Irrawadi dolphines

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Irrawadi dolphines

  1. 1. Irrawaddy DOLPHINS<br />Presentation by<br />Dr MadhusudanSubudhi<br />
  2. 2. IRRAWADDY DOLPHIN IN CHILIKA LAKE<br />
  3. 3. Taxonomy<br />Kingdom _ Animalia<br />Phylum _ Chordata<br />Class _ Mammalia<br />Order _ Cetacea<br />Family _ Platanistidae<br />Genus _ Orcaella<br />Species _ OrcaellaBrevirostris<br />
  4. 4. Physical description<br />Colour<br />Slaty blue to slaty grey<br />Under parts are slightly paler<br />Length<br />180 to275 cms<br />Body weight<br /> May go up to 190 kg(418 lbs)<br />
  5. 5. Gross Anatomy<br />
  6. 6. Gross anatomy<br />Bulging fore head<br />A very short beak<br />Pectoral fin is broadly triangular<br />Small dorsal fin towards posterior end of the back<br />U shaped blowhole opens to the front(unlike other sps)<br />12 to 19 teeth on each side of each jaw. Narrow pointed peg like teeth about 1cm length<br />
  7. 7. Gross Anatomy (contd)<br />Two unique anatomical features of this sps:<br />Stomach is divided into two into two compartments<br />Muscular part & glandular part<br />Cardiac sphincter is absent<br />
  8. 8. Male reproductive organ of dead Irrawadidolphinedesected by Dr M.subudhi & MrMumtajalli khan.<br />
  9. 9. Grossly healthy kidneys of a dead Irrawady dolphin dissected by Dr M.Subudhi & Mr.Mumtazalli Khan<br />
  10. 10. Physical behavior<br />They prefer coastal, brackish & fresh water of tropical & subtropical Indo pacific.<br />Feeds on fishes ,crustaceans, cephalopods & fish eggs.<br />Breathes at 70 to 150 seconds intervals.<br />Usually dives for an average of 30 to60 seconds but larger dives up to 12 minutes have been recorded.<br />Swim rate recorded up to 25 kms/hour.<br />
  11. 11. Physical behavior(contd)<br />Irrawadi dolphins are less active than other dolphins<br />Only the uppermost part of dorsal fin becomes visible during a slow rolling dive<br />They never bow ride<br />
  12. 12. Breeding behavior<br />Sexually mature around 4to 6 years age<br />Gestation period is 14 months<br />In Semeyang lake/Mahakam river(Malaya) mating season recorded to be April toJune<br />But in Jakarta calves borne between July to december<br />New borne measures 96cm,body weight 12.3kg.Body weight at weaning aapx.45kg.<br />Though calves consume fish at 6months age but nursed up to 2 years<br />
  13. 13. Origin<br />Ayeyarwady river or Irrawaddy river which flows from north to south in Myanmar.<br />Name derived from the Sanskrit word Iravati(minor Goddess in Indian mythology) or from her son Airabat the elephant<br />Irrawaddy is the largest river of Burma about 2170 km long<br />
  14. 14. Panoramic view of Irrawaddy river<br />
  15. 15. Panoramic view of Irrawaddy river<br />
  16. 16. World wide habitats & population<br />
  17. 17. Panoramic view of Irrawaddy river<br />
  18. 18. Bangladesh as fresh,brackish & salt water habitat<br />Sundarban delta<br /> Mangrove forest<br />
  19. 19. Chilika lake as brackish water habitat<br />Chilika near sea mouth<br />Nalaban<br />
  20. 20. Panoramic view of inner Malampaya sound (Philipines)Brackish water habitat<br />
  21. 21. Brackish water habitat of Sangkhala lake(Thailand)<br />
  22. 22. Categorization of IUCN red list<br />Extinct<br />Ex- Extinct<br />Ew- Extinct in the wild<br />Endangered<br />Cr- Critically endangered<br />En- Endangered<br />Vu- Vulnerable<br />Lower list<br />NT- Near threatened<br />LC- Least concerned<br />Cd- Conservation dependant<br />
  23. 23. Analysis of threat as per IUCN red list<br />Irrawaddy dolphin is classified as VULNERABLE<br /> on the IUCN red list and listed in appendix-1 of<br /> CITES (Conservation of International trade in endangered species)<br />In Mahakam river & Malampaya sound classified as<br /> critically endangered <br />
  24. 24. Threats<br />Irrawaddy dolphins are more susceptible to<br /> human conflicts than most other dolphins<br /> who live farther in the ocean.<br />Drowning in gillnets is the main threat throughout their range.<br />Majority of reported deaths in all subpopulations is due to accidental capture<br /> and drowning in gill nets, dragnets, bottomset crab nets(in philipines).<br />
  25. 25. Gillnetting the No 1 threat forIrrawaddy dolphin<br />
  26. 26. Threat:Chilika experience<br />Author has conducted post murtem of 10 dead dolphins between2005 to 2008.<br />4 were putrified enough to opine any cause of death.<br />5 deaths are due to traping followed by drowning in gill nets bearing injuries on tongue,base of the tail and skin exfoliations.<br />1 death is due to lungs desease (focal necrosis<br /> of lungs)<br />
  27. 27. Decomposed dolphin<br />
  28. 28. Lungs of dead Irrawaddy dolphin with focal necrotic lesions<br />
  29. 29. Researchers working on threat analysis & conservation strategies <br />
  30. 30. Threat:Chilika experience<br />Unregulated fishing<br />Introduction newer varieties of fishing nets which are almost invisible under water.<br />Motorized propeller boats, large in number<br />Tourist boats approach much closer to dolphins, even sometimes chase them.<br />Pollution of water, change in salinity, change in water temperature and siltation are less emphasized.<br />
  31. 31. Ongoing conservation initiativesChilika experience<br />Mapping dolphin population, distribution and<br /> movement by using GPS.<br />Imposition of fines on gill and seine netting in Satpada region.(Orissa marine fisheries regulation act)<br />Fines on tourist boats found chasing dolphins<br />Ongoing training in dolphin watching guide- lines by CDA funded by WDCS.<br />Distribution of booklets and pamphlets on sustainable fisheries<br />
  32. 32. Action plan<br />Establishing core conservation areas where gillnets and motorized boats are to be banned.<br />Promoting net attendance rules and providing training on safe release of entangled dolphins.<br />Providing alternative or diversified employment to gillnet fishermen.<br />Research & development with acoustical deterr-ants and reflective nets.<br />

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