Although on present evidence it may not herald an environmental disaster in its own right, news that Pacific pink salmon are turning up in anglers' and netsmen's catches is troubling. It represents one more step in a continuing assault on Britain's rivers and lakes, by alien species, that only anglers and very few others see or even know about.
Some elements of this assault — such as the influx of the new visitor — are natural occurrences. Others have come about through carelessness or greed. Some are the fault of ...