CONCLUSIONS

Tropical estuaries are among the most productive ecosystems of the world. The west flowing rivers from the Western Ghats are relatively smaller compared to the east flowing ones. Their estuaries are naturally lesser in area, but nevertheless endowed with high productivity and species diversity. Area under mangroves is relatively smaller, and especially south-west Indian estuaries hardly merited any consideration for funding under mangrove planting schemes until last one decade or so. For instance, although Honavar Forest Division has 1407.67 sq.km of forests, mangroves cover 3.90 km only, according to our current estimate. Further 1019 ha of potential area for mangrove planting could be readily available as well. Moreover, if disused shrimp farms, in hundreds of ha area, are taken over by the State and restored with mangroves, on mutually agreeable terms with the farmers, that would be an achievement of enormous magnitude in coastal ecological protection and safeguarding of local livelihoods.

On the other hand various all India level surveys on mangroves hardly reported any mangrove areas from the State of Karnataka. Studies in Uttara Kannada estuaries show that despite their smaller sizes, collectively they produce hundreds of crore rupees worth fish, shrimps, edible bivalves, oysters etc. Mangroves play vital role in such productivity and in addition provide shelter and nursery grounds for many fishes. Over 120 bird species are reported from Uttara Kannada estuaries, particularly the ones with more mangroves. Mangrove soils are known to sequester much more carbon than tropical rain forests per unit area. Mangroves safeguard coastal zones from cyclonic damages, provide certain resistance to tsunamis and protect the shores from erosion. Yet in all India mangrove development programmes coastal Karnataka as such received only very little attention.

What is sorely lacking for the west coast estuaries is lack of any kind of detailed micro-level estuarine mapping to estimate mangrove areas and potential areas. If micro-level  mangrove mapping is available high quality management systems can be implemented with better planning. Therefore, at the behest of Honavar Forest Division in Uttara Kannada, the current study was made. Forest range-wise, and beat-wise, as well as estuary and creek-wise maps prepared depicting mangrove areas and potential areas for planting, in relation to salinity levels, will enable preparation of better projects in future for mangrove development. We recommend that such exercises be carried out for the entire west coast to gain a comprehensive picture of mangroves, including preparations of species-wise distribution maps enabling better conservation of this very vital coastal resource, meriting Coastal Regulation Zone I status, from any further fragmentation and dissolution.   

Acknowledgement: We are grateful to the Ministry of Environment and Forests, Government of India, the Ministry of Science and Technology (DST), Government of India and Indian Institute of Science for financial and infrastructure support.  We thank Honavar Forest Division and particularly Krishna Udpudi IFS for sponsoring the study. Thanks are due to G.R.Rao for taxonomic assistance.