conservation 2
sustainable exploitation
-international whaling commission:
-main aim: regulate and manage whaling
-populations of many whale species were so depleted by unregulated whaling that commercial whaling was banned in 1986
-blue whales of the Antarctic are at less than 1% of original abundance despite 40yrs of complete protection (green peace)
-IWC conservation methods:
-total protection for certain species
-designation of whale sancturaries
-setting limits on numbers and sizes of whales that can be taken
-protection of sucking mothers and calves
-completing research into whale biology and activities that threaten them (ship strikes and entanglement)
-reasons for whaling:
-aboriginal subsistence: cultural groups that traditionally hunt whales (Inuits in Alaska)
-special permit for whaling / scientific whaling for research (Japan used this to continue whaling until 2014 when a judge ruled it out)
-Iceland and Norway use in an IWC regulation to set their own quota, in 2014 they killed 800 whales
-common fishing policy:
-a series of regulations controlling fishing in the waters of the EU
-aims to ensure fishing and aquaculture are sustainable and provide a healthy source of food for EU citizens
-use the MSY to set fishing quotas
-MSY:
-maximum number of a species that can be sustainably harvested
-there must be enough adults left to reproduce and produce young
-to calculate you need to know:
-death rate, pop. increase rate, number of offspring, pop. size and growth of individuals
-CFP regulations:
-catch quotas to limit the total mass that can be landed
-size limits to manage the size of fish caught, so young go free
-net mesh size regulations that allow smaller fish to escape and survive
-limits on fishing efforts such as max size of fishing boat or num of fishing days
-discard ban to lessen bycatch
-International Tropical Timber Organisation:
-aims to encourage sustainable management of tropical forests
-1990: members agreed to strive for an international trade of tropical timbers from sustainably managed forests by 2000, without unsustainable exploitation
-there is still little evidence for sucess
-protection of habitats / species:
-key features of wildlife and countryside act (1985):
-SSSI: sites of specific scientific interest
-NNR: national nature reserve
-SAC: special area of conservation
-SPA: special protection area
-natura 2000 sites
-ramsar sites
-MNR: marine nature reserves
-LNR: local nature reserve
-MPA: marine protected area
-MCZ: marine conservation zone
captive breeding programs
-in situ conservation: conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural habitats, and in the case of domesticated or cultivated species in the surroundings they have developed about distinctive properties (Convention on biological diversity 1992)
-ex situ conservation: conservation of components of biological diversity outside of their natural habitats (CBD 1992)
-involves breeding in captivity so some young can be released
-species carefully selected as there are limited resources
-factors that influence decisions on captive breed and release programs:
-is the wild population threatened?
-is there are genetically diverse captive populations?
-is in situ conservation successful?
-Is keeping a captive population successful?
-is wild really successful now or in the future?
-problems with keeping species in captivity:
-habitat / species size : too large for captivity?
-food requirements: may be difficult to obtain regularly
-species interactions difficult to replicate .eg, symbiotic relationships
-financial constraints: it's expensive we can't protect everything
-captive breeding program problems:
-many of the species kept in captivity have not bred successfully due to:
-conditions for breeding
-population interaction
-breeding habitat
-gene pool size
-hybridization
-conditions for breeding:
-precise timing for breeding can be vital to increase young survival
-breeding can be triggered by : daylength, lights level, temperature, food / body fat amount
-if conditions are not met with them breeding will not succeed or occur
-eg, kakapo will only breed when it reaches a certain weight
population interactions and breeding success:
-in the wild breeding pairs of birds may choose isolation when breeding
-in captivity the mixing of two groups can lead to conflict and reduced survival of young
-some species breed better when there is a choice of partners while others pair for life
-eg, seahorses path of life and can die due to partner loss
-breeding habitats:
-some species can only breed if they have a specific habitat for courtship, social grouping, hunting and nest buildings
-eg, flamingos only breed in large populations
-hybridization:
-closely related species breeding in captivity but don't naturally meet
-problem with plants due to wind pollination
-offspring may not be particularly suited to live in the wild
-eg, Asiatic and African lion
-gene pool size:
-a small gene pool in captive breeding may cause inbreeding
-harmful recessive genes may become common in offspring
-most recessive genes rare unless the parents are closely related
-eg, the Hawaiian goose became rare due to hunting, introduced predators and loss of habitat:
-a captive breeding program has successfully increased the wild population
-population started with seven so some offspring have poorly adapted feathers for cold winters
-'stud books' are used to record family tree and reduce inbreeding
increasing breeding success
-cryopreservation:
-storage of eggs, semen and embryos by freezing for future breeding
-can be transported much easier than parents and doesn't require parents meeting
-frozen samples can be used many years later even if donors have died
-artificial insemination:
-collection of semen from a male to be inserted into a female
-semen can be stored for years
-avoid transport of donor that could be expensive or dangerous
-meeting and mating can be dangerous for larger animals
-doesn't require the partners to accept each other
-embryo transfer:
-some mammal species in captivity have few breeding partners slowing the rate of offspring production
-for some there may be a larger closely related species that can act as a surrogate mother
1) endangered female treated with hormones to so she ovulates and releases eggs
2) eggs washed out of uterus and fertilized with semen
3) embryo implanted into female of a more common species, its then gives birth to young
4) this means the original can produce more calves than would be possible regularly
-micro propagation of plants:
-tissue culture where clusters of cells can be produced from one sample
-each cell cluster can be cultivated to form an individual plant
-many plants can be produced from a single parent all genetically identical
-cloning:
-low success with wild populations
-deep frozen stem cells could be used in the future
-research is being carried out to see if young can be produced for species that don't read such as the northern white rhinoceros
-key features of successful release programs:
-number of individuals released must be sufficient to establish a viable population
- hard release: (insects, fish and reptiles)
-release with no support involving species with instinctive behaviour
-soft release: (mammals and birds)
-post-release support and gradual release, and provision of food help
-problems faced by released individuals:
-finding and recognising food
-recognising poisonous foods
-recognizing and avoiding predators
-being accepted into social groups
-skills that parents wouldn't have taught / needed in captivity
-seed banks:
-set up to store seeds of wild plants so they don't become globally extinct
-seeds should maintain for biodiversity of wild, rare species
-species chosen are threatened or important (millennium seed bank, Sussex)
-target number of 10,000 seeds per species to produce diverse gene pool
-seeds are stored underground with reinforced vault to reduce risk of major accidents
habitat conservation
-land ownership:
-many wildlife conservation organisations purchase areas to protect the species that already live there (Wildlife Trust)
-organisations manage the habitat to benefit the wildlife
-individual landowners may also make management decisions
-NNRs: designated by UK legislation best examples of complete communities
-SSSIs: designated by UK legislation, areas of best examples of flora fauna and features
-SAC: EU regulation, each country must identify and protect internationally important habitat
-SPA: under EU Birds directive, identify and protect bird important areas
-Ramsar sites: intergovernmental agreement to protect wetland
-voluntary agri-environmental schemes:
-land management is expensive so landowners may own VAS for financial support
-they recognise that much of the British landscape as was affected by farming and continue to use appropriate farming methods
-increasingly intensive farming methods have caused damage from hedgerow removal and pesticide use
-changing farming practices may involve efforts, money and result in reduced incomes
-since the improvements benefit everyone it seems fair to use central funding
-VASes provide financial support for environmentally beneficial developments
-eg, environmentally sensitive areas
-aims:
-conserve wildlife and biodiversity
-maintain and enhance landscape quality and character
-protect the historic environment
-promote public access and understanding
-protect natural resources
-points on the VAS scheme are awarded for:
-beetle banks: natural predators and reduced pesticide use
-hedgerow, stone wall and ditch management
-field buffer strips to protect rivers
-wild bird seeds: to provide winter bird food
-low input grasslands: to protect wild flowers
-protected archaeological sites
-management to reduce soil erosion
-protection of in field trees
-higher payments from extra schemes:
-wildflower rich grass field margins
-unharvested conservation field headlands for winter bird food
-restoration of wet grassland for waders and wild foul
-water meadow restoration
-public access
-maintenance of saltmarsh, hedgerows, orchards, ponds, woodlands
-habitat creation and management:
-an increasingly important part of environmental management
-can be intentional or unintentional habitat creation
-unintentional habitat creation:
-humans have always created habitats unsuitable to the natives but they may be suitable for new species to colonize
-habitats created due to human activity include:
-reservoir
-flooded sand and gravel pits
-roadside verges
-hedge ground
-ornamental gardens