Escuela de Administración de Recursos Naturales

A workshop was convened in Washington, DC on 19-21 June 2012 to review the available information on the relationship between spawning stock and recruitment for western Atlantic bluefin tuna (Thunnus thynnus), a critical part of the scientific advice for management of the stock. The workshop participants noted that considerable attention has been paid to the form of the relationship between stock and recruitment, but that insufficient attention had been paid to the consequences of different hypotheses about that relationship. We suggest a simple decision table approach, using well-developed methods, for informing on the consequences of different policy choices given the uncertainty in the productive capacity and future trajectory of the stock. This will enable the scientific advice to move beyond a debate about the form of the stock and recruitment relationship and provide a more informative set of information for management. Based on the decision table analysis, considering alternative hypotheses about stock and recruitment using the available data, the results indicate that for rebuilding of spawning stock and yield in the long-term, fishing mortality rates should be kept low. Higher values are only advantageous if the primary goal is short-term yield at the expense of long-term rebuilding of the biomass. Higher values pertain to tradeoffs with yield in short and long term. An intermediate goal would be to reduce F enough to rebuild SSB to near 30,000 mt. At this level of SSB, information on the potential for the stock to increase recruitment and rebuild to a higher level should be apparent. Finally, the workshop participants identified a set of issues in the stock assessment that need further investigation and development to continuously improve the scientific advice provided through the assessment process.

These realities reinforce the importance of understanding, assessing and effectively managing coastal fisheries. This is the key theme of the documentto examine the various approaches and challenges arising in the assessment and management of coastal fisheries within the LAC region. For the purpose of this document, the term 'coastal fisheries' refers to three main types: subsistence fisheries, traditional fisheries (artisanal), and advanced artisanal (or semi-industrial) fisheries. The adaptability of fishers, which enables them to switch gears and target species, makes it difficult in some cases to differentiate among these three types, but broadly the main distinction made here is between coastal fisheries and industrial or recreational fisheries. Coastal fisheries tend to share certain features, such as high mobility of fishers, transboundary issues related to shared resources, high competition among user groups, seasonal use of resources, and multiple livelihoods (

This paper presents an overview of the key characteristics of small-scale coastal marine fisheries in Latin America and the Caribbean as well as an examination of some of the weaknesses, gaps, and challenges faced in fisheries assessment and management within the region. The information here is based largely on discussions involving a range of scientists, managers and fishers at the first CoastFish conference ("Coastal fisheries in Latin America and the Caribbean") held in Merida, Mexico in 2004 and literature review. Small-scale fisheries in this region, as elsewhere, share similar characteristics including multi-gear and multispecies, low capital and labour intensive, remote landing sites, large number of migrant and seasonal workers, and weak market and bargaining power among fishers. Common issues facing these fisheries are resource overexploitation, complex and dynamic fleet interactions, competition and conflicts between fleets (small-scale, industrial and recreational), and post-harvest problems, such as lack of infrastructure. Research in the region focuses mainly on biological-ecological aspects, with limited attention paid to socioeconomic issues. Collection of catch data is common in most countries, at least for the main target species, but its reliability has been questioned in many cases, especially when a multi-species fishery is in place. Management tools frequently used are 'input control', e.g., size limit, gear restriction, closed season, closed area, and fishing permits. Finally, legal frameworks typically exist to regulate fisheries in most countries, but lack of success in management could be attributed to a lack of surveillance, weak institutions, unclear legal management instruments, and limited involvement of fishers in the management process. Based on the above, we discuss ways to address gaps and challenges in the assessment and management of small-scale fisheries in Latin America and the Caribbean.

From all of the fishing resources in the Caribbean region, a shared metapopulation of spiny lobster (Panulirus argus) has the highest market value, which together with its abundance and wide distribution, makes it the main source of income for a large number of coastal communities. Within this region, responsible use of shared marine areas, like the Mesoamerican barrier ecosystem, where multi-gear artisanal fisheries distributed in area of resource distribution play a significant role in affecting different components of the spiny lobster population structure and, in harvesting incidentally a high diversity of reef species, require approaches to manage multiple and competing uses of this marine area. The move towards EAF in the spiny lobster fishery of the Mesoamerican barrier ecosystem should be on an incremental and adaptive management basis in view of (i) much greater uncertainties when trying to include other species, habitats, and ecological interdependencies present in this ecosystem; (ii) the time needed to learn the principles of the EAF approach and acquire knowledge and information on the Mesoamerican barrier ecosystem. This involves more extensive coverage of capacity building in the countries involved for applying EAF; and (iii) the need to carefully assess the distributional implications of EAF interventions between coastal states and within them. For artisanal fisheries, EAF objectives and principles need to be revised and expanded to better reflect social, economic and institutional implications of management decisions. The need for considering data collection, advanced modelling and risk analysis for the use of sustainability indicators and reference points within the ecosystem approaches to fishery management, is also discussed. Understanding of EAF in the context of co-management and community-based management seems to be a priority.

Resumen Los ácidos grasos insaturados son de interés en la actualidad por su potencial para reducir enfermedades cardiovasculares, primera causa de muerte en el mundo. Por su contenido de ácidos grasos esenciales, el pescado es uno de los productos alimenticios de mayor demanda entre la población. Uno de los procesos más populares para el consumo de pescado en la Península de Yucatán, México es la fritura. Sin embargo, estudios demuestran que la fritura de alimentos genera cambios en la composición de lípidos generando ácidos grasos trans. El objetivo del presente estudio fue evaluar el perfil de ácidos grasos del Mero (Epinephelus morio) crudo y procesado con diferentes tipos de aceite comercial. Los resultados mostraron un contenido graso en E. morio crudo de 1.68%. El porcentaje de aceite extraído y absorbido por el producto al ser frito con aceite de maíz, girasol/canola, soya y cártamo se encontró en un rango de 2.3-3.93 y 26.95-57.25%, respectivamente. El perfil lipídico obtenido por CG-MS sugirió la formación de ácidos grasos trans por isomerización y efecto de la temperatura de freído. Sin embargo ácidos grasos esenciales como el oleico y linoleico fueron absorbidos por E. morio al ser frito con aceite de cártamo y girasol/canola, respectivamente.

The Fourth Biennial Conference of the North American Association of Fisheries Economics (NAAFE) was a forum for presenting papers dealing with the role of economics in mitigating unsustainability of fisheries and in contributing to responsible and sustainable development of aquaculture. Professional associations like NAAFE also contribute toward ensuring humanity's freedom from hunger, by advancing and communicating knowledge towards improving the efficiency of the production and distribution of fisheries and aquaculture products in a sustainable manner, and by raising the level of nutrition and standard of living in coastal communities. In the Bangkok, Mauritius, and Cambodia meetings organized by FAO in this decade, unsustainability of fisheries was attributed to seven main factors: (i) lack of solid governance structures; (ii) incomplete knowledge of marine ecosystems; (iii) fishery complexities, and the associated uncertainties; (iv) inadequate incentives and subsidies that stimulate overcapacity; (v) stock fluctuations due to natural causes; (vi) growing demand of limited fish resources; and (vii) poverty and lack of alternatives for coastal development (Swan and Greboval 2006; Caddy and Seijo 2005). To address some of these factors, the NAAFE 2007 forum was organized into 17 sessions dealing with ecosystem approaches to manage fisheries; spatial bioeconomic modeling and management of metapopulations; rights-based fisheries approaches of co-management; community-based management and individual transferable quotas (ITQs); valuation of ecosystem services and biodiversity; recreational fisheries; and trade, traceability, and marketing of fisheries and aquaculture products. The forum also offered five special sessions focusing on very important topics that included: application of harvest right-based concepts to the management of recreational fishing; future of aquaculture development in the region; fisheries subsidies: their scope and impacts; alternative approaches to discounting in the management of marine fisheries; and a plenary session on future policy challenges for sustainably managing fisheries in the region. Scientists from Brazil,

This study presents a bioeconomic analysis of artificial shelter performance in a fishery targeting a spiny lobster meta-population, with spatially allocated, individual exclusive benthic property rights for shelter introduction and harvest of species. Insights into fishers’ short-run decisions and fishing strategies are also provided. Spatiotemporal bioeconomic performance of shelters located in ten fishing areas during four seasons was compared using two-way ANOVAs and Pearson correlations. Results show that there was spatiotemporal heterogeneity in bioeconomic variables among fishing areas, with mean catch per unit effort (CPUE, kg shelter–1) ranging from 0.42 kg to 1.3 kg per trip, mean quasi-profits of variable costs per shelter harvested ranging from USD6.00 to USD19.57 per trip, and mean quasi-profits of variable costs ranging from USD338 to USD1069 per trip. Positive moderate correlations between shelter density and CPUE (kg shelter–1 km–2) were found. Bioeconomic performanc...

The management of marine fisheries needs to undergo dramatic change in the new millennium, in response to the well–documented evidence of global overfishing and the general depletion of commercial fish stocks. The axioms of sustainable development and equilibrium productivity of wild ecosystems are identified as misleading concepts, which nonetheless underlie current approaches to the management of living marine resources. Current trends in marine fisheries landings worldwide provide little evidence of sustainability of marine resources under current management paradigms, where biological, economic and social aspects of fisheries are usually treated as different disciplines. While open–access conditions are less widespread than formerly, except for many straddling and highly migratory resources, fishers usually have access to the resource year–round throughout its range. Despite quotas, the nominal control of capacity and technical measures protecting juveniles, top–down management ...

The improvement of survival in some species due to the close coexistence between individuals is a concept that has caught the attention of scientists over the years. This behaviour has been documented in many taxa, including species which support commercial fisheries. In recent years, a better understanding of the mechanisms associated with the Allee effect has shown its importance in population dynamics and probably plays a more important role than previously thought. In this article, the Allee effect was analysed by means of a spatial bioeconomic model. The Allee effect component was the positive relationship between the mating probability and the density of spawners. A depensation function with an offset to the right side of the origin represented the fraction of females that mated based on density. When the model did not include the Allee effect, the fishery reached the bioeconomic equilibrium; however, when the Allee effect was considered, the fishery did not reach equilibrium,...

The fishery supported by Octopus maya Voss and Solis, 1966, has been managed with season closure, minimum legal size and gear restrictions. The opening of the fishing season occurs during the breeding season of this species, which could create concerns regarding sustainability. To analyse the implication of this regulation, the dynamics of the fishery was modelled using an age-structured dynamic model, accounting for females' behaviour for parental care. Four scenarios were tested to evaluate the performance of potential changes in the scheduling of the time span of the fishing season. The response variables were total biomass, spawning biomass, recruitment, and catch, assuming no changes in the fishing technique. In scenarios one and two, when fishing season opened earlier than current dates (status quo), there was a significant reduction of catch and the spawning biomass in the third year. When simulations postponed the opening of the season (scenarios three and four), the annual catches and spawning stock experienced an increase in the third year regarding the status quo. The results of the analysis showed that the use of a selective gear (bait-based) and the behaviour of parental care of females during reproduction, offer a buffer to maintain the stock, despite the fishing season operating in part of the reproductive period.

This work reports on how benefits were distributed among fishers of two rights-based managed small-scale spiny lobster (Panulirus argus) fisheries, presenting individually and collectively based territorial use rights regimes. In the individually based fishery of Punta Allen, members of the local fishing cooperative have exclusive access to individual fishing grounds and target only spiny lobsters. The collectively based regime occurs in a multispecies fishery (including spiny lobsters) of two nearby fishing communities of northeastern Yucatan. Each of the fishing cooperatives of these two communities has its own exclusive lobster fishing area. However, the two communities have jointly agreed to share their exclusive areas. Data from fishing cooperative logbooks were used to calculate fishing revenues per fisher for the lobster fishing season 2017/2018. In the case of the multispecies fishery, fishing revenues of each fisher were assessed by the weighted average of catch composition value. To evaluate the fishing benefits spread, Lorenz curves and Gini indexes (G) were calculated using the fishing revenue distribution among participating fishers. Calculated G values had a range of [0.263, 0.367], with the collectively based territorial use rights fisheries having the lowest inequality levels of the fisheries reported in this study. These findings could indicate that fishing revenues in the two analyzed fisheries are spread more equally than most fisheries where distributional performance has been assessed. This could be evidence that cooperation may positively influence the relatively high distributional performance of fisheries managed under these rights-based regimes. A comparison with other worldwide fisheries whose G has been reported is included.

Illegal fishing (θ j) affects recovery time-lines and produce economic losses for having to extend moratoria, especially when targeting high value species. The lack of data concerning the level of θ j creates an uncertain context for decision maker to establish duration of moratorium or the need of extending it over time. With the use of a dynamic bioeconomic model on a high value species under moratorium, we calculate how a stock recovery timeline is affected by different states of the nature of possible levels of illegal fishing (θ j). This study also calculates the foregone net present value of resource rent when having to extend the moratoria because of existing possible levels of illegal fishing (states of nature θ j). Decision matrices without probabilities of occurrence of θ j were developed to support decision making concerning recovery timelines. Using stock biomass as the performance variable, the precautionary Minimax decision criteria was applied to select the moratoria timeline decision under possible states of nature of illegal fishing. We found that optimum moratorium duration depends on possible levels of illegal fishing taking place at the moment of deciding when could be possible to reopen a vulnerable species fishery. A Monte Carlo analysis was also undertaken to calculate the risk of falling below the stock recovery target reference point (TRP = B MSY) with alternative moratoria timelines given a range of possible illegal fishing exploitation rates.

Capture-based aquaculture (CBA) is a production strategy that consists of using juveniles from wild populations for rearing. During 2008, CBA produced 20% of total marine aquaculture with an estimated value of USD 1.7 billion (Lovatelli & Holthus, 2008). The most iconic and polemical species cultured under this scheme are bluefin tunas (BFT) (Metian, Pouil, Boustany, & Troell, 2014). At global scale, CBA of BFT showed an annual mean growth rate of ≈8% and an annual production volume of over 27 thousand metric tons (Metian

A critical problem in the production of Nile tilapia Oreochromis niloticus in intensive and hyper-intensive systems is the heterogeneity of body sizes as it influences the final production and economic yield. The objective of this study was to calculate the bioeconomic effect of size heterogeneity on the production of Nile tilapia at a commercial level and to determine the optimum harvest time (OHT) considering four minimum marketable sizes target (Mms = 350, 400, 450, 500 g). Two seeding strategies were evaluated: homogeneous seeding (HM) with a 96.55 ± 24.51 g initial body weight and heterogeneous seeding (HT) with a 100.17 ± 5.91 g initial weight. Fish from both treatments were stocked at 40 fish m-3 in triplicate using a randomized design. The calculated quasi-profits of variable costs showed an inversely proportional relationship with the minimum market size in both groups. The smaller size dispersion in HM generated higher profits than HT. The OHT for Mms [350, 500 g] of HM po...

Se presentan reflexiones y estrategias que contribuyan a formar capacidades de investigacion en universidades privadas con investigadores jovenes comprometidos con el avance del conocimiento en su area de investigacion asi como con su entorno natural y social. Mediante una combinacion de formacion en el aula y formacion experiencial, se presentan las habilidades investigativas a desarrollar y los ejes de formacion universitaria que contribuyen a formar investigadores. Adicionalmente a esta formacion basica se plantea la necesidad de generar las condiciones para desarrollar las habilidades de investigacion en la practica, laborando en areas experimentales en las que se colabore con grupos de investigacion activos.

The economic consequence of the mismanagement of world fishery resources is estimated to be in the order of US$ 50 billion per year in terms of the difference between potential and actual net economic benefits from marine fisheries. Moving from the current situation of inefficient over-use toward efficient and sustainable fisheries outcomes will involve not only attention to biology and ecology but also the managing of political and economic processes and replacing incentives that damage ecosystems with those that foster improved governance and responsible use. Economic analysis can contribute to the successful implementation of ecosystem-based management and the ecosystem approach to fisheries in the Caribbean Region in many areas. In this chapter, economic models and methodologies are outlined, and suggestions for incorporating economics into the large marine ecosystem policy cycle are provided.