman, spare that tree!

                           Touch not a single bough!

                        In youth it sheltered me,

                             And I’ll protect it now.

                                                George Pope Morris

 

Twelve years ago at this time we had just returned from Costa Rica to celebrate Christmas at home. Close to where we had stayed we watched the beginning of a new building going up, using steel instead of wood.

In this country with vast forests and where all steel is imported, why wouldn’t they use wood? I was told that it was to preserve the trees. When I asked what the building was going to be, I was told… but you need to read to the end of this column to find out!

There is an estimate that humans have cut down or damaged three quarters of the forests that existed before we became the dominant animal on the planet. Costa Rica is no exception; Ticos had cut down large portions of its forests. Fortunately, thanks to that country’s exceptionally good conservation policies and good luck, second growth forests now cover about a seventh of the country’s land area.

We rented a cozy cabin for most of the 3 months that we lived in Monteverde. Perhaps its best quality was its location, bordering the Children’s Eternal Rain Forest. Trees in this area had been cut down for agriculture, and more recently they were allowed to regrow. The land was bought with donations from all over the world. Most impressively, the movement to preserve and rehabilitate this land was started by Swedish elementary school children.

Trees are pretty amazing. In addition to being attractive and fun to climb, they provide shade and purify air and water. They are also part of the carbon cycle, as many kids can tell you. Using sunlight for energy, they suck out carbon dioxide from the air, synthesize cellulose and release oxygen. If that wood burns, the CO2 is returned to the atmosphere. If a tree is allowed to slowly decompose, some of its carbon joins the soil and increases its fertility.

All trees are not created equal, however. In a natural forest there are many different species of trees, plus undergrowth, all filling different ecological niches. On the other hand, a tree monoculture, especially if treated with lots of chemicals, is a poor substitute for a natural forest.

Shade-grown coffee is an example of a good compromise between agricultural production and good ecology. Trees shade the coffee bushes as well as providing homes for many beneficial animals. Hungry birds gobble up harmful insects on the coffee bushes, for example.

Part of the reason we selected Monteverde, Costa Rica as the place to spend a sabbatical was the Quaker connection. Several Quaker families chose to live in the only country in the world that did not have a military force; they founded Monteverde in 1951. They bought a large amount of land very inexpensively, and preserved much of it to insure the purity of their water supply. This uncut, undeveloped cloud forest has become a haven for plants and animals—and for the biologists who study them.

Brazil, in stark contrast to Costa Rica, has been unable to control devastation of its Amazon rainforest. Called the “lungs of the planet”, the Amazon is the world’s largest rainforest and is key for the planet’s health. In 2014 the destruction (by harvesting tropical wood and clearing for cattle and other agriculture) has increased by 16%. An area larger than Delaware was cut down in just one year!

Palm oil production is big business in some Asian countries. Often grown in huge plantations, in Indonesia alone the land devoted to palm oil monoculture is almost as large as Connecticut. The native forest is often burned to prepare for the land for planting oil palms, causing terrible air quality. Sadly, this has lead to the destruction of habitat for orangutans and tigers, among other creatures.

What can we do to spare tropical trees? Avoid buying products made with exotic woods. Eat less beef—you’ll be healthier, too! When possible, pass up foods that contain tropical oils such as palm oil.

We visited Monteverde about a year after the sabbatical and found a group of people outside that little building built with steel instead of wood. Most of them were kids, since school had just let out, and they all looked happy—for a good reason. The shop was selling locally made ice cream! Indeed, Monteverde has some of the best ice cream I’ve ever tasted—coffee is my favorite flavor.

© Richard Grossman MD, 2015

Creative Commons Attribution 3.0 United States
This work is licensed under a Creative Commons Attribution 3.0 United States.