Sahabat Alam Malaysia (SAM) calls for the protection of frog habitat and a halt in eating of this useful amphibian, all for sensible reasons that we often choose to ignore in pursuit of the so-called economic development.
We desperately need them to control the insect population. Frogs feed on pests such as grasshoppers, mosquitoes, and flies. Largely insectivorous, each frog can eat more than its weight (about 200 grams) each day and this can be translated into a significant amount of insects.
Tadpoles feed on algae and plants thereby keeping waterways clean while some species do feed on mosquito larvae. Studies have shown that tadpoles do feed on the eggs of aedes mosquitoes.
Mosquitoes, in fact, kill the most number of humans – 725,000 fatalities per year – with the diseases that they carry and transmit. In Malaysia, there were almost 20,000 dengue fever cases in 2015 alone.
It must also be noted that aedes mosquitoes, better known to transmit viruses that cause dengue and zika, are also responsible for yellow fever, West Nile fever, chikungunya, eastern equine encephalitis, and other lesser known diseases. In 2012 there were 4,725 reported malaria cases caused by anopheles mosquitoes in Malaysia.
To control these diseases, we have to protect the frogs. In Malaysia there are two types of paddy frogs, Rana Cancrivora and the R. Limnocharis, and they are responsible in feeding on the many insect species that live in the paddy field ecosystem. The paddy crop serves as the insects’ food source and frogs help to eradicate insect pests in rice paddies. Frogs in the field could reduce populations of stemborers, planthoppers and prevent rice sheath blight indirectly by reducing insects that transmit disease pathogens. Thus, in reality frogs are farmers’ best friends.
Moreover, frogs are part of the food web, being hunted and fed upon by other predators such as birds, bats and snakes.
The importance of frogs should not be overlooked as about 10 per cent of Nobel Prizes in Physiology and Medicine resulted from research using frogs. It was also reported that a group of Russian researchers found more than 76 antimicrobial peptides on the skin of the European Common Brown Frog. These peptides are potential candidates in preventing pathogenic and antibiotic resistant bacterial strains.
Frog population in Malaysia is already endangered by the rampant clearing of jungle for cultivation and also by pollution. Being amphibians, toxic chemicals from the environment – both on land and in water – are easily absorbed through their thin permeable skin. The pollution of waterways has either killed them or may cause grotesque mutation by chemicals such as endocrine disruptors.
It is ironical that farmers appeared to prefer spraying their fields with expensive toxic chemicals rather than making use of frogs as an efficient pest control. Herbicides, pesticides and chemical fertilisers remain as frogs’ biggest threat.
Instead of protecting them to keep pests under control, frogs were caught and sold at markets such as Air Itam and Batu Lanchang markets. Pulau Tikus and Mt. Erskine markets have ceased selling frogs since the sellers either deal directly with the restaurants or that frogs are hard to come by these days.
The Rana Cancrivora is in great demand by local restaurants. At the markets there is an irregular supply of frogs and they are readily snapped up by housewives whenever available. However, it is not known whether the voracious appetite for frogs has depleted the frog population in Malaysia as there has been no survey into their numbers.
SAM also wonders if the frogs sold in the market are exposed to chemical pollutants, particularly endocrine disruptors that can trigger cancerous tumours, birth defects, and other developmental disorders.
There is a serious concern lately by scientists and biologists worldwide who noted the mysterious disappearance of frogs and toads. Professor Mike Tyler in Australia warned that the world’s amphibian population is heading towards extinction which is an indication of grave environmental damage, heralding a potential disaster for humanity. Scientists reported that whole amphibian populations have disappeared or declined from many countries (the United States, India, Japan and Australia), even in protected reserves.
Thus, in view of frogs’ important role in our ecological system, SAM urges the government to completely ban the capturing, selling, and killing of frogs.
S M Mohamed Idris