Overexploitation, the key term for today, is the use of a natural resource by humans to a point that is unsustainable.
Factors which contribute to overexploitation include:
There are many different types of overexploitation, and today we will cover a few of these types.
| Types of Overexplotation | Description | Example |
|---|---|---|
| Fur Trade | In the past, when one animal would become rare for use, another animal source would then be used. | In the beginning of the 1900s, squirrels and minks were becoming rarer and harder to find for use in clothing. In response, the sea otter was heavily hunted and harvested as a replacement, but it nearly became extinct in the process. |
| Fishing Industry | Current commercial fishing practices and harvest is exceeding fish populations' recharge and reproduction rates. The majority of the big predatory fish at the top of the food chain have been overharvested so much that they can no longer be fished. Now, fish lower down on the food chain are being harvested. | In the Great Lakes, sturgeon populations have declined from overfishing. |
| Amphibians and Reptiles | Amphibians and reptiles are overharvested for food, skins, souvenirs, and medicines. Many amphibians and reptiles have long lifespans, slow growth, and low reproductive rates, which makes it even harder for them to recover from overexploitation. | Snakeskin boots are still popular today, and many snake populations are in danger due to these fashionable accessories. |
| Pet Trade | Exotic animals are sold as pets, with even some being sold to be stuffed as collector items. | Some animals, like the loris, sell for extremely cheap in impoverished countries. The illegal traders then turn around and sell the wild animals in developed nations for thousands of dollars. |
Overexploitation of one species can have repercussions on the rest of an ecosystem. The decline in one species' population, which is food for another, would result in the second species' decline as well.
This interdependent relationship is illustrated in the food web, shown below.
Another instance illustrating the impact of overexploitation occurs when two competing species balance each other in an ecosystem and one is overexploited. In turn, the second species' population could skyrocket and cause further effects in the ecosystem.
Conservation biology is the study of impacts to biodiversity with the intention of conserving biodiversity. The physical structure of a landscape can play a large role in biodiversity health. Habitat fragmentation, or land that is developed for human use, causes habitats to shrink in size and creates more boundaries and edges between ecosystems.
Conservation biologists tend to attempt to mitigate this problem by creating corridors of land between habitat areas that allow ecology to be more mobile, and can stabilize biodiversity. Conservation biologists study the dynamics of ecology to aid in establishing protected areas and slow the loss of biodiversity.
A challenge to conserving species is that it often requires resolving conflicts between the habitat needs of species and human desires. Sustainability seeks to provide for human needs while conserving biodiversity.
Tools to address and mitigate the impacts of overexploitation include:
| Tool | Purpose |
|---|---|
| National laws | Regulate the trade in endangered species |
| International agreements | Restrict overexploitation of species |
| Hunting restrictions | Restrict hunting based off of annual quotas |
| Economic incentives | Discourage overexploitation through both positive and negative incentives. Positive incentives would include compensation in the forms of cash, goods, or services to encourage particular conservation practices, while negative incentives would include fines and penalties for poaching. |
It is important to note that even the best scientific knowledge and practices to manage exploitation can be challenging to implement, and often fail due to institutional difficulties.
Source: Adapted from Sophia instructor Jensen Morgan, FOOD CHAIN PD HTTP://BIT.LY/1AZRYWM
