An impact is a dead fish. Catch is a dead fish in your boat. If you release a fish there is an impact (mortality) of 10-14% depending on location. In addition there is an impact assigned for fish that engage your gear but escape. Nets are also assigned a release mortality of 14-56% depending on net type and location. They also have an assigned net drop out mortality.

What is missing is the impact of seals and sea lions. At times they harvest as much from nets as the fishermen without an assigned impact.

Sorry this is off the thread topic but there was some miss understanding of what an impact is.