By Michael Bengwayan {This article has been posted in the following services: the British Gemini News Service, the US Environmental News Service and the Philippine Post}
Baguio City (July 12, 2000) --- Some of the country's amphibians and reptiles, particularly frogs and salamanders, are becoming extinct. As a result, mosquitos, including the malaria-transmitting Anopheles and the deadly dengue-causing Aedes Aegypti, are multiplying in great numbers further endangering the health of thousands of Filipinos.
In last week's National Biodiversity Conservation Priority Setting Workshop here, two reputable scientists acknowledged the disappearance of Philippine amphibians. Dr. Letecia Afuang, Conservation International (CI) Program Manager and a leading Philippine herpetologist, an expert on amphibians and Prof. Erlinda Bestre who does biological research in north Luzon for the Benguet State University (BSU), said amphibian population in the last ten years have drastically gone down. Afuang, who is an assistant professor at the University of the Philipines at Los Banos (UPLB) has been in charge of the assessment of conservation status of Philippine amphibians. She said that there is a lack of awareness in the broader Filipino community of Philippine amphibians and their relevance, leading to the destruction of the creatures. Bestre said amphibians are one of nature's best predators and contributed significantly in controlling populations of pests which transmit diseases and are harmful to the agriculture industry. The decline of amphibian population can result to serious implications is its is not averted, she added.
Extinct Frogs
Already, four Philippine frogs are extinct in Benguet and perhaps in other parts of the country, according to Bestre. These are the Philippine bullfrog (Rana magna), the field frog or "palakang bukid" (Rana vittegena), freshwater frog or "palakang tubigan" (Rana modeie) and the Philippine toad (Bufo marinus). Lizards and salamanders have also been observed to be disappearing, Bestre said.
The loss of amphibians, particularly in Benguet is caused by excessive use of pesticides, herbicides, inorganic fertilizers and other chemicals, Bestre believes. Benguet is the country's heaviest pesticide user, spending more than $240 million a year, a study by the chemical company former Ciba Geigy revealed. The Benguet-based environmental ngo ITAG which is in environmental and agricultural research added that chemicals have combined effects which can offset or kill large populations of amphibians through chemical contamination, oestrogenic effects and acid precipitation. These are particularly caused by fertilizers and herbicides. Organochlorine pesticides like endosulfan are potential poisons to amphibians as shown by their toxic effects on fishes, frogs and tadpoles when they find their way to rivers and springwaters, ITAG added.
Disease Outbreak
The "silence of the frogs" in many parts of the Cordillera region has resulted to the sudden emergence of dengue fever, even in areas with no previous history of the disease. According to the regional Department of Health (DOH) program officer for dengue prevention and control Dr. Tony Bautista, dengue mosquitos are now prevalent in Benguet, Mountain Province, Ifugao and Kalinga. Last year, more than 1,500 cases were reported in the said provinces, a few of which resulted to death of the victims he added.
Dengue is a tropical disease caused by a virus of the mosquito Aedes Aegypti. It is characterized by high fever, headache, rashes, and severe joint and muscle pains. Extreme cases result to bleeding and death of the victim. With the outbreak of the rainy season, DOH regional information officer Bonifacio Bengwayan Jr. said some 17 dengue victims have now been reported in Baguio City, Last year, all the municipalities of Benguet were hit by dengue with La Trinidad and Mankayan having the most number of cases as well as dengue-related casualties, Bengwayan said.
Noted medical researcher Dr. Charles Cheng, medical director of the Baguio-Filipino Chinese Hospital theorized that the notable increase of the malaria-transmitting Anopheles mosquito in the region has direct relationship to the dwindling amphibian population. "Frogs and lizards have always controlled the population of insects pests. That is not the case today. As their natural habitats are destroyed by human activity, we are experiencing the results of such ecological destruction like the emergence of mosquitos that cause malaria and dengue", he said.
Why Should Amphibians Matter?
Besides controlling populations of insect pests and disease-causing insects, amphibians have global ecological, economic and medicinal values. Amphibians are an important part of the ecological balance of many habitats and their loss should be a cause of worldwide concern. Large masses of amphibians provide food for bigger animals in the food chain even as they themselves control population of smaller animals and insects. They are useful in reducing the number of insect pests that destroy crops and natural vegetation. Frogs are commercially exploited as food, notably by the Europeans, particularly the French who import thousands of tons of frog legs annually. Frogs' importance to agriculture was demonstrated in 1985 when Bangladesh, one of France's major exporters of frogs stopped exporting because they noted the increase of armyworms in ricefields due to the massive harvest of field frogs. Frogs are natural predators of armyworms In the medical world, amphibians are potential sources of medicine. Frog secretions were long known as having hallucinogenic effects as well as effects to human central nervous and the respiratory systems. In 1998, Michael Zasloff of the US National Institute of Health (NIH) said NIH has identified a new class of anti-microbial compounds in the skin secretions of frogs. The compounds which are peptides are called magamins which constitute a vertebrate chemical defense system for immunity. It is now being studied for possible AIDS treatment.
The poison frog which grow no longer than a nail have long been used by South American natives in treating their wounds by rubbing the poison frogs on wounds and cuts. It causes the injured to sleep and awake with keener senses, NIH says. The Australian tree frog was lately discovered by Japanese scientists to produce caerulien, a compound used for chronic schizophrenic victims. It was also found successful in Germany for curing "atomic glut", a condition in which the muscles of the gut collapses. A South American frog was recently discovered by US researchers as containing a substance which is 200 times more powerful than morphine as a painkiller. Last year, Australian scientists also found out that the desert frog produces a natural glue that could replace stitches after surgery. The latest medical finding was that of the discovery of a secretion in frogs called magainin. This provides natural antiobiotic effects.
Worldwide Phenomenon
The decline of amphibian population is worldwide. Over the last 50 years many species have remarkably gone down in numbers. Some species have become extinct. In many cases, the decline are a direct response to the impact of human activities such as habitat destruction or pollution acting at a local level. Towards the late 1980s, biologists from many parts of the world reported declines in amphibian populations in apparently prestine habitats, such as national parks and nature reserves where local effects could not be implicated. This led to the suggestion that there may be more global factors that are adversely affecting amphibians. The Declining Amphibian Population Task Force (DAPTF) of the International Union for the Conservation of Nature (IUCN) believes ionizing radiation of ultra violet B resulting from ozone layer depletion has something to do with the decline. The introduction of exotic competitors especially alien invasive species, like the Japanese bullfrog which was introduced in the Philippines during the Second World War, are also contributory factors, DAPTF said.
DAPTF was established in 1991 consisting of 3,000 scientists and conservationists from 90 countries worldwide. Its mission is to determine the nature, extent and causes of decline of amphibians throughout the world and to promote means by which declines can be halted or reversed. DAPTF says the Leopard and Cascade frogs in the US are now extinct So is it with Cost Rica's Golden toad, as well as 14 other Australian species. The Species Survival Commission of IUCN says five more species, three of which are in Asia, are in danger of becoming extinct.
What is Being Done About It?
At a minimal scale, Philippine scientists like Dr. Afuang are exhausting their resources to save Philippine amphibians. A diorama depicting the biological and ecological attributes of Philippine frogs is being undertaken by Dr. Afuang at the UPLB Museum of Natural History. A travelling educational and information campaign for elementary schools has also been launched to orient pupils on the importance of amphibians. Dr. Angel Alcala, former Chairman of the Commission for Higher Education(CHED) and well-known scientist has also done important researches in the conservation of amphibians. It was noted recently by farmers in Benguet that not only are amphibians vanishing. A few are appearing with deformities; with three or five legs or no legs at all. In many places in this province and Baguio City, there are no frogs to be heard. Their silence is should not be surprising. It is a message that, as they vanish and change, so will humans too.
