Natural Phenomenon: Acclimatisation of Fish
Summary
Acclimatisation of fish was not a government initiative but one led by influential private citizens. Acclimatisation dramatically changed the freshwater ecology of Tasmania in the nineteenth century. Although the first European settlers brought utilitarian plants and animals, from the 1820s people sought to create English gardens and recreations.
Details
Goldfish arrived around 1856 and Morton Allport brought in live tench, perch and European carp in 1858, but the Holy Grail was the prospect of a local salmon fishery. Trials began in the 1840s and the Royal Society became the venture's driving force. In 1860 the government recognised the organising group as 'Salmon Commissioners'. They held authority over all fishing, in the sea and in freshwater, for almost the next sixty years. All fishing was regulated in order to maximise the chance of establishing a salmon fishery.
The Commissioners failed to acclimatise their first choice, the Atlantic salmon, but by 1867 trout had gained a firm foothold in Tasmanian rivers. Enthusiastic anglers formed associations, built hatcheries, and spread trout throughout the island. They divided into two groups: the poorer were keen to fish by the most effective means, but the Commissioners were determined to encourage more sporting methods, preferably the use of artificial flies and lures on light lines. Gradually the law cemented this preference. Commercial hatcheries established in the late 1980s finally brought Atlantic salmon to the coastal seas when escapees from fish farms began to join the ecosystem.
The acclimatisation of Pacific oysters in the mid-twentieth century affected some parts of estuarine ecology, and the inadvertent establishment of a variety of species somewhat later due to ballast water discharges has had a more important influence.
Tony Harrison