Australian Environmental Concerns

Erica Romero

Overfishing and Illegal Fishing

Overfishing has already decreased part of Australia's fish stocks to dangerously low levels. Two major factors account for this problem; the fact that some areas have low biological productivity (and hence fish stocks do not regenerate quickly), along intensive fishing efforts by commercial and recreational fisheries.

In 2005, 17 of 82 species that were assessed in Australian waters were classified as over fished. Species that remain subject to overfishing and/or are over fished include the southern bluefin tuna; blue warehou; silver trevally; orange roughy; and bigeye tuna in the Pacific and Indian Oceans beyond the Australian Fishing Zone (AFZ).

Illegal fishing places further pressure on some species, with patagonian toothfish in the Southern Ocean and shark (for fins) in northern Australian waters being the worst affected.

5 Pros

  • There's a large variety of fish available for purchase to people around the world.
  • Fishing serves as an alternative to farmers whose land crops have lost value.
  • Feeds the world's demand for seafood.
  • Has an impact on the world's GDP.
  • Fishing employs millions of people.

5 Cons

  • Thousands of fish are kept in an artificial environment
  • Over 70 percent of world fish stocks are fully exploited or are already over fished
  • Impacts the ecology of the ocean
  • Decreases global fish stocks
  • 70% of the world's fish species are depleted or fully exploited

Introduction of Exotic Species

An estimated 20 pests or diseases is gained in Australia each year. Such pests include: cane toads, rabbits, willows and, more recently, black striped mussels and red fire ants. Because of habitat modification and predation, the populations of animals like feral cats, foxes and rabbits have significantly reduced and many have even become extinct. The modification of habitats and predation has caused a major ongoing problem in Australia. There has been more than 2,500 species of plants introduced here, and weeds have had a major impact on ecosystems here. Weeds have invaded almost every part of the landscape. Also responsible for the introduction of exotic species, ballast water from shipping has introduced more than 250 species to maybe even 500 species, into Australian waters. The introduction of exotic species has affected native animals by predation, competition for food and shelter, destroying habitat, and spreading diseases. Exotic species may cause soil erosion.

5 Pros

  • Exotic species increase biodiversity.
  • Exotic species typically have few predators or fatal diseases and have a high reproductive rate.
  • Present good resources for studies in the scientific field.
  • Exotic animals can be captured and killed for meat trade.
  • Genetic Diversity

5 Cons

  • Exotic Species bring diseases.
  • Compete with native species for food.
  • Disrupt ecosystems.
  • May cause soil erosion.
  • May contribute to extinction of native species.