There is growing awareness of the need for fishery management policies that are robust to changing environmental, social, and economic pressures. Here we use conventional bioeconomic theory to demonstrate that inherent biological constraints combined with nonlinear supply-demand relationships can generate threshold effects due to harvesting. As a result, increases in overall demand due to human...

I examine the e¤ect of age-distribution of the society on economic growth through technological progress. I build a multisector economy model that involves population pyramid. I characterize the steady-state of the model for low and high population growth rate. Higher population growth rate yields faster TFP and output growth in the long-run. I analyze dynamic behavior of the economy. I calibra...

Population monitoring is central to most demographic studies and conservation efforts, but it may not always be directed at the most appropriate life stage. We used stochastic simulation modeling to evaluate the effectiveness of a monitoring program for a well-studied population of Eastern Imperial Eagles (Aquila heliaca) in Kazakhstan. Specifically, we asked whether the most appropriate data w...

Structured population models are increasingly used in decision making, but typically have many entries that are unknown or highly uncertain. We present an approach for the systematic analysis of the effect of uncertainties on long-term population growth or decay. Many decisions for threatened and endangered species are made with poor or no information. We can still make decisions under these ci...

this study was conducted to collect comprehensive identification about markhoz goat population and to simulate past dynamics of the population under its living conditions.census data of the population size and the required parametersfor the simulation modelwere obtained frompublished data or were collected in its habitat in the last 3 years. in this study, past population dynamics and expected ...

This paper presents the use of fuzzy inference to provide a viable modeling and simulation methodology for the estimation of population growth in any country or region. The study is motivated by the classical complex and time-consuming growth modeling and prediction methods. The related design issues are presented and the fuzzy inference model for population growth is derived. The human social ...

We study the simple-stellar-population-equivalent (SSP-equivalent) age and chemical composition measured from the Lick/IDS line-strength indices of composite stellar populations (CSP). We build two sets of ∼30000 CSP models using stellar populations synthesis models, combining an old population and a young population with a range of ages and chemical compositions representative of early-type ga...

population dynamic parameters of red mullet, mullus barbatus (n=592) caught by trawlers operating in arzew gulf (algeria) in the western mediterranean were studied. samples were collected between february 2013 and january 2014. females ranged from 10.9-23.2 cm in total length and 12-149.2 g in weight whereas males length was comprised between 12.6 and 19.7 cm and weight between 21.3 and 99.9 g....

the present research aimed to study the growth and reproductive parameters of common kilka clupeonella caspia in southern caspian sea in 2010. after measuring the length and weight of 3774 samples, they were dissected, sex determined and female gonads were weighed. sexual maturity classification was carried out based on six stages. age was determined using sagitta otoliths. length-weight relati...