The fisheries supply chains integrate multiple and heterogeneous agents linked through commercial (buyer/seller) relationships. In a large and competitive trade market, every agent can choose his/her partners, but the functioning of the supply chain depends on the aggregation of every agent's decisions that configures the global network of relationships. In...
Fish consumption in Mexico is considered low (around 12 kg per person per year) and non-homogeneously distributed across the country. One of the reasons for this situation is the scarcity of wholesale selling sites. In this context, the Mercado del Mar (MM), located in Guadalajara city, Jalisco, is the second...
This paper analyses the effect of adopting certain policies of internalising environmental costs on the optimal management of farms. In particular, the optimal harvesting time is analysed once these policies have been implemented. Fish growth and contamination diffusion are represented by means of dynamic stochastic models, including the uncertainty inherent...
The optimal harvesting time in a fish farm is analyzed in the paper. Fish population is assumed to be heterogeneous with respect to weight, so a distributed parameter dynamic model is considered. Theoretical and numerical results are obtained and compared with the ones concerning homogeneous fish cultures only. The results...
This study explores the optimal harvesting time in a size-heterogeneous population dynamics. The model includes the effect of population density in both the mortality rate and individual growth. An application to specific conditions of shrimp culture in Mexico is presented. The optimal harvesting rule is numerically found for different economic...
Nile tilapia has been cultivated in intensive systems in Yucatan, Mexico, during the first years of this century. Nevertheless, its adoption faces technical (related to the use of commercial feed) and marketing problems (fixed price of $2.14/Kg), which are analyzed in this paper. To do this, a bioeconomic model of...
Low yields caused by viral diseases and their financial consequences are the most important risks jeopardizing commercial shrimp culture in Mexico. Hence, farmers are continuously testing different production strategies to keep their operations into profitable margins. An optimization model was designed based on a farm's (139 ha) database (2001-2005) to...
Key message Leyland cypress, an intergeneric hybrid, produces the same volatile heartwood compounds as its parental taxa, yellow-cedar and Monterrey cypress. However, the proportion of total sesquiterpenes and some of the individual components appear unique to their respective heartwoods.
Context Leyland cypress, xHesperotropsis leylandii is an intergeneric hybrid between yellow-cedar,...
This study presents (1) the overall concept of assessing non-federal western rangeland soil loss rates at a national scale for determining areas of vulnerability for accelerated soil loss using USDA Natural Resources Conservation Service (NRCS) National Resources Inventory (NRI) data and the Rangeland Hydrology and Erosion Model (RHEM) and (2)...
Intraspecific life history attributes of growth, survival, and reproduction can vary in
response to changes in the physical environment. These changes can induce a cascading effect
across trophic levels. In marine systems, shifts in ocean conditions such as warm and cold phases
of ENSO can change primary production in benthic...
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sea urchin
Strongylocentrotus purpuratus over space and time
T. A. Ebert1,*, J. C. Hernández2,3, M