Sustainable resource management
A fishing ground can produce year after year without ever running out, as long as no more is caught than the population is able to replace. That same idea (not using up a resource faster than it regenerates) is the principle that governs the sustainable management of any living resource.
Renewable and non-renewable resources
An oil well is irreversibly depleted after a few decades of pumping, whereas a well-managed oak wood provides firewood for centuries; however, if we cut down the entire forest in just a few months, it will take hundreds of years to recover, or it may never do so: what determines whether we can go on using a resource indefinitely?
Distinguish between renewable and non-renewable resources by applying them to these three cases: a fishing ground, a riparian forest, and a coal deposit. Explain what…
Distinguish between renewable and non-renewable resources by applying them to these three cases: a fishing ground, a riparian forest, and a coal deposit. Explain what condition must be met for a living resource to continue behaving as renewable.
Define natural resource and classify these four as renewable, renewable only if well managed, or non-renewable, justifying your answer: water from a fossil aquifer,…
Define natural resource and classify these four as renewable, renewable only if well managed, or non-renewable, justifying your answer: water from a fossil aquifer, timber from a managed woodland, oil and wind.
Overexploitation and maximum sustainable yield
Define overexploitation and give a real example of an overexploited living resource, explaining what signal indicates that exploitation exceeds the resource's capacity…
Define overexploitation and give a real example of an overexploited living resource, explaining what signal indicates that exploitation exceeds the resource's capacity for renewal.
Explain what the renewal capacity of a living resource is and what happens when the extraction rate exceeds it continuously, giving a fishing or forestry example.
Explain what the renewal capacity of a living resource is and what happens when the extraction rate exceeds it continuously, giving a fishing or forestry example.
The graph represents the natural renewal rate of a fishery according to its population size and the fleet's annual catch. a) Interpret why renewal is zero at both…
The graph represents the natural renewal rate of a fishery according to its population size and the fleet's annual catch. a) Interpret why renewal is zero at both extremes and maximum at intermediate sizes. b) Explain what point '?' represents and what will happen to the population if the catch remains higher than the renewal rate.
Fisheries and forestry management tools
In the early 1990s, the Newfoundland cod fishery collapsed dramatically after decades of record catches, leaving tens of thousands of fishermen out of work and still not recovered thirty years later: what regulatory instruments can prevent free competition between boats from exhausting the populations they depend on?
Explain what these three tools of sustainable fishing consist of — closed seasons, catch quotas, and minimum size limits — and what biological objective each pursues.
Explain what these three tools of sustainable fishing consist of — closed seasons, catch quotas, and minimum size limits — and what biological objective each pursues.
Explain what information a fisheries manager needs to set a responsible catch quota (stock size, age at first reproduction, annual recruitment) and what risk the fishery…
Explain what information a fisheries manager needs to set a responsible catch quota (stock size, age at first reproduction, annual recruitment) and what risk the fishery runs if the quota is set using outdated data.
Explain what the "tragedy of the commons" is using an open-access fishing ground, and analyse how three tools try to avoid it: individual quotas, fishing reserves…
Explain what the "tragedy of the commons" is using an open-access fishing ground, and analyse how three tools try to avoid it: individual quotas, fishing reserves managed by fishermen's associations, and marine reserves.
Agriculture, aquaculture and water management
Describe two practices that distinguish organic farming from conventional farming (use of inputs, soil management, pest control) and explain what the official organic…
Describe two practices that distinguish organic farming from conventional farming (use of inputs, soil management, pest control) and explain what the official organic production label guarantees.
Aquaculture already provides nearly half of the fish consumed worldwide. Analyse two advantages and two environmental impacts of fish farms, and explain whether they can…
Aquaculture already provides nearly half of the fish consumed worldwide. Analyse two advantages and two environmental impacts of fish farms, and explain whether they can be considered the definitive solution to overfishing.
Distinguish between water stress and drought, and compare two water management philosophies: increasing supply (inter-basin transfers, desalination plants) versus…
Distinguish between water stress and drought, and compare two water management philosophies: increasing supply (inter-basin transfers, desalination plants) versus managing demand (irrigation efficiency, reuse, tariffs). Indicate one advantage and one limit of each philosophy.