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DocumentOther documentWCPFC: Evaluation of tag mixing assumptions for skipjack, yellowfin and bigeye tuna stock assessments in the western Pacific and Indian Oceans. 2013. WCPFC-SC9-2013/SA-IP-11 2013
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No results found.ng (or mark-recapture) studies generally require the assumption that tagged and untagged individuals (of a particular demographic group) are equally likely to be captured. For tu, this usually translates into the assumption that tagged fish released from a relatively small region (selected for logistical reasons) mix rapidly over a much broader region of interest. In this paper, we apply the Comparison of Paired Recovery Distribution (CPRD) alysis to skipjack (Katsuwonus pelamis), yellowfin (Thu nnus albacares) and bigeye tu (Thunnus obesus) from large-scale tagging programmes in the Western Pacific and Indian Oceans. The CPRD alysis uses chi-square and nearest neighbour permutation statistical tests to calculate the probability that two tag recovery distributions from different release events are drawn from the same spatial distribution. The release events were separated in space and/or time and recovered in the same time window. If there is evidence that the two recovery distributions differ, it follows that tags from the two release events are not fully mixed with each other, such that at least one would also not be mixed with the untagged population either. Recovery events were defined with spatial boundaries corresponding to the most recent stock assessments, and alyses were restricted to release areas that were entirely within the recovery region. In the WCPO, there was strong evidence of incomplete mixing for 5 quarters following release for skipjack and yellowfin tus a nd 1 quarter for bigeye tu. For all 3 species, the observed periods of incomplete mixing is clearly a minimum, as there were insufficient observations to make inferences with respect to longer periods at liberty. In the Indian Ocean, there is strong evidence for incomplete mixing for skipjack for 3 quarters following release, 2 quarters for yellowfin and 1 quarter for bigeye. In contrast to the WCPO, useful numbers of CPRD events of longer duration were identified but did not show consistent com pelling evidence of incomplete mixing. The difference between the Pacific and Indian Ocean results may reflect genuine characteristics of mixing rates (e.g. tu in archipelagic waters seem to migrate shorter distances on average that tu in oceanic waters). However, the failure to detect incomplete mixing in the Indian Ocean may also reflect methodological limitations arising from the opportunistic ture of tag observations (e.g. the spatial distribution of Indian Ocean tag releases and recoveries was more restricted than in the WCPO). We expect that the mixing problem is serious enough to potentially introduce large biases to at least some of these stock assessments, but the magnitude of the biases may not be easy to quantify. -
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BookletHigh-profileFAO Strategy on Climate Change 2022–2031 2022The FAO Strategy on Climate Change 2022–2031 was endorsed by FAO Council in June 2022. This new strategy replaces the previous strategy from 2017 to better FAO's climate action with the Strategic Framework 2022-2031, and other FAO strategies that have been developed since then. The Strategy was elaborated following an inclusive process of consultation with FAO Members, FAO staff from headquarters and decentralized offices, as well as external partners. It articulates FAO's vision for agrifood systems by 2050, around three main pillars of action: at global and regional level, at country level, and at local level. The Strategy also encourages key guiding principles for action, such as science and innovation, inclusiveness, partnerships, and access to finance.
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Book (series)FlagshipThe State of Food Security and Nutrition in the World 2021
Transforming food systems for food security, improved nutrition and affordable healthy diets for all
2021In recent years, several major drivers have put the world off track to ending world hunger and malnutrition in all its forms by 2030. The challenges have grown with the COVID-19 pandemic and related containment measures. This report presents the first global assessment of food insecurity and malnutrition for 2020 and offers some indication of what hunger might look like by 2030 in a scenario further complicated by the enduring effects of the COVID-19 pandemic. It also includes new estimates of the cost and affordability of healthy diets, which provide an important link between the food security and nutrition indicators and the analysis of their trends. Altogether, the report highlights the need for a deeper reflection on how to better address the global food security and nutrition situation.To understand how hunger and malnutrition have reached these critical levels, this report draws on the analyses of the past four editions, which have produced a vast, evidence-based body of knowledge of the major drivers behind the recent changes in food security and nutrition. These drivers, which are increasing in frequency and intensity, include conflicts, climate variability and extremes, and economic slowdowns and downturns – all exacerbated by the underlying causes of poverty and very high and persistent levels of inequality. In addition, millions of people around the world suffer from food insecurity and different forms of malnutrition because they cannot afford the cost of healthy diets. From a synthesized understanding of this knowledge, updates and additional analyses are generated to create a holistic view of the combined effects of these drivers, both on each other and on food systems, and how they negatively affect food security and nutrition around the world.In turn, the evidence informs an in-depth look at how to move from silo solutions to integrated food systems solutions. In this regard, the report proposes transformative pathways that specifically address the challenges posed by the major drivers, also highlighting the types of policy and investment portfolios required to transform food systems for food security, improved nutrition, and affordable healthy diets for all. The report observes that, while the pandemic has caused major setbacks, there is much to be learned from the vulnerabilities and inequalities it has laid bare. If taken to heart, these new insights and wisdom can help get the world back on track towards the goal of ending hunger, food insecurity, and malnutrition in all its forms. -
DocumentGuidelineWORLD PROGRAMME FOR CENSUS OF AGRICULTURE 2020 Volume 2: Operational guidelines
Use of technology for agricultural census data collection
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No results found.20.1 FAO/GS new technology