Coarse woody debris (CWD), while often providing the primary source of structure in small streams, has been frequently subjected to intensive removal efforts with uncertain long-term consequences. We present the integration of a growth and yield model (F V S) with a mechanistic recruitment model (C W D) to simulate long-term effects of both harvesting and CWD removal from streams in northwester...

Harvesting of wild-living animals is often intensive and may selectively target heritable behavioral traits. We studied the exploitation dynamics and the vulnerability consequences of individual heterogeneity in movement-related behaviors in free-ranging pearly razorfish (Xyrichthys novacula). Using underwater-video recording, we firstly document a fast and high exploitation rate of about 60% o...

Seasonally fluctuating water levels, known as 'flood pulses', control the productivity of large river fisheries, but the extent and mechanisms through which flood pulses affect fishery yields are poorly understood. To quantify and better understand flood pulse effects on fishery yields, this study applied regression techniques to a hydrological and fishery record (years 1993-2004) for 42 specie...

This research presents a study of dynamical system which models natural resources. Using fishes and water resources as the case study. In this work model equation was used to determine density We also introduced second stage Runge Kutta method, obtain result for harvesting terms from 10% 50% producing population life in pond after each harvesting.
 work, solution dynamic that can using Run...