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 Was it an inadvertent leak? Was it a secret experiment gone wrong? Did anybody purposefully release it with an ulterior motive? Will it damage the ecology of India’s most valuable marine bioreserve?
Though nobody knows the answers to these queries as yet, scientists are trying to figure out how an alien alga escaped into the Gulf of Mannar from its “confinement” all of a sudden in 2007, though the field trials with this alga was on for almost a decade.
The multi-national company roped in self-help groups in Ramanthapuram, Pudukottai, Tanjore and Tuticorin districts in Tamil Nadu to cultivate the sea weeds and sell the produce to Pepsico.
The standard cultivation practice prevents any chance of the alga’s release in the wild. The process entails anchoring the seaweeds on rafts to prevent the movement of algae, says Amit Bose, executive vice president (export), Pepsico India. The cultivation is done on 3 sq m bamboo rafts, where the seaweed is suspended on nylon ropes and allowed to grow in natural conditions.
According to CSMCRI, there are approximately 8,000 rafts which should yield a minimum of 1,000 tons of dry seaweed per annum at the rate of 140 kg dry weed per raft per year, considering 7 harvests a year.
Below the raft is a nylon net which serves the dual purpose of preventing fish from eating the seaweed and the drifting of the sea weed from the raft, Mr Bose explains. It was thought a fool-proof system to restrict the alga.
But when the Madurai team headed by S Chandrasekharan surveyed the Tamil Nadu coast between August and September, 2007, they spotted two sites, 50 and 100 m from the shore, where the coral was engulfed by this alga.
Through subsequent field visits, the CSMCRI confirmed the “surprising occurrence” of Kappaphycus in Krusadai Island.
“It cannot be described as an invasion as the alga has been spotted in two small spots in the entire island. It’s a localised presence,” argues CSMCRI director Pushpito K Ghosh.
While the area of the entire island is 65.8 acre, the sea weed has been spotted in two sites of approximately 300 sq m each. “Only those two patches had live corals," says Chandrasekharan.
The institute says despite surveying all the islands since January 2005, it did not come across any Kappaphycus in any of the islands including Krusadai.
CSMCRI also examined 15 locations over a 90 km stretch along the Gulf of Mannar coast – from Olakuda (Rameswaram) to Valinokkam (20 km beyond Erwadi) – covering a depth of 0-4 m. Again, no Kappaphycus was encountered in any of the locations.
The institute’s last survey of Krusadai was conducted in March 2007. The team could not spot the alga.
Subsequent to the report by the Madurai group in the journal Current Science, CSMCRI researchers are again scouring the coast as well as the gulf. They will continue to do so for another two months to check if anything unusual happens in August-September. The Madurai group collected the samples in those two months.
Invasion of K alvarezii on coral reefs has been reported in the Pacific in the reefs around Kiribati, Solomon Island and Tonga. Studies carried out in Hawaii islands revealed that the alga had spread from the initial site of introduction to other reefs at a rate of 250 m per year.
The alarm bell for the Indian Ocean region was sounded first in 2005 when the Goa-based National Institute of Oceanography, another CSIR laboratory, described “bioinvasion” of corals in the marine reserve by Kappaphycus alga. But CSMCRI described the 2005 report as a “false alarm”
Following up on the NIO report, the Madurai group spotted these two sites. Ironically the research grant they received was from the CSIR.
So what triggered the escape? Pepsi immediately distanced itself from the controversy, arguing it was not directly involved with the cultivation.
“The trial cultivation in Krusadai Island was closed out in November 2003, but the seed maintenance activity inside the Gulf of Mannar is still carried out by them (CSMCRI). The SHGs never carried out any seaweed cultivation in Krusadai Island or the Gulf of Mannar,” says Mr Bose.
Dr Ghosh, on the other hand, admits that scientists are somewhat puzzled to understand this incident.
“CSMCRI abandoned Kappaphycus germplasm maintenance in Krusadai towards the end of 2003. If our experimental cultivation was the cause, then colonisation should have been observed soon thereafter and noted in our surveys. As that was not the case, it would mean prolonged period of dormancy which is unrealistic,” he counters.
“It’s highly unlikely that the alga will come up suddenly 1.8 km away after a gap of four years,” he says without ruling out the possibility of an irresponsible experimentation by someone who has access to this alga.
But this theory seems to be an unlikely one because the Gulf of Mannar being a restricted area, there are records available of those who visited the area in the Tamil Nadu Wildlife Department. It deepens the mystery further, leaving officials to grope in the dark.
Meanwhile, the Aquaculture Foundation of India, an NGO, has sought permission from the Chief Wildlife warden to inspect the island with the objective of removing any seaweed which may be there. The permission is still awaited.
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