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Depleted fish stocks and ecological disruption

Overfishing has led to a decline in fish populations, smaller fish sizes, and altered marine food webs. Watch video to learn more.

Overfishing has been a growing concern in recent years as the world’s oceans face the depletion of their fish populations. According to the FAO reports in 2019, over 30% of the assessed fish stocks are overfished, making it unsustainable to catch more fish than what the population can support. This not only reduces the size of the fish population but also results in many other effects on the ecosystem, such as smaller fish, earlier maturation, and an altered marine food web.

Overfishing causes the fish population to become vulnerable to environmental fluctuations, leading to local extinctions, population collapse, and reduced resilience to disasters. One of the consequences of overfishing is the aggregation of fish populations at certain points, making them more susceptible to natural disasters. The exploitation of fish stocks results in an unstable population that can easily be affected by environmental events. Overfishing also affects the evolution of fish populations, leading to smaller and younger fish with weaker maternal effects.

Review questions:

  • What are the consequences of overfishing on the marine ecosystem?
  • What is the impact of overfishing on fish populations, and what are the characteristics of overfished stocks?
  • How does overfishing affect the evolution of fish populations?
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SDG 14: Global Action for Marine Conservation

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FutureLearn - Learning For Life

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