Over fishing is one of the problems facing the fish industry. Image credit MediaWiki

ZIMSEC O Level Geography Notes: Natural Resources: Fishing:Problems affecting the world’s fishing industry

  • Slight changes in conditions in the continental shelves alter the food chain.
  • This reduces fish production.
  • An example is the decline in anchovy fish production off the coast of Peru.
  • The environmental change has been a result of changes in the flow of ocean currents.
  • Coastal Peru is normally washed by the cold Peruvian current from the South.
  • This current is rich in nutrients.
  • The area is occasionally invaded by a warm current from the equatorial areas to the North.
  • This current is called the El Nino.
  • This invasion affects the mixing of water due to upwelling.
  • This results in a reduction in plant life and hence fish for that period.
  • This leads to a decline in anchovy fish which feed on small plants (plankton).
  • Changes in the condition of the continental shelf can result from pollution.
  • Pollution can be caused by industries, oil spills or human settlement.
  • Pollution has highly altered coastal environments in western North America, Western Europe and China.
  • Pollution causes a reduction in plankton, thus drastically reducing fish population in the affected areas.
  • Poor management of fisheries and a rising demand for fish, in both the developing and developed countries has resulted in over-fishing.
  • Most of the world’s major fisheries are now over-fished.
  • Fishing nations are now obsessed by the need for maximum profit and market demands for fish rather than the need to maintain fish stocks at sustainable levels.
  • Fish are not given time to mature and reproduce before harvest.
  • Rich countries are now entering into fishing agreements with developing countries to extend their fishing grounds.
  • For example Namibia entered into a fishing venture with Spain.
  • The problem of over-fishing is therefore being exported to the developing countries.

To access more topics go to the O Level Geography Notes page