Tag-induced mortality (TIM) biases many capture-recapture studies, leading to abnormally high mortality estimates in the first-year post-tagging. Although models exist to account for this bias, estimating TIM has been problematic and restricted to artificial environments. Here, we use a method for estimating Jasus edwardsii (Hutton, 1875) TIM in situ and demonstrate the conditions under which accurate estimates can be achieved. We use a long-term capture-mark-recapture study conducted since 2000 at the Crayfish Point Scientific Reserve (CPSR), Hobart, Tasmania, Australia, to estimate the rate of in situ tag induced mortality and demonstrate the assumptions relating to sampling design that are required to achieve accurate estimates. TIM estimates were high and relatively similar for both males and females. The similarity between sexes would indicate that for this species, combined sex estimates may be sufficient, which requires substantially less effort. Estimates of TIM were sensitive to the number of recaptured lobsters and at least 15 lobsters, tagged in an initial survey, had to be captured in two subsequent surveys. As recapture rates for lobsters over two subsequent recapture events are relatively low, this resulted in a large number of lobsters needing to be tagged in the initial survey. Given that most tagging studies have at least three surveys, we suggest that the design incorporate the ability to also estimate TIM. This is particularly important if tagging studies are used to estimate population parameters for exploited species, as not accounting for TIM would lead to overestimation of resources and inappropriate catch allocations.

Identification, understanding and prediction of the factors that drive species to heightened risk of extinction are important goals for conservation, especially since few areas on the planet remain unaffected by human activities. Global extinction risk assessments of an entire family of ecologically complex marine fishes (family: Sparidae), using the International Union for Conservation of Nature Red List process, showed that 8.6% (13 species) of sparids are threatened. Intense fishing pressure and habitat destruction are the main reasons for the observed population declines. A further 7.9% (12 species) are classified as Near Threatened. The majority of the sparids (69.5%) are assessed as Least Concern, and these tended to have smaller body sizes, more widespread distributions, and shorter life spans. The remaining 21 species (13.9%) are listed as Data Deficient. In addition to presenting the first global assessment of sparid extinction risk, a Random Forest model identified correlates of extinction risk in the Sparidae using 33 biological and threat variables. The model correctly classified up to 90% of Red List category placements and showed complex interactions between intrinsic and extrinsic predictors. Larger body size was the most important predictor of extinction risk.Sparids with greater maximum sizes, ages, and turnover rates are at higher extinction risk. Conversely, lower area of occupancy and depth limit confer elevated risk. This analysis adds to the growing body of predictive extinction risk models in marine fishes and presents an opportunity to identify and mitigate threats affecting similar groups of highly-valued and ecologically important marine fishes. (C) 2016 Elsevier Ltd. All rights reserved.

Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters) were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day) and four levels of the number of sampling-days (2, 4, 6 and 7 days). The most parsimonious Cormack-Jolly-Seber (CJS) model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery.

A long-term tagging dataset on southern rock lobster (Jasus edwardsii) conducted at the Crayfish Point Scientific Reserve near Hobart, Tasmania, Australia, was used to determine how survey number and survey duration affected the precision of survival estimates of male and female lobsters to ensure sustainable exploitation of the population. Tagging surveys were undertaken twice yearly during 2000-2003 with unequal time-intervals between surveys and then once a year with equal time-intervals during 2004-2012 during the January-February period. The most parsimonious Cormack-Jolly-Seber model for estimating survival of lobsters was dependent on (i) timing of the tagging and recapture surveys, (ii) time between consecutive recapture surveys, and (iii) gender. The number of surveys required to provide a precise survival probability varied with gender and time between recapture surveys. For surveys where there was unequal time between recapture surveys, seven and five surveys were required for female and male lobsters, respectively, whereas only five surveys were required when annual surveys were undertaken. Thus, lobster tagging projects using annual surveys should ideally extend to at least 5 years, which is beyond the 3-year project duration common in marine science.

Tasmanian Seafood Industry Research, Development and Extension Award - Presented to the Tasmanian Small Pelagics Researchers - Jeremy Lyle, John Keane and Colin Buxton (IMAS) and Beth Fulton and Tony Smith (CSIRO)

Marine protected areas (MPAs) are an important and increasing component of marine conservation strategy, but their effectiveness is variable and debated; now a study has assembled data from a global sample of MPAs and demonstrates that effectiveness depends on five key properties: whether any fishing is allowed, enforcement levels, age, size and degree of isolation. Marine protected areas are an important and increasing component of marine conservation strategy, but their effectiveness is variable and much debated. These authors assemble data from a global sample of fished regions and 87 marine protected areas and demonstrate that the effectiveness of a protected area depends on five key properties: how much fishing is allowed, enforcement levels, how long protection has been in place, area and degree of isolation. Conservation is assured only when all five of these boxes have been ticked. In line with global targets agreed under the Convention on Biological Diversity, the number of marine protected areas (MPAs) is increasing rapidly, yet socio-economic benefits generated by MPAs remain difficult to predict and under debate1,2. MPAs often fail to reach their full potential as a consequence of factors such as illegal harvesting, regulations that legally allow detrimental harvesting, or emigration of animals outside boundaries because of continuous habitat or inadequate size of reserve3,4,5. Here we show that the conservation benefits of 87 MPAs investigated worldwide increase exponentially with the accumulation of five key features: no take, well enforced, old (>10 years), large (>100 km2), and isolated by deep water or sand. Using effective MPAs with four or five key features as an unfished standard, comparisons of underwater survey data from effective MPAs with predictions based on survey data from fished coasts indicate that total fish biomass has declined about two-thirds from historical baselines as a result of fishing. Effective MPAs also had twice as many large (>250 mm total length) fish species per transect, five times more large fish biomass, and fourteen times more shark biomass than fished areas. Most (59%) of the MPAs studied had only one or two key features and were not ecologically distinguishable from fished sites. Our results show that global conservation targets based on area alone will not optimize protection of marine biodiversity. More emphasis is needed on better MPA design, durable management and compliance to ensure that MPAs achieve their desired conservation value.

The net movement of individuals from marine reserves (also known as no-take marine protected areas) to the remaining fishing grounds is known as spillover and is frequently used to promote reserves to fishers on the grounds that it will benefit fisheries. Here we consider how mismanaged a fishery must be before spillover from a reserve is able to provide a net benefit for a fishery. For our model fishery, density of the species being harvested becomes higher in the reserve than in the fished area but the reduction in the density and yield of the fished area was such that the net effect of the closure was negative, except when the fishery was mismanaged. The extent to which effort had to exceed traditional management targets before reserves led to a spillover benefit varied with rates of growth and movement of the model species. In general, for well-managed fisheries, the loss of yield from the use of reserves was less for species with greater movement and slower growth. The spillover benefit became more pronounced with increasing mis-management of the stocks remaining available to the fishery. This model-based result is consistent with the literature of field-based research where a spillover benefit from reserves has only been detected when the fishery is highly depleted, often where traditional fisheries management controls are absent. We conclude that reserves in jurisdictions with well-managed fisheries are unlikely to provide a net spillover benefit.

An Ecopath with Ecosim (EwE) model was developed that represents the marine shelf environment surrounding the island state of Tasmania (south of mainland Australia). Climate change scenarios representing a range of potential impacts (30% increase or decrease over a century) on marine primary productivity were investigated. Temperature changes and other impacts were not investigated. This analysis uncovered an asymmetric set of system responses. Modeled increases in primary productivity predict increases in the biomass of most groups, especially shallow filter-feeders (which includes oysters), fished macrozoobenthos which includes rock lobsters (Jesus edwardsii) and octopus. In contrast the group of unfished macrozoobenthos (sea stars, whelks) decreased their relative biomass as primary productivity increased. All modeled fisheries responded to varying primary production levels. The most responsive modeled fisheries were for flathead (Platycephalidae) and for those offshore. Of the groups of special conservation interest (marine mammals and seabirds) the most responsive was the dolphin group - though all responded. (C) 2012 Elsevier B.V. All rights reserved.

The absence of properly identified mechanisms to adequately protect the marine environment remains a major shortcoming in Australia’s commitment to biodiversity conservation. The current commitment to a National Representative System of Marine Protected Areas (NRSMPA) falls far short of providing adequate protection against the suite of existing and potential threats even though areas are designated as being ‘protected’. In this paper it is argued that the actions taken under the NRSMPA are disproportionately concentrated on regulating fishing, including the closing of areas in so-called sanctuary zones to all types of fishing. In the absence of clearly identified threats from most forms of fishing and without assessment of how best to manage those few fishing threats that have been identified, such actions are inefficient and mostly inappropriate. Moreover, they do not provide adequate protection against the full suite of threats to marine environments. Adequate measures for the proper conservation of these areas and/or the protection of marine biodiversity more generally are not being provided and in most cases threats are not even adequately described and evaluated.

Given the level of interest in the jack mackerel (Trachurus declivis) daily egg production method (DEPM) assessment reported by Neira (2011) and, in particular, focus on the estimation of mean daily egg production (P0), IMAS have undertaken a re-analysis of the reported egg density data using a range of alternative model fitting methods suggested in the literature. Specifically, we have followed Ward et al. (2011) who compared several methods and their application in Australian sardine (Sardinops sagax) assessments.

Terrestrial reserves and national parks have taken many forms and they continue to be directed toward variable and often imprecisely defined outcomes. A prominent contemporary focus is to pursue the continuance of biodiversity. To this aim the concept of protecting comprehensive, effectively managed and representative areas from overt development, such as urban sprawl and agriculture, has been globally adopted. Within Australia ‘effectively managed’, has been replaced by ‘adequate’, a poorly defined term which is interpreted optimistically and combined with ‘comprehensive’ and ‘representative’ to create the CAR principle. This principle was first developed within the Australian forestry sector to guide management in addressing a very specific threat to a clearly identified component of biodiversity in limited and well defined areas; the preservation of declining stands of some tree species within limited old growth forests. Even though the CAR principle is central to Australia's process of developing a network of marine protected areas (MPAs) its relevance to marine systems has not been demonstrated. Its efficacy for the conservation of marine environments is questioned. The uncritical transposition of terrestrial management paradigms, including the CAR principle, to the marine realm has misled marine management. It is argued that disproportionate commitment to terrestrial principles, including CAR, and unjustified advocacy for MPAs generally have biased public perception and management efforts to the detriment of effective marine conservation and sustainable use of marine resources.