Research Progress on Fish Barrier Measures

AbstractFishway is an artificial flume for fish migration through sluice gates or dams, which is widely used worldwide as an effective means to restore ecological connectivity of rivers. However, since the inlet of fishway is quite narrow compared to the width of the river, it is difficult for fish to find the inlet of fishway, and fish are easily attracted by the relatively high speed of water flow generated by turbines and cross the dam from turbines, resulting in a large number of fish casualties, so fish barrier measures play an important role in preventing fish from entering turbines, intakes and guiding fish into fishway inlets. This paper collects the main representative types of physical barrier and behavioral barrier, summarizes their advantages, disadvantages and application conditions, and analyzes their applications. It is found that most of the existing fish barrier measures are applicable to the downstream passage, while the upstream passage mainly attracts fish by setting up water auxiliary water systems at the inlet, and a few electric fence and acoustic system are also applied at present; in the near future, the hybrid fish barrier measures with physical barriers as the main body and behavioral barriers as the auxiliary will be the mainstream because of the more stable performance of physical barriers; behavioral barrier have the advantages of saving space, not affected by debris in water, and not causing head loss, but they are still in the experimental stage due to the unstable effect of fish interception, easy to be affected by water body or other external conditions, and high technical requirements. The efficient and stable behavioral barriers have certain research prospects.