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MeetingMeeting documentStock and risk assessments on bigeye tuna (Thunnus obesus) in the Indian Ocean based on AD Model Builder implemented Age-Structured Production Model (ASPM) 2013
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MeetingMeeting documentStock and risk assessment of bigeye tuna (Thunnus obesus) in the Indian Ocean by Age-Structured Production Model (ASPM 2013
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No results found.We applied an Age-Structured Production Model (ASPM) to assess the status of the bigeye tu stock (Thunnus obesus) in the Indian Ocean using 61 years of data (1952-2012). The assessment results suggested that MSY=120,500 tons (catch in 2012=99,899 tons) and the SSB ratio (2012) is near the MSY level (1.10), while F ratio (2012) is much lower than the MSY level (0.42). The results suggested that the bigeye stock is in the healthy condition and the projection based on the current catch level (99,89 9 tons) suggest that the current level can increase the stock from 2013 and after. -
MeetingMeeting documentStock assessment of bigeye tuna (Thunnus obesus) in the Indian Ocean using ASAP 2013
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No results found.Bigeye tu, Thunnus obesus (Lowe, 1839), is a large epi- and mesopelagic fish distributed in tropical and subtropical waters of Indian Ocean. The bigeye tu (BET) resource was initially harvested by longlines since the 1950s and now is one of the main economic tu recourses in the Indian Ocean. They are currently caught by longliners (deep-freezing and fresh-tu longliners), purse seiners (free-school and associated school), pole and line, and other small fleets as well. Stock assessments of BET in the Indian Ocean in recent years were conducted using forward-projecting based models such as Stock Synthesis (Shono et al., 2009; Kolody et al., 2010), Virtual population alysis (VPA) (Nishida and Takeuchi, 1999), and age-structured production model (ASMP)(Nishida and Rademeyer, 2011). These assessments suggested the Indian Ocean BET there was low probability that the stock has been overfished and overfishing is probably not occurring (Kolody et al., 2010; Nishida and Rademeyer, 2011). However, it should be cautious that the BET assessments were associated with many uncertainties according to explorations of extensive sensitivity alysis (Kolody et al., 2010). Following the uncertainty remaining in the assessments carried out for the previous Working Party on Tropical Tus (WPTT) meetings in 2010 and 2011, the WPTT recommended that bigeye tu would be the priority species for stock assessments in 2013 (IOTC–WPTT14, 2012). This working paper presented a stock assessment of Indian Ocean BE T using Age Structured Assessment Program (ASAP, Version 3; NOAA Fisheries Toolbox, 2011). ASAP is a formal stock assessment model and has been used for assessing many commercially exploited stocks, e.g. red grouper, yellowtail flounder, Pacific sardine, Greenland halibut, Gulf of Maine cod, Florida lobster (see NOAA Fisheries Toolbox, http://nft.nefsc.noaa.gov). The assessment included a base-case model and sensitivity alyses designed for the consideration of altertive key assumption regarding population dymics (i.e., the steepness parameter of the stock-recruitment relationship), and weighting scheme for the most important two abundance indices being used to tune the model. Stock status was evaluated based on fishing mortality and spawning stock biomass based reference points. Kobe plots will be presented to show historical trends in stock status, as recommended by the Scientific Committed (SC, 2012?). The current assessment was not considered to be fil and it would be revised and im proved based on the consensus in recommendations and comments reached on the WPTT15 meeting.
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Book (series)FlagshipThe State of the World's Land and Water Resources for Food and Agriculture (SOLAW)
Managing systems at risk
2011This edition of The State of the World’s Land and Water Resources for Food and Agriculture presents objective and comprehensive information and analyses on the current state, trends and challenges facing two of the most important agricultural production factors: land and water. Land and water resources are central to agriculture and rural development, and are intrinsically linked to global challenges of food insecurity and poverty, climate change adaptation and mitigation, as well as d egradation and depletion of natural resources that affect the livelihoods of millions of rural people across the world. Current projections indicate that world population will increase from 6.9 billion people today to 9.1 billion in 2050. In addition, economic progress, notably in the emerging countries, translates into increased demand for food and diversified diets. World food demand will surge as a result, and it is projected that food production will increase by 70 percent in t he world and by 100 percent in the developing countries. Yet both land and water resources, the basis of our food production, are finite and already under heavy stress, and future agricultural production will need to be more productive and more sustainable at the same time. -
Book (series)Technical studyFishing with beach seines 2011
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No results found.This document provides a global overview of beach seine fisheries and identifies key issues relevant for the responsible use of beach seines and the sustainable livelihoods of beach seine fishers. It also gives guidelines for fisheries managers and other stakeholders on how best to address the issues of management processes and measures, which have the mutually beneficial goals of restoring and conserving the health of fishery resources and their habitats and safeguarding the livelihoo ds of fishers and their communities. The document draws on the findings of case studies coordinated and funded by the Food and Agriculture Organization of the United Nations (FAO) Fisheries and Aquaculture Department in the Gambia, India, Kenya, Mozambique, Peru and Sri Lanka, and by the FAO/United Kingdom Department for International Development (DFID) Sustainable Fisheries Livelihoods Programme (SFLP) in Benin, Ghana and Togo. In addition to the findings of the case studies, other studies and publications on beach seines were reviewed and used for the preparation of this document. -
Book (stand-alone)General interest bookHarmonized World Soil Database version 2.0 2023
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No results found.The Harmonized World Soil Database version 2.0 (HWSD v2.0) is a unique global soil inventory providing information on the morphological, chemical and physical properties of soils at approximately 1 km resolution. Its main objective is to be useful for modelers and to serve as a basis for prospective studies on agroecological zoning, food security and the impacts of climate change. HWSD v2.0 also serves an educational function, illustrating the geographical distribution of soils as well as their properties globally. HWSD v2.0 is easily accessible and user-friendly.