The Hindu : Kerala News : Pathrakadavu: `three fish species face extinction threat'

Online edition of India's National Newspaper
Saturday, Jun 26, 2004

Kerala

Kerala

Pathrakadavu: `three fish species face extinction threat'

By Our Staff Reporter

PALAKKAD, JUNE 25 . A study on the `Irreversible damage to endemic and endangered aquatic fauna' in the Kunthi river caused by the construction of the proposed Pathrakadavu hydro-electric project notes that "three species of fish that are found exclusively in the Kunthi river" would be wiped out.

The study by Elizabeth Joseph, Fisheries Scientist and former Associate Professor, Kerala Agricultural University, found that "any disturbance to this river ecosystem will amount to the disappearance of many species whose existence is already threatened".

As per the National Bureau of Fish Genetic Resources (NBFGR), a total of 57 species of fishes have been reported in the Kunthi river as recently as the year 2000. Of these, 45 species are endemic to the Western Ghats, of which 13 species are endemic to the Kerala part of the Western Ghats. Of these, three species are found exclusively in the Kunthi river. They are Horalaliosa Joshuai Silas (fishery status not reported); Garra merioni (endangered) and Homalaptera pillai (vulnerable). (A `vulnerable' species is one whose population is on the decline and any change in habitat parameters can take the species to the `endangered' status).

As per the International Union for Conservation of Nature and Natural Resources (IUCN) categorisation, 38 of the 57 species of fishes found in the Kunthi river came under critically endangered (4), endangered (18), vulnerable (7), lower risk near threatened (4), lower risk least concern (2) and data deficient (3) species.

However, the Rapid Environment Impact Assessment (EIA) of the Pathrakadavu hydro-electric project reports only 18 species of fishes in the Kunthi and claims that no fishes belonging to the IUCN categories of endangered, rare and vulnerable species are found there. This is contrary to the actual situation prevalent at the proposed project site.

"There are some blatant errors with respect to the fishes reported from this area in the EIA, Dr. Elizabeth said.

Migration: The EIA report also makes special mention of the absence of fish migration in the area. This cannot be accepted, since the report is restricted to the pre-monsoon months only, while most Indian fishes exhibit migration for breeding purposes, with the onset of monsoon.

Adaptation: The EIA report refers to a strange adaptive behaviour that may be resorted to by the aquatic fauna, once a free-flowing (lotic) ecosystem is converted into the stagnant (lentic) ecosystem. It is well known that the physcio-chemical factors of the two systems are very different and adaptation, if any, would take a long time as an evolutionary process only. Even today, the Indian Major Carps (Catla, Rohu and Mrigal) of the Ganga, Yamuna and Brahmaputra do not breed in lentic culture systems, without human assistance such as hormone injection. So, when a pristine hill stream like the Kunthi, is converted into lentic habitat, it is almost certain that the species whose biology and breeding cycles are yet to be studied, would be wiped out in no time, the study said.

Pisciculture: The EIA report recommended introduction of fishes such as Labco dara, L. dyocheilus and Schizotherox sp. for controlling vectors. Since none of these species belongs to the Kunthi river (Schizotherox sp. is found in the Himalayan waters and cannot withstand temperatures above 20 degrees Centigrade), they are as good as exotic varieties as far as the present fish population of the Kunthi is concerned.

Thus, any move to introduce these species to the Kunthi could have drastic effect on the endemic fish population. Under no circumstance, should any such move be considered, as we already have experienced the negative impacts of similar attempts in the past. It may be noted that the introduction of the Indian Major Carps and Tilapia into our reservoirs has resulted in the near wipe-out of most of our indigenous carp varieties.

The study said that the EIA reports the generation of muck and dust by the rock excavation and quarry operation at the site. The fragile ecosystem with its vulnerable and endangered species population would not be able to withstand the negative impact of these sedimentation and turbidity factors, together with the tremors and noise pollution.

The study said the data on the impact of the project on the aquatic fauna, especially fishes, as reported in the Rapid EIA, was not reliable. The true picture indicates that any disturbance to this river ecosystem will amount to the disappearance of many species whose existence is already threatened, it said.

Hence, the proposed Pathrakadavu hydro-electric project should be given up to save the precious endemic species that depend on this fragile ecosystem, Dr. Elizabeth said.

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