Don’t blame our ancestors for the environmental degradation that we see today. They were given the job of clearing the land after miners and timber cutters reaped the benefits of the rich resources that seemed endless. Many farmers in the 1920s had to clear the land in order to take up the option of ‘freehold title’.

It is what we have allowed to happen in the last twenty years that has taken its toll on our environmental quality. Instead of using hard work to kill and control weeds and pests in our crops, we now sit in our air-conditioned tractors and spray a cocktail of poisons to kill grass, weeds, insects, fungi and any other life forms we don’t want on our farms. Our streams are now even infested with pest fish and some aquatic plants that were introduced by people for selfish reasons or just out of plain ignorance.

What we need is for all members of the community to band together to make a difference and improve environmental quality. Groups such as Landcare, Waterwatch, ICM committees and community tree-planting schemes should work together to rehabilitate degraded areas and highlight land management issues. Such groups do a great job of improving habitat for native fish and platypus. This makes it more difficult for exotic pest fish such as carp, tilapia and gambusia to flourish.

Instead of saying that our grandparents have damaged the environment, we should be out there getting our hands dirty and our brows sweaty by planting trees and cleaning up degraded areas. We shouldn’t sit on our hands and whinge about what those who lived before us did so many years ago under very different circumstances.

Yours sincerely
Bill Taylor

Student resource i.1b

The North Queensland Times
4 Lillypillly St
Atherton QLD 4870

Dear Editor

Our degraded waterways are a breeding ground for exotic pest fish. These pests can’t ‘mix it’ with our native fish species. You hardly ever find them dominating a clear, pristine waterway where large, native, predatory fish can pick them off.

Can you find many barra, Murray cod, bass or black bream in a dirty, shallow, muddy hole that was once a clean-flowing stream? Probably not, but you would be able to find carp flourishing. If you live near a degraded stream populated by carp, tilapia, gambusia or any other introduced pest fish, you owe it to your children and grandchildren to start to clean it up — now!!

Maybe they might be able to catch a feed of fish (that are great to eat) like you once did.

Regards
Sue Gudgeon

Student resource i.1c

The Editor
Condamine Gazette
17 Bunyip St
Condamine QLD 4416

Dear Editor

Carp and tilapia have been given ‘bad’ press from conservationists, local government officials and the DPI. These people just don’t notice an opportunity when they see one.

These two fish species have been used in Europe and Asia as the basis for a great food industry. Carp have been a favourite food in China and Europe for centuries and tilapia hybrids are the cornerstone of a huge fish farming industry in South-East Asia.

Competitions have been held recently to catch carp. This created jobs. Companies used the carp to make fertiliser and this lead to many opportunities for employment. If pest fish were used for food and products such as fertiliser, then native fish species stand a greater chance of being protected and natural resources such as natural phosphate rock can be managed sustainably.

Regards
Elizabeth Perch

Student resource i.1d

The Editor
The Herald Mail
67 Gariboldi St
East Brisbane QLD 4169

Dear Editor

I believe that exotic pest fish species such as carp, tilapia and mosquito fish are like a cancer in our native streams.

These fish are capable of rapidly breeding to huge numbers in our streams. This overcrowds our native fish species and displaces them. It is said that native fish species such as Murray cod have been displaced by carp. In other places, tilapia displaces similarly sized fish such as black bream. These exotic pest fish breed more frequently and often in greater numbers than native fish.

Exotic pest fish are known to eat a variety of foods, which can disadvantage particular native fish species that target specific food sources. Carp and tilapia are omnivores — eating plants and small aquatic invertebrates such as insects. These food sources are also consumed by a variety of animals in the natural ecological food web. Some of our larger fish may not have sufficient small food for their populations to survive in a stream, dam or billabong.

Exotic pest fish can live in a degraded habitat but native fish species are less tolerant. For example, carp feeding behaviour (roiling) under-cuts river banks. As a result, trees are undermined and fall into streams. Erosion of the bank follows and the stream becomes shallower and more turbid.

If this exotic pest fish cancer is not effectively treated quickly (in the next 10–20 years) then I believe that sadly, the only place you’ll see our magnificent native fish is in museums or reference books.

Yours sincerely

Simon Bass

Student resource i.1e

The Editor
The Gold Coast Courier
453 Gold Coast Highway

Palm Beach QLD 4221

Dear Editor

The aquarium industry has often been blamed for the introduction of exotic pest fish. While some of these fish species have become pests I believe that introducing native fish species to other ‘new’ streams can cause just as much damage. The aquarium industry boomed in the late 1960s and early 1970s. Many new fish enthusiasts may have released fish into our streams not realising the impact it would have a decade later. Most species such as guppies, mollies and swordtails have lived in our waterways without causing harm to native fish species or the environment.

Sometimes acts of nature have caused accidental releases into our streams. Recently, many Australian streams have experienced record flood levels and many outside ponds holding aquarium fish have been flushed out by floodwaters. Even native fish introduced into our streams or lakes can cause problems. Native fish from Tinaroo Dam on the Atherton Tableland were introduced into nearby Lake Eacham with devastating outcomes. In fact, they killed off the native Lake Eacham rainbow fish which was only found in that lake.

Many dams in Queensland and other states have been stocked with sports fish not native to that area. For example, yellow-belly (golden perch) from western and southwestern rivers were introduced into dams and rivers flowing east.

Not all introduced fish are bad. If you want to get rid of exotic introduced fish then you should also do something about wiping out introduced native sports fish from our streams as well.

Yours sincerely
Ken Cod

Student resource i.1f

The Editor
Queensland Fishing Weekly
PO Box 78
Bundaberg QLD 4670

Dear Ed

Exotic fish species living in our streams have often been criticised by conservationists and others for harming our environment. While species such as carp, tilapia and mosquito fish have been called pest fish, they are not all bad.

Our ancestors introduced European sports fish into streams with a view to providing a recreational fishery. The native fish in southern regions of Australia were too few and not as good for sports fishing as fish such as trout, redfin or salmon. Even today not much is known about the habits of many of our native fish. Introduced fish have been studied for centuries in some cases, so a viable population could be established reasonably quickly.

Many jobs are associated with a viable introduced species fishery. Fishing guides, proprietors of fishing lodges and boat charters and hire, bait collectors and growers and even scientists working for government departments owe their living to the vision of our ancestors in introducing exotic fish species.

If you disregard just a few exotic pest fish, many introduced fish such as trout, red-fin have become an important part of fish-lore.

Yours sincerely
Percy Bream

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