Prospects for leucaena on the Ord

For the past few years, the Department of Agriculture has been fattening cattle on the forage shrub leucaena which is grown under irrigation with pangola grass. About 400ha of leucaena is under commercial production in the Kimberley. Cattle grazing leucaena show promising growth rates but other problems need to be overcome before its use is more widely adopted. Leucaena establishes slowly. It is also costly to transport fattened cattle to southern abbatoirs

Changes in the population and community structure of corals during recent disturbances (February 2016-October 2017) on Maldivian coral reefs

Climate change is the greatest threat to coral reef ecosystems. In particular, increasing ocean temperatures are causing severe and widespread coral bleaching, contributing to extensive coral loss and degradation of coral reef habitats globally. Effects of coral bleaching are not however, equally apportioned among different corals, leading to shifts in population and community structure. This study explored variation in bleaching susceptibility and mortality associated with the 2016 severe mass bleaching in the Central Maldives Archipelago. Five dominant coral taxa (tabular Acropora, Acropora humilis, Acropora muricata, Pocillopora and massive Porites) were surveyed in February 2016 and October 2017 to test for changes in abundance and size structure. Substantial taxonomic differences in rates of mortality were observed; the most severely affected taxa, Acropora, were virtually extirpated during the course of this study, whereas some other taxa (most notably, massive Porites) were relatively unaffected. However, even the least affected corals exhibited marked changes in population structure. In February 2016 (prior to recent mass-bleaching), size-frequency distributions of all coral taxa were dominated by larger size classes with over-centralized, peaked distributions (negatively skewed with positive kurtosis) reflecting a mature population structure. In October 2017, after the bleaching, coral populations were dominated by smaller and medium size classes, reflecting high levels of mortality and injury among larger coral colonies. Pronounced changes in coral populations and communities in the Maldives, caused by coral bleaching and other disturbances (outbreaks of crown-of-thorns starfish and sedimentation), will constrain recovery capacity, further compounding upon recent coral loss

Differences in demographic traits of four butterflyfish species between two reefs of the Great Barrier Reef separated by 1,200 km

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Coral Reefs 31 (2012): 169-177, doi:10.1007/s00338-011-0838-z.Many species demonstrate variation in life history attributes in response to gradients in environmental conditions. For fishes, major drivers of life history variation are changes in temperature and food availability. This study examined large-scale variation in the demography of four species of butterflyfishes (Chaetodon citrinellus, C. lunulatus, C. melannotus, and C. trifascialis) between two locations on Australia’s Great Barrier Reef (Lizard Island and One Tree Island, separated by approximately 1200km). Variation in age-based demographic parameters was assessed using the re-parameterised von Bertalanffy growth function. All species displayed measurable differences in body size between locations, with individuals achieving a larger adult size at the higher latitude site (One Tree Island) for three of the four species examined. Resources and abundances of the study species were also measured, revealing some significant differences between locations. For example, for C. trifascialis, there was no difference in its preferred resource or in abundance between locations, yet it achieved a larger body size at the higher latitude location, suggesting a response to temperature. For some species, resources and abundances did vary between locations, limiting the ability to distinguish between a demographic response to temperature as opposed to a response to food or competition. Future studies of life histories and demographics at large spatial scales will need to consider the potentially confounding roles of temperature, resource usage and availability, and abundance / competition in order to disentangle the effects of these environmental variables.This work was supported by a National Science Foundation (USA) Graduate Research Fellowship (MLB) and by PADI Project A.W.A.R.E. (MLB).2012-11-1

Demographic histories shape population genomics of the common coral grouper (Plectropomus leopardus)

Many coral reef fishes display remarkable genetic and phenotypic variation across their geographic ranges. Understanding how historical and contemporary processes have shaped these patterns remains a focal question in evolutionary biology since they reveal how diversity is generated and how it may respond to future environmental change. Here, we compare the population genomics and demographic histories of a commercially and ecologically important coral reef fish, the common coral grouper (Plectropomus leopardus [Lacepede 1802]), across two adjoining regions (the Great Barrier Reef; GBR, and the Coral Sea, Australia) spanning approximately 14 degrees of latitude and 9 degrees of longitude. We analysed 4548 single nucleotide polymorphism (SNP) markers across 11 sites and show that genetic connectivity between regions is low, despite their relative proximity (similar to 100km) and an absence of any obvious geographic barrier. Inferred demographic histories using 10,479 markers suggest that the Coral Sea population was founded by a small number of GBR individuals and that divergence occurred similar to 190 kya under a model of isolation with asymmetric migration. We detected population expansions in both regions, but estimates of contemporary effective population sizes were approximately 50% smaller in Coral Sea sites, which also had lower genetic diversity. Our results suggest that P. leopardus in the Coral Sea have experienced a long period of isolation that precedes the recent glacial period (similar to 10-120 kya) and may be vulnerable to localized disturbances due to their relative reliance on local larval replenishment. While it is difficult to determine the underlying events that led to the divergence of the Coral Sea and GBR lineages, we show that even geographically proximate populations of a widely dispersed coral reef fish can have vastly different evolutionary histories

Recent advances in understanding the effects of climate change on coral reefs

Climate change is one of the greatest threats to the persistence of coral reefs. Sustained and ongoing increases in ocean temperatures and acidification are altering the structure and function of reefs globally. Here, we summarise recent advances in our understanding of the effects of climate change on scleractinian corals and reef fish. Although there is considerable among-species variability in responses to increasing temperature and seawater chemistry, changing temperature regimes are likely to have the greatest influence on the structure of coral and fish assemblages, at least over short–medium timeframes. Recent evidence of increases in coral bleaching thresholds, local genetic adaptation and inheritance of heat tolerance suggest that coral populations may have some capacity to respond to warming, although the extent to which these changes can keep pace with changing environmental conditions is unknown. For coral reef fishes, current evidence indicates increasing seawater temperature will be a major determinant of future assemblages, through both habitat degradation and direct effects on physiology and behaviour. The effects of climate change are, however, being compounded by a range of anthropogenic disturbances, which may undermine the capacity of coral reef organisms to acclimate and/or adapt to specific changes in environmental conditions

Larval settlement in echinoderms: a review of processes and patterns

Echinoderms are a common component of benthic marine ecosystems, with many being ecologically and/or economically important. Like many marine organisms, most echinoderms have a bipartite life history with a planktonic larval phase and a benthic adult phase. The transition between these phases (i.e. settlement) is complex and comprises a cascade of events including the location, exploration and selection of suitable benthic habitat, and metamorphosis to adapt from a pelagic to a benthic lifestyle. This review provides a comprehensive synthesis of the various processes involved in the settlement phase across all five extant classes of echinoderms. Central to the review is a detailed assessment of settlement behaviour and the diverse mechanisms of settlement induction. Most echinoderms, including keystone sea urchins, starfishes and sea cucumbers, do not settle indiscriminately; specific environmental conditions or cues are often necessary for settlement to occur, resulting in marked spatial and temporal variability in settlement rates. Fluctuations in settlement, in turn, lead to major changes in the local abundance of echinoderms and often have profound ecological consequences, due to the pivotal role that many echinoderms play in ecosystem functioning. Given important knowledge gaps persist, this review also explores opportunities for future research to advance our understanding of this critical early life-history phase

An annotated bibliography of the research on marine organisms and environments at Christmas Island and the Cocos (Keeling) Islands

Christmas Island and the Cocos (Keeling) Islands represent a unique marine biodiversity hotspot because of the overlap between two major biogeographic provinces (Indian and Pacific Ocean) and the high proportion of endemic species. In this paper, we compile existing scientific literature pertaining to marine organisms and environments at these islands to determine the current state of knowledge and identify major knowledge gaps. In total, 1066 studies have been published, including 582 peer-reviewed journal articles (55% of all publications), 332 reports, 141 books or book chapters, and 11 theses. These studies extend back to 1697, but most (83%) are post-1970. Seabirds have been the most studied group (43% of all publications), followed by land crabs (13%). There has been very little research on plankton (<0.3% of all studies), despite the diversity of marine species that have larval stages (including land crabs) and the importance of plankton to ecosystem function. Most invertebrate groups have received little attention or have not been studied. The taxonomic bias in marine research at these islands means that most of the invertebrates are yet to be documented. Some of these groups (e.g., Polychaeta, Copepoda, and anchialine fauna) are known for their high degree of endemism and are likely to contain new species, thereby increasing the biodiversity value of the islands. That whole families (even phyla) are yet to be studied highlights the infancy in some areas of marine research and adding to species lists for unstudied or understudied groups is one priority that would increase the conservation importance of these islands. Without this knowledge, the ability to monitor, detect or predict anthropogenic impacts on marine species is severely restricted, and therefore limits the development of management strategies aimed at conserving the unique marine biodiversity of these islands. Further studies on functional processes and research related directly to impacts are also needed. Increasing studies that directly relate to management questions will provide guidance to managers charged with protecting the environment. Improved decision making in conservation management will occur through increased directed research and monitoring

Habitat associations of juvenile versus adult butterflyfishes

Author Posting. © Springer-Verlag, 2008. This is the author's version of the work. It is posted here by permission of Springer-Verlag for personal use, not for redistribution. The definitive version was published in Coral Reefs 27 (2008): 541-551, doi:10.1007/s00338-008-0357-8.Many coral reef fishes exhibit distinct ontogenetic shifts in habitat use while some species settle directly in adult habitats, but there is not any general explanation to account for these differences in settlement strategies among coral reef fishes. This study compared distribution patterns and habitat associations of juvenile (young of the year) butterflyfishes to those of adult conspecifics. Three species, Chaetodon auriga, Chaetodon melannotus, and Chaetodon vagabundus, all of which have limited reliance on coral for food, exhibited marked differences in habitat association of juvenile versus adult individuals. Juveniles of these species were consistently found in shallow-water habitats, whereas adult conspecifics were widely distributed throughout a range of habitats. Juveniles of seven other species (Chaetodon aureofasciatus, Chaetodon baronessa, Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon plebeius, Chaetodon rainfordi, and Chaetodon trifascialis), all of which feed predominantly on live corals, settled directly into habitat occupied by adult conspecifics. Butterflyfishes with strong reliance on corals appear to be constrained to settle in habitats that provide access to essential prey resources, precluding their use of distinct juvenile habitats. More generalist butterflyfishes, however, appear to utilise distinct juvenile habitats and exhibit marked differences in the distribution of juveniles versus adults.This research was funded by a JCU Program Grant to MSP, while MLB was supported by an NSF (USA) Graduate Research Fellowship

Evaluating a traditional medicine policy in South Africa: phase 1 development of a policy assessment tool

Background: Policies that empower individuals and communities may be appropriate for public health, and more broadly. Simple, transparent and acceptable tools are therefore required to evaluate policies from an empowerment perspective. In 2008, the South African Department of Health (DOHSA) drafted a policy to endorse the integration of African Traditional Medicine (ATM) into the public health sector, following the World Health Organization's (WHO) long-standing directives. Objective: The purpose of this study is to critically analyze this policy using a novel evaluation tool. Design: A 12-point ‘Policy Empowerment Index’ (PEI) is introduced, and used to classify and score the policy according to five theoretical policy types. The evaluation was based on a stepwise review and associated publications: policy drafts, policy statements and news announcements. Results: According to the assessment tool, the ATM policy was marginally ‘supportive’ of constituent empowerment, although several ‘directive’ features were also observed. The importance of ATM to SA's communities and the promotion of education, employment, entrepreneurship and peripheral resource mobilization were the main empowering elements. Centralised conception, planning and implementation, the absence of provisions for local adaptations and the authoritative legislation context were sub-optimal features. Conclusions: South Africa's ATM legislation may need to further involve communities in policy design and implementation to capitalise upon the broader benefits of community empowerment. However, the iterative nature of method and evaluation is important. Indeed, they are proposed as points to initiate participatory development, and improve policy evaluation . Such instruments can empower constituents in the political process