3.2 Human Impact on Biodiversity (DP IB Environmental Systems & Societies (ESS): SL): Flashcards
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Define overharvesting.
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Cards in this collection (56)
Define overharvesting.
Overharvesting is the harvesting of a species at a rate faster than its natural reproduction, leading to population decline.
Which fish population in the North Sea collapsed due to overharvesting?
Atlantic cod in the North Sea collapsed due to overharvesting.
True or False?
Overharvesting is classified as an indirect threat to biodiversity.
False.
Overharvesting is classified as a direct threat, along with poaching and the illegal pet trade.
Define poaching.
Poaching is the illegal hunting or capturing of wildlife, often for trade or consumption.
Poaching for ivory has caused a decline in which species?
Poaching for ivory has caused a decline in African elephant populations.
True or False?
Habitat loss is classified as a direct threat to biodiversity.
False.
Habitat loss is classified as an indirect threat to biodiversity.
Which human activity is a major cause of rainforest habitat loss in the Amazon?
Clearing of rainforest for cattle ranching is a major cause of habitat loss in the Amazon.
How does climate change threaten species such as polar bears?
Climate change threatens polar bears through the melting of polar ice caps, which destroys their habitat.
Define invasive alien species.
An invasive alien species is a non-native species introduced into an ecosystem that disrupts native species and ecosystems.
Which invasive plant species in the UK outcompetes native plants and damages buildings?
Japanese knotweed outcompetes native plants and damages buildings in the UK.
Why do grey squirrels threaten native red squirrels in the UK?
Grey squirrels outcompete red squirrels for resources and carry squirrelpox, a virus fatal to red squirrels but harmless to greys.
In the UK grey squirrel case study, culling programmes aim to reduce grey squirrel numbers and protect .
In the UK grey squirrel case study, culling programmes aim to reduce grey squirrel numbers and protect red squirrels.
Define cumulative effects.
Cumulative effects occur when negative impacts on an ecosystem are amplified because multiple threats act together, reducing its resilience.
In the coral reef example, how do overfishing and climate change combine to threaten the ecosystem?
Overfishing weakens the reef's resilience to coral bleaching caused by climate change, making ecosystem collapse more likely.
Define IUCN.
The IUCN (International Union for Conservation of Nature) is the global authority on the status of the natural world and the measures needed to safeguard it.
What does the IUCN publish that lists the conservation status of species worldwide?
The IUCN publishes the IUCN Red List of Threatened Species.
Why does assigning a global conservation status to a species matter?
It publicises a species' vulnerability, helping governments, NGOs and individuals select appropriate conservation priorities and strategies.
True or False?
Species in higher trophic levels are usually at a lower risk of extinction than those in lower trophic levels.
False.
Animals in higher trophic levels are usually at a greater risk of extinction.
Define endemicity.
Endemicity is the degree to which a species is only found in a single specific area.
A smaller population size usually puts a species at a risk of extinction.
A smaller population size usually puts a species at a greater risk of extinction.
What does a species' "breeding potential" refer to in a conservation status assessment?
Breeding potential refers to a species' reproductive potential and behaviour.
How does habitat fragmentation affect a species' conservation status?
A greater degree of habitat fragmentation increases a species' risk of extinction.
What does the IUCN category "CR" stand for?
"CR" stands for critically endangered.
What is the difference between the IUCN categories "EW" and "EX"?
"EW" means extinct in the wild (survives only in captivity), while "EX" means extinct (no individuals remain anywhere).
What does the IUCN category "DD" mean?
"DD" means data deficient: there is not enough data to assign the species a conservation category.
True or False?
The IUCN has evaluated the extinction risk of over half of the world's described species.
False.
Extinction risk has been evaluated for less than 5% of the world's described species.
Roughly how many species had been assessed by the IUCN by 2023?
By 2023, the IUCN had assessed just under 160,000 species.
Which North American bird, once numbering in the billions, was driven to extinction by overhunting and habitat destruction?
The passenger pigeon was driven to extinction by overhunting and habitat destruction.
Define Ectopistes migratorius.
Ectopistes migratorius is the scientific name for the passenger pigeon, once one of the most abundant birds in North America.
The passenger pigeon went extinct in .
The passenger pigeon went extinct in 1914.
What was the Thylacine, also known as the Tasmanian Tiger?
The Thylacine (Tasmanian Tiger) was a carnivorous marsupial native to Tasmania, driven extinct by hunting, habitat loss and disease from introduced species.
True or False?
The last known Tasmanian tiger died in the wild in 1936.
False.
The last known Tasmanian tiger died in captivity in 1936.
What are the primary causes of the Sumatran orangutan's decline?
The Sumatran orangutan's decline is primarily caused by habitat destruction from logging and agriculture, and by illegal hunting for the pet trade.
Roughly how many Sumatran orangutans remain in the wild?
Roughly 14,000 Sumatran orangutans remain in the wild.
Define Diceros bicornis.
Diceros bicornis is the scientific name for the black rhinoceros, a critically endangered mammal native to Africa.
What has caused the black rhinoceros to become critically endangered?
The black rhinoceros is critically endangered due to poaching for its horn, habitat loss, and civil unrest across its range.
The black rhinoceros population has declined by over % since the 1960s.
The black rhinoceros population has declined by over 90% since the 1960s.
Name a conservation strategy being used to try to save the black rhinoceros.
Conservation strategies for the black rhinoceros include anti-poaching patrols, habitat restoration and captive breeding programmes.
Which conservation interventions helped the Southern white rhinoceros recover from the brink of extinction?
Increased law enforcement, habitat protection and captive breeding programmes helped the Southern white rhinoceros recover.
True or False?
The Southern white rhinoceros population has fully recovered and faces no remaining threats.
False.
Although its population has recovered to over 18,000, the Southern white rhinoceros is still threatened by poaching and habitat loss.
Which harmful pesticide, linked to eggshell thinning in bald eagles, was banned as part of their recovery?
DDT was banned as part of the bald eagle's recovery.
About how many bald eagle breeding pairs existed in the 1960s, before conservation intervention?
There were fewer than 500 breeding pairs of bald eagles in the 1960s.
Thanks to conservation efforts, the bald eagle population has recovered to over breeding pairs today.
Thanks to conservation efforts, the bald eagle population has recovered to over 10,000 breeding pairs today.
Define the tragedy of the commons.
The tragedy of the commons describes the overuse and depletion of a shared resource that occurs when individuals act in their own self-interest rather than the common good.
What is the ultimate consequence of the tragedy of the commons for a shared resource?
It leads to the degradation of the resource, making it unavailable for future use.
True or False?
The tragedy of the commons only applies to the overharvesting of natural resources.
False.
It also applies to the contamination and degradation of ecosystems by human activity, such as pollution.
How can overexploitation of natural resources threaten ecosystems?
Resources are used faster than they can be replenished, leading to resource depletion and potentially ecosystem collapse.
What effects can the tragedy of the commons have on biodiversity?
It can cause the loss of habitats and species, and reduce genetic diversity, weakening ecosystem resilience.
Which fish stock collapsed on the Grand Banks off Newfoundland due to overfishing?
Cod stocks collapsed on the Grand Banks off Newfoundland due to overfishing.
What factors contributed to the collapse of cod stocks on the Grand Banks?
Intensive fishing by local and international fleets, using advanced technology with no effective regulation, caused the collapse.
True or False?
Cod stocks on the Grand Banks have fully recovered to their historical levels following fishing moratoriums.
False.
Despite strict regulations and moratoriums, cod stocks have recovered slowly and remain well below historical levels.
Overfishing on the Grand Banks caused the of the region's fishing industry.
Overfishing on the Grand Banks caused the economic collapse of the region's fishing industry.
Which ocean gyre is home to the Great Pacific Garbage Patch?
The North Pacific Gyre is home to the Great Pacific Garbage Patch.
Why is plastic debris in ocean gyres such a persistent problem?
Plastics are non-biodegradable and persist in the environment for hundreds of years.
How does plastic pollution enter the marine food chain?
Plastic debris breaks down into microplastics, which enter the food chain.
True or False?
Marine animals are unaffected by ingesting plastic debris.
False.
Marine animals that ingest plastics can suffer injury and death.
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