Interactive effects of temperature and salinity on otolith chemistry: challenges for determining environmental histories of fish

Copyright © 2002 NRC CanadaThe concentrations of elements and isotopes in fish otoliths may provide a method of reconstructing movements of fish by differentiating between water bodies of different temperatures and salinities. However, before otoliths can be used to reconstruct environmental histories of fish, it is necessary to assess the effects of seawater temperature and salinity on otolith microchemistry. Using controlled laboratory experiments, juvenile black bream, Acanthopagrus butcheri (family Sparidae), were reared for 50 days in aquaria of varying temperatures and salinities using three experimental designs: temperature x salinity, temperature only, and salinity only. Temperature and salinity interacted to significantly affect the elemental concentration ratios of Sr:Ca and Ba:Ca and the concentrations of isotopes 7delta;[sup13] C and δ[sup18] O in otoliths. The single-factor experiments showed that temperature significantly affected the concentration ratios of Sr:Ca and Ba:Ca and the concentrations of δ[sup13]C and δ[sup18]O in otoliths, whereas salinity alone did not affect the concen-tration ratios of any elements but did affect both isotopes. The concentration ratios of Mg:Ca and Mn:Ca varied considerably among fish within the same treatment level and showed little or no effects due to temperature and (or) salinity. The significant interactive effects of temperature and salinity on otolith microchemistry highlight the need for a multifactorial approach to testing hypotheses regarding the environmental histories of fish.Travis S. Elsdon and Bronwyn M. Gillander

Production status of GaAs/Ge solar cells and panels

GaAs/Ge solar cells with lot average efficiencies in excess of 18 percent were produced by MOCVD growth techniques. A description of the cell, its performance and the production facility are discussed. Production GaAs/Ge cells of this type were recently assembled into circuits and bonded to aluminum honeycomb panels to be used as the solar array for the British UOSAT-F program

Proximity and size of neighbouring habitat affects invertebrate diversity

Copyright © 2005 Inter-Research.Species richness and abundance of animals in a particular habitat are often not independent of neighbouring habitats. Concern centres on whether changes to adjacent habitats (e.g. unprotected habitats) can affect the conservation value of protected habitats. The extent to which these concerns are real may be affected by differences in dispersal mode and capacity of the target animals. We tested the interactive effects of size (small vs. large) and isolation (near vs. far) of neighbouring habitats on the assemblage composition, species richness and abundance of 2 taxonomic groups with contrasting adult dispersal modes; copepods as water column swimmers and polychaetes as benthic crawlers. Artificial habitats that are structurally similar to natural articulated coralline algae were used because manipulation of habitat size (small: 40 × 40 mm, large: 120 × 120 mm) and isolation (near 100 mm, far 300 mm) was easier. The different levels of size and isolation used were within the range seen in natural habitats at the study site. Isolation of habitats had a greater effect on assemblages of polychaetes, as may be expected for more limited dispersers. The composition of polychaetes differed between near and far habitats independent of their size, while copepod composition only differed between sizes of habitat when they were far apart. While we predicted that greater abundance and species richness would occur in habitats adjacent to large habitats, only polychaetes were consistent with this pattern. Copepod richness and abundance, in contrast, were greater in habitats that were far from small habitats, providing evidence for the ‘nearest refuge hypothesis’. These results reinforce the need to consider issues of dispersal and proximity to neighbouring habitats when planning protected areas to achieve conservation goals.Bayden D. Russell, Bronwyn M. Gillanders and Sean D. Connel

Optimizing antibiotic therapy-the Aberdeen experience

ObjectiveTo study the quality and continuity of treatment in the Acute Medicines Assessment Unit (AMAU) with regard to empirical prescription of antibiotics, mode of administration, adherence to ward antibiotic policy, as well as collection, awareness and utilization of microbiological investigations.MethodsA prospective study over a 3-month period at the AMAU, Aberdeen Royal Infirmary (ARI), a teaching hospital in north-eastern Scotland, was performed. The study included all patients started on empirical antibiotics on admission to the AMAU and followed up until their discharge.ResultsOf 1303 patients admitted, 221 (17%) were started on empirical antibiotics. This was in accordance with hospital antibiotic policy in 52% of cases. Appropriate specimens were taken from 77% of patients. Culture results showed that 29% (n = 65) of the patients had clinically significant growth of organisms. Of the 65 patients with clinically significant culture results, 49% (n = 32) were on an inappropriate empirical regimen. In 55%, the medication was not changed to a more appropriate antibiotic. In 72% of the patients with a negative culture, the culture report had no obvious effect on the duration or type of antibiotic being administered. Intravenous antibiotics were used in 60% of patients.ConclusionThis study demonstrates a significant overuse of antibiotics, especially intravenous forms, despite a paucity of positive sepsis parameters and chest X-ray findings in these patients The duration of treatment could be shortened and an early switch policy introduced if culture results and sepsis profiles were taken into consideration, as there was a large number of unproven infections. Suggestions are made about how these improvements in prescribing could be made within the current administrative set-up of AMAUs

Mechanisms of population structuring in giant Australian cuttlefish Sepia apama

While a suite of approaches have been developed to describe the scale, rate and spatial structure of exchange among populations, a lack of mechanistic understanding will invariably compromise predictions of population-level responses to ecosystem modification. In this study, we measured the energetics and sustained swimming capacity of giant Australian cuttlefish Sepia apama and combined these data with information on the life-history strategy, behaviour and circulation patterns experienced by the species to predict scales of connectivity throughout parts of their range. The swimming capacity of adult and juvenile S. apama was poor compared to most other cephalopods, with most individuals incapable of maintaining swimming above 15 cm s−1. Our estimate of optimal swimming speed (6–7 cm s−1) and dispersal potential were consistent with the observed fine-scale population structure of the species. By comparing observed and predicted population connectivity, we identified several mechanisms that are likely to have driven fine-scale population structure in this species, which will assist in the interpretation of future population declines.Nicholas L. Payne, Edward P. Snelling, Jayson M. Semmens, Bronwyn M. Gillander

Brief Engagement and Acceptance Coaching for Hospice Settings (the BEACHeS study): Results from a Phase I study of acceptability and initial effectiveness in people with non-curative cancer.

Objectives: Transitioning into palliative care is psychologically demanding for people with advanced cancer, and there is a need for acceptable and effective interventions to support this. We aimed to develop and pilot test a brief Acceptance and Commitment Therapy (ACT) based intervention to improve quality of life and distress. Methods: Our mixed-method design included: (i) quantitative effectiveness testing using Single Case Experimental Design (SCED), (ii) qualitative interviews with participants, and (iii) focus groups with hospice staff. The five-session, in-person intervention was delivered to 10 participants; five completed at least 80%. Results: At baseline, participants reported poor quality of life but low distress. Most experienced substantial physical health deterioration during the study. SCED analysis methods did not show conclusively significant effects, but there was some indication that outcome improvement followed changes in expected intervention processes variables. Quantitative and qualitative data together demonstrates acceptability, perceived effectiveness and safety of the intervention. Qualitative interviews and focus groups were also used to gain feedback on intervention content and to make design recommendations to maximise success of later feasibility trials. Conclusions: This study adds to the growing evidence base for ACT in people with advanced cancer. A number of potential intervention mechanisms, for example a distress-buffering hypothesis, are raised by our data and these should be addressed in future research using randomised controlled trial designs. Our methodological recommendations—including recruiting non-cancer diagnoses, and earlier in the treatment trajectory—likely apply more broadly to the delivery of psychological intervention in the palliative care setting

Direct radiocarbon dating of fish otoliths from mulloway (Argyrosomus japonicus) and black bream (Acanthopagrus butcheri) from Long Point, Coorong, South Australia

Accelerator Mass Spectrometry (AMS) radiocarbon dates (n=20) determined on fish otoliths from mulloway (Argyrosomus japonicus) and black bream (Acanthopagrus butcheri) are reported from five sites at Long Point, Coorong, South Australia. The dates range from 2938–2529 to 326–1 cal. BP, extending the known period of occupation of Long Point. Previous dating at the sites indicated intensive occupation of the area from 2455–2134 cal. BP. Results provide a detailed local chronology for the region, contributing to a more comprehensive understanding of Aboriginal use of Ngarrindjeri lands and waters. This study validates the use of fish otoliths for radiocarbon dating and reveals how dating different materials can result in different midden chronologies

Assessing connectivity in South Australia's Marine Parks Network

Alice Jones, Michelle Waycott, Simon Bryars, Alison Wright and Bronwyn Gillander

Eight habitats, 38 threats and 55 experts: Assessing ecological risk in a multi-use marine region

Published: May 10, 2017Identifying the relative risk human activities pose to a habitat, and the ecosystem services they provide, can guide management prioritisation and resource allocation. Using a combination of expert elicitation to assess the probable effect of a threat and existing data to assess the level of threat exposure, we conducted a risk assessment for 38 human-mediated threats to eight marine habitats (totalling 304 threat-habitat combinations) in Spencer Gulf, Australia. We developed a score-based survey to collate expert opinion and assess the relative effect of each threat to each habitat, as well as a novel and independent measure of knowledge-based uncertainty. Fifty-five experts representing multiple sectors and institutions participated in the study, with 6 to 15 survey responses per habitat (n = 81 surveys). We identified key threats specific to each habitat; overall, climate change threats received the highest risk rankings, with nutrient discharge identified as a key local-scale stressor. Invasive species and most fishing-related threats, which are commonly identified as major threats to the marine environment, were ranked as low-tier threats to Spencer Gulf, emphasising the importance of regionally-relevant assessments. Further, we identified critical knowledge gaps and quantified uncertainty scores for each risk. Our approach will facilitate prioritisation of resource allocation in a region of increasing social, economic and environmental importance, and can be applied to marine regions where empirical data are lacking.Zoë A. Doubleday, Alice R. Jones, Marty R. Deveney, Tim M. Ward, Bronwyn M. Gillander