article_snippet.sent: In the south-west of Western Australia 90 per cent of Our native fish and 100 per cent of the crayfish are only found there, so the rivers are refuges for the native fish and when the rivers are forced to coexist with introduced species, the rivers just don't do very well.'
article_snippet.sent: In Perth we're aware of a couple of parasites.
article_snippet.sent: Pest carps: 'In the south-west of Western Australia 90 per cent of the fish and 100 per cent of the crayfish are only found there,' Pest added . '
article_snippet.sent: we've now found it in three rivers around Perth and south of Perth. '
article_snippet.sent: It's been only in the last decade that we've discovered a lot of parasites and disease that we don't know a lot about - there's a lot of things that have come in to Australia that we really don't know anything about.'
article_snippet.sent: Research conducted by Dr Morgan and Stephen Beatty found that at least 13 species of fish had been introduced into south-western Australia, with pet owners believed to be the biggest culprits.
article_snippet.sent: What you see up and down Western Australia's coast is a lot of pest fishes are right in town centres and almost every town has one.'
article_snippet.sent: The problem is not unique to Western Australia's.
article_snippet.sent: The problem is not unique to Western Australia's.