SUITABILITY LEVEL: P6
RELATED SCIENCE THEME (TOPIC):
- INTERACTIONS (MAN’S IMPACT ON THE ENVIRONMENT)
- INTERACTIONS (POPULATIONS AND COMMUNITIES)
- INTERACTIONS (WEB OF LIFE)
Yes! This bizarre-looking fish is known as the paddlefish. If this fish looks prehistoric to you, you have a reason to think so as it had existed for 15 million years.
The paddlefish lived in the Yangtze river. Unfortunately, much as we would like to see this fish first hand, it has been recently declared extinct by the Yangtze River Fisheries Research Institute.
The paddle fish was the largest freshwater fish in China, its size averaging 2-3 metres and fully grown adults can grow up to a length of 7m. Its huge size was also its bane as it was hard to raise in captivity. This makes breeding and conserving it an arduous task.
Though given the status ‘first class protected fish’ at the beginning of this century, its dwindling population succumbed to the devastating impact of over fishing in the longest river in China.
On 1 January 2020, China imposed a 10-year fishing ban on key areas of the Yangtze river to protect the river’s rich biodiversity but this has come a little too late for the paddlefish.
- ‘The Baiji, or Yangtze river dolphin’ – classified as functionally extinct. https://www.theguardian.com/world/2016/oct/11/china-extinct-dolphin-returned-yangtze-river-baiji
- How does overfishing affect the biodiversity in a community of different populations of organisms in a habitat? http://www.eschooltoday.com/overfishing/impact-of-overfishing.html
APPLICATION OF CONCEPTS LEARNT:
Overfishing can cause the population of any particular specie of fish to decrease as the rate at which fishes are caught is too high for its population to replace through natural reproduction. The decrease in the population of any particular specie of organism can also affect the population of other organisms directly or indirectly related to it.
For instance, when sharks are removed from the sea, the other sea organisms further down the food chain will also be negatively impacted. With no predators to control their population, the prey of these sharks will experience a sharp increase in their population thus leading to increased competition for a limited supply of food. This will then cause their food source to be rapidly depleted, which may possibly lead to their population also decreasing as many will die from the lack of food.