Aquatic ecology and Biodiversity

Unit 12- Biodiversity and conservation

12.2.7. Methods of conservation
Identification and protection of sites for conservation of biological diversity is basically by
• In- situ conservation
• Ex- situ conservation
In- situ conservation
It helps to maintain high genetic variability for introduction of improved varieties and to reduce problems of maintenance of brood stock in-site condition and transportation. In-situ conservation means "on-site conservation". It is the process of protecting an endangered plant or animal species in its natural habitat either by protecting or cleaning up the habitat itself or by defending the species from predators. The benefit due to in-situ conservation is that it maintains recovering populations in the surrounding where they have developed their distinctive properties. Another is that this strategy helps to ensure the ongoing processes of evolution and adaptation within their environments.
Stock enhancement through ranching is feasible only (i) if there is an incomplete, colonization of available habitat by juveniles and (ii) if the tropic capacity of the habitat is under-utilized by a stock and/or its competitors. Conservation of species in aquaculture is gaining importance in rehabilitation programmes of endangered/threatened fishes. It implies aquaculture for conservation and recovery of endangered fish populations by increasing the effective population size of the threatened species. Examples

Ex-situ conservation
Ex-situ conservation means literally off-site conservation. It is the process of protecting an endangered species of plant or animal by removing part of the population from a threatened habitat and placing it in a new location, which may be a wild area or within the care of humans.
The two main pillars of ex- situ conservation programmes are (i) live gene bank and (ii) gamete / embryo Bank. In a live gene bank, the endangered species are reared in captivity, bred therein and genetically managed avoiding inbreeding depression, domestication and unintended selection. In gamete / embryo bank, adequate samples representatives of the natural genetic variants of endangered species are kept in suspended state of animation under extra low temperature (-196 ºC) in liquid nitrogen. Establishment of gene bank by cryopreserved milt, eggs and embryos assures further availability of genetic materials of threatened categories and for intensive breeding programmes of economically important species. It helps for rehabilitation of endangered species.
Use biomarkers such as Molecular genetics tools- PCR, chromosomes, Electrophoresis and DNA sequencing etc. used in the conservation of biological resources is gaining more importance today.
• For stock identification
• For resolving taxonomic ambiguity in fishes, crustaceans, molluses, mammals, corals.
Agencies in India
• NBFGR – Lucknow
• CMFRI – Cochi
• CIFA – Bhubaneshwar
• NIO – Goa