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MeetingMeeting documentStudy of the growth of yellowfin tuna (Thunnus albacares) in the Indian Ocean based on length frequency data from 2000 to 2004. 2005
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DocumentOther documentInvestigating the influence of length-frequency data on the stock assessment of Indian Ocean bigeye tuna 2013
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No results found.Most integrated stock assessment models are fit to altertive sources of data like indices of abundance and length/age composition of catches in specific fisheries. While indices of abundance are often standardized over time, not much attention is paid to the temporal stability of the length/age data. A sequential approach to fitting model outputs to all sources of data, varying the weight given to the length composition data, for Indian Ocean bigeye tu (Thunnus obesus) is examined in this paper. The sensitivity of the bigeye tu stock assessment to assumptions regarding the size-selectivity of key fisheries and the relative weight of size frequency data in the stock assessment is examined. Logistic, double normal, and cubic spline selectivity functions are used to model the size composition of catches in the main industrial fisheries (longline and purse seine). Overall, there is a poor fit of stock assessment models to the individual length frequency observations collected from these fi sheries, although margil improvements of fit were made when temporally variable selectivity was implemented in the SS-III framework using the above described functions. The most influential factor in the assessment was the weighting of the length composition data relative to the indices of stock abundance. Contradictory sigls between these two data sources have a large effect on spawning biomass dymics, and inference based on these weightings can produce different magement conclusions. We examin ed altertive hypotheses and discuss the merits of fitting to all sources of data, or discounting some information if it has been unreliably collected over time. We emphasize that understanding the data is key to performing a well-calibrated stock assessment, and further refinements to the approach pursued here are discussed. -
MeetingMeeting documentStudy of the growth of Yellowfin tuna (Thunnus albacares) in the Western Indian Ocean based on length frequency data 2013
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Book (series)FlagshipThe State of Food Security and Nutrition in the World 2023
Urbanization, agrifood systems transformation and healthy diets across the rural–urban continuum
2023This report provides an update on global progress towards the targets of ending hunger (SDG Target 2.1) and all forms of malnutrition (SDG Target 2.2) and estimates on the number of people who are unable to afford a healthy diet. Since its 2017 edition, this report has repeatedly highlighted that the intensification and interaction of conflict, climate extremes and economic slowdowns and downturns, combined with highly unaffordable nutritious foods and growing inequality, are pushing us off track to meet the SDG 2 targets. However, other important megatrends must also be factored into the analysis to fully understand the challenges and opportunities for meeting the SDG 2 targets. One such megatrend, and the focus of this year’s report, is urbanization. New evidence shows that food purchases in some countries are no longer high only among urban households but also among rural households. Consumption of highly processed foods is also increasing in peri-urban and rural areas of some countries. These changes are affecting people’s food security and nutrition in ways that differ depending on where they live across the rural–urban continuum. This timely and relevant theme is aligned with the United Nations General Assembly-endorsed New Urban Agenda, and the report provides recommendations on the policies, investments and actions needed to address the challenges of agrifood systems transformation under urbanization and to enable opportunities for ensuring access to affordable healthy diets for everyone. -
Policy briefPolicy briefOutcomes and lessons learned from the Koronivia UNFCCC negotiations on agriculture and food security, and the way forward after COP 27
Brief note
2023Also available in:
No results found.The Koronivia Joint Work on Agriculture (KJWA) was established at COP23 to address six topics in the agricultural sector's role in climate change. KJWA has contributed to sharing scientific and technical knowledge, but limitations remain in translating outcomes into concrete climate actions. The new four-year joint work on the implementation of climate action on agriculture and food security, which prioritizes ending hunger and considers national circumstances, includes the creation of an online portal for sharing information. The four-year agenda is shaped and broadened through the submission of views by parties, observers, and civil society and will be considered by SBSTA and SBI in June 2023. -
Brochure, flyer, fact-sheetBrochureJoint Programme on Gender Transformative Approaches for Food Security and Nutrition
2022 in Review
2023Also available in:
No results found.The 'JP GTA - 2022 In Review' offers a snapshot of the milestones, achievements and activities of the Joint Programme over the course of the past year, with links to articles, publications and event recordings. The report is structured along the four pillars of the JP GTA, with sections focusing on knowledge generation, country-level activities, capacity development and learning, and policy support and institutional engagement. The page on 'knowledge generation' offers an overview of resources published or facilitated by the JP GTA in 2022. Under 'country-level activities' readers will find a summary of the key activities and achievements of the Joint Programme in Ecuador and Malawi. The section on 'capacity development and learning' delves into the JP GTA’s initiatives to share lessons from the Programme and build colleagues' and partners' knowledge and skills. The final pages on 'policy support and institutional engagement' highlight major global and corporate initiatives supported by the JP GTA.