Summary: Pondering Bass Mortality
Understanding the factors that contribute to bass mortality (deaths) is important
when assessing management options for bass fisheries. Let's discuss the components of
mortality in bass populations and what they mean for fishing. We usually separate
mortality into two components: fishing and natural mortality.
Fishing mortality is obviously mortality associated with fishing. Fishing
mortality has several components including harvest, fish that die from being caught and
immediately released, and tournament mortality. Tournament mortality is from fish that
die from the additional stress of being confined in livewells, transported, pass through
weigh-in procedures, and released.
Bass fisheries represent a unique situation in fisheries, because harvest of bass has
declined through the years due to changes in angler behavior from catch and release.
Compared to many species such as crappie, walleye, and striped bass, largemouth bass
fisheries nowadays typically have very high rates of voluntary release, meaning that
anglers release fish that are above the length limit and legal to harvest. Recent creel
survey data from the southeastern US indicate that voluntary release of bass is often over
75%, meaning that over 75% of all fish legal to harvest are released. In some lakes it's
been measured at over 90%! The result of catch-and-release fishing is that harvest has
declined and fishing mortality levels are generally lower than they were 20 years ago.
This is obviously good news and has contributed to maintaining good fisheries despite