?We have to be very careful. It is because of corals that there are beaches. They are so important in the whole functioning and protection of the shores.? This reaction from Dr Deolall Daby, associate professor for Marine and Environmental Sciences at the University of Mauritius comes in the wake of the presentation of the Aquatic Business Activities Bill. The authorities are already considering the implementation of fish farms in the lagoon. Proposed sites have been identified by Idéeaquaculture, a French consultant firm that assessed the start-up of red drum (Sciaenops ocellata) and tropical sea-bream (Rhabdosargus sarba) in 2005 at the Ferme Marine de Mahébourg.

The proposed sites are found in the lagoon of Tamarin, Bambous-Virieux, Trou-aux-Biches, Cap-Malheureux, Mahébourg and Poste-Lafayette, some in the open sea, near Le Morne and Flat Island, while three other farms would operate inland. It is those found in the sea that are causing concern among environmentalists.

Dr Deolall Daby contributed to studies on the Environmental Impact Assessment of human activity on corals with fellow scholars from the University of Wales. While being not necessarily against the development of aquatic business, he questions the exact location of the sites: ?Each lagoon has its specificities. Some sites may be appropriate, some not at all. Once we add nutrients to water, we have rapid disruption.?

So it is not clear from what has been carried out in Mahébourg how the new sites will react to the farms. ?One essential aspect is the current patterns. Currents dictate the direction of everything that flows in the water. Nutrients used to feed the fish in the farm can propagate with the flow and accumulate on corals.?

This accumulation may have effects on temperature, transparency, salinity of water or its PH, that are associated with polyp development, and whose disturbance may threaten, or kill, corals. Since the public is not aware of important details of the projects, Dr Daby recommends close assessment studies before the beginning of any activity and scrupulous technical monitoring of the quality of water if anything is implemented.

Another threat, according to Dr Deolall Daby, is algae blooms. A view shared by Ian Watt, marine biologist and director of Reef Conservation Mauritius, a non-governmental organization. The algae proliferate by devouring the nutrients and their presence affects the level of oxygen that conditions life in the lagoon. ?There is reasonable flushing in most of our lagoons to prevent the algae from choking completely other forms of life. But the whole system will be affected.?

Identification of sites

More scaring still are the sharks that might be attracted by the concentration of fish and food. ?The presence of farms may work as the Fish Aggregating Devices that were once put in the sea. Even if the lagoons are mostly protected by their natural barrier, baby sharks may first pass through and come back at adult age through passes?, observes Dr Deolall Daby. Especially if some sites are found near the passes. ?Aquatic farms need fairly deep water to develop properly. Sharks will have no trouble to come in their vicinity?, warns Ian Watt.

?How did they identify the sites??, adds marine biologist Ian Watt. At this stage, it appears that that was the task of Idéeaquaculture. Whom no one, except the authorities, knows the exact criteria. Ideeaquaculture is specialized in technical and socio-economical feasibility studies, technical surveys, economic and financial analysis. Jacques Trichereau, a professional in aquatic business activities, supervised the master plan. Present in Mauritius in March, he could not be contacted yesterday, as he is away on business in the Pacific Ocean.

Ideeaquaculture?s consultant came in March to recommend species for the new farms, ?red drum?, ?cordonnier?, ?barramundi? and ?cobia? notably because of their high levels of reproduction. But do the fishes grown or to be grown fit the Mauritian environment. ?Longines that are bred in Mahébourg are indeed from the Atlantic. They can react diversely to tropical waters, developing viruses, affecting the food chain. One should be very careful when choosing the species, especially when we know that local fish that are grown in Albion are proper for our marine environment : gueule pavé and brine?, indicates Ian Watt.

?The intensive fish farming that seems to be emerging may not be bad as such?, concludes an environmentalist. But I believe that the local community should also have its say?, he adds. This may be possible provided there is more transparency.