AN ANALYSIS OF POLICY CHANGES IN THE CANADIAN FEED GRAIN MARKET

This paper examines changes in the welfare of Canadian barley and livestock producers attributable to a substantial alteration of Canadian domestic feed grain policy in 1974. Three welfare effects are determined – institutional, destabilization, and risk response. Generally, the analytical results confirmed initial hypotheses, with the exclusion of a positive relationship between price risk and barley production on the Prairies. This positive relationship, theorized to result from the risk reduction effect of yearly stabilized Canadian Wheat Board initial prices, enhanced the welfare benefits of the policy change.Agricultural and Food Policy,

Assessment of Key Dugong and Turtle Seagrass Resources in North-west Torres Strait

Seagrasses are one of the most productive marine habitats on earth that provide food for herbivores like dugongs (Dugong dugon) and green sea turtles (Chelonia mydas). Torres Strait contains extensive seagrass meadows, the largest dugong population in the world, and a globally significant population of green turtles. Assessing and managing seagrass resources in Torres Strait requires adequate baseline information. North-west Torres Strait was identified in a 2014 review as an important hunting and fishing ground for Torres Strait Islanders with large dugong and turtle populations, but where seagrass data was lacking. The project aim was to provide information on intertidal and subtidal seagrass in north-west Torres Strait detailing seagrass distribution, biomass, species composition, and other benthic characteristics (algae, macro-invertebrates). Boat and helicopter surveys were conducted November 2015 to January 2016. Seagrass information recorded included presence/absence, percent cover, above ground biomass, species composition and diversity. Other benthic information included percent cover of algae (by functional group) and macro-invertebrates. Boat-based surveys were conducted in collaboration with TSRA LSMU Rangers from Boigu Island and Saibai Island. North-west Torres Strait contains extensive seagrass habitat. Seagrass was present at 43% of the 853 sites surveyed. Seagrass area mapped was 60 263 ha across 34 meadows. Ten seagrass species from three families were identified. The most dominant species in terms of contribution to mean biomass was T. hemprichii (35%); H. uninervis was the most commonly occurring species. Extensive dugong feeding trails (DFTs) were present in intertidal meadows along the Papua New Guinea shoreline and around Boigu Island. Coral communities were the dominant form of benthic macro-invertebrates. Extensive algae habitat was throughout the region. Subtidal seagrass meadows were extensive in the area bounded by Deliverance, Turnagain and Boigu Islands, but sparse elsewhere, likely due to strong currents south of Deliverance Island and poor underwater visibility from suspended sediments close to Papua New Guinea. The presence of dugong feeding trails in intertidal meadows and frequent turtle and dugong sightings during the surveys identifies the region as ideal foraging habitat. Subtidal meadow distribution mapped in this study overlaps spatially with very high dugong and turtle density distributions recorded during aerial surveys. Effective management and planning requires current, spatially relevant seagrass information at the scale of individual communities’ sea country to inform community-based Turtle and Dugong Management Plans and will require cooperation with adjacent Papua New Guinea coastal communities. Recommendations include: (1) Establish baseline seagrass information in high-very high dugong density areas between Turnagain and Gabba Islands, Orman Reefs and the eastern boundary of the Dugong Sanctuary; (2) Establish a seagrass long-term monitoring program in regions of high-very high dugong density; (3) Continue collaboration with TSRA LSMU Rangers for seagrass surveys and monitoring

A framework for defining seagrass habitat for the Great Barrier Reef, Australia

This report describes a framework to define seagrass habitat and seagrass desired state for the Great Barrier Reef (GBR). We developed this by defining assessment zones using key physical attributes for the GBR. The assessment zones were developed with two main objectives: (1) to assess the representativeness of existing seagrass data throughout the GBR; and (2) to provide a framework in which to develop seagrass desired state (i.e. condition targets). We defined assessment zones using spatial data that reflect environmental and benthic condition likely to affect seagrass distribution, diversity and density. These include: (1) latitude, defined as regions using 6 Natural Resource Management (NRM) boundaries, (2) influence from and proximity to land (estuarine, coastal, reef, and offshore water bodies), and (3) water depth (intertidal, shallow subtidal 10m) resulting in 68 zones for the GBR. The largest assessment zone was the offshore water body in every region. Deep subtidal was the largest depth zone in coastal, reef, and offshore waters in each region. The estuarine deep subtidal zone was limited. Zones are seagrass-centric and not analogous to the Great Barrier Reef Marine Park zoning. Data from extensive seagrass surveys and long-term monitoring across the GBR since the early 1980s provides information on seagrass presence/absence, species composition, abundance, and spatial extent. Data rich areas include coastal and estuarine intertidal and shallow subtidal zones. Data from reef and offshore zones, and in deep subtidal zones, are more limited as it comes from sporadic one-off surveys and few meadows have been mapped. Available seagrass data ranges from sporadic large-scale survey data with low to medium spatial and low temporal resolution, to high spatial and high temporal resolution data collected seasonally at discrete sites. Defining these assessment zones is a critical first step in defining habitat types and quantifying desired state for GBR seagrasses. Habitat attributes not included in the zones, such as sediment type and exposure to wind and waves, as well as new seagrass biomass data will be used to update the framework, turning it into a full habitat assessment for defining desired state. A case study based in Cleveland Bay, as well as previous research, will be used to identify how this framework will be updated. Seagrass desired state is an ecological target that can be used to assess the effectiveness of management strategies to protect seagrass of the GBR. Desired state analysis requires data with medium to high spatial and temporal resolution that allows assessment in the context of disturbance events, recovery trajectories, and seasonal fluctuations. Robust analysis will be restricted to locations within zones where continuous data collection has occurred, e.g. the Marine Monitoring Program (MMP) and Queensland Ports Seagrass Monitoring Program (QPSMP), and for an adequate time span (generally >10 years)

Spatial variation in the effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus

The effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus populations were compared between coral reefs open or closed (no-take marine reserves) to fishing and among four geographic regions of the Great Barrier Reef (GBR), Australia. The specific reproductive metrics investigated were the sex ratio, the proportion of vitellogenic females and the spawning fraction of local populations. Sex ratios became increasingly male biased with length and age, as expected for a protogyne, but were more male biased in southern regions of the GBR (Mackay and Storm Cay) than in northern regions (Lizard Island and Townsville) across all lengths and ages. The proportion of vitellogenic females also increased with length and age. Female P. leopardus were capable of daily spawning during the spawning season, but on average spawned every 4·3 days. Mature females spawned most frequently on Townsville reserve reefs (every 2·3 days) and Lizard Island fished reefs (every 3·2 days). Females on Mackay reefs open to fishing showed no evidence of spawning over 4 years of sampling, while females on reserve reefs spawned only once every 2–3 months. No effect of length on spawning frequency was detected. Spawning frequency increased with age on Lizard Island fished reefs, declined with age on Storm Cay fished reefs, and declined with age on reserve reefs in all regions. It is hypothesized that the variation in P. leopardus sex ratios and spawning frequency among GBR regions is primarily driven by water temperature, while no-take management zones influence spawning frequency depending on the region in which the reserve is located. Male bias and lack of spawning activity on southern GBR, where densities of adult P. leopardus are highest, suggest that recruits may be supplied from central or northern GBR. Significant regional variation in reproductive traits suggests that a regional approach to management of P. leopardus is appropriate and highlights the need for considering spatial variation in reproduction where reserves are used as fishery or conservation management tools

Measurement of CP Violation at the Υ(4S)\Upsilon(4S) without Time Ordering or Δt\Delta t

I derive the expressions for the CP-violating asymmetry arising from interference between mixed and direct decays in the Upsilon(4S) system, for the case in which only one of the B decay times is observed, integrating over the decay time of the other B. I observe that neither the difference of the decay times Delta t, nor even their time-ordering, need be detected. A technique for measurement of the CP-violating weak decay parameter sin(2beta) is described which exploits this observation.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

What can we learn from phi_1 and B_d^0 -> pi^+ pi^- ?

We discuss what we can understand from $\phi_1$ and $B^0_d\to \pi^+ \pi^-$ decay mode. Using a convention without weak phases $\phi_2$ and $\phi_3$, we can solve the parameters from the time-depended CP asymmetry. If we can put a condition the contribution from penguin except for the CKM factor including in the diagram is small, then we can lead the allowed region of $R_t$ or $\phi_2$ by using the convention.Comment: 7 pages, 4 figures, references and comments adde

Vegetative fragment production as a means of propagule dispersal for tropical seagrass meadows

Background and aims: Long distance dispersal (LDD) contributes to the replenishment and recovery of tropical seagrass habitats exposed to disturbance, such as cyclones and infrastructure development. However, our current knowledge regarding the physical attributes of seagrass fragments that influence LDD predominantly stems from temperate species and regions. The goal of this paper is to measure seagrass fragment density and viability in two tropical species, assessing various factors influencing their distribution. Methods: We measured the density and viability of floating seagrass fragments for two tropical seagrass species (Zostera muelleri and Halodule uninervis) in two coastal seagrass meadows in the central Great Barrier Reef World Heritage Area, Australia. We assessed the effect of wind speed, wind direction, seagrass growing/senescent season, seagrass meadow density, meadow location and dugong foraging intensity on fragment density. We also measured seagrass fragment structure and fragment viability; i.e., potential to establish into a new plant. Key results: We found that seagrass meadow density, season, wind direction and wind speed influenced total fragment density, while season and wind speed influenced the density of viable fragments. Dugong foraging intensity did not influence fragment density. Our results indicate that wave action from winds combined with high seagrass meadow density increases seagrass fragment creation, and that more fragments are produced during the growing than the senescent season. Seagrass fragments classified as viable for Z. muelleri and H. uninervis had significantly more shoots and leaves than non-viable fragments. We collected 0.63 (±0.08 SE) floating viable fragments 100 m−2 in the growing season, and 0.13 (±0.03 SE) viable fragments 100 m−2 in the senescent season. Over a third (38%) of all fragments collected were viable. Conclusion: There is likely to be a large number of viable seagrass fragments available for long distance dispersal. This study's outputs can inform dispersal and connectivity models that are used to direct seagrass ecosystem management and conservation strategies

BioConcens: Biomass and bioenergy production agriculture – consequences for soil fertility, environment, spread of animal parasites and socio-economy

The research programme called “international research cooperation and organic integrity” was commenced for a period 2006-2010. It is coordinated by DARCOF (The Danish Research Centre for Organic Farming). The whole programme, with acronym DARCOF III, consists of 15 projects (http://www.darcof.dk/research/darcofiii/index.html). One of them is BIOCONCENS - Biomass and bioenergy production in organic farming – consequences for soil fertility, environment, spread of animal parasites and socio-economy (http://www.bioconcens.elr.dk/uk/). The production of bioenergy in organic agriculture (OA) can reduce its dependency of fossil fuels and decrease green house gasses emission; consequently it will increase sustainability of organic farms. Biorefinery concept based on co-production of biogas, bioethanol and protein fodder in organic farming will be developed within the BIOCONCENS project and the background for the project and the different work packages will be presented in this paper

The role of dugong and turtle grazing in Torres Strait seagrass declines: Exclusion experiments show the role of green turtle and dugong grazing in structuring Torres Strait seagrass meadows

• Seagrass declines in western Torres Strait that occurred in 2019 and 2020 have been recognised as a concern by the local community. Grazing by dugongs and green turtles was identified as a possible cause of these declines. • Exclusion cages were used at two of the affected seagrass meadows (Orman Reefs and Mabuyag Island) to understand how herbivory by green turtles and dugongs (megaherbivores) was impacting seagrass meadows. • Where grazing pressure was removed (inside exclusion cages) the seagrass canopy height and biomass were significantly higher than the open to grazing control plots at both locations by the end of the seven-month experiment. • Grazing pressure is very high at both sites and herbivory is likely to be contributing to the seagrass declines in these meadows. This seems to be driven principally by green turtle grazing. • Based on the declines recorded in the long-term monitoring program at these meadows and the results from this study, it seems likely that megaherbivore grazing may have been a key driver of the declines at the Orman Reefs site, and grazing pressure is continuing to lead to reduced seagrass abundance at both sites. • Studying megaherbivore movements and the changing spatial status of seagrass across the broader region would increase understanding of the dynamics of these plant-animal interactions in the region. This would also help to establish whether grazing is the sole cause of declines at these sites, or part of natural cycles linked to other drivers such as wind, sediment movements or other impacts to seagrasses • This study confirms megaherbivore grazing is a key element in shaping seagrass dynamics in Torres Strait and points to the value of further assessments of megaherbivore and seagrass dynamics in northern Australia

What lies beneath: predicting seagrass below-ground biomass from above-ground biomass, environmental conditions and seagrass community composition

Seagrass condition, resilience and ecosystem services are affected by the below-ground tissues (BGr) but these are rarely monitored. In this study we compiled historical data across northern Australia to investigate biomass allocation strategies in 13 tropical seagrass species. There was sufficient data to undertake statistical analysis for five species: Cymodocea serrulata, Halophila mutts, Halodule uninervis, Thalassia hemprichii, and Zostera muelleri. The response of below-ground biomass (BGr) to above-ground biomass (AGr) and other environmental and seagrass community composition predictor variables were assessed using Generalized Linear Models. Environmental data included: region, season, sediment type, water depth, proximity to land-based sources of pollution, and a light stress index. Seagrass community data included: species diversity and dominant species class (colonising, opportunistic or persistant) based on biomass. The predictor variables explained 84-97% of variance in BGr on the log-scale depending on the species. Multi-species meadows showed a greater investment into BGr than mono-specific meadows and when dominated by opportunistic or persistent seagrass species. This greater investment into BGr is likely to enhance their resistance to disturbances if carbohydrate storage reserves also increase with biomass. Region was very important for the estimation of BGr from AGr in four species (not in C. serrulata). No temporally changing environmental features were included in the models, therefore, they cannot be used to predict local-scale responses of BGr to environmental change. We used a case study for Cairns Harbour to predict BGr by applying the models to AGr measured at 362 sites in 2017. This case study demonstrates how the model can be used to estimate BGr when only AGr is measured. However, the general approach can be applied broadly with suitable calibration data for model development providing a more complete assessment of seagrass resources and their potential to provide ecosystem services