Introduction to conservation medicine and threats to biodiversity – Flashcards
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True or false: Infectious disease (ID) incidence has clearly increased during recent decades
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True
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Why is it important to educate vet students in conservation medicine and ecosystem health?
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- global trade in wild animals - increasing number of emerging infectious diseases - numerous environmental threats (habitat fragmentation, climate change) linked to anthropogenic change
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What is conservation biology?
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- Applied science associated with the management of biological diversity - Draws on methods and problem solving skills from many disciplines - Bio, Physics, Chem, Animal Behaviour, Ecology, Genetics, Geography, Mathematical modelling, Medicine, Philosophy, Sociology, Politics, Stats - Trade off between 'realism of practical applications and pure research'
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What is an ecosystem?
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A community of living organisms and the environment in which they live, interacting to form a whole functional system. - Resilient - Complex - Interrelationships - Interdependencies
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What is conservation medicine/ecohealth?
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- Conservation medicine is an emerging interdisciplinary field that studies the relationship between human and animal health and environmental conditions - Term was first used in the mid 1990s and represents a paradigm shift in both medicine and environmentalism - It is also known as Ecohealth, Ecological medicine or Environmental medicine
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What is the primary goal of conservation medicine?
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The pursuit of ecological health or by extension, the health of ecosystems and their inhabitants. - The interactions among human induced changes in climate, habitat, biodiversity and ecology - The emergence of pathogens, parasites and pollutants - Health within animal (incl human) and plant communities
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What is One Health?
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In 2008, four international organisations, Food and Agriculture Organization (FAO), World Health Organization (OIE), the United Nations Children's Fund, the World Bank joined forces to produce a strategic document entitled: 'Contributing to One World, One Health: a Strategic Framework for Reducing Risks of Infectious Diseases at the Animal-Human-Ecosystems Interface'. ie. more medicine, less biological diversity
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Why should we care about the earth's biodiversity loss?
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1. We have a moral obligation to care 2. Biodiversity as aesthetic value 3. Humans depends on many plants and animals for its survival 4. Humans depend on intact ecosystems to provide basic services (ecosystem services) such as recycling of our atmosphere and water. 5. Economic value - food materials, ecotourism, recreation
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What advances were made with the Environment Protection and Biodiversity Conservation Act 1999.
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- access to biological resources in Commonwealth areas - import and export of plants and animals (wildlife) and products derived from wildlife - protection and management of World Heritage properties, National and Commonwealth Heritage places, Ramsar wetlands and Commonwealth reserves - establishment of the Australian Whale Sanctuary in Australia's exclusive economic zone - Illegal to use nuclear power
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How many critically endangered spp are there in Australia?
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5 Frogs 9 Reptiles 16 Birds 6 Mammals + 38 other endangered spp
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What is biodiversity?
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Biodiversity occurs in all environments on Earth - on land, in rivers and lakes, and in the seas and oceans. Genetic diversity, Species diversity and Ecosystem diversity
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What is genetic diversity?
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- the variety of genetic information contained in individual organisms. - at this level species may vary in their tolerance of heat or cold, or resistance to diseases, etc
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What is species diversity?
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- the variety of species. - at this level, we find the basic types of organisms that most people are familiar with, including wild and domesticated species of plants and animals and wild and laboratory- cultured species of microorganism
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What is ecosystem diversity?
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- the variety of habitats, ecological communities and ecological processes. - at the ecosystem level, we can identify aggregations of species within different environmental settings that constitute broad habitat types, ecological communities and ecosystems such as grasslands, woodlands, rivers and estuaries.
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What are background or "normal" rates of extinction?
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One - two species per year
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Describe the massive extinction crisis threatening global biodiversity
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- There have been at least five episodes of mass extinctions in the past, during which anywhere from 60 to 96% of existing species became extinct. - 99% of all existing species that have ever existed are now extinct. - Volcanic eruptions and asteroid impacts are among the prime suspects for the cause of previous mass extinctions - including demise of the dinosaurs.
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How does the current SIXTH mass extinction differ from previous ones?
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- It is human induced "the ANTHROPOCENE" - Rate of extinction is 1000-10000 times greater than would be expected by natural extinction rates. - Last mass extinction - Palaeocene-Eocene Thermal Maximum occurred 55millionyearsago - No idea of how many species exist on Earth. Only a fraction (~1.5 million of an estimated 5 million) have been formally described, and even fewer assessed for their conservation status. - How do we conserve what we don't know exists? - IUCN Red List of Threatened Species notes that 36% of the 47,677 species assessed are threatened with extinction
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What are the benefits that humans derive from ecosystems?
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- Dubbed "ecosystem services" - breathable air - fertile soils - productive forests and fisheries - cultural benefits such as recreational hunting or inspirational values. Such ecosystem services are obtained only if ecosystems include the biodiversity that guarantees the functional processes necessary to deliver them.
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How do populations go extinct?
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Examples include: - Effects of Habitat Change Wallabies in Australia - Effects of introduced predators Lord Howe woodhen/Stephen Island Wren - Side effects of pest control Black footed ferret - Effects of poorly controlled commercial hunting Musk oxen in Canada - Effects of unregulated recreational hunting Arabian Oryx - Effect of competition with introduced species Hawaiian birds - Effect of Environmental contaminants Californian condors
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What is the notion of "land sickness" suggested by Aldo Leopold?
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referring to the breakdown of regional terrestrial (and aquatic) ecosystems to whole landscapes by human activities.
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What is a healthy ecosystem identified as?
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"Sustainable and stable state of ecological systems capable of maintaining organization, autonomy and resistance to stress"
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What is a unhealthy ecosystem characterised as?
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"Identified that stressed ecosystems are characterized by reduced biodiversity and altered primary and secondary productivity but also by increased disease prevalence, reduced efficiency of nutrient cycling, increased dominance of exotic species, and increased dominance by smaller, shorter-lived opportunistic species"
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What is Ecosystem Distress Syndrome?
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- How we determine if an ecosystem is struggling - A high prevalence of diseases is one of the key indicators of the pathology of ecosystems, and a sick ecological system increases the health risks of its components. - ...a collection of symptoms signaling that an ecosystem is being pushed to its limits. EDS indicates the transformation of an ecosystems into something different, usually something less productive, something less useful to humans.
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Give examples of what is happening with EDS:
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- Biological impoverishment: loss of biodiversity & disruption of ecological processes - Global toxification: contaminants, hazardous waste and endocrine disruptors - Global climate change/ ozone depletion - Human ecological footprint expands as a result of population growth - Overloaded air - clarity, ozone, chemicals, effects on plant growth & wildlife health, etc. - Overloaded water - loss of wetlands, decreased water quality, sediments, contaminants, decreased health of organisms - Overloaded soils - loss of biodiversity & productivity of communities, loss of functions of soil (absorption, transformation & recycling), erosion (affects water) - - septic systems, storm drains, pavement effects - Loss of biodiversity - shift in dominance of biota from the larger, longer-lived life forms that are specialists in their food requirements to smaller, shorter-lived forms that are generalists - Loss of biological productivity as a consequence
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To what extent is habitat modification leading to big problems in biodiversity?
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- 83% of the earths land surface has been transformed by human activity - About 60% of the earths ecosystems are considered degraded or used unsustainably - 20% of coral reefs have been destroyed and 20% degraded - Of the threatened spp 80% mammals and 60% of birds have suffered declines ass with habitat loss Note: In biodiversity hotspots - there is time lag between loss of habitat and loss of species
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How is habitat modification leading to affects on biodiversity?
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- Agriculture *Crops, wood plantations, livestock, aquaculture - Extraction *Mining, fisheries, wood, coral removal, ground water extraction - Infrastructure development *Industry, human settlement, transportation, dams, tourism, recreation, telecommunications - Pollution *Atmospheric, Land, Water - Biotic Changes *Invasive species, change in native spp dynamics
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What is one of the most significant modes of habitat modification when it comes to loss of biodiversity?
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Land clearance for agriculture purposes Note: 50% of forests and woodlands that existed at the time of European settlement have been cleared for agriculture and structure of biotic composition of large proprotions of other types of vegetation have been modified
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What is the principal cause of land degradation in Australia?
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Agriculture - >50% of Australian continent suffers from various forms of land degradation ie: *soil erosion by wind and water * salinity * decline of soil structure * vegetation degradation
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What has affected habitats in the Adelaide area since it was colonised around 1836?
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- Habitat affected - Introduction of hunting - Clearing of habitat Over grazing - New diseases Introduced predators
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How have mammals in the Adelaide area been affected by loss of habitats following colonisation?
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- 50% of mammal species extinct - Most susceptible - critical weight range - 35g-5.5kg 40sp before 1836 - now 20sp - 11 introduced spp - 1836- 1840 - pigs and cats arrived - 1858-1860 - rabbits and foxes arrived - By 1909 spotted tailed quoll gone - By 1923 eastern quoll gone - 10 years before foxes - ?disease - By 1931 12 species were gone - 1sp every 4y - 1931 Koala introduced
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Why are birds considered to be a "biodiversity indicator"/extinction debt?
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- Action now leads to extinction later
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How did birds fare when it came to habitat changes in adelaide following colonisation?
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- Fared much better than mammals - 18% of birds are now considered threatened - 1836 - 285sp - 2002 - 21spp gone - - 7% Introductions - competition - 1868- starling, goldfinch and skylark - 1885 - sparrow, blackbird, feral pigeon Losses - By 1959 - Glossy black cockatoo , Square tailed kite 1959-2002 - 15more spp gone incl swift parrot
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Which mammal spp have been lost from the Adelaide area?
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Brush tailed and Burrowing bettong Brush tailed phascogale Common and Southern hairy nosed wombat Dingo Eastern and Spotted tailed quolls Fat tailed dunnarts Feathertail glider Bilby Numbat Platypus Tammary Wallaby and Euro Western barred bandicoot Western pygmy possum
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How have reptiles in the Adelaide area fared?
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56spp in 1836 and now but some have come and gone - Skinks commonly seen - Goanna vulnerable - heath and sand - Pygmy blue tongue skink - gone
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Define exotic:
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Introduced to the local area
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Define endemic:
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Found in the local area and not found anywhere else
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Define native:
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Found in Australia but may be elsewhere
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How does invasive species and range expansion affect biodiversity?
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- Introduced animals implicated c 40% of historic extinctions global and they continue to threaten wildlife species with extinction - Drive population decline through predation, competition, disease - The extinction of many Australian mammal spp and pop decline currently threatened are usually directly or indirectly associated with introduced animals (fox, cat) and herbivores (rabbit, other introduced browsers and grazers and livestock) - Habitat destruction is the primary threatening process BUT threatened species in decline can be driven to extinction by introduced animals
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How has the galah benefited from changes in the environment brought about by human activities?
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- Benefited from changes in environment brought about by human activities - Seed eater - Expands most of continent - In 18th C - near watercourses - Expansion due to * Clearing of land for agriculture * Provision of dams * Establishment of pasture crops * Use trees where there are remnant populations ie. even though galahs were a native species, changes in the landscape has caused them to become a pest
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How have galahs had negative consequences on other species?
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- Very aggressive and competitive for nesting sites ie. * Glossy black cockatoo in KI * YTBC in Eyres Peninsula * WTBC in WA
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How do camels cause damage to infrastructure?
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- Damage fences and infrastructure at cattle watering points, particularly bull camels during rut - Damage houses seeking water - Damage waters of cultural significance - Collision risk - railways and highways (2 human deaths in 2008, Darwin Alice Springs railway blocked for 24 hours in 2006).
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How have camels damaged native vegetation?
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- Selectively consume some rare plant species: Santalum acuminatum (quandong) S. lanceolatum (plumbush) Pittosporum augustifolium (native apricot) Ventilago viminalis (supplejack) Acacia sesiliceps (curly pod wattle) Erythrina verspertilo (bean tree) - Tear down branches up to 10 cm diameter and exfoliate some shrubs - Congregate around salt pans and cause tramping damage e.g. to Swainsona microcalyx
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How have camels caused loss of pastoral production in Australia?
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- Competition with cattle *Food * Water - Fouling waterholes - Disturbance to cattle - Escape of cattle (damaged fences and yards) - Damage to dog fence - Estimated $3.4 million
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How has over exploitation and trade lead to a loss of biodiversity?
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- A significant factor that has driven pop declines and species extinction - Often linked synergistically to other human induced threatening processes - Most countries that biodiversity rich are often developing countries and have levels of poverty - Both livelihood and survival of the rural poor on wildlife trade - Difficult to quantify - Wildlife trade produces goods incl food, 'medicine', ornaments, pets etc - In addition, there can be effects on non target spp and some animals can be introduced into new regions - Some of the trade is legal in most countries, but some is illegal - Second only to the narcotics trade
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How is over exploitation and trade not being recognised and accounted for by current economic systems?
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- Current economic systems fail to recognise and account for the exploitation of the environment and 'natural capital' - The destruction of nature is often seen in terms of profit when in fact the continued erosion of natural capital is likely to lead to ecological collapse and consequently collapse of the market systems that have relied upon it - Globalisation has had a large impact on the worldwide animal trade. - The worldwide movement of animals has increased the potential for the translocation of zoonotic diseases, which pose serious risks to human and animal health. - Almost 38 million live amphibians, birds, mammals and reptiles were legally imported into the USA from 163 countries between 2000 and 2004
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Which species are most commonly overexploited?
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- Most overexploited species or groups of species are marine fish and invertebrates, trees, animals hunted for bushmeat, and plants and animals harvested for the medicinal and pet trade - Wet markets and the demand for bushmeat in many parts of the world, especially in Southeast Asia and Africa, are a major source of emerging zoonoses. - Illustrated by outbreaks of Ebola virus in Western Africa and highly pathogenic avian influenza in Asia. - In Africa, the bushmeat trade generates hundreds of millions of dollars. **public health concern**
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How is climate change impacting biodiversity?
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- Unprecedented rates of climate change and global warming currently associated with human activities - Global warming has affected species geographical distributional ranges and timing of breeding, migration and flowering - Estimated that 18-35% of plant and animal species will be committed to extinction by 2050 due to climate change
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What is the current rate of human induced warming?
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- RAte of warming 0.2-0.6C per decade - Compare this with the average change from 15-7000 years ago that was approx 0.005 per decate. - A low range optimisitc estimate of 2C in the 21st century will shift the Earths global mean surface temp into conditions which have not existed for 3 million years
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Which country is responsible for the releasing the largest amounts of greenhouse gases?
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Per capita - Australia (large proportion associated with agriculture)
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What effects do changes in climate have?
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- Changes in the climate thorough its affect on temperature, rainfall patterns, water balances and extreme climatic events (El Nino South Oscillation and La Nina events) directly affects the environmental processes of the ecosystems of wild animals and plants. - Climate directly influences the distribution ranges of animals and plants and the ability of them to survive in geographic regions - There will be shifts in vegetation and many ecosystem will not be able to support wildlife in the future - Biotic communities have adapted to changes in climate in the past, but the rapid rates of change may exceed the capabilities of many spp to adapt to changing ecosystems - Climate change has important implications for the inevitable effects associated with disruption to human popn, on the vectors of disease and on the conservation of biodiversity
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How is coal an issue when it comes to climate change?
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- Coal = most carbon dense of all fossil fuels, produces more Co2 than electricity generated from oil or gas - Emissions from renewable sources, such as hydroelectricity, nuclear energy, solar, and wind are roughly 100 x lower again - China gets most of its coal from Australia - No single commercial coal fired generating plant in the entire world is removing CO2 from its emissions
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How is environmental contamination related to loss of biodiversity?
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- Environmental contaminants have been proven to cause popn decline - Organochlorine pesticides caused egg shells to thin, which affected Peregrine falcon popns in 60s (Cumulative affect in the food chain) - May predispose animals to disease by reducing immune systems and lowering disease resistance - Pollutants cause endocrine disruption affecting reproductive success and survival of wildlife popn
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How are the Gyps vultures an example of how environmental contamination can relate to loss of biodiversity?
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- Three Gyps spp in India (originally 40 million) * White backed vulture G bengalensis * Long billed G indicus * Slender billed G tenuirostris - All are scavengers and were seen in huge numbers, providing an essential role in clearing carcuses. - An initial decline was noted in 1999, with subsequent decline over 99-03 (down to 60k) - Effects on ecosystem were huge: * changes to ecosystem due to carcase accumulation, unhealthy ecosystem * increase in feral dogs with concomitant increase in rabies * now india has highest rate of rabies in people in the world * water contamination * spread of diseases ie Anthrax, FMD, TB - Cause of the decline was found to be: * A veterinary & human NSAID causing visceral gout & toxicity - no signs of infection * Diclofenac detected in tissues of the dead birds (used in humans since the 70s, widely & cheaply available in India and beyond as as a veterinary drug, commonly used in ruminants, potential for lethal levels to be consumed by a vulture in one sitting * Computer model showed that 1 in 250 carcases with residues would lead to decline observed
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What solutions were proposed to halt the decline in vulture numbers in India?
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- In may 2006, the Indian government ordered a halt to the production and sale of the vet drug diclofenac within 3 months - An alternative drug Meloxicam was found to have no adverse rxn in vultures - Increase rabies vax in people and dogs - Dsex dogs - Remove dogs but who scavenges? - Save the rest of the birds by captive breeding --> insurance popn, release and monitor wild popn
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How does inbreeding lead to loss of genetic diversity?
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Inbreeding of related individuals may result in more recessive deleterious traits manifesting themselves in offspring
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What are the effects of inbreeding?
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- Reduced fertility both in litter size and sperm viability - Increased genetic disorders - Fluctuating facial asymmetry - Lower birth rate - Higher infant mortality - Slower growth rate - Smaller adult size - Loss of immune system function
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How does inbreeding depression affect popn?
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- Inbreeding depression resulting in reduced fitness is often considered as a factor in driving population decline - Many threatened species have low genetic diversity but difficult to work out how this might have an effect on population - Loss of reproductive capacity associated with inbreeding depression in some koala populations - Inbreeding depression is not a phenomenon that will inevitably occur - Given enough time and a sufficiently small gene pool, deleterious alleles may be eliminated by natural selection and genetic drift.
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How is is inbreeding depression thought to be demonstrated in the captive cheetah?
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- Cheetah shows low genetic diversity in captivity - Survey of 16 litters shows that more inbreeding = lighter birth weight = higher mortality rate - Higher susceptibility to Feline herpes virus and FIP (50%-60%) - However this is not seen in the Wild cheetah, so may not be an inbreeding depression more a manifestation of captive popn
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How do introduced, emerging and reemerging pathogens cause popn decline?
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- Diseases such as Kakapo, Distemper virus (lions) , Feather and Beak disease, Chytridiomycosis have been shown to cause decline in a number of endangered spp - Disease can pose a threat to declining popns that in trouble due to other threats and may be final factor dirving spp to extiction - Introduced diseases can have serious impacts on naieve populations - Warming in recent decades has caused latitudinal shifts of vectors and diseases is supported by lab and field studies showing that arthropod vectors and parasites die or fail to develop below threshold temps, rates of vector repro, popn growth and biting increase (to a limit) with increasing temp and parasite development rates and period of infectivity increase with temp
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How did distemper virus affect the lion population in the Serengiti?
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Spillover of Distemper virus to the wild carnivores from domestic dogs introduced by the local communities surrounding the park.
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How did distemper virus affect the lion population in the Serengiti?
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Spillover of Distemper virus to the wild carnivores from domestic dogs introduced by the local communities surrounding the park.
