Stimulating investment in pearl farming in ... - World Fish Center

Water Temperature and Cyclone Frequency in the Pacific: Implications for Pearl Farming Final, June 2008Figure 6 shows that the variation in average monthly SST values was generally greater offthe Northern coast of Australia than in the South Pacific countries of interest. The maximumaverage monthly SST values in northern Australia, however, were similar to those recordedin Papua New Guinea and the Solomon Islands, but greater than those in the other Pacificcountries. The average monthly SST values were more similar among locations in theSolomon Islands than among locations in the other countries, probably because the formerhave a less extensive geographic distribution. In most countries, the average monthlytemperature declines with latitude. August was the coldest month of the year throughoutthe Cook Islands and Fiji, but only at some locations in French Polynesia, Papua NewGuinea, the Solomon Islands and Vanuatu. At the other locations, the minimum monthlySST values occurred either in July, throughout July and August, in September or throughoutAugust and September. The occurrence of the warmest month of the year was even morevariable, occurring in January, February, March or April or from November-February,January to February, February to March, February to April or March to April.2.4.2 Surface Temperature Search ToolSST data for some of the locations in northern Australia where pearls farms have beenestablished were obtained by using the web-based surface temperature search tool(Directorate of Oceanography and Meteorology, Department of Defence, Australia 2007).These data are predicted average monthly SSTs based on data within a 1° latitude andlongitude radius of a coastal town and do not therefore take into account localenvironmental factors. They are provided by the US Naval Oceanographic Office whoprocess AVHRR data from the polar operational environmental satellites NOAA-14 andNOAA-15 (Paul Sliogeris, pers. comm.). The data are calibrated against drifting buoymeasurements and represents a 10 day composite analysis of sea surface temperature.The mean monthly sea temperature ranges for these locations are:• Houtman Abrolhos Islands – 20.4 °C to 23.9 °C;• Carnarvon - 21.5 °C to 25.3 °C;• Broome - 23.4 °C to 29.0 °C;• Exmouth – 23.9 °C to 28.1 °C;• Dampier - 24.1 °C to 28.4 °C;• Coburg Peninsula - 26.5 °C to 30.0 °C;• Prince of Wales Island, Torres Strait - 26.7 °C to 29.2 °C; and• Hervey Bay – 21.3 °C to 26.3 °C.Figure 7a indicates that the minimum monthly temperatures and monthly maxima were notcoincident at the six locations on the north-west coast. The minimum temperaturesoccurred in August at Broome and the Coburg Peninsula, in September in the Houtman-Abrolhos Islands, but from August through to September at the other locations. Themaximum temperatures were recorded in January at Broome and the Coburg Peninsula, butin March at the Abrolhos Islands, Exmouth and Dampier and in April at Carnarvon. Thetrends at the two widely spaced locations on the north-east, however, were similar, exceptthat the maximum temperature was maintained over a three month period (January toMarch) at Prince of Wales Island, but for January only at Hervey Bay (Figure 7b).The Ecology Lab Pty Ltd – Marine and Freshwater Studies Page 9