Muhammad Moazzam Khan and HameraAisha write about threats facing Pakistan’s amphibian population.
Frogs and toads have been a part of customs, traditions, ancient lore and legend for centuries. However, today they are declining rapidly the world over. In 2004, an IUCN assessment showed that one-third of the world’s amphibian population had disappeared. The reasons included habitat loss, diseases, invasive species, pollution and climate change.
Amphibian species are scarce in Pakistan, with only one order, Anura, represented by 21 species and belonging to twelve genera of four major families. Although amphibians are also found at over 4,000 metres in the Himalayan and the Karakoram mountain ranges, a small population of any given species is restricted to only a limited range.
Rapid urbanization is the most important factor that has led to the decline in the population of amphibians, especially frogs and toads. In Pakistan, there has been great destruction of their suitable breeding habitats. Some of the most affected areas where amphibian populations have declined include Karachi, Lahore, Islamabad/Rawalpindi, Gujranwala, Wazirabad, Sheikhupura and Faisalabad, just to name a few cities. The thinning populations of amphibians in Pakistan require special attention, especially for species from the cold climate zones of Pakistan.
Populations of some species such as the bullfrog (Sphaerothecastrachani) have completely been wiped out because of increased pollution and sand mining in Malir River, Karachi. There are other such examples in the rest of the country. Scientists agree that the amphibian fauna of Pakistan is not well diversified and their populations are limited.
Further, the chytrid fungus is driving amphibians all over the world to mass extinction. It has been reported that the fungus has already exterminated salamanders in Europe. Bd, a new species of chytrid, is considered particularly harmful and appears to be capable of infecting most of the world’s 6,000 amphibian species, leading to devastating population declines and species extinction. An infection from chytridiomycosis is transmitted by spores, which spread through water or moisture and infect the skin of amphibians.
Amphibians that are commonly kept in captivity as pets and laboratory animals may already be infected with the disease. Quarantine of amphibians before they enter an established amphibian collection is required as a precaution. New entrants may be kept separately from the established collection for at least 60 to 90 days which will allow for observation for signs of disease and to perform laboratory testing. Regular surveillance for a Bd infection in the amphibian collection should also be carried out.
In Pakistan, fish and amphibian imports are not quarantined, thus wild populations of amphibians are prone to fungal diseases. A major percentage of fish and amphibians are imported from Hong Kong, Thailand and other southeast Asian countries which are known to have Bd. The need for strengthening of quarantine services is required and the Animal Quarantine Department must start inspecting the trade of live aquatic animals, in order to ensure that fatal diseases are not introduced in Pakistan.
Hamera Aisha is Manager Conservation, WWF-Pakistan and Muhammad Moazzam Khan is Technical Advisor, Marine Fisheries for WWF-Pakistan.