Lesson 9 of 9 / Organisms and their environment
Conservation and sustainable use
How can people use resources while keeping ecosystems functioning?
I can explain how species conservation and sustainable resource use maintain biodiversity and ecosystem relationships.
I can connect conservation and sustainable resource use to biodiversity and ecosystem function.Syllabus
Syllabus K325, Topic 11(i). Connect conservation and sustainable resource use to biodiversity and ecosystem function.
About 5 min
Make a guess. You are not marked.
A fishery catches only adult fish and leaves some alive. Is it fishing sustainably?
Show the answer
Not unless enough fish remain to replace losses.
Sustainable use keeps the catch within what the population can renew, and protects breeding and nursery areas.
The key idea
Conservation protects species and habitats; sustainable use keeps extraction within the capacity for renewal while maintaining ecosystem functions.
Biodiversity includes the variety of living organisms. An ecosystem includes organisms and their physical surroundings, connected by feeding and other relationships.
Explore the idea
Does the plan protect renewal?
A catch limit reduces extraction, but clearing nursery habitat can reduce recruitment. The same allowed catch may no longer be sustainable if fewer young fish survive.
Original causal comparison. Fish symbols illustrate a possible mechanism, not a quantified prediction. Sustainable use also depends on enforcement, other species and local livelihoods.
Explanation
Species depend on habitats, food sources, pollinators, decomposers and many other relationships. Protecting an animal while allowing its habitat to disappear is unlikely to secure its survival. Conservation therefore includes protecting and restoring habitats as well as addressing direct threats to species.
Mangroves provide feeding and nursery habitats, stabilise shorelines and store carbon. Tropical rainforests support many species and complex interactions; coral reefs provide shelter and feeding areas for diverse marine organisms. Damage to these habitats affects more than one named species.
Sustainable use allows resources to be used without exhausting them or undermining the system that renews them. Examples include regulated harvesting, protection of breeding areas, reduced destructive fishing and carefully managed forestry. A harvest below estimated regrowth can still be harmful if it destroys breeding habitat or removes an important food source.
Evaluate conservation using evidence over time: habitat area and condition, breeding success, population trends and impacts on other species. Enforcement, local livelihoods and community participation affect whether a plan works in practice. A protected area on a map is insufficient if damaging activities continue inside it.
Ecosystems are dynamic. Populations fluctuate naturally, and conservation does not freeze every number. The aim is to maintain biodiversity, functioning relationships and the capacity to persist and recover, while considering the people who depend on the resources.
Step by step
- 1
Identify what is at risk
Specify the species, habitat or resource and the pressure affecting it.
- 2
Explain the protection mechanism
For example, protecting breeding habitat supports recruitment of new individuals into a population.
- 3
Assess use and evidence
Compare extraction with renewal and monitor wider habitat and food-web effects.
Worked example
A mangrove fishing proposal
A community limits fish catches but plans to clear a mangrove nursery area. Explain why catch limits alone may not make the fishery sustainable.
One way to explain it
Mangroves provide nursery habitat for many young fish. Clearing them can reduce survival and recruitment, lowering the population's capacity to replace harvested fish. Sustainable management needs both appropriate catch limits and protection of the habitats and relationships that support renewal.
Why this answer works
- Link the habitat to a life-stage function.
- Connect recruitment to replacement of harvested individuals.
- Evaluate the whole plan rather than a single headline measure.
Watch out for this
A student says: "Sustainable use means taking any quantity as long as some organisms remain." What is wrong with this?
Show the answer
A population must be able to replace losses and maintain its ecological role. Habitat damage, breeding success and effects on other species also matter.
In the real world
Restoring mangroves on Pulau Ubin
At Sungei Durian on Pulau Ubin, NParks is restoring about four hectares of old aquaculture ponds to mangrove, with about 9,000 trees, most of them taking root naturally. NParks and OCBC estimate the trees could take up to 30 million kg of carbon dioxide in their lifetimes, and say a mangrove ecosystem, with its mud, can store three to four times as much carbon as a land ecosystem.
Check your understanding
Which proposal most directly protects both a fish resource and its capacity to renew?
Show the answer
Protect nursery habitat, regulate catches and monitor population recovery.
This links habitat, extraction and evidence about renewal rather than treating any one measure as sufficient.
Quick recall
How can people use resources while keeping ecosystems functioning?