With the fish in the water, monitor the gills and mouth for regular and consistent breathing. If the fish is breathing regularly, reassess its condition with the righting response test in step 2. It can then be released if it passes this test. If the fish fails to breath regularly, it is highly impaired and needs to be assessed further with step 4.
3. Regular ventilation
Holding the fish in the water, tilt it side to side while watching its eyes. If the fishes eyes remain level as it is tilted, it passes the test and should be allowed to recover further before again being tested in Steps 2 and/or 3 as needed. If the fish’s eyes roll as it is being tilted then it is in very poor condition and needs substantial time and minimal handling to recover in well oxygenated water before being retested.
This process allows anglers to quickly and effectively, measure the physical condition of a fish and determine if it can be successfully released. The entire process is summarized in the flow chart on the next page.
4. Eye tracking