Gulf of Mannar Conservation Team,Sri Lanka: 2011

Double blow to fast disappearing Dugongs
December 22, 2010 by A.R.M.Haleem
The Navy seized two carcasses of rare Dugongs (large marine mammal) in Mannar and arrested the fishermen who had them in their possession last week.
The suspects were handed over to the police while the National Aquatic Resources Research & Development Agency (NARA) was called in for technical assistance and expertise. It was suspected that the Dugongs were killed as a result of a dynamite blast usually used to catch fish. The carcasses were brought to Colombo for a post mortem.
The Dugong known as the Muhudu Ura in Sinhala is one of the marine mammals that live in the coastal waters of Sri Lanka. Also called a Sea Cow, Dugong feeds on sea grass and other water plants that grow at the bottom of the sea. Their numbers have declined globally and in our waters and the Gulf of Mannar is believed to be one of the rare spots where this elusive species is found today.
According to internet sources more than 100 Dugongs were killed in the 1950s annually for commercial purposes until the species gained legal protection under the Fauna and Flora Protection Amendments in 1970. The Dugong has a slow rate of reproduction, so fishing has an adverse effect on its population growth. Even though the Dugong is categorized as a ‘Vulnerable’ species by the IUCN Red List of Threatened Species, the local situation is dismal.
Once abundant, the Dugong has become a rare sight now in Sri Lanka. Although it is illegal to catch them, they get trapped in fishing nets and fall victim to fishing methods like dynamiting.
NARA chairman Dr. Hiran Jayawardene who is also a Marine Mammals expert said they were hoping to conduct more research and take urgent measures to protect the fast disappearing Dugongs in Sri Lanka.

armhaleem@gmail.com

Mangrove Tree Planting Project

Project implementation Agency: Coast Conservation Department, District Secretariat, Mannar.

Project Period: 3 Years 10 Months

Funding Agency: United Nations Development Programme, Mannar.

Executive summary:

The prolonged conflicted situation in North hampered development activities and environment improvement activities were not given priorities in that context. Likewise the Mannar causeway and the bridge was also neglected for the reconstruction process in last 3 decades and the passengers were using the old narrow bridge which was constructed during the Dutch period. It was damaged during conflict situation and later was set-up temporarily which could be used cross only the 10 MT weight vehicles. Similarly the 3km causeway was also damaged without proper maintenances. During the conflicted situation the mangroves were cut down for security purpose beside the causeway and the bridge. Earlier the mangroves by the side of the causeway were creating good biodiversity environment for the fishing as well as for the birds especially the migrant birds.

At present the Causeway was reconstructed widely and the new Bridge also constructed to connect the Mannar Island with the Mainland.

Under this project mangrove belts by the side of the cause way will be established to enable an environment for fish breeding ground for variety of species of fish, beautify the causeway to increase aesthetic value and act as a disaster mitigation measure to avoid the coastal erosion and wind break. The project will be implemented through the Costal Conservation Unit, Kachcheri –Mannar under the supervision of GA and DS of Mannar town. This project will also build the capacity of the Costal Conservation Unit of Mannar which was recently established.

1. Background of the Project:

Mannar district located in the North-Western part of the Sri Lanka covers 2,002 sq km including the island of Mannar, approximately 3% of the total land area of Sri Lanka. Mannar district has a marine coast line with a stretch of 163 km, from Theavanpiddi in the North to Mullikkulam in south. According to the Mannar district fisheries extension officers, the pre-war fisher folk population in Mannar consisted of 16,159 persons from 4,402 fishing families and 32 fishing villages, approximately 16% of the population of the district. Mannar district, including the Mannar Island, is surrounded by rich fishing areas. Most productive fishing ground lie in the Palk Bay and the Gulf of Mannar. The Palk Bay and Gulf of Mannar coastal waters over continental shelf contain a variety of species of fin fish, shell fish and holothurians. Encircling the Mannar Island is a shallow continental shelf with rich fishing banks, pearl bank and prawn banks as well as extensive area of 3,828 ha with brackish water and mangroves.

The Thalladi-Mannar bridge road (Figure: 1) is the dyke that connects the Thallaimannar Island with the main land, North Western Sri Lanka. The dyke is approximately 4km long and runs across a brackish-water body where some species of mangroves (Avicennia marina, Rhizophora mucronata, Excoecaria agallocha) were found as thick forest. Although these natural mangroves have been here for a long, sufficient extend of new growth in to adjacent open coastal areas is not seen. This has been a result of three reasons; first, the hydrology of the area is rather stagnant and does not help for transporting seeds from mangroves to open areas. Second, the available limited number of mangrove trees is not capable of producing enough number of seeds to be distributed in to new areas. Third, the matured trees were cut down for security and for fire wood. As results of these seed limitation and poor hydrology,and destruction the either sides of the Thalladi-mannar bridge road remain uncovered by mangroves whilst the water quality and soil factors are appropriate for mangroves (personal observations). This highlights the need for any human-mediated mangrove planting activity along the dyke that artificially introduces mangrove seeds of a suitable species enhancing the recruitments. Presence of frequent shallow brackish-water having salinity of 30-20ppt along the dyke is mostly appropriate for the mangrove Rhizophora mucronata. Also, some of the naturally growing Rhizophora mucronata trees in the sites indicate that this species is successful for the site. As shown by kumara et al (2010) for Kalpitiya lagoon, high growth performances can be obtained from a high density (0.4m to 0.6m spacing) Rhizophora mucronata planting work linked with a few year long post-planting care procedures. Creation of a mangrove belt along the full length of the Thalladi-Mannar bridge road will also enhance the aesthetic value of the site helping the growing tourism in the region. The aerial root mass of Rhizophora mucronata that will grow in to shallow water will provide ideal surfaces for algae and other attaching communities that are food for commercially valuable fish. The Rhizophora mucronata stands along the dyke will therefore attract more fish helping the local fisheries indirectly. The trees to be established by this activity will enhance the natural propagations once they become matured and will continue to absorb considerable amount of CO₂ from the atmospheres acting against the global warming and also will act as a wind barrier which will help to prevent erosion and safety for the travelers.

1. Problem Analysis:

Due to the deforesting of the mangroves the bird population which were residing in the forest were displaced and taken refuge in the town area making the town a noisy and smelly area causing difficulties for the people and create conflict mentality in people not to care for the nature. The natural barrier for the coast was removed and it exposes the causeway to wind and sea erosion. The causeway was constructed after a very longtime and there is a need to keep and maintain it in full-scale for the future generation.

Mostly the drainage channels in the town area open up at the lagoon closer to the Bridge and discharge effluents which pollute the lagoon as well as the shore. Mangroves act as a natural purifier of these pollutants. The Mannar lagoon has a rich diversity of fish species due to the shallow spread of sea water over extensive extent which produces oxygen, algae and worms which are good food for the fish. The lagoon fishing was the livelihood of the poor fishermen when the mangroves were present in the Mannar lagoon in both sides of the causeway but now and the poor fishermen have lost their livelihood and working for the rich fishermen. This project will support to the poor fishermen to restart their lagoon fishing by the mangroves creation.

Due the increased development activities more number of vehicles and people are being flooding to Mannar and higher CO2 emissions are observed in the Mannar town area. Mannar island forest is being destroyed for development activities and for fire wood. Reforestation in the island will not be an easy task due to the water shortage

The Mangroves remove CO2 through photosynthesis from atmosphere and prevent methane production from the boggy soil, thereby reducing the problems of green house gases and temperature rise. The mangroves fix CO2 per unit area, greater than the phytoplankton do in the tropical oceans (Kathiresan and Bingham, 2001)

Also Mangroves exhibit higher tolerance to sunlight and UV-B than other halophytes (kathiresan and Moorthy, 1993). In fact, seedlings of Rhizophora exposed to low UV-B radiation (equivalent to 10% of ozone depletion) show an increase of 45% in net photosynthetic rates. However under high UV-B (40%), a 59% drop of the photosynthesis occurs (Moorthy and Kathiresan, 1997 a,b). Thus the mangroves mitigate the vulnerable effect of UV at lower intensity.

1. Project Justification:

a. Environment:

After the conflicted situation ended the fishing activities and development activities have been accelerated. The Mannar gulf has much potential for fishing as there are high number of fish species and fish breeding grounds available. The increased fishing activities will effort much pressure on the fish stock and it is necessary to create more fish breeding areas to sustain the depleting fish population. The project will support the lagoon fishermen by accelerating the fish production through establishing a mangrove zone which increases fingerlings production especially for prawns. The displaced birds and migratory birds will be provided with shelter and breeding space that will enhance the bio diversity of the region which will in turn increases the tourist income to the island. The displaced cranes will move back to the mangrove forest. The entrance of the Mannar town will be given a new look that ensures clean and beauty by this project.