Let mangroves grow, naturally

By Sajitha PREMATUNGE

When you hear the word 'Puttalam' what comes to your mind? Donkeys! But there is something else Puttalam is associated with - mangroves. According to the latest statistics Puttalam is home to about 25 varieties of mangroves of which 14 are true mangroves - that grow only in the mangrove habitats and 12 are mangrove associates that can be found further inland as well. Dominant mangrove species in the area include Rhizophora mucronata and Avicennia marina. Among them Scyphiphora hydrophyllaceae is a very rare species and Sianometra iripa is critically endangered.

It is an ecosystem with many economic as well as ecological uses such as providing breeding grounds for fish and invertebrates, providing wood, food and medicines among other invaluable uses such as security from extreme weather conditions and natural disasters such as tsunami.

"Mangroves are considered one of the ecosystems with the highest productivity", said Dilup Chandranimal, Assistant Program Officer, IUCN. Mangroves are a living ecosystem that has a constant relationship with rivers and the sea. They thrive in brackish water regions - convergence zone of sea and river such as lagoons and deltas.

Mangroves are a unique ecosystem, said Dilup. Plants in mangrove ecosystems are specially adapted to their environment. Apart from the fact that they require a lot of sun, they thrive in swampy soil that many other plants cannot grow in, they are also resistant to wind and tidal variations.

Root adaptations provide stability for mangrove species in the soft sediments along shorelines. Buttress roots, prop roots and aerial roots include some of the root adaptations. Special reproductive adaptations such as viviparity (bringing forth live young, as with most mammals) ensure the longevity of the mangrove communities. "Seeds of mangrove species germinate on the tree", said Dilup, "embedding itself in the mud as it drops."

Better conservation methods

IUCN Coastal Livelihood and Policy Unit Head Kapila Gunarathne said mangroves are not just one species but a community, contrary to this attitude most people use only Rhizophora mucronata in the replanting process, for the sole reason that it's the easiest to plant.

Regeneration of mangroves should be done with broader understanding after careful research, International Union for Conservation of Nature (IUCN), Country Representative Dr. Ranjith Mahindapala said.

He said it is always advisable to facilitate the natural regeneration of mangroves than artificially replanting it, emphasizing that it is not scientifically sound to grow mangroves everywhere. Mangroves have many uses that can be quite detrimental if not studied carefully. "Mangroves trap polluting sediments from the rivers from entering the lagoon", said Dr. Ranjith Mahindapala. Mangroves help sedimentation and with time the formation of new land, filling up the lagoon. In fact, it is obvious that the lagoon has been encroached upon in the guise of mangrove regeneration.

Threats

Sri Lanka's second largest lagoon - 32,750 ha in extent - includes the Kala oya estuary - one of Sri Lanka's largest mangrove habitats - the Mee oya estuary, the Dutch Bay and Portugal Bay. The Puttalam lagoon has been under threat for the past two decades due to shrimp farming, expansion of salt pans, unsustainable fishing practices, expansion of settlements, unwise use of agrochemicals and urbanization.

IUCN Sri Lanka Office has formulated a mangrove replanting project in addition to providing alternate livelihoods for fisher families, raising awareness, assisting in land use methods and solid waste management in and around the Puttlam lagoon.

Alternatives

Over 3,000 fishermen make use of resources in the lagoon. The IUCN has initiated community based supplementary income generation methods for women in order to reduce pressure on the lagoons fish resources through over fishing.

Fifteen homesteads of fisher families were selected to cultivate Aloe Vera, by the Marine and Coastal Resources Foundation (MCRCF), with the help of local fisheries societies. Aloe Vera, an important base for cosmetics, and thrive in the dry, sandy conditions of Puttlam.

Deepika Edirisinghe now has a lush home garden of Aloe Vera that earns her around Rs. 6,500 a month. She says her new life is easier because she didn't have to go through all that trouble that came with the business of fishing. She only has to water the plants once a week.

These fisher women were trained in Aloe Vera nursery maintenance, planting and aftercare of plantations and post-harvest techniques.

In addition to the income from fishing they earn, over Rs 5,000 a month. Given the significant income some fishermen have also started Aloe Vera cultivation. Ten percent of the funds are allocated for sustainability. IUCN's next step is to establish an Aloe Vera jell producing plant in the area. So far there are only three such places in Sri Lanka.

Home garden cultivation is another successful community based supplementary income generation method. Fifty-five fisher families received plants and agricultural equipment from the IUCN.

In the simple village of Thirikkapallama is one of the most successful home gardens. It is so successful that Asanka Kumara, a member of St. Anthony's Fisheries Cooperative Society says that, although initially there was a huge resistance to this alternative to fishing, because of the high income fishermen have started to show more interest in homegarden. A fishing family can earn up to Rs. 15,000 from a homegarden. "The fishing market is too far and we cannot afford freezers to store fish" said Asanka Kumara. "This is a more stable source of income".In areas where fish populations dwindle from time to time crab farming was adopted as an alternate source of income. Small crabs that were found caught in fishing nets were put in special cages distributed by the IUCN, then submerged in the sea. Waste from fishing industry was used as food for fattening the crabs.