Aquaculture : a sustainable sector?

Hailed as one of the most promising emerging sectors in Mauritius, aquaculture has come a long way to show its potential. However, this activity is not only raising doubts regarding its impact on the marine ecosystem but also because of the perception that caged fish are attracting sharks in our lagoons.

Last week saw the first fish harvest from ten aquaculture cages at Grand River South East. The total catch from this mini-farm run by fishermen and fishermen’s cooperatives was nearly 1.5 tonnes. The extent of the catch from such a small farm gives an indication of the huge potential of the aquaculture sector in Mauritius.

Official figures indicate that the total production of aquaculture fish has risen from 565.5 tonnes ein 2010 to 1,012 tonnes in 2016. The sector is attracting entrepreneurs and our lagoons are gradually seeing the setting up of caged farming.

According to the ‘Aquaculture Master Plan’ of the ministry of Ocean Economy, around 21 sites for aquaculture development have been identified in Mauritius and there is potential for an annual production of 29,000 tonnes of fish in the medium term and 39,000 tonnes of fish in the long term from fish farming in the sea.

We are still far from our objectives but the sector is currently going through a difficult phase. With the sighting of sharks in our waters and protests from civil society and trade unions, the future of aquaculture seems unstable.

Who are opposing?

NGOs, fishermen, environmental activists and actors of the tourism industry are not convinced of the sustainability of the aquaculture sector and are showing concerns over the negative impact on the environment and on the tourism industry. The ‘Platform Moris Lanvironman’, the coalition regrouping Rezistans ek Alternativ, the Syndicat des Pêcheurs and the Regroupman peser Bambous, among others, are voicing out their concerns on this issue.

On the other hand, thousands of Mauritian citizens are expressing their fears on social networks. The AHRIM (Association of Hotels and Restaurants of Mauritius) is equally feeling concerned with the frequent sighting of sharks in our shallow waters, which could be damaging to the tourism industry.

On its side, the Ministry maintains that aquaculture is not a threat, neither to our environment nor to our tourism and it is soon issuing a communiqué to clarify issues. Some stakeholders decline to comment on the issue because of pending cases or litigations involving aquaculture farms.

The case against aquaculture

Is aquaculture good or bad?  Opinions diverge on the issue. While opponents claim aquaculture can pollute the marine environment, proponents argue that pollution is caused in unregulated fish farm regions. If strict regulations are imposed and enforced, then the environment is not only protected but also preserved.

Though aquaculture has been a method of food production for thousands of years, it is today a method of supplementing wild caught fish in order to feed an ever-growing global population. But it does involve cramming hundreds of thousands of fish into gigantic submerged nets or cages.

Feed and excrement draw sharks, which smell food from more than a mile away. However, no official report has yet concluded that the sighting of sharks in our lagoons is directly linked to aquaculture activities, although there is a strong perception among various stakeholders. Another environmental impact is the buildup of nutrients and effluents on the sea floor below the cages.

Because the fish are contained in one place at high densities, their waste – which includes both solids and dissolved nutrients – has the potential to build up below the cages and in the surrounding area and create damaging dead zones near aquaculture sites.

Another often repeated concern is the effect of the farmed fish on local wild fisheries. Disease and parasite outbreaks in fish farms can spread rapidly among farmed fish because of the high densities at which they are kept, and disease may spread to wild fish populations.

Promoting aquaculture

The Board of Investment has been actively promoting aquaculture as an emerging sector. Investment opportunities exist in lagoon cage culture with a production range of 300 to 500 tonnes per production unit, offshore lagoon cage culture with an approximate production capacity of 2,000 tonnes per production unit, inland aquaculture farms, tuna ranching and fattening in cages and hi-tech production techniques such as aqua pods.

Mauritius having preferential market access for its seafood products to the European market through a partial EPA, the US market under the AGOA as well as COMESA and SADC   countries, aquaculture is seen as a viable sector for investors.  One of the most successful projects implemented in Mauritius is the Ferme Marine de Mahebourg which produces mainly the ‘red drum’ fish variety.

The two farm sites are located on the eastern coast close to Pointe aux Feuilles. The two sites were both selected after extensive surveys to ensure excellent water quality whilst protecting the environment. Both sites are approximately 3km from the coast where the water depth is 25m and where the current is driven by the prevailing Trade Winds.

Each site has today 10 circular floating cages with a depth of 5m to 8m. The stock in the cages is fed at regular intervals during the day using feed that, according to the company, is certified free from all artificial additives and genetically modified ingredients ensuring excellent quality of the fish.

Dr. Ambithimaru Laxminarayana : “Not a threat if technology is eco-friendly”

Dr Ambithimaru laxminarayana, a consultant and aquaculture expert, claims that aquaculture cannot be a threat if the technology is eco-friendly.

“The carrying capacity of the water body and environment should be given due consideration before commencing any aquaculture operation. Since fish production from capture fisheries has almost reached the maximum sustainable yield levels in many parts of the world, aquaculture is the only way to meet the requirement of the fish needed for food security of any country. Therefore, eco-friendly methods of aquaculture need to be encouraged all over the world,” explains the consultant who has worked in various countries, including Mauritius in the past.

Dr. Ambithimaru Laxminarayana is currently based in Cochin, Kerala, in India and has served the World Bank, FAO, JICA and ADB, among others.

A management approach

There is the aspect of management approach. The co-existence of different activities allowing each other to do business without disturbing each other - A nation should decide what they want and sometimes we want to have everything. Sea activities, underwater activities, fish for restaurants, oysters in our plates.

Contacted by Nawshin Mahadooa, her professor Morishita Joji, who is also a Commissioner of the International Whaling Commission, states that “in Japan, fisheries management is done in a very special way. Fisheries rights provide exclusive rights to local fishermen to use the sea surface for aquaculture. This right is not opened to anybody else. And the basic rights are awarded to Fisheries cooperatives which have full control over the fishing grounds that they own.

E.g if a developer wants to reclaim that fishing ground, then the developer needs to compensate the fisheries cooperatives. Sea ownership is quite close to land ownership.” What is required is proper zoning.

Which part of the coastal area should be designated to recreational activities and which part to aquaculture production? People in these localities should sit down and talk about their priorities for their villages.

This would decrease the competition for the tourist activities and aquaculture to co-exist; else all we will have will be protestors against economic development. Decisions can be made by public opinion voting etc.

Nawshin Mahadooa:“It’s a question of what we want”

Nawshin Mahadooa, a Mauritian national currently studying for a Master’s in Marine Policy and International Management at the Tokyo University of Marine Science and Technology, says she feels there are three main concerns with regards to aquaculture: (1) Aquaculture if done as a profit-making activity only, someone needs to be responsible for the damage;  all around the world, aquaculture has attracted sharks due to unconsumed fish feed that accumulates towards the bottom of the cages and this may attract other species towards this area of the lagoon, and (3) the possible spread of diseases through contamination of aquaculture species can cause massive death of fish and even destroy the whole indigenous fish population.

Yet, statistics show that aquaculture is growing and contributing to food security. Aquaculture production is even higher than capture fisheries.

“My opinion is that there are many ways to do aquaculture. We have to know the way. All stakeholders concerned should participate because people should know what they have to know. We need to be knowledgeable about spread of diseases, marine/sediment pollution, local marine ecosystem, natural sciences and field of economy i.e aquaculture for international trade, marketing, processing, etc. We need to fill in the legal gap that governs aquaculture. There are thousands and thousands of regulations for aquaculture but yet there seem to be a shortage of competencies when it comes to local aquaculture production,” explains Nawshin Mahadooa.

“Obviously, we cannot copy everything from other countries. If there are no such competencies the political priority should define the future of aquaculture: do we rely on external trade, domestic production or tourism? Or do we become environmentalist nations where we give more importance to preserving nature than exploiting nature?”

She says that in every way, people need to look at all the details before saying NO to aquaculture. For this to happen, project proposals must provide very accurate information for assessment. If not, we will face only protestors who say no without hearing the details and simply based on their personal experiences. But suggestions could be different if the approach is different.

Mauritius could proceed like the western countries - take the time it takes to issue the permits. In Australia, a permit may take 10 years to be issued. Governing the sea means governing each line and boundary that has been drawn by the laws of the sea but biological species do not need to respect these boundaries.

The sharks are free to swim anywhere in the ocean. It is the human who needs to know their boundaries and limits, concludes Nawshin, who is also doing research work on the coexistence of multiple marine activities.