Infertility problems and mental health symptoms in a community-based sample: depressive symptoms among infertile men, but not women

Most researchers agree that men’s and women’s experiences of infertility are fundamentally different, and impacts upon the nature of psychological distress encountered. However, design flaws, including non-random samples unrepresentative of the general population, compromise many existing studies. Data derived from a random general community sample provides prevalence of current infertility, and permits examination of longitudinal associations between mental health symptoms and infertility among 1,978 participants aged 28-32 years. In the previous 12-months, infertility was experienced by 2.1% and 5.4% partnered men and women. Infertility independently predicted depressive symptomatology in men, and anxiety symptoms among women. Gender differences were sustained, even controlling for prior depression and anxiety. Health professionals are encouraged to proactively enquire about affective symptoms experienced by both women and men with infertility problems

Initial population model fits to the humpback breeding stocks D, E1 and Oceania

This document provides initial results of population model fits to the Southern Hemisphere humpback whale breeding stocks D (West Australia), E1 (East Australia) and Oceania. The purpose of this document is to put preliminary results on the table to facilitate further discussion and model runs at IWC 64. The initial results indicate that breeding stock D is near to its pristine abundance, stock E1 is at an intermediate level, and Oceania is still heavily depleted. There are inconsistencies between the model and the various relative abundance indices for stock D, which need further discussion

A note on the sensitivity of hake assessments to the choice of the central year for the shift from a primarily M. Capensis to primarily M. Paradoxus fishery

At the February 18 meeting of the DWG, there was a request from Industry for further assessment runs for different choices for the central year for the switch from a primarily M. capensis to a primarily M. paradoxus deep-sea trawl fishery. This note reports the results from such assessment runs for a set of choices for this central year ranging from 1940 to 1972. Fig. 1 shows time trends of the proportion of M. capensis in the catch for these alternatives. These results are repeated for three different choices for the natural mortality vector assumed: both the high and low options put forward for the Reference Set (RS) in Rademeyer and Butterworth (2010), and also for the intermediate vector chosen for the Reference Case (RC = RS1). All runs show results for a modified Ricker choice for the stock-recruitment relationship, as for the RC

Report on progress with refined hake assessment

Work is in progress on developing refined Operating Models for the hake resource to form the basis for the simulation testing of the next OMP due for adoption late in 2010. The primary form of model used is likely to be an extension of the area-specific selectivity-based approach used in 2006 (i.e. using changes in selectivity by area rather than explicit movement models to reflect changes in hake distribution with age). Two key new features, as recommended by the International Stock Assessment Workshop held in December 2008, are accounting for gender differences (because male and female hake grow at different rates, confounding the interpretation of length distribution data if this is not taken into account), and fitting directly to age-length data rather than to derived age distributions to account properly for biases that otherwise enter evaluations. We attach a DRAFT on the associated assessment paper currently under development. Note that this is NOT final, either in terms of editing or (preliminary) results shown, but is provided now to FACILITATE FEEDBACK. The primary task of the international stock assessment workshop taking place over November 30 to December 4 will be to review progress with the development of Operating Models and make recommendations for their finalisation early in the new year. Towards this end, work must now be sharply focussed to ensure that results of analyses to be tabled at the start of that workshop are as informative as possible. Accordingly feedback is requested from DWG members and observers (and will also be requested of the three-person international panel) on the following

A spatially structured stock assessment for the South African hake resource with movement based on a gravity model, and including fitting to outputs from the GeoPop Model

The gravity model of explicit spatial movement for the two South African hake species is extended to take account of advice from a mini-task group as on the plausibility of some earlier estimates of movement proportions and to incorporate information from the a GeoPop model to hake survey information over the 1998-2012 period. Addition of the GeoPop data leads to increasing M. capensis but decreasing M. paradoxus estimates of abundance over recent years. There is little impact on nearly all estimates of movement parameters

Sustainable management initiatives for the Southern African hake fisheries over recent years

The predominantly trawl fishery for hake contributes about half the landed value of all of South Africa's commercial fisheries, and is approaching the largest contributor to Namibia's gross domestic product (GDP). Two hake species are taken by these fisheries: shallow-water hake Merluccius capensis Castelnau, 1861 and deep-water hake Merluccius paradoxus Franca, 1960. The present management framework separates the resources into three areas: Namibia and the South African West and South Coasts. Some 30 yrs ago, particularly as a result of rapidly increasing foreign fishing effort over the preceding decade, all of these hake stocks had been severely depleted. We address the question of how successfully sustainable utilization and resource recovery has been achieved since that time. Although there has indeed been some recovery —to a greater extent for the stocks off South Africa—the historical record indicates over-optimistic appraisals of likely recovery rates and sustainable yield levels over this period, and some of the reasons for this are discussed. Certain key assessment questions remain: why is recruitment variability estimated to be so low, natural mortality so high, and why do estimates of stock-recruitment steepness, survey selectivity-at-age and bias in swept-area survey estimates differ so greatly between the stocks? For the most part, total allowable catch (TAC) for these fisheries over the past decade have been set using Operational Management Procedures (OMPs), pre-set rules applied to pre-specified resource monitoring data, where the selection of the procedure to be used is based upon simulation testing to ensure adequate robustness to uncertainties in data and model-structure, in the spirit of a precautionary approach. We discuss the ability in practice of this approach to achieve the necessary adaptive framework for management and summarize planned future initiatives towards refining this OMP approach. These include changing from the present species-aggregated to separate procedures for M. capensis and M. paradoxus. This is necessitated particularly by an increasing longline component in the South African hake fishery, which focuses on M. capensis and takes mainly 6+ aged fish, compared to the mainly 3+ by the trawlers

Building a bridge between the May and the September Reference Cases for the South African resource and related matters

An investigation of the reasons for the changes in particularly M. paradoxus assessment results from the May to the September Reference Case (RC) assessments shows these to be almost entirely a consequence of the changed formulations for selectivities, with updating of and further years’ data having little impact. The probability of a TAC drop of greater than 5% under the current OMP is not high, and in terms of the September RC is not forecast to occur with more than 5% probability before the end of the decade

Statistical catch at length assessment methodology for Atlantic Bluefin tuna

A description of the Statistical catch at Length (SCAL) assessment methodology is given, covering both the formulation of the population dynamics and the penalised log likelihood used for fitting to data. Parameter value inputs for recent applications to East Atlantic and Mediterranean as well as to West Atlantic bluefin tuna are provided, together with the data used on those occasions

Further candidate management procedures projections for the South African hake resource

This document reports further developments in the hake OMP revision process. First the requested 150 000t upper cap is placed on the TAC, and tunings to different average TACs over the next 10 years are contrasted, together with options for a prefixed TAC for the next two years. The option of a soft lower cap on the TAC of 125 000t is explored, linked to a metarule for overriding this if the overall abundance index for M. paradoxus falls below a specified threshold. While it seems more likely than not that the introduction of this soft lower cap would make for a more stable fishery, there remains an appreciable chance that it may necessitate larger TAC reductions, and to lower TAC levels, than would otherwise be the case. Options to reduce the “lag” effects between changes in resource trends and in the TAC are explored, but with little success; basing the control rule on abundance index averages over the last two rather than last three years leads to greater interannual TAC variability. Results for an initial exploration of robustness to decreases in carrying capacity (a possible effect of climate change) point to the importance of further development of metarules to override the constraint on the 5% maximum downward TAC adjustment