At Eco Preservation Society we advocate two common sense long-term goals:

Common Sense Goal #1: Within thirty years we must replace fossil fuels as an energy source.

Common Sense Goal #2: Over the next one hundred years we must sequestered the excess carbon that has been added to the atmosphere over the last one hundred years.

As important as it is to reduce our CO2 emissions, it is also important to remove the excess CO2 that we have already put into the atmosphere. Certainly over the next 30 years we will be producing much more CO2 before we begin to produce less. To suggest that we should choose emissions over sequestation is a false choice. We must focus on both.

Further, when talking about Carbon Neutral or Carbon Offsets, reforestation is not only a “viable option”; it is our “only option”. Investing in future technologies to reduce emissions does NOTHING to remove the CO2 that we have already dumped into the atmosphere. There is only ONE viable and proven way to remove CO2 from the atmosphere and that is through the growth of trees and vegetation.

Common sense must prevail. The notion that planting trees is detrimental to the cause of protecting our environment does not pass the common sense test. Critics correctly note that as carbon sinks a forests ability to sequester carbon may follow a saw tooth pattern. However it is a fallacy to suggest that because carbon retention in our forests does not follow a linear pattern that it is somehow diminished in importance. This is non-sense! Simply because our understanding of these processes may be more complex than once thought, that does not mean that these processes are any less important to our future.

Those that argue that reforestation efforts are only “feel good” solutions because an individual tree may not permanently sequestered the carbon in its biomass are presenting an overly simplistic argument. An analogous argument could be made that one should not open a bank account because not ALL of the money that you deposit into that account remains there permanently. The concept of effectively managing a bank account does not require that every dollar you put into the account remain there forever. The concept is that money flows in and out and over time successful money manager will grow that account. This is how we need to look at our forests, as a renewable resource that plays an unparalleled and unique role in sequestering carbon from our atmosphere.

There is a danger that when we grasp at headlines like “Reforestation Contributes to Global Warming” that we promote an overly simplistic view of the problem. The headlines garnered by the Livermore Study were so seductive for so many, particularly those that have an interest in the emission reduction side of the Carbon Offset debate. However carbon cycle is only one factor in the equation of protecting our environment. Along with reducing CO2 emissions and removing the excess CO2 that has already been emitted, we should not loose sight of the role that trees play in the water cycle and in the production of the oxygen that we breath. The notion that environmentalist can make blanket statements like: “planting trees north of the Canadian bordered contributes to Global Warming” and to have so many accept these findings without serious scrutiny should be cause for great concern within the environmental community. It is no wonder that those in the business community look at us environmentalist as a bunch of flakes.

We must do better

At Eco Preservation Society we believe that we need to re-examine all of our options in sequestering carbon. Today there are many web sites that feature Carbon Calculators that tell us about our individual Carbon Footprint. Yet in all of the Carbon Footprint Calculators, none take into account the amount of carbon that an affluent family has sequestered in their 4000 square foot wood structured home. We must do better!

Looking at the wood products industry as a possible solution to Global Warming problem is a politically incorrect discussion within the environmental movement. We must to take a fresh look at reforestation and forestry as a sustainable resource.

In the past the forestry industry has given us mono-habitats and clear cutting. These are obvious negative impacts and we must do better. How much more engineering and planning would it really require to manage these resources in a more diverse manner?

In the future we can do better and we need to take a fresh look at how we approach these issues.

Clearly the Lawrence Livermore study is not the final word. It only serves to awaken us to the fact that the complexities of the problems that we face are much greater than we once imagined. It is fair to conclude from the Livermore Study that overly simplistic monolithic solutions such as “Universal Tree Planting” are not viable. At the same time, overly simplistic conclusions drawn from the Livermore Study are equally inappropriate.

As leaders in the environmental movement it is important that we are responsible with the information that we feed to the public. We loose credibility with the public when we grasp at sensational headlines and do not deliver on thoughtful and meaningful examination of these critical issues.

Solutions Moving Forward:

Perhaps it is time for us to reexamine the concept of deforestation, both in terms of methods and importance. Deforestation occurs in nature, it serves a purpose in nature’s cycles. Without question our last remaining old growth forest and primary rain forests must absolutely be protected. However when it comes to the management of lands that have already been deforested there are other options that have not been considered. For those interested in this topic see our article on the Resource Revolution.

Over the last century there have been vast amounts of lands that have been deforested and converted to pasturelands and croplands that should be converted back to forestlands and wildlife habitat. The key to realizing this goal is to provide economic incentives for landowners to covert these lands back to forests.

We see 3 sources of revenue incentives for conservation minded landowners.

First, financial incentives can come in the form of selective harvesting of trees in a diverse forest environment. Instead of planting a “mono crop” of trees that would be harvested all at once, a diverse environment could be created with a variety of trees that grow at different rates. Trees could be harvested in a selective manner at different times based on a variety of factors. Instead of wiping an entire habitat, trees can be harvested in a manner that preserves the habitat.

Second, this staggered harvest approach means that the forests will retain their value not only as a habitat, but as recreational areas as well. Recreational activities would be an additional source of revenue for the land owner: hiking trails, cross-country skiing, canopy tours, horseback riding, GPS tracking games, trail biking, ATV tours, ect, ect.

Finally, with the ability to sell carbon credits, there is a third possible source of revenue for the landowner.

Conclusions

It took us a century to create our problems with the environment; we need to take a long-term view at solving them. Realistically it is going to take us 30 years to phase out fossil fuels; there will be more damage to correct during that time. We need to start now and reforestation is the answer. We are conditioned to seek immediate gratification and we are not satisfied unless we achieve instant results. Instant results are not a realistic expectation for solving our environmental problems. From our view a longer-term approach is required. The key is for our generation to initiate the process and to raise our children with understanding that this will be the biggest challenge facing their generation. We need to provide our children with the values and the education so that they will have the tools and the imagination to solve these problems within their lifetime. The future belongs to our children and it is up to us to provide them the means to make their future a bright one. This is a living legacy that is our responsibility to deliver upon for future generations. This is the goal of the Eco Preservation Society.

Kevin Peterson, CEO
Eco Preservation Society
EcoPreservationSociety.org

Part 1 - Does Reforestation Contribute to Global Warming?
Part 2 - Reforestation, Aldedo and Lawrence Livermore Study
Part 3 - Rain Forests: The World’s Air Conditioner
Part 4 - Planting Trees in Cities
Part 5 - Does Reforestation Contribute to Global Warming? - A second look at the Livermore Study
Part 6 - Getting Our Priorities Straight - Common Sense Solutions to Climate Change

From Amphibian Ark

Amphibians are an important component of the global ecosystem, as indicators of environmental health and contributors to human health. They watched the dinosaurs come and go, but today almost half of them are themselves threatened with extinction. Addressing the amphibian extinction crisis represents the greatest species conservation challenge in the history of humanity.

The global conservation community has formulated a response in the Amphibian Conservation Action Plan, and an integral part of that response is the Amphibian Ark, in which select species that would otherwise go extinct will be maintained in captivity until they can be secured in the wild. Without immediate captive management as a stopgap component of an integrated conservation effort, hundreds of species could become extinct.

Addressing the amphibian extinction crisis represents the greatest species conservation challenge in the history of humanity. One third to one half of all amphibian species are threatened with extinction, with probably more than 120 already gone in recent years. The IUCN Global Amphibian Assessment has alerted us to the fact that hundreds of species face threats that cannot be mitigated in the wild, they require zoos to save them in the short term until adequate conservation measures to secure wild populations can be developed. Comparable calls to action are included in other IUCN documents.

The World Association of Zoos and Aquariums (WAZA) has joined with two branches of the IUCN Species Survival Commission (IUCN/SSC) - the Conservation Breeding Specialist Group (CBSG) and the Amphibian Specialist Group (ASG) - to form the Amphibian Ark (AArk). Since 2006 the Amphibian Ark has been helping the ex situ community to address the captive components of the Amphibian Conservation Action Plan, saving as many species as possible by providing global coordination, technical guidance, training, necessary linkages to other IUCN groups, communications, and guiding publicity and capital campaigns.

Without immediate captive management as a stopgap component of an integrated conservation effort, hundreds of species will become extinct. This conservation challenge is one that we, the ex situ community, are uniquely capable of addressing. Never before has the conservation community at large charged zoos and aquariums with a task of this magnitude. This is an opportunity for every zoo and aquarium, regardless of size, to make a vital conservation contribution, and for our community to be broadly acknowledged as a credible conservation partner. Supporting this call to action is clearly within the financial capacity of all zoos and aquariums, and engages the diverse expertise found within all institutions. Our goal is 100% participation of WAZA zoos and aquariums and the regional associations. If we do not respond immediately and on an unprecedented scale, much of an entire vertebrate class will be lost, and we will have failed in our most basic conservation mission as defined in the World Zoo and Aquarium Conservation Strategy.

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To Help Save Mono Titi - CLICK HERE

Related Stories:
More about the Saving Mono Titi documentary
A history of African Palm Production
Ten Reasons not to feed the monkeys.
Costa Rican company leads Resource Revolution

Other Resurces:
Saving Mono Titi Web Site
Eco Preservation Society
Kids Saving the Rainforest
ASCOMOTI

It has been suspected for some time that global warming may cause widespread amphibian extinctions. In a study published in 2006 by J. Alan Pounds suggested that many harlequin frog species (Atelopus) across Central and South America have disappeared due to deadly infectious diseases spurred by changing water and air temperatures.

At one time the Harlequin Frog (actually a toad) was thought to be extinct. In 2003 the Harlequin Frog was rediscovered in the primary rain forest of the Rainmaker Reserve on the Central Pacific Coast of Costa Rica.

“Disease is the bullet killing frogs, but climate change is pulling the trigger,” said Pounds, lead study author and resident scientist at Costa Rica’s Monteverde Cloud Forest Preserve.

“Global warming is wreaking havoc on amphibians and will cause staggering losses of biodiversity if we don’t do something fast.”

The World Conservation Union (IUCN) has listed this frog as Critically Endangered and facing an extremely high risk of extinction in the wild, because most of them have disappeared since 1988. In 1996, in fact, scientists feared that all of the more than one hundred populations known to exist in Costa Rica were already gone. Seven years later, however, a tiny population was discovered at Rainmaker Reserve.

About two-thirds of the 110 known harlequin frog species are believed to have vanished during the 1980s and 1990s. The primary culprit, Pounds suggests, is the disease-causing chytrid fungus Batrachochytrium dendrobatidis.

Amphibian skin is extremely thin, which makes frogs acutely sensitive to even minor changes in temperature, humidity, and air or water quality. It also makes frogs more susceptible to chytrid fungus.

The new study suggests that temperature extremes may have previously helped keep the deadly disease in check. But new climate cycles are now moderating those annual temperature swings.

Global warming has increased evaporation in the tropical mountains of the Americas, which in turn has promoted cloud formation, the study reports. That cloud cover may have actually decreased daytime temperatures by blocking sunlight. At the same time, it may have served as an insulating blanket to raise nighttime highs.

Pounds believes the combination has created ideal conditions for the spread of the frog-killing fungus, which grows and reproduces best at temperatures between 63° and 77°F (17° and 25°C).

Related Article about Rainmaker Reserve.

Related Article About Amphibians in Costa Rica

Harlequin Frogs True Toads and Relatives: Bufonidae - Harlequin Frog (atelopus Varius): Species Accounts

Extraordinary Video from Rainmaker Reserve

.

Special to A.M. Costa Rica
http://www.amcostarica.com

Sharks are disappearing from the world’s oceans. The numbers of many large shark species have declined by more than half due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and swordfish fisheries, where millions of sharks are taken by accident each year.

Now, the global status of large sharks has been assessed by the World Conservation Union, which is widely recognized as the most comprehensive, scientific-based information source on the threat status of plants and animals.

“As a result of high and mostly unrestricted fishing pressure, many sharks are now considered to be at risk of extinction,” explained Julia Baum, a member of the union’s Shark Specialist Group

“Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red List as globally endangered due to overfishing and high demand for its valuable fins in the shark fin trade,” added Ms. Baum, who is a postdoctoral fellow at Scripps Institution of Oceanography.

Ms. Baum pointed out that fishing for sharks in international waters is unrestricted, and she supports a recently adopted United Nations resolution calling for immediate shark catch limits as well as a meaningful ban on shark finning, the practice of removing only a shark’s fins and dumping the still live but now helpless shark into the ocean to die.

Costa Rica is a major supplier to the international shark fin trade.

Research at Canada’s Dalhousie University over the past five years, conducted by Ms. Baum and the late Ransom Myers, demonstrated the magnitude of shark declines in the northwest Atlantic Ocean. All species the team looked at had declined by over 50 per cent since the early 1970s. For many large coastal shark species, the declines were much greater: tiger, scalloped hammerhead, bull and dusky shark populations have all plummeted by more than 95 per cent.

A commercial fish factory vessel was boarded this month by Costa Rican officials because they said it was involved in illegal fishing in the protected area of Isla del Coco. However, investigators had to let the 25-person crew go because there was uncertainty in the law regarding this kind of activity. The crew was seeking tuna but sharks, including hammerheads for which the waters around the island are famous are likely victims, too.

The issue still is being discussed in prosecutorial circles.

Shark Finning in Costa Rica (Warning: This video is disturbing)

( We would to thank everyone at Treehugger.com that contributed to this series. We are grateful for your insights and ideas.)

At Eco Preservation Society we advocate two common sense long-term goals:

Common Sense Goal #1: Within thirty years we must replace fossil fuels as an energy source.

Common Sense Goal #2: Over the next one hundred years we must sequestered the excess carbon that has been added to the atmosphere over the last one hundred years.

As important as it is to reduce our CO2 emissions, it is also important to remove the excess CO2 that we have already put into the atmosphere. Certainly over the next 30 years we will be producing much more CO2 before we begin to produce less. To suggest that we should choose emissions over sequestation is a false choice. We must focus on both.

Further, when talking about Carbon Neutral or Carbon Offsets, reforestation is not only a “viable option”; it is our “only option”. Investing in future technologies to reduce emissions does NOTHING to remove the CO2 that we have already dumped into the atmosphere. There is only ONE viable and proven way to remove CO2 from the atmosphere and that is through the growth of trees and vegetation.

Common sense must prevail. The notion that planting trees is detrimental to the cause of protecting our environment does not pass the common sense test. Critics correctly note that as carbon sinks a forests ability to sequester carbon may follow a saw tooth pattern. However it is a fallacy to suggest that because carbon retention in our forests does not follow a linear pattern that it is somehow diminished in importance. This is non-sense! Simply because our understanding of these processes may be more complex than once thought, that does not mean that these processes are any less important to our future.

Those that argue that reforestation efforts are only “feel good” solutions because an individual tree may not permanently sequestered the carbon in its biomass are presenting an overly simplistic argument. An analogous argument could be made that one should not open a bank account because not ALL of the money that you deposit into that account remains there permanently. The concept of effectively managing a bank account does not require that every dollar you put into the account remain there forever. The concept is that money flows in and out and over time successful money manager will grow that account. This is how we need to look at our forests, as a renewable resource that plays an unparalleled and unique role in sequestering carbon from our atmosphere.

There is a danger that when we grasp at headlines like “Reforestation Contributes to Global Warming” that we promote an overly simplistic view of the problem. The headlines garnered by the Livermore Study were so seductive for so many, particularly those that have an interest in the emission reduction side of the Carbon Offset debate. However carbon cycle is only one factor in the equation of protecting our environment. Along with reducing CO2 emissions and removing the excess CO2 that has already been emitted, we should not loose sight of the role that trees play in the water cycle and in the production of the oxygen that we breath. The notion that environmentalist can make blanket statements like: “planting trees north of the Canadian bordered contributes to Global Warming” and to have so many accept these findings without serious scrutiny should be cause for great concern within the environmental community. It is no wonder that those in the business community look at us environmentalist as a bunch of flakes.

We must do better

At Eco Preservation Society we believe that we need to re-examine all of our options in sequestering carbon. Today there are many web sites that feature Carbon Calculators that tell us about our individual Carbon Footprint. Yet in all of the Carbon Footprint Calculators, none take into account the amount of carbon that an affluent family has sequestered in their 4000 square foot wood structured home. We must do better!

Looking at the wood products industry as a possible solution to Global Warming problem is a politically incorrect discussion within the environmental movement. We must to take a fresh look at reforestation and forestry as a sustainable resource.

In the past the forestry industry has given us mono-habitats and clear cutting. These are obvious negative impacts and we must do better. How much more engineering and planning would it really require to manage these resources in a more diverse manner?

In the future we can do better and we need to take a fresh look at how we approach these issues.

Clearly the Lawrence Livermore study is not the final word. It only serves to awaken us to the fact that the complexities of the problems that we face are much greater than we once imagined. It is fair to conclude from the Livermore Study that overly simplistic monolithic solutions such as “Universal Tree Planting” are not viable. At the same time, overly simplistic conclusions drawn from the Livermore Study are equally inappropriate.

As leaders in the environmental movement it is important that we are responsible with the information that we feed to the public. We loose credibility with the public when we grasp at sensational headlines and do not deliver on thoughtful and meaningful examination of these critical issues.

Solutions Moving Forward:

Perhaps it is time for us to reexamine the concept of deforestation, both in terms of methods and importance. Deforestation occurs in nature, it serves a purpose in nature’s cycles. Without question our last remaining old growth forest and primary rain forests must absolutely be protected. However when it comes to the management of lands that have already been deforested there are other options that have not been considered. For those interested in this topic see our article on the Resource Revolution.

Over the last century there have been vast amounts of lands that have been deforested and converted to pasturelands and croplands that should be converted back to forestlands and wildlife habitat. The key to realizing this goal is to provide economic incentives for landowners to covert these lands back to forests.

We see 3 sources of revenue incentives for conservation minded landowners.

First, financial incentives can come in the form of selective harvesting of trees in a diverse forest environment. Instead of planting a “mono crop” of trees that would be harvested all at once, a diverse environment could be created with a variety of trees that grow at different rates. Trees could be harvested in a selective manner at different times based on a variety of factors. Instead of wiping an entire habitat, trees can be harvested in a manner that preserves the habitat.

Second, this staggered harvest approach means that the forests will retain their value not only as a habitat, but as recreational areas as well. Recreational activities would be an additional source of revenue for the land owner: hiking trails, cross-country skiing, canopy tours, horseback riding, GPS tracking games, trail biking, ATV tours, ect, ect.

Finally, with the ability to sell carbon credits, there is a third possible source of revenue for the landowner.

Conclusions

It took us a century to create our problems with the environment; we need to take a long-term view at solving them. Realistically it is going to take us 30 years to phase out fossil fuels; there will be more damage to correct during that time. We need to start now and reforestation is the answer. We are conditioned to seek immediate gratification and we are not satisfied unless we achieve instant results. Instant results are not a realistic expectation for solving our environmental problems. From our view a longer-term approach is required. The key is for our generation to initiate the process and to raise our children with understanding that this will be the biggest challenge facing their generation. We need to provide our children with the values and the education so that they will have the tools and the imagination to solve these problems within their lifetime. The future belongs to our children and it is up to us to provide them the means to make their future a bright one. This is a living legacy that is our responsibility to deliver upon for future generations. This is the goal of the Eco Preservation Society.

Kevin Peterson, CEO
Eco Preservation Society
EcoPreservationSociety.org

Part 1 – Does Reforestation Contribute to Global Warming?
Part 2 – Reforestation, Aldedo and Lawrence Livermore Study
Part 3 - Rain Forests: The World’s Air Conditioner
Part 4 - Planting Trees in Cities
Part 5 - Does Reforestation Contribute to Global Warming? - A second look at the Livermore Study
Part 6 - Getting Our Priorities Straight - Common Sense Solutions to Climate Change

by Richard Garrigues

In the nebulous zone between high and low tide, where freshwater meets saltwater and the ground is neither liquid nor solid, grow the mangroves.

Inhabitants of inter-tidal zones throughout the tropics and subtropics, mangroves are a most curious collection of plants. It is easy to make the erroneous assumption that the different kinds of mangrove trees are closely related species adapted to the unique conditions in which they grow. Even their English common names (red mangrove, black mangrove, white mangrove, buttonwood mangrove, etc.) lend to the idea that these are merely different species of the same plant family, as if they were maples or oaks.

In reality, the mangroves are a wonderful example of convergent evolution—a situation in which totally unrelated organisms have evolved certain similarities simply because those are the characteristics best suited for making use of a particular resource. And in this case the resource is a place where a plant might grow if it can overcome the two major difficulties faced by mangroves: the salinity of the sea water which saturates the ground they grow in and the absence of oxygen in that same saturated mud.

In Costa Rica there are seven species of mangrove trees from four very different plant families: the red mangroves (Rhizophora mangle and R. harrisonii, Rhizophoraceae), the black mangroves (Avicennia germinans and A. bicolor, Verbenaceae), the tea mangrove (Pelliciera rhizophorae, Theaceae), the white mangrove (Laguncularia racemosa, Combretaceae), and the buttonwood mangrove (Conocarpus erectus, Combretaceae). In Costa Rica, any and all of these plants are called mangle (man-gley) and the association in which they grow a manglar.

Of the mangroves found in Costa Rica, the red mangrove is the most easily recognized with its striking aerial prop roots, which often branch one or more times before reaching the ground. The primary function of these roots is not to support the tree but to aid in the aeration of the plant’s sap system.

The black mangrove, and to some extent the white mangrove, cope with the lack of air in the mucky substrate by developing vertical extensions from their roots which stick above the soil level and (at low tide) accomplish oxygen exchange. The tea mangrove has pronounced buttresses which act as aerators. The buttonwood mangrove effectively avoids this problem by growing on the back edges or higher ground within a mangrove swamp, thus reducing the likelihood of having the soil around its roots supersaturated except at extreme high tides.

Mangroves have developed various ways to deal with the problem of high salt concentrations in the water around them. Some species secrete salt from their roots and/or leaves. Pacific coast black mangroves can be observed in the dry season with salt crystals along the outer edges of their leaves (secretion of salt through the leaves happens throughout the year, but is not usually observed in the rainy season because the rain washes off the salt).

In some mangroves, such as the red mangrove, salt is stored in the older leaves which soon fall off the tree. And in other species, it appears that salt is simply tolerated in much higher levels than is common in most plants.

As a result of the rather severe conditions where mangroves grow, there is not much plant diversity. Correspondingly, the animal life associated with mangroves is not nearly as diverse as it is in other lowland habitats in Costa Rica. Nevertheless, what mangrove swamps may lack in numbers of species they make up for with numbers of individuals.

At certain times of the year the tops of mangrove trees are filled with nesting birds. In the Tempisque River, the Isla de Pájaros, or Bird Island, is an impressive example of this phenomenon. Each year hundreds of Wood Storks, Roseate Spoonbills, Anhingas, and Neotropical Cormorants reproduce on this protected patch of mid-river mangroves.

In the mangrove of Damas Island you will find White Faced Monkey which many a visitor will have a close encounter. But please, do not feed the monkeys.

Part of the reason for the concentration of nesting and roosting birds in the mangroves could be that it serves as a sanctuary from terrestrial and climbing predators. The bases of the trees are under water almost nearly of the time and even when they are exposed by receding tides, the soft mud that surrounds them is a deterrent to many creatures.

Below the water’s surface in areas where mangroves grow one can find a high diversity of life forms. Among the mangrove’s root systems many marine organisms live or spend a portion of their lives. Such creatures include algae, corals, barnacles, sponges, oysters, crabs, lobsters, shrimps, octopi, and fishes. The importance of mangroves to the health of the marine ecosystem is immeasurable.

Unfortunately, in Costa Rica and the rest of the world, mangrove forests are being destroyed and their sites converted to fish pens, rice paddies, salt-drying ponds, cattle pasture, tourist developments and human settlements. Mangrove wood makes good fuel and excellent charcoal, but over-harvesting has contributed to their demise. Additionally, the red mangrove is an important source of tannin (used in processing leather), but the stripping of the bark to get the tannin kills the individual trees.

All mangroves in Costa Rica are protected by law, but there is not always someone around to enforce the law. Nevertheless, there are still large areas of mangroves lining estuaries and mouths of rivers and streams along the Pacific coast of Costa Rica. Mangrove development is not as common on the Caribbean coast, because there is little variation in the height of the tides, but one area where some very tall red mangroves can be seen is along the extensive canal system between Limón and Tortuguero.

Wednesday September 5, 2007

In recent years, scientists and conservationists have been working to raise public awareness of a global decline in amphibian populations. Herpetologists first started noting that amphibian populations were falling at many of their study sites in the 1980s. Those early reports were anecdotal and many experts doubted that the observed declines were cause for concern (the argument was that populations of amphibians fluctuate over time and the decline could have been merely natural variation).

But by 1990, a significant global trend had emerged—one that overstepped normal population fluctuations. Herpetologists and conservationists started voicing their concern for the worldwide fate of amphibians. Their message was alarming: of the estimated 5,918 known species of amphibians that inhabit our planet, a staggering 1,856 species were listed as endangered, threatened or vulnerable on the IUCN Red List (Global Amphibian Assessment 2007).

Amphibians are considered to be indicator species for environmental health: they have delicate skin that readily absorbs toxins from their environment; they have few defenses and can fall prey to non-native predators; they rely on both aquatic and terrestrial habitats at various times during their life cycle. If amphibians populations are in decline, it is likely that the quality of the habitat in which they live is suffering.

There are numerous known factors that contribute to amphibian declines—habitat destruction, pollution, the effects of introduced species. Yet research has revealed that even in pristine habitats—those that lie beyond the reach of the bulldozer and crop-duster—amphibians are disappearing at a shocking rate and without explanation. Scientists are now looking to global phenomena for explanations. Climate change, emerging diseases, and increased exposure to UV-B radiation (due to ozone depletion) are all additional factors that could be contributing to falling amphibian populations.

So it seems the question ‘Why are amphibians in decline?’ has no simple answer. Instead, amphibians are disappearing due to a complex mixture of factors which include:

1. Alien Species—Native amphibian populations can suffer decline when alien species are introduced into their habitats. There are a number of ways an introduced species can impact populations of native amphibians. For instance, an amphibian species may become the prey of the introduced species. Alternatively, the introduced species may compete for the same resources required by the native amphibian. It is also possible that the introduced species may form hybrids with the native species and in doing so reduce the prevalence of the native amphibian within the resulting gene pool.
2. Over-Exploitation—Amphibian populations in some parts of the world suffer decline because they are captured for the pet trade or are harvested for human consumption.
3. Habitat Alteration and Destruction—Alteration and destruction of habitat has devastating effects on many organisms and amphibians are no exception. Changes to water drainage, vegetation structure, and habitat composition all impact the ability of amphibians to survive and reproduce. For example, the drainage of wetland areas for agricultural use of the land directly reduces the habitat available for amphibians which require aquatic habitat for breeding and foraging.
4. Global Changes (Climate, UV-B, and Atmospheric Changes)—Global climate change presents a serious threat to amphibians because altered precipitation patterns will likely result in changes to wetland habitat on which amphibians rely. Additionally, increases in UV-B radiation due to ozone depletion have been found to severely impact some species of amphibians.
5. Infectious Diseases—Significant amphibian declines have been associated with infectious diseases such as chytrid fungus and iridoviruses. Chytrid fungal infections in amphibians was first discovered in populations of amphibians in Austrailia but also has been found in Central America and North America.
6. Pesticides and Toxins—The widespread use of pesticides, herbicides, and other synthetic chemicals and pollutants has severely impacted many amphibian populations. In 2006, scientists at the University of California, Berkeley found that mixtures of pesticides were causing amphibian deformities, reducing reproductive success, harming development, and increasing susceptability to diseases such as bacterial meningitis.

Related Articles

Costa Rica’s Harlequin Frog, once thought extinct, flourishes in Rainmaker Reserve

Costa Rica’s Jesus Christ Lizard walks on water

Sources

• Blaustein, A. and B. Bancroft. 2007. “Amphibian Population Declines: Evolutionary Considerations“. Bioscience Vol. 57 No. 5: 437-444.
• Collins, J.P. and A. Storfer. 2003. “Global Amphibian Declines: Sorting the Hypotheses“. Diversity and Distributions 9: 89-98.
• Young, B. E., S. N. Stuart, J. S. Chanson, N. A. Cox, and T. M. Boucher. 2004. Disappearing Jewels: The Status of New World Amphibians. Virginia: NatureServe. Accessed September 5, 2007.
• Global Amphibian Assessment (Globalamphibians.org)
• Pesticide Combination Imperils Frogs (UC Berkeley New)
• Many Amphibians Threatened Worldwide (Live Science)

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