Indian mangroves have a rich diversity

of soil-dwelling organisms which include

micro, meio and macro forms. Mangrove

ecosystem provides an ideal nursery and

breeding ground for most of the marine

and brackish water fish and shellfish.

India has only 2.66% of the world’s mangroves1,

covering an estimated area of

4827 sq. km. The present study area lies

within the margins of lat. 11°90′107″–

11°90′703″N and long. 79°80′547″–

79°81′851″E. Mangrove exists as fringing

vegetation over 168 ha distributed

along the sides of Ariankuppam estuary,

which empties into the Bay of Bengal

(Coromandal coast) at Veerampatinam

on the southeastern coast of Indi

Manjusha, U

Pillai, N G K

Satheeshkumar, P

Senthil Kumar, D

CMFRI Digital Repository

CORRESPONDENCE  CURRENT SCIENCE, VOL. 102, NO. 1, 10 JANUARY 2012 13Puducherry mangroves under sewage pollution threat need  conservation  Indian mangroves have a rich diversity of soil-dwelling organisms which include micro, meio and macro forms. Mangrove ecosystem provides an ideal nursery and breeding ground for most of the marine and brackish water fish and shellfish.  India has only 2.66% of the world’s man-groves1, covering an estimated area of 4827 sq. km. The present study area lies within the margins of lat. 11°90′107″–11°90′703″N and long. 79°80′547″–79°81′851″E. Mangrove exists as fring-ing vegetation over 168 ha distributed along the sides of Ariankuppam estuary, which empties into the Bay of Bengal (Coromandal coast) at Veerampatinam on the southeastern coast of India2.  Mangroves are woody trees and shrubs and are known as Sathuppu Nilakadukal in Tamil. Mangrove forests, though com-mon and widespread, are highly threat-ened. Local communities along with their knowledge about the mangroves are also endangered, while they are still under-represented as scientific research topics3. Mangroves have played an important role in the economics of our coastal population for thousands of years, pro-viding a variety of goods and services, including wood production, support for commercial and subsistence fisheries, aquaculture, salt production and shoreline and coastal erosion control.  The human influence on mangroves has increased over the past three decades, with many countries showing losses of 60–80% or more of the mangrove forest cover that existed in the 1960s; but most of the data showed variable loss rates and there is considerable margin of error in most estimates. The destruction of mangroves is usually proportional to human population density. Major reasons for destruction are urban development, mining, agriculture, overexploitation for timber, aquaculture and overfishing, which can cause imbalance in the man-grove fish communities4,5. The remaining mangrove forests are under massive pre-ssure from clear-cutting, encroachment, hydrological alterations, fertilizers and pesticides, oil spills, storms and climate change5.  In the present study a small patch of mangrove forest in the Puducherry coast, southeast of India was studied (Figure 1). The channels in the mangroves are lined by a luxuriant vegetation of small salt marsh plants, trees, shrubs and thickets, totalling about seven true mangrove  species belonging to three families, 16 mangrove associate plants belonging to 12 families recorded in the study area2. The Avicennia zone forms a small patch of Avicennia marina and A. officinalis dense stand at the mouth region of estu-ary of Veerampattinam. The Rhizophora zone has four patches of Rhizophora mucronata and R. apiculata on the southern part of Thengaithittu and four patches of R. mucronata and R. apiculata near the mouth of estuary. The Acanthus zone – Acanthus ebracteatus and A. illi-cifolius forms dense stand at the western and northern side of Ariyankuppan and Murungapakkam. Bruguiera cylindrica spreads from the western end of Murun-gapakkam up to the eastern end of  Ashram Islet. Avicennia and Rhizophora mixed zone spreads near the bridge. The Sunnambar lake reservoir is the main source of water supply to the Puducherry coastal area; the stream travels a long distance and joins the sea at Veerampat-tinam. Various industrial effluents join the stream and are finally discharged into the inner harbour waters.  In recent years we have conducted benthic surveys in various stations of Puducherry mangroves, and found small and unrecorded species6,7. A total of 76 species were recorded from all the four mangrove stations. This includes mol-lusks 37 (bivalves 16 and gastropods 21), crustaceans (22), amphipods (7), poly-chaetes (6), barnacles (3) and oli-gochaetes (1). Five species of turtles were found in the coastal water and the Olive ridley turtle was found to be nest-ing in the Puducherry coastal area; this needs to be protected. In Puducherry the mangroves are increasingly being threat-ened by population pressure, aquaculture operations and mangrove environment conversion to new shrimp ponds, dredg-ing for landfills, and building ports,  industrial estates and housing estates  for human habitation8. Puducherry coastal area is being polluted due to the dis-charge of industrial, domestic and  agricultural wastes through small tribu-taries and channels into the Bay of Ben-gal9. Satheeshkumar and Khan reported that dissolved oxygen concentration ranged from 3.71 to 5.33 mg/l and sul-phide level was high (40.43 mg/l). More-over, the piercing odour of H2S from deeper sediments could also be smelt during the field study.  The immediate need is to maintain the existing sewage treatment plants so that effluent discharge has a minimum of suspended solids. Thus the Puducherry mangroves need urgent monitoring. In addition, maintenance of the undisturbed areas should be a primary objective, as they represent a constant macro faunal diversity.   Figure 1. A view of Puducherry mangroves. CORRESPONDENCE  CURRENT SCIENCE, VOL. 102, NO. 1, 10 JANUARY 2012 14  1. Ministry of Environment and Forests, Gov-ernment of India, India’s Fourth  National Report to the Convention on Bio-logical Diversity, 2009. 2. Saravanan, K. R., Ilangovan, K. and  Khan, A. B., Trop. Ecol., 2008, 49(1), 91–94. 3. Dahdouh-Guebas, F. S., Collin, D., Lo Seen, P., Rönnbäck, D., Depommier, T. and Ravishankar, K. N., J. Ethnopharma-col. Ethnomed., 2006, 2, 24; doi:10.1186/ 1746-4269-2-24. 4. Spalding, M. D., Blasco, F. and Field,  C. D., World Mangrove Atlas, The Interna-tional Society for Mangrove Ecosystems, Okinawa, 1997. 5. Kathiresan, K. and Qasim, S. Z., Biodiver-sity of Mangrove Ecosystem, Hindustan Publishing Corporation (India), New Delhi, 2005, p. 251. 6. Satheeshkumar, P. and Khan, A. B., Check list., 2011, 7(1), 83–84. 7. Satheeshkumar, P. and Khan, A. B., World J. Zool., 2011, 6(3), 312–317. 8. Thomas, G. and Fernadez, T. V., Indian For., 1995, 120(5), 406–411. 9. Satheeshkumar, P. and Khan, A. B.,  Environ. Monit. Assess., 2011; doi: 10.1007/s10661-011-2222-4.  ACKNOWLEDGEMENTS. P.S. thanks the University Grants Commission, New Delhi for financial support. We thank the Central Marine Fisheries Research Institute, Kochi for providing infrastructural facilities.  P. SATHEESHKUMAR1,* U. MANJUSHA1 N. G. K. PILLAI1 D. SENTHIL KUMAR2  1Central Marine Fisheries Research   Institute, Kochi 682 018, India 2Kandaswamy Kandar Arts and Science   College, Paramathi-Velur 638 181, India *e-mail: indianscientsathish@gmail.com      Wild boars: is elimination the way forward?  The wild boar (Sus scrofa) is suddenly the ‘most popular mammal’ in Kerala. The latest decision of the Kerala Gov-ernment to permit the shooting down of crop-raiding wild boars has sharply divi-ded the state’s ecologists and environ-mentalists. Whether to ‘shoot it down’ or just ‘shoo it away’ is now hotly debated.   In the tropics, human population growth1, habitat encroachment2, changes in land-use patterns3 and problems in the implementation of nature conservation measures4 are some reasons for man–wildlife conflicts. Encountered in all continents, except Antarctica5,6, the wild boar has a high reproductive rate, poten-tially breeding year round7. Man–wild boar conflict continues to be debated  because of the inadequacy or ineffective-ness of any single strategy to stop it8.  Opportunistic omnivores, the wild boars have a marked preference for plant food9. Their foraging patterns are strongly influenced by availability10. Crop type11,12, distance of the crops to forest11, crop ripening period13, popula-tion density14 and availability of natural forest foods11 and season of the year also influence crop raiding. Are various abiotic stresses like wild fire, over har-vesting by herbal medicine suppliers and drought reducing the wild food base of wild boars? Wild boar is also a crucial link in the forest food chain, as it is an important prey species for larger carni-vores. They also ‘till the land’ exposing the ‘soil seed banks’ and aid plant ger-mination. They also devour insects, mice and other detrimental organisms15.  In a forest setting, food ‘hunting’ by wild animals is a normal survival behav-iour. Field crops raised close to the  foraging domain of the wild ungulate are easy prey for them. Given an opportu-nity, they will raid and harvest crops. We still have no evidence of ‘habitual  offenders’ from the world of wild ani-mals, who prefer agricultural crops to wild food. Crop raiding by wild boars is an adaptation behaviour in the wake of both the loss of its natural habitat and progressive decline of its natural wild food base. Easy access to more energy-rich food resources may also have trig-gered a behavioural (abnormal?) pattern. Interestingly, wild boars also raid crop lands for habitat requirements, like ‘wal-lowing’. But like ‘man-eating tigers’, ‘crop-raiding’ wild boars also needs to be managed. Logically, we will have to keep these ‘raiders’ away from the crop fields on a permanent basis. Use of force has limited options in a crop-raiding  scenario involving bigger mammals. Per-mission to wield guns will only open a Pandora’s box, not only for the State Forest Department but also for the  police, the peoples’ representatives and the judiciary as well.  As the foraging behaviour is strongly influenced by the potential escape cover16, one viable strategy will be to keep the farm boundaries clear of palat-able vegetation. Designing open space buffer zones between croplands and  forests can considerably reduce dam-ages17,18. In Kerala, crops such as mango ginger (Curcuma amada Roxb.), which wild boars detest, have been profitably planted in fields bordering forests. Ker-ala farmers have a variety of time-tested wild-boar snares which can be good  deterrents. Wild boar-proof fences are another option (http://www.wild-boar. org.uk/pdf/WildBoar_fencing.pdf). Elec-trical (solar-powered too) fencing is  another successful deterrent19,20. In the West, trained dogs are effective deter-rents. In the rubber plantations of central Kerala, white-coloured plastic sheet fences create panic in the herd (Figure 1). ‘Field patrolling’ by farmer groups on a regular rotation basis can also be a suc-cessful crop protection strategy.   Compatible crop combinations are fundamental for the success of any farm-ing activity. Likewise, cropping patterns should also consider the likely threat perceptions from possible biotic factors (e.g. the wild boars) of an area. Financial and technical support must be given to identify the high-risk croplands (which suffer from biotic stresses) of the state and design appropriate ‘farm plans’. In a land-scarce state like Kerala, farm pro-duces have tremendous social values and implications in food security. The Gov-ernment must also consider introducing appropriate crop insurance schemes for these high-risk croplands to mop up the financial loses in the event of a crop raid. 

Puducherry mangroves under sewage pollution threat need

conservation

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Puducherry mangroves under sewage pollution threat need conservation

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