What is fish farming?
Enjoying Flashcards?
Tell us what you think
What is fish farming?
Fish farming is the practice of raising large numbers of fish in confined enclosures for commercial purposes, primarily to provide food for human consumption.
How does fish farming help to address the issue of overfishing?
Fish farming helps to address overfishing by providing an alternative source of fish protein that reduces the need for wild-caught fish and so reduces the pressure on wild fish populations.
What are the environmental impacts of fish farming?
Environmental impacts of fish farming include:
waste from fish can contaminate surrounding water, leading to eutrophication
parasites and infection can spread from farmed fish to wild fish
fish farms may attract predators and disrupt local food webs
What is a non-indigenous species?
A non-indigenous species is one which is not native to a particular area.
How can non-indigenous species be introduced to an area?
Non-indigenous species can be introduced to an area as follows:
released on purpose, e.g. as a biological control
captive species may escape into the wild
species may be accidentally transported, e.g. by ship
What are some of the negative effects of introducing non-indigenous species?
The negative effects of introducing non-indigenous species include:
increased competition
new predators or prey species introduced to food webs
new diseases
True or False?
Introducing non-indigenous species increases biodiversity.
False.
Introducing non-indigenous species usually results in a decrease in the biodiversity of a habitat.
Define the term eutrophication.
Eutrophication is the process by which increased nutrient availability in a body of water leads to a decrease in dissolved oxygen levels.
Which human activities can contribute to eutrophication?
Human activities that can lead to eutrophication include:
use of chemical fertilisers which run off into nearby water bodies
release of untreated sewage into water bodies
Describe the process of eutrophication.
The process of eutrophication is as follows:
nutrient runoff results in increased growth of aquatic plants at the water surface
aquatic plants below the surface die due to reduced light levels and lack of photosynthesis
bacteria feed on dead plants, using the dead matter to fuel respiration
high rates of aerobic respiration deplete oxygen levels in the water
other aquatic organisms die due to a lack of oxygen
What is an indicator species? (Higher Tier Only)
An indicator species is an organism that is particularly sensitive to certain environmental changes and can be studied to determine the effect of human activities on a habitat or ecosystem.
True or False?
Indicator species can only be used to measure water pollution. (Higher Tier Only)
False.
Indicator species can be used to determine levels of water and air pollution.
What does the presence of stonefly larvae in a stream indicate? (Higher Tier Only)
The presence of stonefly larvae in a stream indicates that the water is not polluted and has high dissolved oxygen levels.
What are two invertebrate species that indicate high levels of water pollution if they are present but other species are absent? (Higher Tier Only)
Two invertebrate species that indicate high levels of water pollution are bloodworms and sludgeworms.
To what type of pollution are lichens particularly sensitive?(Higher Tier Only)
Lichens are particularly sensitive to sulfur dioxide pollution in the air.
True or False?
A high abundance of bushy lichen indicates very polluted air. (Higher Tier Only)
False.
A high abundance of bushy lichen indicates very clean air.
What does the presence of blackspot fungus on rose leaves indicate? (Higher Tier Only)
The presence of blackspot fungus on rose leaves indicates clean air.
What are the disadvantages of using indicator species to assess pollution levels? (Higher Tier Only)
Disadvantages of using indicator species to assess pollution levels are:
they can't give quantitative data on the concentrations of pollutants
their presence or absence can be affected by factors other than pollution
Why is it important to maintain biodiversity?
Maintaining biodiversity is key in maintaining the stability of ecosystems and avoiding disruption which could lead to the loss of species.
True or False?
The loss of one species in an ecosystem has no effect on other species.
False.
The loss of one species would have knock-on effects that would impact other species within the ecosystem.
Define the term conservation.
Conservation is the protection of species or habitats.
How can animal species be conserved?
Animal species can be conserved as follows:
giving habitats protected status
creating new areas of habitat
linking habitats together with habitat corridors
removing non-indigenous species from a habitat
preventing hunting
captive breeding programmes in zoos
What is reforestation?
Reforestation is the planting of trees to recreate diverse woodland habitat.
True or False?
Reforestation has no impact on global carbon balance.
False.
Reforestation helps maintain the global carbon balance by planting trees that remove carbon dioxide from the atmosphere for photosynthesis.