At the heart of the industrial boom: Australian snubfin dolphins in the Capricorn Coast, Queensland, need urgent conservation action

Abstract

The recent industrial boom along the Australian coastline has increased concerns about the long term conservation of snubfin dolphins along the Queensland coast. National assessment of the conservation status and management of the Australian snubfin dolphin is currently hindered by the lack of adequate biological and ecological information throughout most of its range. In response to the issue of determining the conservation status of species with broad ranges, the IUCN has provided a framework for assessing the threatened status of regional populations. In this study we assessed the conservation status of a small geographically isolated population of snubfin dolphins living in the Fitzroy River region, Queensland, Australia, against the IUCN criteria for regional populations. A review of all available sightings data and stranding information indicates that this is the southernmost resident population of snubfin dolphins in Australian waters. The Fitzroy River snubfin dolphin population is composed of less than 100 individuals, with a representative range and core area of less than 400 and 300 km(2) respectively. The area most often used by snubfin dolphins within the representative range and core area was estimated to be about 292 and 191 km(2), respectively. A decrease in representative range, core area and preferred habitat between 14 and 25% is projected to occur if a planned industrial port development were to occur. These results are robust to uncertainty and considering the low level of formal protection and future threats, a classification of this subpopulation under the IUCN Red List as "Endangered" is appropriate.

Figure 1. Map of the Capricorn Coast study area.

Capital letters indicate survey sections: A = Shoalwater Bay, B = Northern Regions, C = Nine Miles Beach, D = Keppel Bay inshore, E = Keppel Islands, F = Fitzroy outer estuary, G = Fitzroy inner estuary and river, H = Curtis Island East Coast, I = North Port Curtis, J = South Port Curtis. Shoalwater Bay Military Training Area = A+B¸ Keppel Bay = D+E+F+G, Port Curtis = I+J.

Figure 2. Discovery curve of marked snubfin dolphins.

Discovery curve showing the cumulative number of snubfin dolphins (grey line) identified in relation to hours of survey effort per month (grey bars) in Keppel Bay between 2006 and 2011.

Figure 3. Limited protection for snubfin dolphins in an increasingly developed environment.

Map of the Keppel Bay survey area showing snubfin records with red circles (A), of the representative range (yellow line) and core areas (red line) in relation to the habitat type (B), to Great Barrier Reef Marine Park zones (C), and to the proposed development (dredging areas, shipping routes, mooring sites, berth and loading areas) in the Fitzroy River estuary (D). Scale bar is located on the bottom right of the figure unless specified in the map.