Population dynamics of the infaunal bivalve, Soletellina alba

The population dynamics of the infaunal bivalve Soletellina alba was investigated at three sites situated within close proximity to the mouth of the Hopkins River estuary. The initial study design was planned to examine the importance of winter flooding to the persistence of this bivalve mollusc within the Hopkins estuary, since mass mortalities have been observed during previous years coincident with periods of winter flooding. Unfortunately, the climatic conditions experienced during this study were atypical compared to the long-term average, so detailed sampling was limited to two, unanticipated, non-flood years rather than two, highly anticipated, flood years. This hampered my ability to conduct complete tests of the importance of winter flooding. Patterns of river discharge and the frequency and duration of mouth opening and closing differed greatly from that expected. Unexpectedly, periods of mouth closure were not always associated with periods of minimal river discharge; low salinities were another unexpected result during an extended period of mouth closure during 1998. As expected, salinities varied considerably with increasing water depth when the estuary mouth was open. Mouth closure lead to salinities becoming more uniform between water depths but hypoxic and anoxic conditions became evident via stratification in the water column at 1 m below the Australian Height Datum (AHD). Other than trends associated with increased water depth, significant variation was not evident between measurements of salinity taken from three sites within close proximity of the estuary mouth (approximately 500 m), or during changes in tide. The most pertinent anomaly was the absence of winter flooding. The distribution and abundance of juvenile and adult S. alba was variable across all Dates, Sites and Channel elevations (i.e. water depths) sampled during this study. An experimental test comparing the recruitment of juveniles at different channel elevations and in sediments of varying particle size was conducted during an exceptionally successful period of recruitment during 1999. The results of these tests showed that recruitment was greatest at the shallowest channel elevation used, and there was little evidence that sediment particle size influenced recruitment. In contrast to 1999, recruitment during 1997 or 1998 was extremely poor. Growth rates were monitored using tagged individuals held in caged and uncaged plots, which revealed that growth was highly variable among individuals, but not between Sites. These tests also revealed that growth was negligible during the colder, winter months, and that the fastest growing individuals were capable of growing 0.2 mm/day. Mixed results were obtained for tests of potential cage artifacts and the influence of handling. Caging and differing amounts of handling did not appear to influence growth, but there was evidence that cages and handling influenced bivalve condition and number of mortalities. These direct tests appeared to be the most appropriate method for determining growth rates of this species, since attempts to analyse length-frequency data were made difficult by the apparent convergence of cohorts, and shell aging is difficult due to the thin, fragile nature of the shell. As expected, mass mortalities were observed during the flood of 1996, but not during the two non-flood years of 1997 and 1998. There were, however, some considerable declines in abundances at some channel elevations during the two non-flood years. However, these declines were attributable to the complete disappearance of individuals, rather than the sudden presence of numerous, recently dead individuals that typify observed declines during winter flooding. The complete disappearance of individuals suggest that S. alba may be capable of post-settlement emigration, or that they were consumed by an unknown predator. Salinity tolerance tests showed that bivalves exposed to low salinities (≤6 ppt), exhibited poorer condition and took longer to re-burrow into sediments than those exposed to greater salinities (≥14 ppt), while death of bivalves exposed to salinities ≤1 ppt occurred after 8 days of exposure. These tests provide evidence that low salinities are probably the principal cause of mass mortalities during winter flooding, although the interaction between salinity, temperature and turbidity also deserve consideration. The results of this study indicate that certain aspects of winter flooding, especially salinity, are responsible for the mass mortalities of S. alba rather than the result of a short-lived life history. I hypothesise that the survival of very young juveniles (between 0.5 and 1 mm shell length) and rapid growth rates are important features of the life history of S. alba that explain its successful persistence within the Hopkins River estuary. The rapid rates of growth suggest that it may be possible for juveniles that survive winter flooding to grow, reach sexual maturity, and reproduce before the onset of the next flood event. Unfortunately, the increased survivorship of juveniles during periods of winter flooding was not demonstrated by this study because of the absence of winter flooding and also relatively poor recruitment. It is highly likely that this species is capable of completing it entire life cycle within the estuary since the absence of other nearby populations, together with periods of mouth closure, are likely to greatly limit the potential contribution made by larvae entering from the surrounding marine environment. This study has added considerably to our knowledge of how infauna cope with life in the intermittently closing estuaries that typify semi-arid coastlines in the Southern Hemisphere.

Seasonal and diet comparisons of the diets of four dominant fish species within the main channel and flood-zone of a small intermittently open estuary in south-eastern Australia

The diets of four highly-abundant, dominant fish species within the Surrey River, a small intermittently open estuary in south-east Australia, were examined from specimens collected between July 2004 and June 2005. These four, similar-sized species (Atherinosoma microstoma, Galaxias maculatus, Philypnodon grandiceps and Pseudogobius olorum) have limited ability to spatially segregate along the length of the estuary owing to its small size relative to other estuarine habitats. All four species fed on a variety of prey items including crustaceans, insects and detritus. Despite this parity, the four species were demonstrated to occupy differing dietary niches that were concluded to be responsible for reducing interspecific feeding competition. Seasonal variations in the diets were observed for A. microstoma and Philypnodon grandiceps, with these species also exhibiting contrasting diel feeding behaviours. The closure of the estuary mouth led to the flooding of its margins, resulting in an increase in the size of the estuary and providing alternative food resources for the fish to exploit. It appears the inundation of the flood-zone facilitated further significant divergence in the diets of the fish and is likely to be of high ecological value to the estuary.

In situ growth of Soletellina alba (Bivalvia: Psammobiidae) in response to detrital supply and mouth status in a seasonally-closed estuary

The supply of detritus is an important food source for many soft-sediment invertebrates, but its importance for their growth and condition is rarely, if ever, tested directly using manipulative field experiments. Therefore, we designed such a study to: (1) test the importance of fine particulate organic matter for the growth and condition of the infaunal bivalve Soletellina alba; (2) indirectly test the feeding mode of S. alba, which has been assumed to be a deposit feeder like other members of the same superfamily (Tellinoidea); (3) compare growth rates across two summers with contrasting patterns of estuary mouth opening/closing; and (4) compare the condition of individuals used in two field studies (i.e. present versus past) and a past laboratory study. Neither growth nor condition differed when organic content of the sediments was varied, which suggests that S. alba is either a suspension feeder or capable of switching modes of feeding. There was considerable interannual variation in growth with greater growth occurring during the summer with a longer period of mouth opening. This suggests that periods of mouth closure may reduce secondary production within seasonally-closed estuaries. Potential artefacts associated with laboratory trials were also identified, with laboratory bivalves exhibiting poorer condition than those used in two field trials. The present study provides no evidence that variable quantities and qualities of organic matter within the sediments influence the growth and condition of S. alba, but future studies should focus on food supplied via the water column when the estuary is open versus closed.

Presence of fish on the shallow flooded margins of a small intermittently open estuary in South Eastern Australia under variable flooding regimes

Shallow water habitats within estuarine systems are believed to be important areas for small fish. While a wide variety of shallow habitats have been studied, the land that becomes inundated by the damming effect after the closure of intermittently open mouths has previously been overlooked. Fish were sampled monthly from both the main channel and flood zone of an intermittently open estuary between July 2004 and June 2005 using minifyke nets during the day and at night. A total of 7,787 fish were collected during the study representing 13 species and 11 families. Philypnodon grandiceps was the most abundant species and, together with Atherinosoma microstoma, Pseudogobius olorum, and Galaxias maculatus, made up 94% of the total catch. Inundation of the flood zone occurred in two discrete forms associated with mouth condition, which consisted of sporadic flooding while the mouth was open, to long-term flooding for 6 months after its closure. Large numbers of fish were captured on the flood zone, which included nine species; however, A. microstoma dominated the catch. A distinct shift in the flood zone fish assemblage occurred between the two mouth conditions, which is likely associated with changes in hydro-period and food availability of the flood zone and physico-chemical parameters in the main channel. There was no longitudinal variation in the fish assemblage in both the main channel and flood zone; similarly, the diel period was found to have little effect on the fish assemblage. The total catch per unit effort did not vary across seasons and suggests that fish abundance within the estuary is stable throughout the year. Unlike other estuarine systems where shallow water fish assemblages may be structured by variations in tide and elevation within the Surrey, freshwater inflow and, more importantly, mouth condition appear to have the greatest influence in composition of the shallow water flood zone fish assemblage of intermittently open estuaries.

Considerations for performing arts organisations in a climate of transition to the open market context in Vietnam

The emergence of a global economy and culture has created a worldwide climate of change since the 1980s. These changes impact on the growth of a national economy and change the significance of sectors in society, for example the service sector, which increasingly accounts for an important part of the economy (Burbules & Torres, 2000). The arts have also been profoundly influenced by social changes, and technological development. While these changes pose new challenges for the arts, most of which struggle for financial viability in an era of globalisation, privatisation and reduced public funding, the developments also open new opportunities for arts companies/artists but require them to possess the capability to identify and adapt to change. This process underlines the necessary new capacities of arts management, arts marketing, arts leaders and artists.

Doi moi - Vietnamese economic reforms in 1986 - provided impetus for change in every sector, resulting in growth of the service sector in Vietnam (UNDP, 2002). Arts organisations in Vietnam found themselves operating in a more competitive environment, forcing them to adjust to this new economic structure. Improved Vietnamese living standards helped to create more demands for a diverse entertainment industry and allowed both the government and individuals to spend more on the arts. A new cultural policy - socialisation (somewhat equivalent to privatisation in Western countries) was implemented in the arts and cultural sector, producing for performing arts organisations (PAOs) as well as a broader cultural milieu in Vietnam, challenges of being self-sustaining but also more autonomy and greater funding diversity. Simultaneously, this led to upgraded artistic standards, improved infrastructure and higher musicians’ salaries; the latter having only experienced slow improvement during the subsidised era.

This paper investigates how social changes affected organisational operations of selected PAOs in Vietnam and Australia. The analysis of how PAOs in each country adjusted to rapid changes will provide experience for learning from each other, particularly for the Vietnamese case. These analyses provide points of discussion, comparison and implications for development of arts management training in Vietnam. Case studies, personal interviews with key participants and policy actors have been used to discern which direction performing arts management should take in order to correspond with Vietnam’s present and future economic situation and its political position in the world.

Fish use of flooded margins of an intermittently open estuary

Fish communities in the shallow flooded margins of an intermittently open estuary were examined over an 18 month period. A distinct shift in the fish assemblage occurred when the mouth of the estuary closed and was associated with changes in the hydro-period, food availability and physico-chemical changes in the main channel.

Riding the wave of open access : providing library research support for scholarly publishing literacy

Researchers are experiencing intense pressures to publish and increase research outputs. Recently many research funders have introduced policies and mandates related to open access, which have contributed to the increasing popularity of open access journals. Dubbed gold open access, open access journals offer researchers another publishing option. However, some publishers with questionable practices and journals of dubious quality have emerged exploiting the ‘author pays’ open access model and researchers' need to publish. Hence an ability to publish research outputs through the most appropriate outlet for a particular field is crucial for researchers in order to maximise the impact of their research. Notwithstanding the proliferation of open access journals, the literature indicates that some researchers may not have a full understanding of the operations, implications and issues around open access and other publishing issues. This understanding is known as scholarly publishing literacy. With knowledge of scholarly publishing and access to resources and tools, academic libraries and librarians are well-positioned to play an active role in providing support to researchers. This paper argues that scholarly publishing literacy should be treated as an extension of information literacy delivered through a broader research support framework. This paper presents a research librarian's perspective, and draws on literature and the author's practice to illustrate key points. Issues for further investigation are identified.

Bellwether procedures for monitoring and planning essential surgical care in low- and middle-income countries: caesarean delivery, laparotomy and treatment of open fractures

BACKGROUND: Surgical conditions represent a significant proportion of the global burden of disease, and therefore, surgery is an essential component of health systems. Achieving universal health coverage requires effective monitoring of access to surgery. However, there is no widely accepted standard for the required capabilities of a first-level hospital. We aimed to determine whether a group of operations could be used to describe the delivery of essential surgical care.

METHODS: We convened an expert panel to identify procedures that might indicate the presence of resources needed to treat an appropriate range of surgical conditions at first-level hospitals. Using data from the World Health Organization Emergency and Essential Surgical Care Global database, collected using the WHO Situational Analysis Tool (SAT), we analysed whether the ability to perform each of these procedures-which we term "bellwether procedures"-was associated with performing a full range of essential surgical procedures.

FINDINGS: The ability to perform caesarean delivery, laparotomy, and treatment of open fracture was closely associated with performing all obstetric, general, basic, emergency, and orthopaedic procedures (p < 0.001) in the population that responded to the WHO SAT Survey. Procedures including cleft lip, cataract, and neonatal surgery did not correlate with performing the bellwether procedures.

INTERPRETATION: Caesarean delivery, laparotomy, and treatment of open fractures should be standard procedures performed at first-level hospitals. With further validation in other populations, local managers and health ministries may find this useful as a benchmark for what first-level hospitals can and should be able to perform on a 24/7 basis in order to ensure delivery of emergency and essential surgical care to their population. Those procedures which did not correlate with the bellwether procedures can be referred to a specialized centre or collected for treatment by a visiting specialist team.