Physics and Fish Bioenergetics

Welcome to the world of fish physics. Many of us understand basic fish behavior and can draw reasonable conclusions about the best position of fishing line. But when we did not think about more, we missed out some of the very interesting fish action details. Before thinking about the concept of biological energy theory of fish, we can not fully understand why we find fish in one place and fish in another. Ultimately, the behavior of fish is the product of bioenergy.

Physicists speak of fables about the laws of physics in fish survey, but they are accustomed to their water world, they do not consider their effects. Fish strongly explain the gentle swaying of plants and their own movement. The law they eventually found was complicated and clumsy. Then, the bright fish has a breakthrough. Probably the complexity reflects a simple basic rule that works in a complex environment. In other words, it is sticky, uncompressible, unevenly fluid, that is, the sea. Initially, knowledgeable fish were ignored, even ridiculous. But slowly, others are aware of their environment, even if their accustomment has a big impact on what they observe.

In addition, changes in body temperature and body size of fish have a major impact on fish growth and bioenergy (cited by Jobling, 1994, Sun et al. Fish growth is closely related to changes in ambient temperature, mainly due to food preferences and changes in fish intake (Sun et al., 2014). Therefore, when food availability is low, fish tend to choose low temperature to meet energy demand. This suggests that metabolic demand affects fish plasticity versus temperature, which indeed indicates a change in food availability to meet energy demand and growth (Killen, 2014)

There are several reasons for mortality. Shear effect, wear on the surface of the drainage canal, turbulence of the stationary pool at the bottom of the dam, rapid changes in speed and pressure when the fish hit the surface, and the physical impact of the energy dissipation device. The way energy is dissipated in a drainage can have a decisive influence on fish mortality. Experiments have shown that marked damage (stiffness, eye and internal organs) occurs when the fish impact velocity on the water surface of the downstream pool exceeds 16 m / s (Bell & Delacy, 1972). After falling 13 meters, the line of water will reach the fish's critical speed. Beyond this limit may cause serious damage and mortality rate will increase rapidly with decreasing (50-60 meters will drop 100% mortality rate)