Human interactions

• Overfishing of wild fish has lead to a rapid decline in the population as younger fish are unable to grow and reproduce.
• Introducing species

  • Introducing new species harm the native species. There is greater competition for good and native species might die out.
• Eutrophication

  • Adding too much fertiliser to a field can increase the growth of plants but also increases growth of algae. Nitrate from fertiliser is washed into the river, ,leading do algae growing. The algae blocks the sunlight from reaching the river and the plants in the water die as they stop producing oxygen. This leads to death of fish species.