A Survey of the Macrocystis pyrifera (L.) C. Agardh Stocks on the East Coast of Tasmania, 1986

A survey of the east Tasmanian coastline from Musselroe Bay to South East Cape revealed a total of 10 km2 of Macrocystis pyrifera (Linnaeus) C. Agardh 1820 kelp forest. Average harvestable quantities based on Alginates (Australia) Company records (1965-72) show that cropping can expect to yield 5 ton/acre or 1.23 kg/m2. This realizes a total of 12,300 tonne available on the East Coast of Tasmania in 1986. Review of past records show fluctuations in total amounts harvested, due possibly to factors such as high oceanic water temperatures with subsequent low nutrient concentrations and storm damage. The survey was conducted from a light aeroplane. Areas of Macrocystis pyrifera beds were marked on 1:100,000 topographical land tenure maps using landmarks as references. Digitising of bed outlines on maps was done using Mapinfo. Weight of Macrocystis per unit area is also estimated from quadrats harvested at a number of sites along the coast.