Search results for "Size selective"
showing 3 items of 3 documents
Experimental size-selective harvesting affects behavioral types of a social fish
2019
In most fisheries, larger fish experience substantially higher mortality than smaller fish. Body length, life history, and behavioral traits are often correlated, such that fisheries-induced changes in size or life history can also alter behavioral traits. However, empirical evidence regarding how size-selective harvesting alters the evolution of behavioral traits in exploited stocks is scarce. We used experimental lines of Zebrafish Danio rerio that were exposed to positively size-selective, negatively size-selective, or random harvest over five generations. Our aim was to investigate whether simulated fishing changed the mean personality of the surviving females five generations after ini…
The Coexistence of Three Species of Daphnia in the Klostersee: iii. The Simulation Model Coda
1991
The population dynamics of three coexisting Daphnia species are described by means of a discrete event simulation model. The model is formulated in the algorithmic language SIMULA which allows very convenient object-oriented programming. Different compartments of a lake are simulated at different levels of integration, each represented by a PROCESS CLASS in SIMULA: The properties of the lake are deposited in a set of meteorological data which were measured in the field. Fish are simulated as a population with properties which are derived from field observations and Daphnia are represented as individuals. The model shows that hypotheses about the stabilizing mechanisms (seasonal change of en…
Rainwater composition over a rural area with special emphasis on the size distribution of insoluble particulate matter
1987
The rainwater composition in the vicinity of Mainz, FRG, has been investigated with special emphasis on insoluble constituents. The number size distribution was determined in the range from 0.1 μm up to 100 μm radius. For particles with r>0.5 μm radius the shape of the size distribution of insoluble particles in rain follows the shape of the average urban and rural aerosol. In this particular size range no major size selective removal processes could be seen. For r<0.5 μm the number size distribution tends to flatten compared to the average aerosol. This might be the indication of a size selective removal process (Greenfield Gap).