Survival of bottlenose dolphin (tursiops sp.) calves at a wild dolphin provisioning program, Tangalooma, Australia

Mortality of calves born to provisioned mothers is identified in the literature as an issue of concern in dolphin provisioning programs. Wild dolphin provisioning at Tangalooma, Moreton Island, Australia has been occurring since 1992. Each evening, up to eight dolphins are provided with fish in a regulated provisioning program. In this paper, calf survival at the Tangalooma provisioning program is reported and contrasted with that from wild populations and from a similar provisioning program at Monkey Mia, Western Australia. At Tangalooma, the calf survival rate is 100%, including both orphaned and first-born calves, both of which are expected to have relatively low survival rates. Possible explanations for the high calf survival rate are explored. These include site attributes such as isolated location and high water quality, aspects of foraging ecology likely to benefit calves of provisioned mothers, and the management regime used in the provisioning program (e.g., duration and timing of provisioning; quality of provisioned fish).

Grazing management influences the dynamics of populations of Stylosanthes hippocampoides (Oxley fine stem stylo)

This paper describes a study to identify those factors which control the persistence of the Subtropical legume Stylosanthes hippocampoides, formerly S. guianensis cv. Oxley (fine stem stylo). The dynamics of S. hippocampoides populations was recorded in permanent quadrats at 2 stocking rates in a grazing study conducted between 1987 and 1992 in south-eastern Queensland. Density of mature plants fluctuated between 10 and 60 plants/m(2) during the 5 years with the major contributing factors being variations in seedling recruitment and survival, which, in turn, reflected the size of the soil seed bank and seasonal rainfall. Plant density was consistently higher at the lower stocking rate of 1 beast/1.5 ha compared with 1 beast/1 ha; however, the effect of stocking rate was minor compared with fluctuation due to seasonal variation in rainfall. The maximum life span of the original plants exceeded 5 years, while the survival of seedling cohorts was strongly impacted by seasonal rainfall. Total exclosure from grazing during summer increased the size of the soil seed bank although a precise time period during summer was not identified, while grazing at the lower stocking pressure produced the same outcome. It was concluded that the large seasonal variation that occurs in S. hippocampoides density is driven by large seasonal variation in seedling recruitment, which, in turn, is influenced by the size of the soil seed bank.

Proceedings of the tropical fruits in human nutrition and health conference 2008

Horticultural industries are Queensland’s second largest primary producer, with a total gross value of more than $1.9 billion in 2008. Queensland’s diverse geography and climate supports the production of more than 120 horticultural products. With a growing worldwide demand for quality, nutritious food Queensland Primary Industries and Fisheries continues to focus its activities on accelerating growth within the sector. The conference, sponsored by the Organisation for Economic Cooperation and Development (OECD) and DPI&F is the first of its kind to examine the latest knowledge on the health properties of tropical fruits. Organising committee member and DPI&F science leader Dr Roger Stanley said the conference would develop international networks to accelerate research in the area.

Technical highlights: Invasive plant and animal research 2008-09

Technical highlights 2008–09, with detailed progress reports on the latest invasive plant and animal research undertaken by Biosecurity Queensland, a service unit of the Department of Employment, Economic Development and Innovation.

IUCN classification zones concord with, but underestimate, the population genetic structure of the zebra shark Stegostoma fasciatum in the Indo-West Pacific

The Indo-West Pacific (IWP), from South Africa in the western Indian Ocean to the western Pacific Ocean, contains some of the most biologically diverse marine habitats on earth, including the greatest biodiversity of chondrichthyan fishes. The region encompasses various densities of human habitation leading to contrasts in the levels of exploitation experienced by chondrichthyans, which are targeted for local consumption and export. The demersal chondrichthyan, the zebra shark, Stegostoma fasciatum, is endemic to the IWP and has two current regional International Union for the Conservation of Nature (IUCN) Red List classifications that reflect differing levels of exploitation: ‘Least Concern’ and ‘Vulnerable’. In this study, we employed mitochondrial ND4 sequence data and 13 microsatellite loci to investigate the population genetic structure of 180 zebra sharks from 13 locations throughout the IWP to test the concordance of IUCN zones with demographic units that have conservation value. Mitochondrial and microsatellite data sets from samples collected throughout northern Australia and Southeast Asia concord with the regional IUCN classifications. However, we found evidence of genetic subdivision within these regions, including subdivision between locations connected by habitat suitable for migration. Furthermore, parametric FST analyses and Bayesian clustering analyses indicated that the primary genetic break within the IWP is not represented by the IUCN classifications but rather is congruent with the Indonesian throughflow current. Our findings indicate that recruitment to areas of high exploitation from nearby healthy populations in zebra sharks is likely to be minimal, and that severe localized depletions are predicted to occur in zebra shark populations throughout the IWP region.