Fear of algae invasion

Published : Sep 26, 2003 00:00 IST

PepsiCo is inviting another controversy with its commercial cultivation of red algae near the Gulf of Mannar Biosphere Reserve, a venture that can pose a threat to the fragile bioreserve.

AS with food and beverages, private enterprise appears to have a free run of the country's environment and ecosystem in the absence of effective regulation. Pepsi Foods Limited (PFL), a subsidiary of the cola multinational PepsiCo, which, along with other beverage-makers is facing a Joint Parliamentary Committee probe following the discovery of pesticides in its aerated beverages, is cultivating alien species of red seaweeds on a commercial basis in Tamil Nadu's Ramanathapuram district, close to the Gulf of Mannar biodiversity hotspot, overlooking the impact it could have on the rich and fragile ecosystem of the region.

Pepsi Foods has contracted out farming of two unique red algae or seaweeds - Eucheuma cottonii and Hypnea musciformis - to fishermen in the Mandapam area, investing Rs.40,000 a hectare, similar to its large-scale contract cultivation of tomatoes, basmati rice, chillies, groundnuts and potatoes in Punjab and Haryana. The seaweed farming, to be done on plots of 0.25 hectares (about 40 metres by 60 metres) each, has a 45-day cycle from planting to harvesting. According to Abhiram Seth, PFL's executive director (exports), the company has allotted 10 ha to each cultivator. And for each plot that is harvested, the farmers plant one more. In a recent interview he gave The Hindu Business Line, Seth said the average annual yield per hectare is 100 tonnes of wet seaweed, which translates into 10 tonnes of dry seaweed or 2.5-3 tonnes of semi-refined carrageenan (a tasteless, gelatine-like substance added to desserts as a stabiliser). Pepsi has already set up a carrageenan extraction unit at Paramakudi, 80 km from Madurai. This is the first instance of commercial cultivation of seaweed in India.

What is wrong with growing the innocuous-looking seaweeds on strings of nylon ropes, which can turn into a million-dollar food additive business? Much, if the past record of such alien species inflicting widespread damage on natural ecosystems is anything to go by. Many scientists fear the worst. In nature, seaweed propagates by two methods - spore formation and vegetative propagation. According to Dr. V. Selvam, a marine biologist and project director at the Mandapam field station of the M.S. Swaminathan Research Foundation (MSSRF), vegetative propagation is not very dangerous as it may not allow the seaweed to proliferate. But if proliferation happens through spores, it can be devastating.

PFL's counter-argument is that the release of the algae was done after more than 10 years of research and after it was found to be compatible with the Indian marine ecology. But scientists do not support this claim. Says G. Ramamurthy of the Muthialpet-based Environmental Conservation Society, who has studied the marine biosphere reserve of the Gulf of Mannar: "Until now there has only been vegetative propagation as the salinity and the marine temperature have not allowed propagation by spores. But even if the temperature rises marginally, which cannot be ruled out, it can be devastating for the ecosystem."

Existing scientific research also does not give a clean chit to the commercial cultivation of alien species. In a report "Environmental Impacts of Seaweed Farming in the Tropics", commissioned by Conservation International, Dr. W. Lindsey Zemke-White, a marine biologist from Auckland University, New Zealand, points out that seaweeds eventually escape from farms and set up free-living populations. The impact of these populations upon the local flora and fauna may vary from location to location. While the exact impact of such seaweeds on the environment has not yet been fully studied, research in places such as Hawaii has shown that they overgrow, kill endemic corals and have a negative impact on the environment. Dr. White argues that there is a need for more scientific research to understand fully the effect of these changes on the whole community. To begin with, he strongly recommends a strict, scientific monitoring system to make sure that the seaweeds do not endanger the ecosystem, which are all related to one another.

This brings to the fore the lack of an independent scientific regulatory body to evaluate and oversee such projects. An assessment by the Convention on Biological Diversity notes that after habitat loss, the second most important factor leading to the loss of native species is the introduction of alien species. Agricultural scientist Dr. M.S. Swaminathan recommends that a rigorous monitoring system be put in place to ensure that no damage is caused to the country's rich but fragile biodiversity in general, and the Mannar Marine Biosphere in particular.

Scientists stress the need for a stringent monitoring mechanism, particularly since several scientific issues relating to the impact of such seaweed farming on the ecosystem remain unanswered. When the Bhavnagar-based Central Salt Marine Chemical Research Institute (CSMCRI), a laboratory of the Council of Scientific and Industrial Research (CSIR), is cultivating seaweeds only on an experimental basis (10 hectares each in Kurusadai islands and in the Pamban area), PFL's plunge into commercial cultivation of seaweeds close to the marine reserve, has caused much indignation among marine biologists.

But PFL sees no threat to the Gulf of Mannar ecosystem as the seaweed "is cultivated only in the Palk Strait and not in the biosphere reserve". Scientists, however, do not seem to buy this argument.

Can the seaweed cultivated by PFL in the Palk Strait affect the Gulf of Mannar biosphere reserve? Yes, says Ramamurthy, as the marine system is an open one. There is a connection between the Palk Strait and the Gulf of Mannar. The spores from the algae can move by tidal action to the Gulf of Mannar.

PFL has apparently got the Tamil Nadu government's permission to cultivate the two red seaweed species on 100 ha along a 10-km stretch of the sea front on the Palk Bay side, close to Mandapam. These seaweeds are considered to be the best source of carrageenan. At room temperature, carrageenan can form varieties of gels that thicken, stabilise and improve the viscosity of food and non-food products, making it the preferred vegetarian additive. It is therefore crucial to the multinational's fast food industry. It is added to almost all the mocha and other upmarket beverages and mocktails. It is also an ingredient in toothpastes, pet foods, processed meat and other food and dairy products. The demand for carrageenan has been rising by 7-8 per cent annually and it sells at over Rs.1 lakh a tonne in world markets. India imports most of its requirement of carrageenan.

Agar, another gelling substance, is an alternative but carrageenan is preferred because of its unique properties of easy extraction and resistance to high temperatures. It is also available in plenty in the wild and in cultivated stocks as compared to agar-producing seaweeds.

Carrageenan currently fetches up to $2,000 a tonne in the world market, the total size of which is valued at over $300 million. Of the world's Eucheuma cottonii production of 1,30,000 tonnes, the Philippines accounts for nearly 80 per cent. Abhiram Seth hopes to export carrageenan worth Rs.20 crores in the first year (2003). "In the medium term, the country could even displace the Philippines as the most low-cost and most efficient carrageenan producer," he had said while announcing to the media the start of the commercial venture this year.

PFL sourced the technology for seaweed cultivation as well as carrageenan extraction from CSMCRI, which apparently imported the seaweed from the Philippines. One twig was imported some 12 years ago, and since then it has multiplied and the algae, according to PFL, is completely acclimatised to Indian conditions. But Ramamurthy does not buy this argument; he says that nowhere in the world has commercial cultivation of seaweed been done with alien species. He wonders if experiments with such alien species, the cultivation of which has the potential to harm the ecosystem, can be allowed in the marine biosphere reserve.

PFL had initially applied to the State government for permission to undertake cultivation on 350 acres along a 35-km stretch of the Gulf of Mannar and the Palk Bay area, as the calm sea there was believed to be conducive to a high average daily growth rate (ADGR) of 8-9 per cent. But since the area fell within the Mannar Marine Biosphere Reserve, it had to settle for the Palk Bay side, where the weeds would have an ADGR of only 2 per cent.

PFL is confident of extending the area of cultivation from the present 100 ha to over 5,000 ha soon. Carrageenan manufacture, according to PFL, will result in import substitution and help save foreign exchange, apart from offering significant employment opportunities to local fishermen.

Seaweed cultivation may be a money-spinner, but scientists are worried about the threat it poses to the ecosystem as it may eventually wipe out valuable natural resources and play havoc with the very foundation of species existence. As Ramamurthy says, a crucial and oft-repeated question is, what is the need for clearing PepsiCo's commercial cultivation of seaweeds in such a hurry, when CSMCRI is still experimenting.

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