Introduction of exotic species in india

Student at College of fisheries, Kawardha Chhattisgarh
27 de Apr de 2017

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Introduction of exotic species in india

  1. INTRUDUCTION OF EXOTIC SPECIES IN INDIAN AQUACULTURE Presented by: Name: Krishna M.F.Sc. 2nd Sem. Dept. of Aquaculture College of fisheries, (JAU), Veraval - 362265
  2. INTRODUCTION  Exotic fish is alien species which is not naive and belonging by nature or origin to another part of the world or brought in from abroad or foreign or strange.  The use of exotic species for fisheries and aquaculture diversification has been practiced since the middle of the 19th century.  Several exotic species have been introduced in the Indian waters and some are now well established too with varying experiences.  Examples: Salmo gairdnerii, Pangasius sutchi, Cyprinus carpio, O. niloticus, H. molitrix, G. affinis, L. vannamei etc.
  3. Cont…  The recent illegal introduction of South American catfish (Pterygoplichthys anisitsi) and Pacu (Piaractus brachypomus) was recorded by NBFGR from river Ganga and river Periyar.  Accidental escapes and even purposeful releases of aquaculture species that are not native to a country create “biological pollution” with irreversible and unpredictable ecological impacts.
  4. S. No. Common name Species Year of introduction Source 1. Common carp C. carpio 1980 Srilanka 2. Bighead carp A. nobilis 1959 Bangladesh 3. Golden carp C. carassius 1968, 1970 England 4. Doctor fish T. Tinca 1974 England 5. tilapia O. mossambica 1972 Bangkok 6. Nile Tilapia O. niloticus 1952 Thailand, Isreal 7. African Catfish C. gariepinus 1978 Thailand 8. Brook trout S. fontinalis 1959 Canada 9. Pangasius sutchi P. hypophthalamus 1997 Vietnam 10. White leg shrimp L. vennamei 2010 USA EXOTIC SPICIES IN INDIAN AQUACULTURE
  5. Source: Raman R.P. et. al, 2013
  6. TRAITS OF EXOTIC SPICIES  Many features have been attributed to invasive species and invaded ecosystem.  The common invasive species traits include:  Fast growth  Rapid reproduction  Phenotypic plasticity  Tolerance of a wide range environmental condition  Ability to live of a wide range of food type
  7. INTRODUCTION OF NEW SPECIES Artificial introduction Occasional introduction Conditions that lead to establishment of exotic species Species-based mechanism Superior Competition
  8. ARTIFICIAL INTRODUCTION  The introduction of new species to specific habitats, or reintroduction of species to the place where it was once common, in order to restore natural balance to gain commercial profit.
  9. OCCASIONAL INTRODUCTION  Many times species are introduced unconsciously or by accident.  This occasional introduction has severe impact on local community structure and balance of ecosystem.
  10. CONDITIONS THAT LEAD TO ESTABLISHMENT OF EXOTIC SPECIES  There are many mechanisms which help in the establishment of exotics in a new environment.  These mechanism generally fall into two different categories:  One for mechanism which focus on the exotic species, and the other which focus on the invaded ecosystem.  In fact, it is a combination of several mechanism that cause an invasive situation to happen.
  11. SPECIES-BASED MECHANISM  Species based characteristics focus on competition among different fish species.  While all fishes are able to compete in some manner in order to survive and persist, invasive species have specific trait or combinations of specific traits that make them especially good competitors.  In some cases it can be as simple as having the ability to grow and reproduce more rapidly than native species or in other case it can be better adaptability in the local environmental conditions; or their feeding habits like that of carnivorous C. gariepinus eating away the competitor and wining the competition
  12. SUPERIOR COMPETITION  A common trait of invasive species is great competitive ability, which can be stronger against fishes in a new habitat than fishes in their native habitat.  There can be huge differences between how an invasive species interacts with its native ecosystem, and with the ecosystem it is invading.  Often, the invading species has a better chance at acquiring resources, which can be water quality, space, food or nutrients etc.  Invasive species can coexist with native species for an extended time, and only gradually does the superior competitive ability of an invasive species become apparent, as its population grow larger and denser, and slowly increases the risk of extinction to other species.
  13. CRITERIA TO BE CONSIDERD IN INTRODUCING NEW SPECIES Fill a needs Not compete with valuable native species Not cross with native species and produce undesirable hybrids Not be accompanied by pests, parasites or diseases and; Live and reproduce in equilibrium with its new environment.
  14. BENEFITS OF EXOTIC SPECIES INTRODUCTION  Improve production and economic benefits from fisheries and aquaculture.  Use of exotic species for fisheries and aquaculture diversification deal with rising demand for food and nutritional security.  The development of aquaculture worldwide.  Approximately 17% of the world’s finfish production is due to exotic species.  Approximately 20 percent of the world’s farmed salmon and directly employs more than 30,000 people.
  15. IMPACTS OF EXOTIC SPECIES Ecological impacts Impacts on Biodiversity Transmission of diseases Genetic dilution Economic impacts
  16. ECOLOGICAL IMPACTS Competition of exotic fishes with the native species for living space with same niche preference, for food with fishes of similar types of feeding habits, or of omnivorous feeding habits ,or predation on native fishes by these, spreading parasites and pathogens, thereby are some common ecological concerns.
  17. IMPACTS ON BIODIVERSITY  Habitat destruction  Invasive species cause loss of biodiversity including species extinction, and changes in hydrology and ecosystem function.  The impact on global biodiversity of human introduction of non- native species that have subsequently become invasive is subjective.
  18. TRANSMISSION OF DISEASES  Of particular concern to exotic species is that the level of uncertainty will be higher with new introductions on what pathogens may be present and may cause problems in the new environment.  The diseases which comes from other country to India is:  Epizootic ulcerative syndrome  Epizootic haemorrhagic necrosis  Taura syndrome and  Yellow head disease.
  19. GENETIC DILUTION  The genetic impact of introduction of exotic fishes on native fishes can be classified into 2 categories:  Reduction of effective population size by the ecological, biological & genetic effect of introduction and,  Alteration/extinction of gene pools of the species/stocks by crossbreeding or hybridization & backcrossing.
  20. ECNOMICAL IMPACT  The economic impacts can be seen at two levels – 1. Capture Fisheries and 2. Aquaculture  Economic costs due to invasive species can be separated into direct costs due to production loss and management costs of invasive species.  Since the exotic fishes never fetch higher price than the native varieties and also the decline of native fish production is observed in the presence of exotic species in natural waters, the total economic returns declined for the stakeholders of the capture fisheries.  In aquaculture however it provided immediate gain, in most cases without consideration of the long term ecological consequences.
  21. CONTROLAND MANAGEMENT OF INTRODUCTION  For effective management of exotic species, knowledge about their ecology, morphology, reproductive biology and physiology is essential.  The management of introduction has to be multi-pronged involving all the stake holders.  It has to be implemented at several scales, from a homeowner working in his or her own backyard to large government agencies like directorate of fisheries of state Govt., ICAR, NBFGR, NFDB etc. taking a state wise and nation-wide approach respectively.  To finally involving major intergovernmental agencies like FAO, NACA, World fish center, ICES, EIFEC etc. to coordinate, monitor and manage the transfers and introduction of species on international level.
  22. The American Fisheries Society protocol consist of the following steps: Rationale Search Preliminary assessment of the impacts Publicity and reviews Experimental research Evaluation and recommendation Introduction
  23. CONCLUSION  India is one of the mega biodiversity country having more than 2700 species of fishes.  There are plenty of cultivable species in the country.  Any further introduction of exotic fish species would be a threat to the existing species diversity.  The introduction of Tilapia, Common carp, Pangasius and white leg shrimp have greater adverse impact on aquatic ecosystem and also on culture practices.  The introduction of exotic species result in competition for limited food, space, ecological niche and may results in genetic erosion, predation and pathogen entry.  In the other hand, introduction of the exotic species can be used for broadening species diversity in aquaculture systems of a particular country and also for economic benefits,  The recent action by the Govt. of India to introduce only SPF L. vennamei and controlled culture of P. hypophthalamus are the new steps in this direction.