Anglers, for their bloodsport, introduced salmonids¹ at the start of the nineteenth century into Australia and New Zealand. This had a massive detrimental impact upon a range of local wildlife:
"Salmonids¹ (among a range of other species) were introduced to temperate Australian and New Zealand freshwaters in the l800s for the benefit of anglers to counter the lack of suitable native sportfish."
DIVERSITY AND NUMBERS OF INVERTEBRATES REDUCED
"Introduced salmonids impact on a variety of native fauna through predation and competition and are implicated in reducing the diversity of macro-invertebrate assemblages and population declines and/or the reduction and fragmentation of the ranges of several species endemic to Australia and/or New Zealand including River Blackfish, many species of galaxiids², and the Tasmanian Mountain Shrimp.
FROGS DRIVEN OUT
"Predation by introduced salmonids is also considered to have played a major role in the population decline of the critically endangered Spotted Tree Frog and possibly other frog species in south eastern Australia.
"Although uncertainty exists, the introduction of salmonids was possibly a major contributing factor to the extinction of the New Zealand Grayling."
BIRD DECLINE AS THEIR FOOD IS TAKEN
"The populations of at least two New Zealand bird species (the Crested Grebe and the Blue Duck) are impacted by salmonid introductions due to a reduction in prey availability (galaxiids and aquatic invertebrates)"
¹ salmonid - belonging or pertaining to the family Salmonidae, including the salmons, trouts, chars, and whitefishes
² galaxiids - a family of mostly small freshwater fish in the southern hemisphere