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Newer Technologies Can Help Save The Fish – The Fish Pass

As one of the most well known aquatic creatures, fish are a vital part of the ocean’s ecosystem. Their migration patterns and eating habits, each cater to the needs of the environment as well as the habitats. However, dams are known to block said needs. These concrete structures, sit at the mouth of a river or lake and control the flow for water, which in turn can be used to generate power for towns and cities. Though many changes have been made to accommodate the presence of fish moving downstream, many have failed, and fish migration continues to be disrupted. The struggle to finding a solution for allowing safe passage for fish is known to be a problem in the 20th century. The reason as to why fish are so affected by the presence of dams is due to the turbines. The turbines of a dam are known for rapid changes in pressure. This change in pressure causes confusion among fish and leaves them susceptible to the onslaught of predators looking for an easy meal.

Studies conducted by researchers showed that fish behavior changed rapidly whenever they approached the dam. Some reported that they saw that some of the fish, approached the dam and then swiftly retreated. Unfortunately, most attempts in researching for a better solution to the issue were unsuccessful. This resulted in a partnership between Larry Weber and John Nestler. Weber was the former director of IIHR. He was a part of a team attempting to analyze the movements of a fish in a nearby hydroelectric dam in the 1990s.

Starting Off Strong

When Weber and Nestler officially joined forces with the U.S. Army corps of Engineers, they began to research what they knew best. Weber’s team provided flow data derived from the use of computational fluid dynamics or otherwise known as CF while Nestler, a fishery biologist, analyzed how the fish responded to the change inflows. As the data progressed and more data were collected, a computer model was developed. This computer model could actively predict how fish would react in a particular change inflow, and this initiative was created by an individual known as Andy Goodwin, who worked together with Nestler. A fish, when exposed to a low-energy flow field, is more likely to swim nose-first. However, if it is exposed to a high-level flow field or is exposed to a higher velocity, then it turns around. This not only helps it to control its speed, but it also helps them escape, as they are pointed in the correct direction.

Starting Off Strong
Starting Off Strong

The Research Behind The Initiative

Another research conducted showed that fish disliked the rapid flow and sudden acceleration. According to weber, the fish can sense the change in acceleration and can actively take measures to avoid it. For example, the acceleration when going up and down a dam is known to be erratic. This causes the fish to prefer to go through the turbines instead. Resulting in confused fish and susceptible dinners for scavenging predators. The numerical fish surrogate is known to be a breakthrough to this day for its help in determining fish behaviors.