A4.2 Conservation of biodiversity Flashcards

Question

When was the first sighting of the Carribbean monk seal? And what did it lead to?

Answer 1

The first sighting of these mammals is recorded in accounts of Christopher Columbus in 1494. Record goes on to state how sailors killed eight seals resting on beach. An account from 17th century describes how fishermen killed hundreds of seals every night to fuel oil lamps & grease machinery. In less than 600 years, Caribbean monk seals had become extinct.

Answer 2

Caribbean monk seals were relentlessly hunted in 18th & 19th centuries for their blubber & other products. Docile & non-aggressive nature of these mammals whose only natural predators were sharks, made hunting easy. In addition, overfishing in waters where they lived, meant that these animals fell short of food sources like fish & molluscs. Deprived of their natural food, many individuals in an already declining population starved to death. Last sighting of the animal was in 1952.

Answer 3

Splendid poison frogs (Oophaga speciosa), last spotted in wild in 1992, were declared extinct in 2020. With their bright colours serving as a warning to predators of their toxicity, these small frogs were once widespread in humid forests of Panama.

Answer 4

One of reasons attributed is a reduction in their geographic range due to activities such as logging, conversion of forests for agriculture & expansion of urban areas. Degradation & loss of their natural habitats led to a decline in pop of frogs. In addition, these frogs were trafficked as part of ‘pet’ trade. Death knell for already declining pop was outbreak of a fungal disease that had been ravaging amphibian pop in tropics.

Answer 5

To sum up, the sixth mass extinction is under way and characterised by an extinction rate far higher than before, unprecedented in the Earth’s history. The case studies point to humans as the primary drivers of the sixth mass extinction. We need to act quickly and with intensity to slow or stop extinctions

Answer 6

Human activity has led to decline & destruction of ecosystems. When entire ecosystems collapse, species dependent on ecosystem are driven to brink of extinction.

Answer 7

Healthy ecosystems have many benefits often referred to as ecosystem services such as: - supplying resources, including water, food, timber and medicines - providing basic services essential for survival, e.g. decomposition of waste, flood control, prevention of erosion, storage of carbon, climate regulation, nutrient cycling, formation of soils, water cycle, etc

Answer 8

The processes and outputs of the ecosystem that directly or indirectly benefit humans.

Answer 9

Mixed dipterocarp forests of southeast Asia are tropical rainforests. Dominant species of trees seen in these forests belong to family Dipterocarpaceae. Deriving its name from its two-winged fruit, Dipterocarpaceae includes nearly 695 species of trees ranging in size from shrubs to towering trees that emerge from the canopy.

Answer 10

Dipterocarps are keystone species, essential for ecosystem services & functions bc: - they support a number of other forms of life - their leaves, fruits and seeds are food sources for many herbivores - decomposition of their falling leaves enriches the forest floor - their roots hold the soil - they provide a home to many forms of life including arboreal animals, birds and epiphytic plants - their canopy forms a large portion of the total canopy, sheltering the underlying layers from the torrential rain - they lock up large amounts of carbon, and so help in capturing and storing atmospheric carbon dioxide and hence, help fight climate change.

Answer 11

Unfortunately, these forests are under threat. Trees are highly prized for their timber & are extensively felled. This has driven many dipterocarp species to brink of extinction. Yet another threat is clearing of forests for palm oil plantations. Palm oil trees (Elaeis guineensis) were brought to southeast Asia by Europeans. Planting of palm oil trees has led to deforestation & clearing of massive tracts of rainforests. Often, to clear forests, stretches are burned down releasing carbon into atmosphere.

Answer 12

Destruction of these forests means that already endangered animals such as elephants & orangutans are losing their homes. Thus, destruction of dipterocarp forests has far-reaching consequences, not only for life they support but also for humans.

Answer 13

Coral reefs found below ocean surfaces, are one of Earth’s most diverse ecosystems & are often called rainforests of the sea. Reefs are home to nearly 25% of world’s marine species, including fish, reptiles, crustaceans & seaweeds. Coral reefs are colonies of coral polyps, with their exoskeletons forming reefs. Symbiotic algae live in tissues of these polyps & give coral its colour

Answer 14

Reefs provide a myriad of benefits: - they sustain food webs - provide food for people - are sources for new medicines - protect coastline from erosion & storms.

Answer 15

However, coral reefs are under great stress & many species of corals are endangered. Threats to reefs include: - pollution, including nutrient-rich fertiliser runoff, hot water from power plants, rubbish, plastic, oil spills - destructive fishing activities e.g. overfishing & use of explosives & cyanide - loss of natural habitat due to coastal development - unsustainable tourism where careless divers damage coral reefs - climate change results in rising ocean temperatures & ocean acidification due to increased absorption of carbon dioxide. This in turn causes corals to expel their algae, leading to bleaching (or whitening) of coral reefs

Answer 16

Bleaching of corals impacts their viability as it stunts their growth & leaves them vulnerable to disease. It also affects other species that depend on reefs. Although coral reefs can recover from bleaching, this takes at least 10–15 years provided environmental conditions improve

Answer 17

- IPBES - IUCN - Contributions by expert scientists and citizen scientists - The Horseshoe Count - Biodiversity surveys

Answer 18

Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) = intergovernmental organisation established by UN to assess & strengthen biodiversity & ecosystem services. IPBES Global Assessment Report On Biodiversity and Ecosystem Services was released in 2019. Report has been compiled by 145 expert authors from 50 diff countries over 3 yrs & states that over a mn plant & animal species are threatened with extinction

Answer 19

IUCN (International Union for Conservation of Nature) looks to address challenges in conserving nature & natural resources. Work of IUCN is supported by NGOs, indigenous peoples’ organisations, volunteer scientists & experts. IUCN Red List of Threatened Species & IUCN Red List of Ecosystems are conservation tools as they seek to assess current status & inform conservation action & policy. IUCN Red List of Ecosystems is a global standard for assessing conservation status of ecosystems. Based on assessments & reassessments of species, IUCN Red List of Threatened Species has nine categories: Extinct (E), Extinct in Wild (EW), Critically Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT), Least Concern (LC), Data Deficient (DD) & Not Evaluated (NE). IUCN Green Status of Species, a part of IUCN Red List, measures conservation success of species.

Answer 20

Besides scientists, contributions to science can also come from general public. Citizen science refers to research conducted with help of general population who aren't professional scientists. Research is often conceived & designed by expert scientists but executed with involvement of interested citizens. Expert scientists provide relevant information about study & methods for data collection. This is used by citizen scientists to gather data. Expert scientists then work with these data to answer their research questions.

Answer 21

Every spring, millions of horseshoe crabs (Limulus polyphemus) migrate to Delaware Bay Shore for spawning. Fossil records indicate that this has been taking place for around 350 million years. Crab spawn is also an important food source for several migratory birds e.g. red knot. Spawn is also used as bait by fishing industry & for medical purposes. To prevent spawn overharvesting, it's vital to undertake a census to understand number of crabs. This census data are then used to limit number of horseshoe crabs harvested for human use. Annual survey is undertaken by volunteers (citizen scientists) who are specially trained to distinguish between male & female crabs & in data recording.

Answer 22

Biodiversity surveys provide valuable info to decision-makers regarding use of resources & species conservation. These usually take place within a defined area & are repeated to get a better understanding of biodiversity. Repeated surveys give info about species richness & evenness, which helps experts understand changes taking place within a community.

Answer 23

Human pop grew exponentially from 1-7 bn in just 200 years. In 2011, human pop = 7 bn & in November 2022, it reached 8 bn

Answer 24

This rapid increase in pop has widespread implications. As pop grows, demand increases for resources including food, water & space. This increasing pressure for resources leads to overexploitation of natural resources & habitat destruction. This, in turn, adversely impacts biodiversity. Current rate of extinction is 100 to 1000 times higher than past, leading to a biodiversity crisis

Answer 25

Overexploitation = overuse of natural resources at rates faster than they can be replenished

Answer 26

Overhunting has led to decline & even extinction of many species. E.g. hunting of Bengal tiger for both sport & for their body parts has led to a drastic decline in their pop & extinction of three subspecies. Although these animals are now a protected species, poaching & habitat destruction further dwindles their pop. Other examples where hunting has led to species being declared threatened include elephant, bison & black rhinoceros. Today, while many countries ban hunting & have stringent policies for protecting endangered species, illegal hunting (poaching) continues.

Answer 27

As demand for space increases, more & more of natural habitats are lost. When habitats change drastically, species adapted to life in these habitats can no longer survive there. E.g. deforestation or clearing of forests for agriculture, damming of rivers & filling of wetlands bring irrevocable changes in habitat

Answer 28

Division of a large continuous habitat into smaller non-contiguous areas.

Answer 29

Urbanisation encroaches on existing natural habitats & can fragment them into smaller habitats. E.g. laying of railway lines through a natural habitat, fragments area into smaller isolated patches. This, in turn, restricts animal mobility, reduces access to resources & increases the risk of extinction. One solution to this is building corridors for safe passage of animals.

Answer 30

As humans colonised diff regions of Earth, they introduced new species either accidentally or deliberately to these environments. These introduced species become invasive alien species when they disrupt existing food chains, reproduce quickly, spread aggressively & outcompete endemic species.

Answer 31

Japanese knotweed, Reynoutria japonica was introduced into ponds of Europe as an ornamental plant.

Answer 32

Pet Burmese pythons were introduced into Everglades of Florida. At top of food chain, pythons feed on local species, ill-equipped to handle these new predators. This has led to a reduction in pop of local species

Answer 33

Global transport has also introduced pests as well as diseases to native species. As consumer demand increases, live animals including goats, sheep, pigs and cows or refrigerated products are transported across world. However, this increases risk of disease transmission. In another example, global trade in amphibians has led to spreading of a fungus native to southern Asia. This in turn has caused a decline in amphibian pop across world. Spread of diseases isn't restricted to animals. Chestnut blight in chestnut trees is caused by a fungus that was present in nursery stock exported to USA from Asia. Common pests that have been transported across globe include cockroaches & rats. While regulatory mechanisms may be in place, chances of transporting pests or their eggs & disease-causing pathogens remain high.

Answer 34

Pollution is one of leading causes of biodiversity loss. Pollution is intro of substances into environment that adversely affect environment. Pollution can take form of air, water & land pollution. Some causes of pollution are outlined below.

Answer 35

Release of sulfur dioxide & nitrogen oxides (a combination of NO and NO2) from industries into air results in acid rain (Rain that becomes acidic due to air pollution, usually presence of oxides sulfur & nitrogen), which has a detrimental effect on plant & animal lives.

Answer 36

There is more info about how pollutants released into water often enter food chain resulting in biomagnification & affecting consumers in.

Answer 37

Accumulation of plastic across habitats is one of biggest threats to biodiversity. Plastic in oceans is often ingested by seabirds & marine turtles. For threatened species like Hawaiian monk seals, plastic pollution pushes them further down path of extinction.

Answer 38

Dumping of rubbish not only pollutes environment, but also can be a breeding ground for pests like flies, cockroaches, rats & mice.

Answer 39

Conservation is protection & sustainable use of resources we have. Conservation biology looks at maintenance of biodiversity by protecting species & their ecosystems. Conservation of biodiversity requires a multi-pronged approach. Diversity in species necessitates that diff measures be taken to conserve diff species

Answer 40

On-site or in situ conservation is a way of conserving animals & plants in their natural habitats while maintaining original biodiversity of area. In situ conservation involves designating, managing & maintaining areas for protection of plant & animal species.

Answer 41

National parks & wildlife sanctuaries are protected terrestrial areas, while marine reserves conserve marine species & habitats. Nature reserves are areas smaller than national parks & protect a particular habitat and/or plants & animals, often declared as endangered. Human activity in these areas is strictly regulated. Responsible tourism, such as conservation safaris, in these areas helps to generate funds that contribute to their maintenance as well as increasing public awareness.

Answer 42

In situ conservation conserves plant or animal species & their habitat. It allows species to continue living in habitat to which they are adapted, preserves their normal behaviour (in case of animal species) & prevents disruptions of food chains. Thus, in situ conservation is less disruptive & more cost-efficient

Answer 43

Off-site or ex situ conservation, plants & animals are conserved outside their natural habitats. Ex situ conservation techniques vary & include zoos, botanical gardens & aquariums.

Answer 44

In some species numbers are too small to sustain species or risk of poaching is high. In these cases, scientists establish gene banks to store ‘biodiversity’, which involve storage of germplasm (or genetic resources). These collections of living material include animals in zoos, plants in botanical gardens, seeds, sperms, eggs, pollen, DNA collections & so on.

Answer 45

Seed banks dehydrate & cool seeds prior to storage. One such example are seed banks created to store original wild strains of food crops such as rice in an effort to conserve their genetic info.

Answer 46

Tissue banks, e.g. DNA & Tissue Bank at Kew, England, store tissue samples from plants

Answer 47

Zoos maintain multiple species of mammals, birds, reptiles & amphibians while botanical gardens conserve plants

Answer 48

Captive breeding = conservation technique for preventing extinction of species whose populations are small, often fragmented & on verge of extinction. Animals in zoos or other places are encouraged to breed & then reintroduced into wild. However, one of major drawbacks of technique is that small pop inherently have a lower genetic diversity & thereby chances increase of passing on unfit genes.

Answer 49

One successful example of this is the Arabian oryx (Oryx leucoryx). Oryx, a type of antelope, became extinct in wild in 1972; however, antelopes existed in zoos. Captive breeding followed by ‘training’ animals for release ensured that species could be released back into wild.

Answer 50

Rewilding = conservation technique by which wildlife & natural processes are allowed to reclaim areas, bringing back biodiversity. In other words, habitat is restored to what it would have been if human disturbance had not happened. Rewilding happens with human intervention as plant & animal species that have disappeared from habitat are reintroduced. This, in turn, helps to rebuild ecosystems. Rewilding Institute run rewilding programmes & initiatives in this area.

Answer 51

Unsustainable human activity often causes a degradation of land & water. Loss could be due to erosion of soil, deforestation, salination...

Answer 52

Land restoration strategies look at recovering & reclaiming degraded ecosystems. Studies have shown that land restoration & management with support from local communities & indigenous people yields higher results as they have a deep knowledge of land. Forests are being restored across world through programmes that engage local communities.

Answer 53

EDGE = Evolutionarily Distinct and Globally Endangered. EDGE of Existence was launched by Zoological Society of London in 2007 as a conservation programme to prioritise conservation of evolutionarily distinct & endangered species. Most poorly known or neglected EDGE species are often selected to prevent them from silently disappearing from face of Earth.

Answer 54

The EDGE species: - are often only surviving members of their genus or even higher taxa - are unique in their appearance, behaviour & genetic makeup - have a unique evolutionary history - are globally endangered

Answer 55

The species are selected according to their: - Evolutionary Distinctiveness (ED) score. ED score is determined by position of the animal on phylogenetic tree. ED scores are higher for species that are evolutionarily more distinct or have fewer closer relatives. - Globally Endangered (GE) score. This is calculated based on IUCN Red List. More endangered species, higher GE score. E.g. critically endangered species have a higher score than endangered species or vulnerable species. Two scores are then combined to produce EDGE score for a species. Higher than average EDGE values indicate that species is threatened with extinction.