Effect of the Queensland Shark Control Program on non-target species: whale, dugong, turtle and dolphin: a review

Abstract

The Queensland Shark Control Program (QSCP) has recorded a long-term annual mortality of 0.1 humpback whale, 2 ‘small whales’ (species uncertain), 20 dugong, <78 turtles (species and number released uncertain), and <19 dolphin (species and number released uncertain). Available population estimates suggest that the historic impact of the QSCP would have been negligible on whales, 0.5% per year of the dugong population in the southern Great Barrier Reef, minor on green and loggerhead turtle populations, and unknown but probably minor on leatherback turtles and dolphin populations. In response to improved methods between 1992 and 1995 the average yearly mortality fell to 0 humpback whales, 4 dugong, 3 loggerhead turtles (11 turtles in total), and 10 dolphin (species uncertain); this suggests no impact on whales, 0.1% per year of the dugong population of the southern Great Barrier Reef, 1.6% of the yearly indigenous harvest of green turtles in eastern Australia, and 0.2% per year of the loggerhead turtle population in Queensland. Lack of population estimates and species identification precluded impact calculations for dolphin. The number of rare, vulnerable and endangered marine animals killed in the QSCP gear each year is in tens rather than thousands and the effect of this incidental mortality on their populations is probably minor.