Over-harvesting facts for kids
Over-harvesting means taking too much from nature. This happens when we use more plants, animals, or resources like water than the Earth can replace. It's like spending money faster than you earn it!
This problem can happen in many ways. It includes farming too much, letting too many animals graze in one area, catching too many fish, or using too much fresh water. When we over-harvest, it causes long-term harm to our planet.
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Why Over-harvesting is a Problem
Over-harvesting is bad for nature and for people. When we damage natural places like forests or wetlands, they are very hard to fix. This harm affects both animals and humans. For example, many wetlands are damaged because people use too much of their water. Sometimes, wetlands are even drained to make land for farms or buildings. When this happens, a healthy and diverse ecosystem is destroyed. This means many different kinds of plants and animals lose their homes.
How Over-harvesting Affects Animals
Over-harvesting also affects animals directly. When too many animals of one population are taken, their numbers can drop quickly. This can even lead to a species becoming extinct, meaning it disappears forever.
A good example of this is overfishing. This is when too many fish are caught, and there aren't enough left to reproduce and keep the population strong. To prevent this, many countries now have rules. For instance, you can only fish or hunt deer and birds at certain times of the year. This protects them during their mating and breeding seasons, when they lay eggs or have their young.
Special natural areas, like national parks or places important for science, are also protected. In some places, like the United Kingdom, it's even against the law to take bird eggs.
The Tragedy of the Commons
One big reason why over-harvesting happens is the large number of people in the world. Sometimes, people want land for other uses, which leads to forests being cut down. A few people might gain from this, but everyone shares the cost. This idea is called the tragedy of the commons. It means that when a resource is shared by everyone, like a common pasture or a fishing ground, people might use it selfishly without thinking about the long-term harm. This can lead to the resource being used up too quickly.
Related pages
Images for kids
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When the giant flightless birds called moa were overexploited to the point of extinction, the giant Haast's eagle that preyed on them also became extinct.
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Cows on Selsley Common. The tragedy of the commons is a useful parable for understanding how overexploitation can occur.
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The Atlantic bluefin tuna is currently overexploited. Scientists say 7,500 tons annually is the sustainable limit, yet the fishing industry continue to harvest 60,000 tons.
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Clear cutting of old growth forests in Canada.
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The rich diversity of marine life inhabiting coral reefs attracts bioprospectors. Many coral reefs are overexploited; threats include coral mining, cyanide and blast fishing, and overfishing in general.
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It is not just humans that overexploit resources. Overgrazing can be caused by native fauna, as shown in the upper right. However, past human overexploitation (leading to elimination of some predators) may be behind the situation.
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The Carolina parakeet was hunted to extinction.
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Overexploiting sea otters resulted in cascade effects which destroyed kelp forest ecosystems.
