Environmental and fishing effects on the dynamic of brown tiger prawn (Penaeus esculentus) in Moreton Bay (Australia)

This analysis of the variations of brown tiger prawn (Penaeus esculentus) catch in the Moreton Bay multispecies trawl fishery estimated catchability using a delay difference model. It integrated several factors responsible for variations in catchability: targeting of fishing effort, increasing fishing power and changing availability. An analysis of covariance was used to define fishing events targeted at brown tiger prawns. A general linear model estimated inter-annual variations of fishing power. Temperature induced changes in prawn behaviour played an important role in the dynamic of this fishery. Maximum likelihood estimates of targeted catchability ($3.92 \pm 0.40 \ 10^{-4}$ boat-days$^{-1}$) were twice as large as non-targeted catchability ($1.91 \pm 0.24 \ 10^{-4}$ boat-days$^{-1}$). The causes of recent decline in fishing effort in this fishery were discussed.Comment: revised manuscript following reviewers comments + adding data and code for reader

Stock Assessment of Ballot's saucer scallop (Ylistrum balloti) in Queensland

This assessment estimates the status of saucer scallops in the main fishing grounds of the Queensland Southern Inshore fishery. The stock assessment data inputs included total harvests, standardised catch rates and fishery independent density estimates.   Analyses suggested that spawning biomass in 2019 fell to around 17 per cent of the unfished level. The report presents recommendations on fishing effort levels to begin rebuilding the stock to levels consistent with 40 per cent of unfished biomass

Quantitative assessment of the Queensland saucer scallop (Amusium balloti) fishery

In recent years (2015 and 2016) there has been growing concern from members of the fishing industry and the Queensland Government over declining catches of legal-sized saucer scallop. This led to a request in mid-2016 by Fisheries Queensland, the fisheries management service within the Department of Agriculture and Fisheries, for an investigative analysis of the status of saucer scallops. The scope of the investigation was limited to a short time frame of three months to urgently analyse the most recent data and undertake a stock assessment. This report provides findings that support the concerns about low abundance of legal-sized scallops. Average catch rates from January 2015 to April 2016 were the lowest in the 39-year record. These recent average catch rates are slightly lower than those in 1996 when the scallop population size fell to low levels and emergency closed areas were implemented by the Government. From these data the model estimates of spawning stock in 2015 are potentially as low as 5-6% of 1977 levels, when the fishery was in its early development

TrackMapper Rises

This project repaired and upgraded non-functional Department of Agriculture and Fisheries (DAF) TrackMapper software, to a faster, functional, user-friendly, web-based application that can be directly accessed by researchers, fishery managers and others. TrackMapper is database software that was developed by DAF researchers in 2007 as part of an externally funded Fisheries Research and Development Corporation project (FRDC project 2002/056 Innovative stock assessment and effort mapping using VMS and electronic logbooks). However, over the last 5-6 years, the program has become incompatible with contemporary Windows-based operating platforms, rendering it inoperable. TrackMapper was developed for the Queensland east coast otter trawl fishery, which is the state’s most valuable commercial fishery, harvesting 7000-8000 t of seafood annually valued at $80-90 million. The most useful feature of TrackMapper is that it can produce maps of fishing effort, catch and catch rates for the fishery at a spatial resolution that is 10-50 times that reported using logbook data alone. This information can be used for a range of fisheries management and research tasks, including the assessment of targeted stocks of prawns, scallops, bugs and stout whiting, as well as impacts on the bottom and other non-target bycatch species. This is noteworthy as much of the fishery occurs in waters of the Great Barrier Reef Marine Park (GBRMP), which has World Heritage status

Stock predictions and population indicators for Australia's east coast saucer scallop fishery

This project undertook analyses to understand the roles of overfishing and the environment on saucer scallops. Results of this study indicated a decline in numbers of spawning scallops. High levels of fishing effort since the 1980s contributed to stock depletion. In addition, environmental influences such as increased sea surface temperatures (SST) may have amplified scallop mortality rates. These findings can be applied to efforts for stock rehabilitation for the scallop fishery between Yeppoon and K’gari (Fraser Island). Recommended management actions include reduction of the spatial intensity of fishing effort applied, and ensuring sufficient annual spawning to support the scallop population and fishery

NPY and MC4R Signaling Regulate Thyroid Hormone Levels during Fasting through Both Central and Peripheral Pathways

SummaryFasting-induced suppression of the hypothalamic-pituitary-thyroid (HPT) axis is an adaptive response to decrease energy expenditure during food deprivation. Previous studies demonstrate that leptin communicates nutritional status to the HPT axis through thyrotropin-releasing hormone (TRH) in the paraventricular nucleus (PVN) of the hypothalamus. Leptin targets TRH neurons either directly or indirectly via the arcuate nucleus through pro-opiomelanocortin (POMC) and agouti-related peptide/neuropeptide Y (AgRP/NPY) neurons. To evaluate the role of these pathways in vivo, we developed double knockout mice that lack both the melanocortin 4 receptor (MC4R) and NPY. We show that NPY is required for fasting-induced suppression of Trh expression in the PVN. However, both MC4R and NPY are required for activation of hepatic pathways that metabolize T4 during the fasting response. Thus, these signaling pathways play a key role in the communication of fasting signals to reduce thyroid hormone levels both centrally and through a peripheral hepatic circuit

Functional responses can unify invasion ecology.

We contend that invasion ecology requires a universal, measurable trait of species and their interactions with resources that predicts key elements of invasibility and ecological impact; here, we advocate that functional responses can help achieve this across taxonomic and trophic groups, among habitats and contexts, and can hence help unify disparate research interests in invasion ecology

Export of malaria proteins requires co-translational processing of the PEXEL motif independent of phosphatidylinositol-3-phosphate binding

Acknowledgements We thank the Red Cross blood bank in Melbourne for human erythrocytes. We thank Svenja Gunther for expression of GBP130 66–196 proteins; Michelle Gazdik and Chris Burns for help in preparing lipids; Lachlan Whitehead (Centre for Dynamic Imaging, Walter and Eliza Hall Institute) for assistance with quantification of export; and David Bocher for help with generation of STEVOR constructs. This work was supported by the National Health and Medical Research Council of Australia (grants 637406, 1010326, 1049811 and 1057960), a Ramaciotti Foundation Establishment Grant (3197/2010), a Victorian State Government Operational Infrastructure Support and Australian Government NHMRC IRIISS, and the Canadian Institutes for Health Research (MOP#130359). J.A.B is an Australian Research Council QEII Fellow, SF was supported by the Research Training Group GRK1459 of the German Research Foundation, and AFC is a Howard Hughes International Scholar.Peer reviewedPublisher PD